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This study tested a mediation model of the relationship with tobacco use, social network quality (level of risk or protection in a network), and substance use (alcohol and/or illicit drugs) with a sample of 301 urban adolescents. It was theorized that social network quality would mediate the effect of tobacco use, accounting for PTSD symptoms and parent-teen relationships, on substance use. Results of path modeling with AMOS showed that the model provided an overall very good fit to the data and demonstrated partial mediation effects of social network quality on substance use. An effect-size measure was applied to determine what proportion of the total effect was mediated by the intervening (social network) variable and produced a moderate effect size (0.31). Results highlight the mediating role of social network quality on risk factors for adolescent substance use and are informative to prevention science in advancing social operational models of substance use. [ABSTRACT FROM AUTHOR]

Background: Approximately 16.5% of U.S. young adults have a cannabis use disorder (CUD) and are at risk for negative outcomes. Treatment can reduce cannabis use, but young adults are less likely to seek help than older adults. Peer Network Counseling-txt (PNC-txt) is a brief, text-delivered, Motivational Interviewing-informed substance use intervention focusing on peer relations and activity spaces as mechanisms for behavioral change. PNC-txt has shown evidence of reducing tobacco and cannabis use with adolescents and young adults, but it has not been tested in the context of legal cannabis use. The current randomized controlled trial sought to expand the evidence regarding the context of PNC-txt effects, comparing one state in which cannabis is legal (Colorado) and one state in which it is not (Tennessee). We hypothesized that participants randomized to PNC-txt would show significant reductions in cannabis use compared to controls, with larger reductions for females and those in Colorado, and that peer relations and activity space would mediate effects., Methods: One thousand, seventy eight 18-25 year olds (CO: 551; TN: 527) who met screening criteria for CUD and biologically-verified cannabis use were randomly assigned to PNC-txt or waitlist control condition. Every other day for 4 weeks, participants assigned to PNC-txt received pre-programmed text conversations, tailored via data from the baseline assessment. Self-report and biological indicators of cannabis use were measured at 1-, 3-, and 6-months., Discussion: Data analysis is underway. Results will provide evidence regarding whether, and how, PNC-txt reduces cannabis use in young adults with CUD., Trial Registration: This trial was prospectively registered on September 28, 2020 with ClinicalTrials.gov (NCT04567394)., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2024. Published by Elsevier Inc.)

Introduction: The co-occurrence of depression with cannabis use worsens both mood and substance use disorder outcomes, with young adults particularly at risk of co-occurrence. This research investigates whether the association of state-level prevalence rates of young adult (age 18-25) depression and cannabis use in the U.S. changed following enactment of recreational (adult use) cannabis legalization between 2008 and 2019., Methods: Annual, state prevalence data on past-year major depressive episode (hereafter, depression) and past-month cannabis use were extracted from the National Survey on Drug Use and Health (N=600 state-year observations). Moderated regression models tested whether the association of depression with cannabis use differed before versus after recreational legalization by comparing prevalence rates of depression and cannabis use in states that enacted recreational legalization to those that did not, while fixing state, year, and medical legalization effects. Data were accessed and analyzed in 2023., Results: Prevalence rates of both depression and cannabis use increased throughout the study period. The positive statistical effect of depression on cannabis use more than doubled in magnitude after legalization (β=0.564, 95% CI=0.291, 0.838) as compared to before (β=0.229, 95% CI=0.049, 0.409), representing a significant change (β=0.335, 95% CI=0.093, 0.577)., Conclusions: These results suggest that the association between prevalence rates of young adult depression and cannabis use strengthened following recreational legalization in the U.S. This is potentially due to increases in cannabis accessibility and the acceptance of the health benefits of cannabis, which may enhance the use of cannabis as a coping mechanism among young adults with depression., (Copyright © 2023 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose : State-level prevalence data are used to investigate whether recreational cannabis legalization moderates the mediated pathway from the perception of low risk of harm, to cannabis use, to cannabis use disorder (CUD) treatment admissions, among adolescents (age 12-17) in the US. Methods : Annual state prevalence measures of perception of low risk, cannabis use, and CUD treatment admissions between 2008 and 2019 ( N  = 542 state-year observations) were collected from the National Survey on Drug Use and Health (NSDUH) and the Treatment Episode Dataset - Admissions (TEDS-A). A two-way fixed effects (state and year) moderated mediation model was used to test whether recreational legalization moderated the indirect effect of perception of low risk on treatment admissions via cannabis use. Results : A positive indirect effect of perceiving cannabis as low risk on CUD treatment admissions via cannabis use was observed prior to legalization but not afterwards. After legalization, the positive association of perceiving cannabis as low risk with cannabis use was strengthened, and the positive association of cannabis use with treatment admissions was suppressed, as compared to before legalization. Discussion : Recreational legalization may alter the social acceptability and medical self-administration of cannabis, potentially leading to CUD treatment utilization decline among adolescents even as risk factors for CUD increase. Linking recreational cannabis legalization to advancing awareness of the health risks associated with adolescent cannabis use and promoting adolescent CUD treatment engagement through mHealth approaches and primary care providers are key to addressing potential adolescent health challenges brought about by expanding cannabis legalization.

Objectives: This study investigates whether the proportion of referrals to cannabis use disorder (CUD) treatment from the criminal justice system declined among adolescents (aged 12-17 years) and young adults (aged 18-24 years) following state recreational (adult use) cannabis legalization in the United States between 2008 and 2019., Methods: Cannabis use disorder treatment referral data were extracted from the Treatment Episode Dataset-Admissions and used to calculate trends in the number and proportion of criminal justice referrals. Difference-in-differences analysis was used to estimate the effect of recreational legalization on the state-level proportion of criminal justice referrals as a share of all admissions., Results: Nationwide, the number and proportion of adolescent and young adult criminal justice referrals to CUD treatment declined over the study period. The proportion of young adult criminal justice referrals declined significantly more rapidly after recreational legalization as compared with before ( β = -0.045; 95% confidence interval, -0.079 to -0.010; P = 0.01). Among adolescents, the trajectory of decline in the proportion of criminal justice referrals did not change significantly following recreational legalization ( β = -0.033; 95% confidence interval, -0.073 to 0.008; P = 0.11)., Conclusions: The decline in the proportion of young adult criminal justice referrals to CUD treatment following recreational legalization is likely due to falling cannabis-related arrests. Although cannabis criminalization may result in court-mandated CUD treatment for some young adults without CUD, the decline in CUD treatment admissions during a period of increasing CUD risk factors associated with recreational legalization represents a key health concern. Promoting screening and other CUD treatment referral sources, such as through primary care, may be warranted., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 American Society of Addiction Medicine.)

