Search

Background: Evidence for substance use-related problems in individuals with mild intellectual disability is sparse and mainly limited to selected psychiatric populations. We evaluated the risk of substance use-related problems in individuals with mild intellectual disability compared to the general population. Additionally, we have performed secondary sibling comparison analyses to account for familial confounding. Methods: We conducted a population-based cohort study of individuals born in Sweden between 1973 and 2003. A total of 18,307 individuals with mild intellectual disability were compared to 915,350 reference individuals from the general population and 18,996 full siblings of individuals with mild intellectual disability. Information on mild intellectual disability and substance use-related problems was obtained from several Swedish national and regional school and healthcare registers. Substance use-related problems were measured via corresponding diagnostic and legal codes and included alcohol use disorder, drug use disorder, alcohol-related somatic disease, conviction for a substance-related crime, and substance-related death. Results: Individuals with mild intellectual disability had a higher risk of any substance use-related problem compared to the general population (HR, 1.81; 95% CI, 1.72–1.91), both in males (HR, 1.76; 95% CI, 1.65–1.89) and females (HR, 1.89; 95% CI, 1.74–2.05). The risks of substance use-related problems were particularly elevated among individuals with mild intellectual disability and psychiatric comorbidities (HR, 2.21–8.24). The associations were attenuated in the sibling comparison models. Conclusions: Individuals with mild intellectual disability, especially those with psychiatric comorbidity, are at an elevated risk of substance use-related problems. Familial factors shared by full siblings contribute considerably to the association between mild intellectual disability and substance use-related problems. © 2024 The Authors. J, Funding: The study has been financed by the grants from the Swedish Research Council for Health, Working Life and Welfare (FORTE, No 2018-01789), MISA (grant 20100825) and Stiftelsen Söderström - Königska sjukhemmet (SLS969059). Agnieszka Butwicka was supported by the Swedish Research Council (No 2017-00788), NordForsk (No 147386) and through the regional agreement on clinical research between Stockholm Region and Karolinska Institutet (ALF, No 20180718) while working on this project. Mark Taylor was supported by a Fellows Award from MQ Mental Health Research (MQ20/19).

IMPORTANCE: Exposure to adverse childhood experiences (ACEs) has consistently been associated with multiple negative mental health outcomes extending into adulthood. However, given that ACEs and psychiatric disorders cluster within families, it remains to be comprehensively assessed to what extent familial confounding contributes to associations between ACEs and clinically confirmed adult psychiatric disorders. OBJECTIVE: To investigate whether associations between ACEs and adult mental health outcomes remain after adjusting for familial (genetic and environmental) confounding. DESIGN, SETTING, AND PARTICIPANTS: This Swedish twin cohort study used a discordant twin pair design based on monozygotic (MZ) and dizygotic (DZ) twins. A total of 25 252 adult twins (aged 18-47 years) from the Swedish Twin Registry born between 1959 and 1998 were followed up from age 19 years until 2016, with a maximum follow-up time of 39 years. Data were analyzed from April 2022 to November 2023. EXPOSURES: A total of 7 ACEs, including family violence, emotional abuse or neglect, physical neglect, physical abuse, sexual abuse, rape, and hate crime, were assessed with items from the Life Stressor Checklist-Revised in a web-based survey. MAIN OUTCOMES AND MEASURES: Adult (ages >18 years) clinical diagnosis of psychiatric disorders (ie, depressive, anxiety, alcohol or drug misuse, or stress-related disorders) were obtained from the Swedish National Patient Register. RESULTS: Of 25 252 twins included in the study (15 038 female [59.6%]; mean [SD] age at ACE assessment, 29.9 [8.7] years), 9751 individuals (38.6%) reported exposure to at least 1 ACE. A greater number of ACEs was associated with increased odds of any psychiatric disorder in the full cohort (odds ratio [OR] per additional ACE, 1.52; 95% CI, 1.48-1.57). The association remained but ORs per additional ACE were attenuated in DZ (1.29; 95% CI, 1.14-1.47) and MZ (1.20; 95% CI, 1.02-1.40) twin pairs. Individuals who were exposed to s, This work was supported by consolidator grant 726413 from the European Research Council and grant of excellence163362-051 from the Icelandic Center for Research to Dr Valdimarsdóttir and by European UnionHorizon 2020 Research and Innovation Action grant 847776 to Dr Fang. Ms Daníelsdóttir was supported by a doctoral grant from the University of Iceland Research Fund.

