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Whereas substance-use researchers have long combined self-report with objective measures of behavior and physiology inside the laboratory, developments in mobile/wearable electronic technology are increasingly allowing for the collection of both subjective and objective information in participants’ daily lives. For self-report, ecological momentary assessment (EMA), as implemented on contemporary smartphones or personal digital assistants, can provide researchers with near-real-time information on participants’ behavior and mood in their natural environments. Data from portable/wearable electronic sensors measuring participants’ internal and external environments can be combined with EMA (e.g., by timestamps recorded on questionnaires) to provide objective information useful in determining the momentary context of behavior and mood and/or validating participants’ self-reports. Here, we review three objective ambulatory monitoring techniques that have have been combined with EMA, with a focus on detecting drug use and/or measuring the behavioral or physiological correlates of mental events (i.e., emotions, cognitions): (1) collection and processing of biological samples in the field to measure drug use or participants’ physiological activity (e.g, hypothalamic-pituitary-adrenal axis activity); (2) global positioning system (GPS) location information to link environmental characteristics (disorder/disadvantage, retail drug outlets) to drug use and affect; (3) ambulatory electronic physiological monitoring (e.g., electrocardiography) to detect drug use and mental events, as advances in machine learning algorithms make it possible to distinguish target changes from confounds (e.g., physical activity). Finally, we consider several other mobile/wearable technologies that hold promise to be combined with EMA, as well as potential challenges faced by researchers working with multiple mobile/wearable technologies simultaneously in the field.

Background Individual trajectories of drug use and drug-related problems are highly heterogeneous. There is no standard taxonomy of these trajectories, but one could be developed by defining natural categories based on changes in symptoms of substance-use disorders over time. Methods Our study was conducted in a community sample in Baltimore, Maryland. At baseline, all participants were using opioids and/or cocaine, but none were in treatment. Drug use and symptomatology were assessed again at 12 months (N = 115). Results We defined Quitters as participants who had not used for at least 30 days at follow-up (17%). For the remaining participants, we performed longitudinal cluster analysis on DSM symptom-counts, identifying three trajectory clusters: newly or persistently Symptomatic (40%) participants, Chippers (21.5%) with few symptoms, and Converted Chippers (21.5%) with improved symptom counts. Logistic regression showed that profiles of Quitters did not resemble Chippers, but instead resembled Symptomatic participants, having high probability of disorderly home neighborhood, nonwhite race, and negative mood. Quitters tended to have two protective factors: initiating opioid-agonist treatment during the study (reffect = 0.25, CL95 0.02–0.48) and lack of polydrug use (reffect = 0.25, CL95 0.004–0.49). Converted Chippers tended to be white, with orderly home neighborhoods and less negative mood (reffects 0.24 to 0.31, CL95 0.01–0.54). Conclusions Changes in DSM symptomology provided a meaningful measure of individual trajectories. Quitters shared psychosocial characteristics with Symptomatic participants, but not with participants who continued to use with few symptoms. This suggests that Quitters abstained out of necessity, not because their problems were less severe.

Real-time monitoring of behavior using Ecological Momentary Assessment (EMA) has provided detailed data about daily temporal patterns of craving and use in cigarette smokers. We have collected similar data from a sample of cocaine and heroin users. Here we analyzed it in the context of its relationship with a societal construct of daily temporal organization: 9-to-5 business hours. In a 28-week prospective study, 112 methadone-maintained polydrug-abusing individuals initiated an electronic-diary entry and provided data each time they used cocaine, heroin, or both during weeks 4 to 28. EMA data were collected for 10,781 person-days and included: 663 cocaine-craving events, 710 cocaine-use events, 288 heroin-craving events, 66 heroin-use events, 630 craving-both-drugs events, and 282 use-of-both-drugs events. At baseline, 34% of the participants reported full-time employment in the preceding 3-year period. Most participants’ current employment status fluctuated throughout the study. In a generalized linear mixed model (SAS Proc Glimmix), cocaine use varied by time of day relative to business hours (p

Marriage has been cited as a protective factor against drug use, but the relationship between marriage and drug use has not been explored longitudinally during addiction treatment. The current study assessed individual trajectories of substance use during treatment as a function of marital status and perceived closeness of the marital relationship. A parallel-process growth model was used to (1) estimate the rate of change in percentage of cocaine-positive and heroin-positive urine samples, and (2) examine the relationship between marital status and drug use trajectories over 35 weeks, during and after treatment. Percent days of use for both drugs were lowest for married participants across all time points. Among married participants, reporting a close relationship with one’s partner predicted less cocaine and heroin use. These findings suggest that being married and having a close relationship with one’s spouse are associated with better outcomes over time. The causal nature of the association is suggested by previous research that has demonstrated the effectiveness of couples therapy as an adjunct to methadone maintenance.

Intravenous drug use is a major vector of HIV transmission. We assessed whether contingency management (CM), in which participants earn reinforcers for drug abstinence, reduces HIV risk behaviors in methadone-maintained opiate- and cocaine-using outpatients. Participants (n=116) were randomly assigned to prize-based CM or to receipt of prize draws noncontingently on a schedule yoked to the CM group. Both groups received methadone and individual counseling throughout treatment. The HIV-Risk Taking Behaviour Scale was administered in written questionnaire form at 2-week intervals (HRBS; [Darke, S., Hall, W., Heather, N., Ward, J., & Wodak, A. (1991). The reliability and validity of a scale to measure HIV risk-taking behaviour among intravenous drug users. AIDS, 5, 181-185]). A mediation analysis was conducted to determine whether abstinence from opiates and cocaine mediated the effect of CM on HRBS scores. Changes in HRBS scores over time differed significantly by treatment (F(9,334)=2.4, p