The current study describes an individual participant data meta-analysis (IPDMA) testing the efficacy of a peer-network counseling (PNC) intervention for preventing substance use escalation in adolescents and young adults. PNC has shown efficacy in reducing substance use among adolescents and young adults across small-scale randomized controlled trials (RCTs). Identifying expected large-scale effects and moderators is an important next step in guiding use of PNC in practice. To this end, we combine three small-scale RCTs to test PNC intervention effects on substance use change in a combined sample of 421 adolescents and young adults (50% intervention, 55% female, 69% Black/African-American, M age [SD] = 17.3 [2.2] years). Our approach combines latent change score modeling in a structural equation modeling (SEM) framework with study-level fixed effects to obtain (a) a more generalizable PNC effect than we could obtain with each constituent sample and (b) greater power and precision for individual-level moderation of treatment effects. We found that although PNC main effects on substance use outcomes (past 30-day cannabis, alcohol, tobacco, and drug use) were not significant, PNC effects were moderated by individual-level pre-intervention substance use frequency. PNC more strongly reduced drug use at the 1-month follow-up and cannabis use at the 3-month follow-up among participants who showed higher baseline use of these substances. Implications of our approach and findings for prevention researchers are discussed., (© 2022. Society for Prevention Research.)

The geospatial dataset presented here represents historical middle 19 th century built environment features for the Chesapeake Bay Eastern Shore region of Maryland, USA, including present-day Cecil, Caroline, Dorchester, Kent, Queen Anne's, Somerset, Talbot, Wicomico, and Worcester counties. Individual geospatial data layers include roads, landings, ferries, churches, shops, mills, schools, hotels, towns with post offices, and towns with court houses. These data were digitized using Simon J. Martenet's (1866) Map of Maryland: Atlas Edition and contemporary geospatial road network data from the Maryland Department of Transportation., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)

Objective: Understanding how recreational cannabis legalization may impact cannabis use disorder (CUD) among adolescents and young adults is key to developing an appropriate public health response. This research investigates whether associations among adolescent and young adult perception of risk of harm from cannabis use, prevalence of past-month cannabis use, and rate of CUD treatment admissions changed following recreational cannabis legalization in the US, 2008-2019., Methods: Data from the NSDUH and TEDS-A datasets are employed in difference-in-differences models of the effect of recreational legalization on perception of risk, cannabis use prevalence, and CUD treatment admissions. Moderated models test whether associations among variables changed following recreational legalization., Results: Following recreational legalization: 1) adolescent and young adult past-month cannabis use prevalence increased; 2) among both adolescents and young adults, the association of lower perception of risk of harm with higher cannabis use prevalence was strengthened; 3) among adolescents, the association of higher cannabis use prevalence with higher CUD treatment admissions was suppressed; and 4) among young adults, an association of higher cannabis use prevalence with lower CUD treatment admissions emerged., Conclusions: Recreational legalization is likely to increase cannabis use among adolescents and young adults who perceive cannabis as less harmful, while at the same time reduce rates of CUD treatment utilization. These trends portend an increase in unmet need for CUD treatment for age groups particularly vulnerable to the development and negative consequences of CUD., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Aims: To examine the use and association of medications for opioid use disorder (MOUD) with treatment completion and retention for criminal justice referred (CJR) admissions to residential treatment., Methods: A retrospective analysis of the Treatment Episode Dataset-Discharge (TEDS-D; 2015-2018) for adults (N = 205,348) admitted to short-term (ST) (< 30 days) or long-term (LT) (>30 days) residential treatment for OUD. Outcomes were MOUD in treatment plans, and treatment completion and retention (ST >10 days; LT > 90 days). Logistic regression analyses were conducted separately for ST and LT settings., Results: CJR admissions were less likely to have MOUD than non-CJR admissions (ST, 11% vs. 21%; LT, 10% vs. 24%, respectively) and were more likely to complete and be retained in treatment. In ST settings, MOUD was associated with higher likelihood of treatment completion and retention. In LT settings, MOUD was associated with higher likelihood of treatment retention and lower likelihood of treatment completion. These associations tended to be slightly weaker for CJR admissions, with the exception of treatment completion in LT settings, but the moderating effect size of CJR status in all models was very small. Small differences in the moderating effect of CJR status by race and ethnicity were observed in LT settings., Conclusions: MOUD is greatly under-utilized for CJR patients, and given that MOUD was associated with positive outcomes, there is a critical need to find ways to increase access to MOUD for CJR patients in residential treatment. Race and ethnicity appear to have relatively little impact on outcomes., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Using cannabis to reduce psychological and physical distress, referred to as self-medication, is a significant risk factor for cannabis use disorder. To better understand this high-risk behavior, a sample of 290 young adults (ages 18-25; 45.6% female) were recruited from two U.S. universities in January and February of 2020 to complete a survey about their cannabis use and self-medication. Results: seventy-six percent endorsed using cannabis to reduce problems such as anxiety, sleep, depression, pain, loneliness, social discomfort, and concentration. When predicting reasons for self-medication with cannabis, logistic regression models showed that lower CUDIT-R scores, experiencing withdrawal, living in a state where cannabis was illegal, and being female were all associated with higher rates of self-medication. Withdrawal symptoms were tested to predict self-medication with cannabis, and only insomnia and loss of appetite were significant predictors. To further explore why young adults self-medicate, each of the original predictors were regressed on seven specified reasons for self-medication. Young adults experiencing withdrawal were more likely to self-medicate for pain. Participants living where cannabis is legal were less likely to self-medicate for anxiety and depression. Living where cannabis is illegal also significantly predicted self-medicating for social discomfort-though the overall model predicting social discomfort was statistically non-significant. Finally, female participants were more likely to self-medicate for anxiety. These results suggest widespread self-medication among young adults with likely CUD and underscore the complexity of their cannabis use. The findings have implications for understanding why young adults use cannabis in relation to psychological and physical distress and for accurately treating young adults with cannabis use disorder.