IMPORTANCE: Attention-deficit/hyperactivity disorder (ADHD) is associated with increased risks of adverse health outcomes including premature death, but it is unclear whether ADHD pharmacotherapy influences the mortality risk. OBJECTIVE: To investigate whether initiation of ADHD pharmacotherapy was associated with reduced mortality risk in individuals with ADHD. DESIGN, SETTING, AND PARTICIPANTS: In an observational nationwide cohort study in Sweden applying the target trial emulation framework, we identified individuals aged 6 through 64 years with an incident diagnosis of ADHD from 2007 through 2018 and no ADHD medication dispensation prior to diagnosis. Follow-up started from ADHD diagnosis until death, emigration, 2 years after ADHD diagnosis, or December 31, 2020, whichever came first. EXPOSURES: ADHD medication initiation was defined as dispensing of medication within 3 months of diagnosis. MAIN OUTCOMES AND MEASURES: We assessed all-cause mortality within 2 years of ADHD diagnosis, as well as natural-cause (eg, physical conditions) and unnatural-cause mortality (eg, unintentional injuries, suicide, and accidental poisonings). RESULTS: Of 148 578 individuals with ADHD (61 356 females [41.3%]), 84 204 (56.7%) initiated ADHD medication. The median age at diagnosis was 17.4 years (IQR, 11.6-29.1 years). The 2-year mortality risk was lower in the initiation treatment strategy group (39.1 per 10 000 individuals) than in the noninitiation treatment strategy group (48.1 per 10 000 individuals), with a risk difference of -8.9 per 10 000 individuals (95% CI, -17.3 to -0.6). ADHD medication initiation was associated with significantly lower rate of all-cause mortality (hazard ratio [HR], 0.79; 95% CI, 0.70 to 0.88) and unnatural-cause mortality (2-year mortality risk, 25.9 per 10 000 individuals vs 33.3 per 10 000 individuals; risk difference, -7.4 per 10 000 individuals; 95% CI, -14.2 to -0.5; HR, 0.75; 95% CI, 0.66 to 0.86), but not natural-cause mortality (2-year mor

OBJECTIVE: Most mental disorders, when examined individually, are associated with an increased risk of cardiometabolic complications. However, these associations might be attributed to a general liability to psychopathology or confounded by unmeasured familial factors. The authors investigated the association between psychiatric conditions in young adulthood and the risk of cardiometabolic complications in middle adulthood, up to 40 years later. METHODS: This cohort study (N=672,823) identified all individuals and their siblings born in Sweden between 1955 and 1962 and followed the cohort through 2013. Logistic regression models were used to estimate the bivariate associations between 10 psychiatric conditions or criminal convictions and five cardiometabolic complications in individuals. A general factor model was used to identify general, internalizing, externalizing, and psychotic factors based on the comorbidity among psychiatric conditions and criminal convictions. The cardiometabolic complications were then regressed on the latent general factor and three uncorrelated specific factors within a structural equation modeling framework in individuals and across sibling pairs. RESULTS: Each psychiatric condition significantly increased the risk of cardiometabolic complications. These associations appeared nonspecific, as multivariate models indicated that most were attributable to the general factor of psychopathology, rather than to specific psychiatric conditions. There were no or only small associations between individuals' general psychopathology and their siblings' cardiometabolic complications. The same pattern was evident for the specific internalizing and psychotic factors. CONCLUSIONS: Associations between mental disorders in early life and later long-term risk of cardiometabolic complications appeared to be attributable to a general liability to psychopathology. Familial coaggregation analyses suggested that the elevated risk could not be attributed to con, Supported by the Swedish Research Council for Health (grant 2017-01358) , ALF Funding from the Stockholm Region (grant 20190712), and the China Scholarship Council.

BACKGROUND AND HYPOTHESIS: Recent research showed that young people who presented to hospital with self-harm in Finland had a significantly elevated risk of later psychosis. We investigated the prospective relationship between hospital presentation for self-harm and risk of psychosis in an unprecedentedly large national Swedish cohort. STUDY DESIGN: We used inpatient and outpatient healthcare registers to identify all individuals born between 1981 and 1993 who were alive and living in Sweden on their 12th birthday and who presented to hospital one or more times with self-harm. We compared them with a matched cohort, followed up for up to 20 years, and compared the cumulative incidence of psychotic disorders. Furthermore, we examined whether the strength of the relationship between hospital presentation for self-harm and later psychosis changed over time by examining for cohort effects. STUDY RESULTS: In total, 28 908 (2.0%) individuals presented to hospital with self-harm without prior psychosis diagnosis during the follow-up. For individuals who presented to hospital with self-harm, the cumulative incidence of diagnosed psychosis was 20.7% at 20 years follow-up (hazard radio = 13.9, 95% CI 13.3-14.6, P-value <5 × 10-308). There was no evidence of a dilution of the effect over time: while the incidence of hospital self-harm presentation increased, this did not result in an attenuation over time of the strength of the relationship between hospital self-harm presentation and subsequent psychosis. CONCLUSIONS: Individuals who present to hospital with self-harm in their teens and 20s represent an important risk group for psychosis prediction and prevention., This work was supported by the Sophia Research Fund (fellowship 921 to K.B.) and the St John of God Research Foundation (project grant to I.K.).