Underreporting of drug use is common and influenced by multiple factors. Cannabis (THC) use nonreporting and its relationship to heroin and cocaine use were investigated in 690 patients enrolled in 25- to 29-week clinical trials of contingency management plus methadone maintenance. Urine specimens and self-reports of drug use were collected 3 times/week. Potential predictors of THC use nonreporting were analyzed by multiple logistic regression; relationships between THC use nonreporting and % cocaine- and opiate-positive urines were analyzed by multiple regression. Compared to non-THC users (n = 317), patients with THC-positive urines (n = 373) were more likely to be male and have more years of THC use, but were not different on other characteristics. Nonreporting to user ratios were: THC 191/373 (51.2%); opiates 17/686 (2.5%); cocaine 21/681 (3.1%). Predictors of THC use nonreporting were low rate of THC-positive urines during treatment, fewer days of THC use in the last 30 before treatment, African-American race, and absence of antisocial personality disorder. Nonreporting of THC use was associated with significantly greater opiate and cocaine use. Contingency management decreased cocaine use in THC nonreporters to the level of reporters. Nonreporting of THC use is a significant predictor of greater cocaine and heroin use. This association can be eliminated with contingency management therapy.

Two common assessment tools for nicotine dependence are the Fagerstrom Test for Nicotine Dependence (FTND) and the Nicotine Dependence section of the Diagnostic Interview Schedule [(DIS)-III-R or -IV based on the Diagnostic and Statistical Manual (DSM)-III-R and -IV, respectively]. The FTND emphasizes morning smoking and overall "heaviness" of smoking. The DSM emphasizes adverse consequences, desire to cut down, and mood changes during withdrawal. We tested (1) how the DSM-III-R diagnosis of Nicotine Dependence is related to FTND score; and (2) how the (a) DSM-III-R or (b) elevated FTND score is related to longer smoking histories, greater psychiatric symptomatology, and tobacco liking scores. Retrospective chart reviews were conducted on 370 smokers, the majority (55.9%) of whom had a current DSM-III-R diagnosis of Substance Dependence other than nicotine. All subjects had completed the FTND, the DIS-III-R, the Symptom Checklist-90-Revised (SCL-90-R), and a survey on drug liking. Agreement statistics were calculated between the DSM-II-R diagnosis of Nicotine Dependence and various cutoff scores values that were assigned as thresholds for nicotine dependence on the FTND. At no cutoff score did the two instruments reliably agree; the highest kappa (at a cutoff of FTND > or = 7) was 0.205. At cutoffs above 5, the FTND diagnosed fewer cases than the DSM-III-R. Multiple regression analysis showed that DSM diagnosis was associated with greater psychiatric symptomatology on the SCL-90-R, while FTND scores were associated with greater tobacco liking. The FTND and the DSM-III-R appear to measure different aspects of the tobacco dependence process. Specifically, the FTND may provide a stronger measure of physical dependence, while the DSM may tap other domains such as awareness of dependence, behaviors resulting from that awareness, and psychiatric symptomatology. Disagreements between the FTND and the DSM are likely to become greater with the changes in the DSM-IV.

Relationships among tobacco smoking, tobacco craving, and other drug use and craving may have treatment implications in polydrug-dependent individuals.We conducted the first ecological momentary assessment (EMA) study to investigate how smoking is related to other drug use and craving during daily life. For up to 20 weeks, 106 methadone-maintained outpatients carried PalmPilots (PDAs). They reported their craving, mood, behaviors, environment, and cigarette-smoking status in 2 to 5 random-prompt entries/day and initiated PDA entries when they used cocaine or heroin or had a discrete episode of craving for cocaine or heroin.Smoking frequency increased linearly with random-prompt ratings of tobacco craving, cocaine craving, and craving for both cocaine and heroin. Smoking frequency was greater during discrete episodes of cocaine use and craving than during random-prompt reports of low craving for cocaine. This pattern was also significant for dual cocaine and heroin use and craving. Smoking and tobacco craving were each considerably reduced during periods of urine-verified abstinence from cocaine, and there was a (nonsignificant) tendency for morning smoking to be especially reduced during those periods.This EMA study confirms that smoking and tobacco craving are strongly associated with the use of and craving for cocaine and heroin. Together with prior findings, our data suggest that tobacco and cocaine may each increase craving for (and likelihood of continued use of) themselves and each other. Treatment for tobacco dependence should probably be offered concurrently with (rather than only after) initiation of treatment for other substance-use disorders.

Cocaine use is associated with injecting and sexual HIV risk behaviors. This study was a randomized controlled trial of behavioral interventions for cocaine dependence and HIV risk behaviors among dually (cocaine and heroin) dependent outpatients. Methadone maintenance was augmented with cognitive-behavioral therapy (CBT), contingency management (CM), both (CBT + CM), or neither. The study sample (n = 81) was 52% female, 70% African American, and 37.9 ± 7.0 years old. Proportions reporting HIV risk behaviors at intake were: 96.3% (78 / 81) injection drug use, 56.8% (46 / 81) sharing needles, 30.9% (25 / 81) unprotected sex, 28.4% (23 / 81) trading sex for money or drugs. Proportions who no longer reported behaviors at study exit were: 51.3% (40 / 78) injection drug use, 91.3% (42 / 46) sharing needles, 88% (22 / 25) unprotected sex, 91.3% (21 / 23) trading sex for money or drugs. Participants receiving CBT + CM were more likely to report cessation of unprotected sex relative to control (OR = 5.44, 95% CI 1.14–26.0, p = 0.034) but this effect was no longer significant after adjusting for drug-negative urines. These results suggest broad beneficial effects of methadone maintenance augmented with behavioral interventions for reducing HIV risk behaviors.