This study leverages data from a pilot randomized controlled trial to investigate whether the effectiveness of a text-delivered mHealth intervention targeting adolescent depression and anxiety differs according to residential- and activity space-based measures of exposure to community-level socioeconomic disadvantage. For depression, we find that intervention efficacy is significantly stronger for youth residing in more disadvantaged neighborhoods, even after controlling for individual level socioeconomic status, as well as marginal moderating effects of activity space-based neighborhood disadvantage on treatment efficacy. We do not find evidence of treatment efficacy moderation by neighborhood disadvantage regarding anxiety. While the generalizability of our findings is restricted to this sample and for this intervention, this research serves as a motivating example and initial evidence for how mHealth intervention efficacy can vary by characteristics of the environment, in particular community-level disadvantage. Future clinical research should investigate whether the effectiveness of mHealth interventions may be enhanced by personalization based on an individual's contextual environmental exposures., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objective: This short communication reports on the association of annual measures of young adult (age 18-24) past month cannabis use with cannabis use disorder (CUD) treatment admissions by state in the U.S. from 2008 to 2017., Methods: Annual data on percentage of past month cannabis use and the total number of CUD treatment admissions among young adults were acquired for each state from SAMHSA NSDUH and TEDS-A data sets. For each state, the correlation over time between cannabis use and treatment admissions rate was calculated and visualized in a choropleth map. Fixed-effects regression, where effects are fixed by state, was used to investigate the association of cannabis use with treatment admissions rate., Results: In 38 out of 50 states, including seven out of the eight states legalizing recreational cannabis during the study period, as young adult cannabis use increased, treatment admissions declined. Cannabis use is significantly and negatively associated with treatment admissions (β = -7.21, 95% CI = -11.88, -2.54), even after controlling for health insurance coverage, criminal justice referral, treatment center availability, and cannabis legalization status., Conclusions: While it is possible that across the U.S. more young adults are using cannabis without developing CUD, we speculate that increasing social acceptance of cannabis use, and declining perception of harm, may influence treatment seeking behavior, potentially resulting in growing unmet need for CUD treatment among young adults. Monitoring state-level trends in cannabis use, CUD prevalence, and treatment admissions is key to developing CUD prevention and treatment policies targeted to timely, state-specific conditions., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: This study examines racial/ethnic disparities in the use of medications for opioid use disorder (MOUD) in residential treatment and the influence of race/ethnicity on the association between MOUD use and treatment retention and completion., Methods: Data were extracted from SAMHSA's 2015-2017 Treatment Episode Dataset-Discharge (TEDS-D) datasets for adult opioid admissions/discharges to short-term (ST) (30 days or less) (N = 83,032) or long-term (LT) (> 30 days) residential treatment settings (N=61,626). Logistic regression estimated the likelihood of MOUD use among racial/ethnic groups and the moderation of race/ethnicity on the probability of treatment completion and retention, controlling for background factors., Results: After adjusting for covariates, compared to Whites, MOUD use was less likely for Blacks in ST (OR = 0.728) and LT settings (OR = 0.725) and slightly less likely for Hispanics in ST settings (OR = 0.859) but slightly more likely for Hispanics in LT settings (OR = 1.107). In ST settings, compared to Whites, the positive effect of MOUD on retention was enhanced for Blacks (OR = 1.191) and Hispanics (OR = 1.234), and the positive effect on treatment completion was enhanced for Hispanics (OR = 1.144). In LT settings, the negative association between MOUD and treatment completion was enhanced for Hispanics (OR = 0.776)., Conclusions: Access to medications for opioid use disorder in short term residential treatment is particularly beneficial for Blacks and Hispanics, though adjusted models indicate they are less likely to receive it compared to Whites. Results are mixed for long-term residential treatment. Residential addiction treatment may represent an important setting for mitigating low rates of medication initiation and early discontinuation for minority patients., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: A public health concern stemming from recreational marijuana legalization (RML) is the idea that marijuana may act as a "gateway" drug among youth and young adults, where growing marijuana use will lead to increasing substance use disorder (SUD) for "harder" illicit drugs. This study investigates whether SUD treatment admissions for cocaine, opioids, and methamphetamines increased following RML enactment in Colorado and Washington for adolescents and emerging adults., Methods: We entered annual 2008-2017 treatment admissions data from the SAMHSA Treatment Episode Dataset - Admissions (TEDS-A) into difference-in-differences models to investigate whether the difference in treatment admissions for cocaine, opioids, and methamphetamines among adolescents (12-17), early emerging adults (18-20), and late emerging adults (21-24) before versus after RML enactment differed between Colorado and Washington and states without RML., Results: There was no significant difference (p < 0.05) between Colorado and Washington and other states in the pre- versus postlegalization trajectories of SUD treatment admissions for cocaine, opioids, or methamphetamines for adolescents (β = -0.152, 95% CI = -0.500, 0.196; β = -0.374, 95% CI = -1.188, 0.439; β = 0.787, 95% CI = -0.511, 2.084, respectively), early emerging adults (β = -0.153, 95% CI = -0.762, 0.455; β = 0.960, 95% CI = -4.771, 6.692; β = 0.406, 95% CI = -2.232, 3.044, respectively) or late emerging adults (β = -0.347, 95% CI = -1.506, 0.812; β = -4.417, 95% CI = -16.264, 7.431; β = 1.804, 95% CI = -2.315, 5.923, respectively)., Conclusion: RML in Washington and Colorado was not associated with an increase in adolescent or emerging adult SUD treatment admissions for opioids, cocaine, or methamphetamines. Future studies should extend this research to other states, other substances, for older adults, and over longer time periods; and consider how the effects of drug policies may differ across different jurisdictions., (Copyright © 2020 Elsevier Inc. All rights reserved.)

While urban greenspace is increasingly recognized as important to mental health, its role in substance use is understudied. This exploratory study investigates the interaction of greenspace with peer network health, sex, and executive function (EF) in models of substance use among a sample of disadvantaged, urban youth. Adolescents and their parents were recruited from a hospital in the mid-Atlantic region of the U.S. Residential greenspace at the streetscape level was derived from analysis of Google Street View imagery. Logistic regression models were used to test the moderating effect of greenspace on the association between peer network health and substance use, as well as additional moderating effects of sex and EF. The significant negative association of peer network health with substance use occurred only among youth residing in high greenspace environments, a moderating effect which was stronger among youth with high EF deficit. The moderating effect of greenspace did not differ between girls and boys. Greenspace may play an important role in moderating peer influences on substance use among disadvantaged, urban adolescents, and such moderation may differ according to an individual's level of EF. This research provides evidence of differences in environmental susceptibility regarding contextual mechanisms of substance use among youth, and it informs the development of targeted substance use interventions that leverage social and environmental influences on adolescent substance use.