OBJECTIVE: To estimate the risk of all cause and cause specific mortality in people with obsessive-compulsive disorder (OCD) compared with matched unaffected people from the general population and with their unaffected siblings. DESIGN: Population based matched cohort and sibling cohort study. SETTING: Register linkage in Sweden. PARTICIPANTS: Population based cohort including 61 378 people with OCD and 613 780 unaffected people matched (1:10) on sex, birth year, and county of residence; sibling cohort consisting of 34 085 people with OCD and 47 874 unaffected full siblings. Cohorts were followed up for a median time of 8.1 years during the period from 1 January 1973 to 31 December 2020. MAIN OUTCOME MEASURES: All cause and cause specific mortality. RESULTS: 4787 people with OCD and 30 619 unaffected people died during the study period (crude mortality rate 8.1 and 5.1 per 1000 person years, respectively). In stratified Cox proportional hazards models adjusted for birth year, sex, county, migrant status (born in Sweden versus abroad), and sociodemographic variables (latest recorded education, civil status, and family income), people with OCD had an increased risk of all cause mortality (hazard ratio 1.82, 95% confidence interval 1.76 to 1.89) and mortality due to natural causes (1.31, 1.27 to 1.37) and unnatural causes (3.30, 3.05 to 3.57). Among the natural causes of death, those due to endocrine, nutritional, and metabolic diseases, mental and behavioural disorders, and diseases of the nervous, circulatory, respiratory, digestive, and genitourinary systems were higher in the OCD cohort. Conversely, the risk of death due to neoplasms was lower in the OCD cohort compared with the unaffected cohort. Among the unnatural causes, suicide showed the highest hazard ratio, followed by accidents. The results were robust to adjustment for psychiatric comorbidities and familial confounding. CONCLUSIONS: Non-communicable diseases and external causes of death, including suicide

IMPORTANCE: Hypochondriasis, also known as health anxiety disorder, is a prevalent, yet underdiagnosed psychiatric disorder characterized by persistent preoccupation about having serious and progressive physical disorders. The risk of mortality among individuals with hypochondriasis is unknown. OBJECTIVE: To investigate all-cause and cause-specific mortality among a large cohort of individuals with hypochondriasis. DESIGN, SETTING, AND PARTICIPANTS: This Swedish nationwide matched-cohort study included 4129 individuals with a validated International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) diagnosis of hypochondriasis assigned between January 1, 1997, and December 31, 2020, and 41 290 demographically matched individuals without hypochondriasis. Individuals with diagnoses of dysmorphophobia (body dysmorphic disorder) assigned during the same period were excluded from the cohort. Statistical analyses were conducted between May 5 and September 27, 2023. EXPOSURE: Validated ICD-10 diagnoses of hypochondriasis in the National Patient Register. MAIN OUTCOME AND MEASURES: All-cause and cause-specific mortality in the Cause of Death Register. Covariates included birth year, sex, county of residence, country of birth (Sweden vs abroad), latest recorded education, civil status, family income, and lifetime psychiatric comorbidities. Stratified Cox proportional hazards regression models were used to estimate the hazard ratios (HRs) and 95% CIs of all-cause and cause-specific mortality. RESULTS: Of the 4129 individuals with hypochondriasis (2342 women [56.7%]; median age at first diagnosis, 34.5 years [IQR, 26.3-46.1 years]) and 41 290 demographically matched individuals without hypochondriasis (23 420 women [56.7%]; median age at matching, 34.5 years [IQR, 26.4-46.2 years]) in the study, 268 individuals with hypochondriasis and 1761 individuals without hypochondriasis died during the study period, corresponding to crude mortali

IMPORTANCE: Use of attention-deficit/hyperactivity disorder (ADHD) medications has increased substantially over the past decades. However, the potential risk of cardiovascular disease (CVD) associated with long-term ADHD medication use remains unclear. OBJECTIVE: To assess the association between long-term use of ADHD medication and the risk of CVD. DESIGN, SETTING, AND PARTICIPANTS: This case-control study included individuals in Sweden aged 6 to 64 years who received an incident diagnosis of ADHD or ADHD medication dispensation between January 1, 2007, and December 31, 2020. Data on ADHD and CVD diagnoses and ADHD medication dispensation were obtained from the Swedish National Inpatient Register and the Swedish Prescribed Drug Register, respectively. Cases included individuals with ADHD and an incident CVD diagnosis (ischemic heart diseases, cerebrovascular diseases, hypertension, heart failure, arrhythmias, thromboembolic disease, arterial disease, and other forms of heart disease). Incidence density sampling was used to match cases with up to 5 controls without CVD based on age, sex, and calendar time. Cases and controls had the same duration of follow-up. EXPOSURE: Cumulative duration of ADHD medication use up to 14 years. MAIN OUTCOMES AND MEASURES: The primary outcome was incident CVD. The association between CVD and cumulative duration of ADHD medication use was measured using adjusted odds ratios (AORs) with 95% CIs. RESULTS: Of 278 027 individuals with ADHD aged 6 to 64 years, 10 388 with CVD were identified (median [IQR] age, 34.6 [20.0-45.7] years; 6154 males [59.2%]) and matched with 51 672 control participants without CVD (median [IQR] age, 34.6 [19.8-45.6] years; 30 601 males [59.2%]). Median (IQR) follow-up time in both groups was 4.1 (1.9-6.8) years. Longer cumulative duration of ADHD medication use was associated with an increased risk of CVD compared with nonuse (0 to ≤1 year: AOR, 0.99 [95% CI, 0.93-1.06]; 1 to ≤2 years: AOR, 1.09 [95% CI, 1.01-1