Incorporating geographic information science and technology (GIS&T) into COVID-19 pandemic surveillance, modeling, and response enhances understanding and control of the disease. Applications of GIS&T include 1) developing spatial data infrastructures for surveillance and data sharing, 2) incorporating mobility data in infectious disease forecasting, 3) using geospatial technologies for digital contact tracing, 4) integrating geographic data in COVID-19 modeling, 5) investigating geographic social vulnerabilities and health disparities, and 6) communicating the status of the disease or status of facilities for return-to-normal operations. Locations and availability of personal protective equipment, ventilators, hospital beds, and other items can be optimized with the use of GIS&T. Challenges include protection of individual privacy and civil liberties and closer collaboration among the fields of geography, medicine, public health, and public policy.

Background: This study examines whether MOUD increases treatment completion and retention in both short-term (ST) and long-term (LT) residential programs using a national dataset., Methods: Data were extracted from the 2015-2017 TEDS-D (Treatment Episode Dataset-Discharge) datasets for opioid using adults in ST (n = 87,296) and LT (n = 66,623) residential treatment. Primary outcome variables were treatment completion and retention (ST: length of stay >10 days; LT: >90 days). Logistic regression estimated the effects of MOUD on the probability of treatment completion and retention separately for ST and LT residential treatment, controlling for individual background characteristics., Results: Only 18% of clients in residential treatment programs had MOUD in their treatment plans. For ST residential treatment, MOUD was associated with a 40% increased likelihood of treatment completion (OR = 1.404) and 34% increased retention (OR = 1.337). For LT residential treatment, MOUD was associated with a 26% reduced likelihood of treatment completion (OR = 0.743) and no significant increase in retention. Post hoc analysis suggests insurance coverage may be influencing outcomes., Conclusions: Despite MOUD being a standard of care for OUD, MOUD is particularly under-utilized in residential treatment. Further research should focus on how best to integrate MOUD within short-term residential treatment and to explore the potential viability of MOUD in long-term residential programs. Given the risk of overdose following residential treatment, for at least short-term residential programs, this setting may be advantageous for integrating psychosocial treatments with early MOUD engagement in a structured therapeutic environment as part of a long-term continuum of care recovery program., Competing Interests: Declaration of Competing Interest No conflict declared., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Emotional factors such as stress and anxiety contribute to risk of substance use in adolescents. Descriptive measures of within-person affect variability are often used to predict morbidity, but indices derived from theoretical models may provide more interpretable alternatives. A continuous-time state-space model of emotion regulation as closed-loop feedback control was used to estimate the homeostatic tendency of affect in each of 94 adolescent participants. The resulting indices of emotion regulation were then compared to within-person affect sum score means and standard deviations in predicting total counts of nicotine, alcohol, and cannabis use. Model-based emotion regulation was significantly associated with lower frequencies of nicotine, alcohol, and cannabis use, while mean negative affect sum score was associated with higher frequencies. Model comparisons revealed that while model-based predictors and descriptive statistics explained similar amounts of variance in substance use, the explained variance proportions were independent between the approaches. The greatest predictive value was achieved by a combined model with both sets of affect indices. We conclude that theoretically defined and model-estimated individual characteristics may serve an important role in conceptualizing and predicting substance use behavior., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Introduction: There is concern that recreational marijuana legalization (RML) may lead to increased cannabis use disorder (CUD) among youth due to increased marijuana use. This study investigates whether adolescent substance use disorder treatment admissions for marijuana use increased in Colorado and Washington following RML., Methods: Annual data on 2008-2017 treatment admissions for marijuana use from the SAMHSA TEDS-A dataset for adolescents age 12-17 were used to model state treatment admissions trends. Difference-in-differences models were used to investigate whether treatment admissions increased following RML in Colorado/Washington compared to non-RML states, after adjusting for socioeconomic characteristics and treatment availability., Results: Over all states in the analysis, the rate of adolescent treatment admissions for marijuana use declined significantly over the study period (β=-3.375, 95 % CI=-4.842, -1.907), with the mean rate falling nearly in half. The decline in admissions rate was greater in Colorado and Washington compared to non-RML states following RML, though this difference was not significant (β=-7.671, 95 % CI=-38.798, 23.456)., Conclusion: Adolescent treatment admissions for marijuana use did not increase in Colorado and Washington following RML. This may be because youth marijuana use did not increase, CUD did not increase (even if use did increase), or treatment seeking behaviors changed due to shifts in attitudes and perceptions of risk towards marijuana use., Competing Interests: Declaration of Competing Interest None declared., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Slowing traffic speed in urban areas has been shown to reduce pedestrian injuries and fatalities due to automobile accidents. This research aims to measure how brick and granite block paving materials, which were widely used historically prior to the use of asphalt paving in many cities, may influence free flow traffic speed. Traffic speeds for 690 vehicles traversing street blocks paved with asphalt, granite block, and brick materials were measured using a radar gun on a sample of 18 matched pair (asphalt and historic paving material) street blocks in Philadelphia, Pennsylvania. Fixed effects linear regression was used to estimate the effect of paving material on vehicle speed after controlling for the street class (e.g., arterial versus local road) and the matched pair. Results indicate that brick reduced speeds by approximately 3 mph (~5 km/h) and granite block reduced speeds by approximately 7 mph (~11 km/h), as compared to asphalt paved city streets, which we attribute to drivers intentionally slowing due to road roughness. This research suggests that brick and granite block paving materials may be an effective traffic calming strategy, having implications for reducing negative health outcomes associated with pedestrian-automobile collisions.

Adolescents with depression disorders have higher rates of substance use. In order to advance contextually relevant mental health interventions, basic research is needed to test social ecological mechanisms hypothesized to influence adolescent depression and substance use. Accordingly, we conducted growth curve modeling with a sample of 248 urban adolescents to determine if depression's effect on substance use was dependent upon peer network health (sum of peer risk and protective behaviors) and activity space risk (likelihood of high-risk behaviors at routine locations). Results showed that peer network health moderated the effects of depression on substance use, but this effect was not altered by activity space risk. These findings suggest the importance of peer network health relative to depression and substance use, particularly for young adolescents.

This research investigates racial and ethnic disparities in outpatient substance use disorder treatment completion and duration in treatment, for different substances, across the US, using the national 2014 Treatment Episode Dataset-Discharge (TEDS-D) data set. Moderated fixed effects logistic regression models assessed effects of race/ethnicity on length of stay in treatment and treatment completion for different substances of use. Moderated models also assessed the differential effect of length of stay on treatment completion among Blacks, Hispanics, and Whites. While Blacks and Hispanics both have significantly lower treatment completion rates than Whites, treatment duration is substantially similar across the three groups. Blacks and Hispanics generally take longer to complete treatment than Whites, though this varies by substance for Hispanics. Disparities in treatment completion persist even after controlling for treatment duration. These results indicate that observed racial and ethnic disparities in treatment completion are not due to differences in length of stay in treatment. Economic, cultural, accessibility, or, potentially, discriminatory, factors may suppress the likelihood of treatment completion for minorities and result in longer treatment durations required for completion. Recognition by treatment providers of the unique challenges to treatment completion faced by minorities may enhance treatment outcomes for minorities in the US., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Introduction: Experiencing relational victimization (e.g., peer exclusion, untrue rumors) during adolescence can have negative social-emotional consequences, including increased antisocial behavior and substance use. The negative impact of relational victimization may be lessened by spending time with supportive, prosocial peers., Methods: This study examined the concurrent and predictive associations between relational victimization and peer affiliates' prosocial behaviors in 244 predominately African American adolescents (ages 13-14) living in U.S. urban neighborhoods. Questionnaires were collected every six months for two years. Overt victimization was controlled for in the analysis and the moderation of gender and antisocial behaviors were tested., Results: Peer affiliates' prosocial behavior was stable across the two years. Relational victimization was not associated with peers' prosocial behavior at baseline or across time. Gender did not moderate the association between relational victimization and peers' prosocial behavior. Moderating effects were found for antisocial behavior; relational victimization was positively associated with peer affiliates' prosocial behavior but only for adolescents who were low on antisocial behavior at baseline., Conclusions: For African American youth, efforts to reduce relational aggression and increase peer support in prosocial activities prior to adolescence may be useful for preventing social-emotional problems., (Copyright © 2019 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.)

This research presents a pilot study to develop and compare methods of geographic imputation for estimating the location of missing activity space data collected using geographic ecological momentary assessment (GEMA). As a demonstration, we use data from a previously published analysis of the effect of neighborhood disadvantage, captured at the U.S. Census Bureau tract level, on momentary psychological stress among a sample of 137 urban adolescents. We investigate the impact of listwise deletion on model results and test two geographic imputation techniques adapted for activity space data from hot deck and centroid imputation approaches. Our results indicate that listwise deletion can bias estimates of place effects on health, and that these impacts are mitigated by the use of geographic imputation, particularly regarding inflation of the standard errors. These geographic imputation techniques may be extended in future research by incorporating approaches from the non-spatial imputation literature as well as from conventional geographic imputation and spatial interpolation research that focus on non-activity space data., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Background: An understudied, yet important area of youth development research is the examination of how place affects critical psychosocial processes such as identity formation, problem solving, emotional regulation, and in particular with adolescents, belongingness, autonomy, social competency, and behavioral health. A growing spatially informed literature indicates that youth interact with meaningful places as environmental strategies, shaping developmental trajectories related to behavioral health., Objectives: The objective is to investigate the relationship between place preference and health behavior among adolescents, with a focus on substance use behavior, specifically, cannabis use. We theorize that cannabis use is associated with place preference for urban, city types of places, and that this particular place preference interacts with close peer network behaviors., Methods: To understand the role of preferred locations, close peer relations, and mental health on cannabis use, 248 adolescents (ages 13 to 14) were studied longitudinally. Logistic regression models tested the moderating effects of peer network health (sum of close friends risk and protective behaviors) on selecting city locations (urban stress/neighborhoods) as preferred places, and subsequent cannabis use., Results: Results indicated that peer network health moderated the effects of choosing city locations as favorite, increasing the odds of cannabis use more than eight-fold at 24 months., Conclusions: Favorite places located in city environments appear to interact with peer risk behaviors influencing the cannabis use of young urban adolescents, even after controlling for the influence of baseline cannabis use, neighborhood disorder the home neighborhood, age, gender, and mental health effects.

Background: The present study examined racial/ethnic disparities in initial treatment episode completion for adult clients reporting opioids as their primary problem substance in large US metropolitan areas., Methods: Data were extracted from the 2013 TEDS-D dataset (Treatment Episode Dataset-Discharge) for the 42 largest US metropolitan statistical areas (MSAs). Fixed effects logistic regression controlling for MSA was used to estimate the effect of race/ethnicity on the likelihood of treatment completion. The model was repeated for each individual MSA in a stratified design to compare the geographic variation in racial/ethnic disparities, controlling for gender, age, education, employment, living arrangement, treatment setting, medication-assisted treatment, referral source, route of administration, and number of substances used at admission., Results: Only 28% of clients completed treatment, and the results from the fixed effects model indicate that blacks and Hispanics are less likely to complete treatment compared to whites. However, the stratified analysis of individual MSAs found only three of the 42 MSAs had racial/ethnic disparities in treatment completion, with the New York City (NYC) MSA largely responsible for the disparities in the combined sample. Supplementary analyses suggest that there are greater differences between whites and minority clients in the NYC MSA vs. other cities on characteristics associated with treatment completion (e.g., residential treatment setting)., Conclusion: This study underscores the need for improving treatment retention for all opioid using clients in large metropolitan areas in the US, particularly for minority clients in those localities where disparities exist, and for better understanding the geographic context for treatment outcomes., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The representation of place is a key theoretical advancement that Geographic Information Science can offer to improve the understanding of environmental determinants of health, but developing robust computational representations of place requires a substantial departure from conventional notions of geographic representation in Geographic Information Systems (GIS). Unlike conventional GIS representations based on either objects or locations, we suggest place representation should incorporate dynamic subjective, experiential, and relational aspects of place, as the influence of place on health behavior concerns not only the features that can be objectively observed at a particular location but also the environmental perceptions of the individual, as molded by biological, social, and experiential characteristics. In addition, assessments of environmental exposures on health outcomes should focus on individuals' time-activity patterns and microenvironment profiles, which form a potentially unique personalized exposure environment for each individual. Addressing these representational challenges via collaborative research has the potential to advance both Geographic Information Science and health research.

This study investigates the momentary association between urban greenspace, captured using Normalized Difference Vegetation Index (NDVI) derived from Landsat imagery, and psychological stress, captured using Geographic Ecological Momentary Assessment (GEMA), in the activity spaces of a sample of primarily African American adolescents residing in Richmond, Virginia. We employ generalized estimating equations (GEE) to estimate the effect of exposure to urban greenspace on stress and test for moderation by sex, emotional dysregulation, season, neighborhood disadvantage, and whether the observation occurs at home or elsewhere. Results indicate that urban greenspace is associated with lower stress when subjects are away from home, which we speculate is due to the properties of stress reduction and attention restoration associated with exposure to natural areas, and to the primacy of other family dynamics mechanisms of stress within the home. Subjects may also seek out urban greenspaces at times of lower stress or explicitly for purposes of stress reduction. The greenspace-stress association away from home did not differ by sex, emotional dysregulation, neighborhood disadvantage, or season, the latter of which suggests that the observed greenspace-stress relationship is associated with being in a natural environment rather than strictly exposure to abundant green vegetation. Given the association of urban greenspace with lower stress found here and in other studies, future research should address the mediated pathways between greenspace, stress, and stress-related negative health outcomes for different population subgroups as a means toward understanding and addressing health disparities.

The school environment is extremely salient in young adolescents' lives. Adolescents who have unfavorable attitudes toward school and teachers are at elevated risk for dropping out of school and engaging in behavioral health risks. Peer network health-a summation of the positive and negative behaviors in which one's close friend group engages-may be one way by which attitudes toward school exert influence on youth substance use. Utilizing a sample of 248 primarily African-American young urban adolescents, we tested a moderated mediation model to determine if the indirect effect of attitude to school on cannabis involvement through peer network health was conditioned on gender. Attitude toward school measured at baseline was the predictor (X), peer network health measured at 6 months was the mediator (M), cannabis involvement (including use, offers to use, and refusals to use) measured at 24 months was the outcome (Y), and gender was the moderator (W). Results indicated that negative attitudes toward school were indirectly associated with increased cannabis involvement through peer network health. This relationship was not moderated by gender. Adolescents in our sample with negative attitudes toward school were more likely to receive more offers to use cannabis and to use cannabis more frequently through the perceived health behaviors of their close friends. Implications from these results point to opportunities to leverage the dynamic associations among school experiences, friends, and cannabis involvement, such as offers and use.

Few studies have examined in detail how specific behaviors of close friends put adolescents at risk for specific types of substance use. Using a prospective, longitudinal design, we examined how well the substance use of 248 young urban adolescents was predicted by perceptions of their 3 closest friends' problematic behaviors: (1) using substances, (2) offering substances, and (3) engaging with friends in risky behavior (substance use, illegal behavior, violent behavior, or high-risk sexual behavior). Longitudinal multivariate repeated measures models were tested to predict tobacco, alcohol, and cannabis use and perceived closeness was tested as a moderator of the effects of perceptions of problematic peer behavior. Perceptions of peer substance use were significantly associated with tobacco use, and closeness moderated the influence of peer substance use and offers to use substances on tobacco use. Perceptions of problematic peer behaviors were not significantly associated with alcohol use and closeness was not significant as a moderator. Perceptions of peer substance use was significantly associated with cannabis use, and closeness moderated the influence of perceptions of peer risk behaviors, peer substance use, and offers to use substances on cannabis use. Results implicate the importance of understanding problematic peer behavior within the context of close, adolescent friendships. Adolescents with close friends who were substance users, who made offers to use substances, and who engaged in risky behaviors were more likely to use tobacco and cannabis. Perceptions of young adolescents' close friends' behaviors influenced their substance use up to 2 years later. (PsycINFO Database Record, ((c) 2017 APA, all rights reserved).)

Background: Geographic ecological momentary assessment (GEMA) combines ecological momentary assessment (EMA) with global positioning systems (GPS) and geographic information systems (GIS). This study evaluates the spatial accuracy of GEMA location data and bias due to subject and environmental data characteristics., Methods: Using data for 72 subjects enrolled in a study of urban adolescent substance use, we compared the GPS-based location of EMA responses in which the subject indicated they were at home to the geocoded home address. We calculated the percentage of EMA locations within a sixteenth, eighth, quarter, and half miles from the home, and the percentage within the same tract and block group as the home. We investigated if the accuracy measures were associated with subject demographics, substance use, and emotional dysregulation, as well as environmental characteristics of the home neighborhood., Results: Half of all subjects had more than 88% of their EMA locations within a half mile, 72% within a quarter mile, 55% within an eighth mile, 50% within a sixteenth of a mile, 83% in the correct tract, and 71% in the correct block group. There were no significant associations with subject or environmental characteristics., Conclusions: Results support the use of GEMA for analyzing subjects' exposures to urban environments. Researchers should be aware of the issue of spatial accuracy inherent in GEMA, and interpret results accordingly. Understanding spatial accuracy is particularly relevant for the development of 'ecological momentary interventions' (EMI), which may depend on accurate location information, though issues of privacy protection remain a concern., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: The current study investigated the moderating effect of peer networks on neighborhood disorder's association with substance use in a sample of primarily African American urban adolescents., Methods: A convenience sample of 248 adolescents was recruited from urban health care settings and followed for two years, assessing psychological, social, and geographic risk and protective characteristics. A subset of 106 substance using participants were used for the analyses. A moderation model was tested to determine if the influence of neighborhood disorder (percent vacant housing, assault index, percent single parent headed households, percent home owner occupied, percent below poverty line) on substance use was moderated by peer network health (sum of peer risk and protective behaviors)., Results: Evidence for hypothesized peer network moderation was supported. A latent growth model found that peer network health is most strongly associated with lower baseline substance use for young adolescents residing in more disordered neighborhoods. Over the course of two years (ages approximately 14-16) this protective effect declines, and the decline is stronger for more disordered neighborhoods., Conclusions: Understanding the longitudinal moderating effects of peer networks within high-risk urban settings is important to the development and testing of contextually sensitive peer-based interventions., Results: suggest that targeting the potential protective qualities of peer networks may be a promising approach for interventions seeking to reduce substance use, particularly among younger urban adolescents living in high-risk neighborhoods., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Although adolescent tobacco use has declined in the last 10 years, African American high school seniors' past 30-day use has increased by 12 %, and as they age they are more likely to report lifetime use of tobacco. Very few urban youth are enrolled in evidenced-based smoking prevention and cessation programming. Therefore, we tested a text messaging smoking cessation intervention designed to engage urban youth through an automated texting program utilizing motivational interviewing-based peer network counseling. We recruited 200 adolescents (90.5 % African American) into a randomized controlled trial that delivered either the experimental intervention of 30 personalized motivational interviewing-based peer network counseling messages, or the attention control intervention, consisting of text messages covering general (non-smoking related) health habits. All adolescents were provided smart phones for the study and were assessed at baseline, and at 1, 3, and 6 months post intervention. Utilizing repeated measures general linear models we examined the effects of the intervention while controlling for race, gender, age, presence of a smoker in the home, and mental health counseling. At 6 months, participants in the experimental condition significantly decreased the number of days they smoked cigarettes and the number of cigarettes they smoked per day; they significantly increased their intentions not to smoke in the future; and significantly increased peer social support among girls. For boys, participants in the experimental condition significantly reduced the number of close friends in their networks who smoke daily compared to those in the control condition. Effect sizes ranged from small to large. These results provide encouraging evidence of the efficacy of text messaging interventions to reduce smoking among adolescents and our intervention holds promise as a large-scale public health preventive intervention platform.

Background: This study investigates whether residential exposure to tobacco outlets (i.e., convenience stores and other stores selling tobacco) is associated with attitudes towards smoking among a sample of urban, primarily African American, adolescent smokers., Methods: Cross-sectional survey data for 197 adolescents were integrated with spatial data on tobacco outlets via subject home addresses. Ordinal regression was employed to test hypotheses that closer proximity to, and higher concentrations of, tobacco outlets are associated with higher measures of intention to continue to smoke in the future, weaker self-efficacy related to stopping smoking, and more accepting social norms related to smoking, while controlling for characteristics of age, gender, family and peer smoking contexts, and level of nicotine dependence. Moderation by age and gender was also investigated., Results: Higher residential tobacco outlet density is significantly associated with a greater intention to smoke in the next 3 months, a lower readiness to stop smoking, and a greater likelihood of accepting a cigarette from a friend. Residential proximity to a tobacco outlet is significantly associated with a greater intention to smoke 5 years on. Evidence of a relationship between exposure to tobacco outlets and social norms related to smoking was not found, nor was there evidence for moderation of these relationships by age or gender., Conclusions: These results suggest that among urban adolescents who currently smoke, higher residential exposure to tobacco outlets is associated with greater predisposition towards future smoking and lower self-evaluation of the ability to stop smoking.

Background: This study investigates the association of activity space-based exposure to neighborhood disadvantage with momentary perceived stress and safety, and the moderation of substance use on those associations, among a sample of 139 urban, primarily African American, adolescents., Method: Geospatial technologies are integrated with Ecological Momentary Assessment (EMA) to capture exposure to neighborhood disadvantage and perceived stress and safety in the activity space. A relative neighborhood disadvantage measure for each subject is calculated by conditioning the neighborhood disadvantage observed at the EMA location on that of the home neighborhood. Generalized estimating equations (GEE) are used to model the effect of relative neighborhood disadvantage on momentary perceived stress and safety, and the extent to which substance use moderates those associations., Results: Relative neighborhood disadvantage is significantly associated with higher perceived stress, lower perceived safety, and greater substance use involvement. The association of relative neighborhood disadvantage with stress is significantly stronger among those with greater substance use involvement., Conclusion: This research highlights the value of integrating geospatial technologies with EMA and developing personalized measures of environmental exposure for investigating neighborhood effects on substance use, and suggests substance use intervention strategies aimed at neighborhood conditions. Future research should seek to disentangle the causal pathways of influence and selection that relate neighborhood environment, stress, and substance use, while also accounting for the role of gender and family and peer social contexts., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: This study investigates the impact of residential versus outpatient treatment setting on treatment completion, and how this impact might vary by demographic characteristics and drug of choice, using a national sample of publicly funded substance abuse programs in the United States., Methods: This is a retrospective analysis using data extracted from the 2011 Substance Abuse and Mental Health Services Administration (SAMHSA) Treatment Episode Data Set (TEDS-D). A total of 318,924 cases were analyzed using logistic regression, fixed-effects logistic regression, and moderated fixed-effects logistic regression., Results: Residential programs reported a 65% completion rate compared to 52% for outpatient settings. After controlling for other confounding factors, clients in residential treatment were nearly three times as likely as clients in outpatient treatment to complete treatment. The effect of residential treatment on treatment completion was not significantly moderated by gender, but it was for age, drug of choice, and race/ethnicity. Residential compared to outpatient treatment increased the likelihood of completion to a greater degree for older clients, Whites, and opioid abusers, as compared to younger clients, non-Whites, and alcohol and other substance users, respectively., Conclusion: We speculate that for opioid abusers, as compared to abusers of other drugs, residential treatment settings provide greater protection from environmental and social triggers that may lead to relapse and non-completion of treatment. Greater use of residential treatment should be explored for opioid users in particular., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Substance use disorders are widely recognized as one of the most pressing global public health problems, and recent research indicates that environmental factors, including access and exposure to substances of abuse, neighborhood disadvantage and disorder, and environmental barriers to treatment, influence substance use behaviors. Racial and socioeconomic inequities in the factors that create risky substance use environments may engender disparities in rates of substance use disorders and treatment outcomes. Environmental justice researchers, with substantial experience in addressing racial and ethnic inequities in environmental risk from technological and other hazards, should consider similar inequities in risky substance use environments as an environmental justice issue. Research should aim at illustrating where, why, and how such inequities in risky substance use environments occur, the implications of such inequities for disparities in substance use disorders and treatment outcomes, and the implications for tobacco, alcohol, and drug policies and prevention and treatment programs.

Introduction: Neighborhood features such as the density of tobacco outlets relative to one's home and evaluations of safety of one's activity space (routine locations), are known to influence health behaviors. Understanding the time-varying nature of these aspects of the urban ecology provides unique insights into the dynamic interactions of individuals and their environments., Methods: The present study tested the time-varying effects of tobacco outlets and perceived safety within a randomized controlled trial of an adolescent text-messaging smoking intervention. We used ecological momentary assessment data (EMA) from an automated text-messaging smoking cessation randomized trial with 197 primarily African American urban adolescents. We employed a time-varying effect model to estimate the effects of density of tobacco outlets within one-half mile of participants' home locations (time-invariant covariate) and evaluations of safety of their activity space (time-varying covariate) on momentary smoking over 6 months by treatment condition. The time-varying effect model approach models behavioral change and associations of coefficients expressed dynamically and graphically represented as smooth functions of time., Results: Differences in trajectories of smoking between treatment conditions were apparent over the course of the study. During months 2 and 6, the association between tobacco outlet density and smoking was significantly stronger in the control condition, suggesting treatment dampens this association during these time periods. The intervention also significantly reduced the association of perceived safety and smoking among the treatment condition during months 3 through 6., Conclusions: Results support testing the time-varying effects of urban ecological features and perceptions of safety among adolescents in text-based smoking cessation interventions., Implications: This study makes a unique contribution towards understanding the time-varying effects of urban neighborhoods on adolescent tobacco use within the context of a text-delivered intervention. Helping to adjust the long-held conceptualization of intervention effects as a static outcome, to that of a dynamic, time-varying process, is an important contribution of this study. The ability to specify when behavioral change occurs within the context of a randomized control trial provides understanding into the time-varying treatment effects of text-based smoking intervention. For example, researchers can modify the intervention to have strategically timed booster sessions that align with when the odds of smoking begin to increase in order to provide more precise treatment. The current study results show that increasing support to participants during months 2 and 4 may help suppress smoking over the course of a 6-month intervention., (© The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Limited research is available that explains complex contextual and interactive effects of microsystems such as family relationships, peer networks, and place-based influences have on urban adolescent substance use. We contend that research into these complex processes is improved by integrating psychological, social, and geographic data to better understand urban adolescent substance use involvement. Accordingly, we tested a longitudinal, 3-way moderation model to determine if the direct effect of teen-parent relationships on substance use involvement is moderated by peer network characteristics, which in turn is moderated by the risk and protective attributes within urban adolescents' activity spaces, among a sample of 248 adolescents. Results revealed that peer networks moderate the effects of relations with parents on substance use involvement for those adolescents with higher levels of risk attributes within their activity space, but not for those who spend time in locations with less risk. Thus, the teen-parent relationship interacts with peer net-work characteristics, for those urban adolescents whose activity space is constituted within high-risk environments. We conclude that peer networks have important interactive effects with family relationships that influence substance use, and that this is particularly salient for young adolescents who are exposed to risky environments. This finding underscores the importance of continued study into the interrelations among microsystems of urban adolescents, and provides further support that substance use is a social practice that is constituted within the unique geography of young adolescents' lives.

This study investigates how racial and ethnic disparities in treatment episode completion vary across different problem substances in an urban sample of 416,224 outpatient treatment discharges drawn from the 2011 U.S. Treatment Episode Dataset-Discharge (TEDS-D) data set. Fixed effects logistic regression is employed to test for the association of race and ethnicity with treatment episode completion for different substances of use while controlling for confounding demographic, socioeconomic, and geographic clustering factors. Results show that African Americans and Hispanics are less likely to complete a treatment episode than Whites, and that these disparities vary among users of different substances. For African Americans, this disparity is observed over all substances, but is particularly acute among users of alcohol and methamphetamine, substances for which African Americans generally have lower rates of use disorder as compared to Whites. For Hispanics, this disparity is driven primarily by users of heroin, for which Hispanics are only 75% as likely as Whites to complete a treatment episode. For users of cocaine and methamphetamine, there is no significant difference between Hispanics and Whites in the likelihood of treatment episode completion. These results contribute to emerging research on the mechanisms of substance use disorder treatment outcomes and highlight the need for culturally appropriate treatment programs to enhance treatment program retention and associated positive post-treatment outcomes., (Copyright © 2015 Elsevier Inc. All rights reserved.)

This study investigates the role of tobacco outlet density in a randomized controlled trial of a text messaging-based smoking cessation intervention conducted among a sample of 187 primarily African American youth in a midsize U.S. city. A moderated mediation model was used to test whether the indirect effect of residential tobacco outlet density on future smoking was mediated by the intention to smoke, and whether this indirect effect differed between adolescents who received the intervention and those who did not. Results indicated that tobacco outlet density is associated with intention to smoke, which predicts future smoking, and that the indirect effect of tobacco outlet density on future smoking is moderated by the intervention. Tobacco outlet density and the intervention can be viewed as competing forces on future smoking behavior, where higher tobacco outlet density acts to mitigate the sensitivity of an adolescent to the intervention's intended effect. Smoking cessation interventions applied to youth should consider tobacco outlet density as a contextual condition that can influence treatment outcomes., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The psychological construct, readiness to change, is established as a central construct within behavioral change theories such as motivational interviewing (MI). Less is known about the interplay of mechanisms for change within adolescent treatment populations. Understanding the timing and interactive influence that adolescents' readiness to stop smoking and peer smoking have on subsequent tobacco use is important to advance intervention research. Toward this end, we used ecological momentary assessment (EMA) data from an automated texting smoking intervention randomized controlled trial to model the interactive effects of readiness to stop smoking and friends smoking on adolescent tobacco use. Two hundred adolescents were randomized into experimental treatment or attention control conditions, provided smart phones, and were followed for 6 months. African American youth represented the majority of the sample. We collected monthly EMA data for 6 months on friends smoking and readiness to stop smoking as well as survey outcome data. We tested a moderated mediation model using bias corrected bootstrapping to determine if the indirect effect of treatment on cigarettes smoked through readiness to stop smoking was moderated by friends smoking. Findings revealed that readiness to stop smoking mediated the effects of treatment on cigarettes smoked for those adolescents with fewer friends smoking, but not for those with more friends smoking. These results support importance of peer-focused interventions with urban adolescents and provide target mechanisms for future research., (Copyright © 2015 Elsevier Inc. All rights reserved.)