Background and Hypothesis: Recent research showed that young people who presented to hospital with self-harm in Finland had a significantly elevated risk of later psychosis. We investigated the prospective relationship between hospital presentation for self-harm and risk of psychosis in an unprecedentedly large national Swedish cohort. Study Design: We used inpatient and outpatient healthcare registers to identify all individuals born between 1981 and 1993 who were alive and living in Sweden on their 12th birthday and who presented to hospital one or more times with self-harm. We compared them with a matched cohort, followed up for up to 20 years, and compared the cumulative incidence of psychotic disorders. Furthermore, we examined whether the strength of the relationship between hospital presentation for self-harm and later psychosis changed over time by examining for cohort effects. Study Results: In total, 28 908 (2.0%) individuals presented to hospital with self-harm without prior psychosis diagnosis during the follow-up. For individuals who presented to hospital with self-harm, the cumulative incidence of diagnosed psychosis was 20.7% at 20 years follow-up (hazard radio = 13.9, 95% CI 13.3–14.6, P-value <5 × 10 −308). There was no evidence of a dilution of the effect over time: while the incidence of hospital self-harm presentation increased, this did not result in an attenuation over time of the strength of the relationship between hospital self-harm presentation and subsequent psychosis. Conclusions: Individuals who present to hospital with self-harm in their teens and 20s represent an important risk group for psychosis prediction and prevention.

BACKGROUND: Avoidant restrictive food intake disorder (ARFID) is a feeding and eating disorder, characterized by limited variety and/or quantity of food intake impacting physical health and psychosocial functioning. Children with ARFID often present with a range of psychiatric and somatic symptoms, and therefore consult various pediatric subspecialties; large-scale studies mapping comorbidities are however lacking. To characterize health care needs of people with ARFID, we systematically investigated ARFID-related mental and somatic conditions in 616 children with ARFID and >30,000 children without ARFID. METHODS: In a Swedish twin cohort, we identified the ARFID phenotype in 6-12-year-old children based on parent-reports and register data. From >1,000 diagnostic ICD-codes, we specified mental and somatic conditions within/across ICD-chapters, number of distinct per-person diagnoses, and inpatient treatment days between birth and 18th birthday (90 outcomes). Hazard ratios (HR) and incidence rate ratios (IRR) were calculated. FINDINGS: Relative risks of neurodevelopmental, gastrointestinal, endocrine/metabolic, respiratory, neurological, and allergic disorders were substantially increased in ARFID (e.g., autism HR[CI95%]=9.7[7.5-12.5], intellectual disability 10.3[7.6-13.9], gastroesophageal reflux disease 6.7[4.6-9.9], pituitary conditions 5.6[2.7-11.3], chronic lower respiratory diseases 4.9[2.4-10.1], epilepsy 5.8[4.1-8.2]). ARFID was not associated with elevated risks of autoimmune illnesses and obsessive-compulsive disorder. Children with ARFID had a significantly higher number of distinct mental diagnoses (IRR[CI95%]=4.7[4.0-5.4]) and longer duration of hospitalizations (IRR[CI95%]=5.5[1.7-17.6]) compared with children without ARFID. Children with ARFID were diagnosed earlier with a mental condition than children without ARFID. No sex-specific differences emerged. INTERPRETATION: This study yields the broadest and most detailed evidence of co-existing men

BACKGROUND: Lower autonomic arousal is a well-known correlate of criminal offending and other risk-taking behaviors in men, but few studies have investigated this association in women. AIM: To test associations between autonomic arousal and criminal offending as well as unintentional injuries among female conscripts. METHODS: All women born 1958-1994 in Sweden who participated in voluntary military conscription (n = 12,499) were identified by linking Swedish population-based registers. Predictors were resting heart rate (RHR) and systolic blood pressure (SBP). Covariates were height, weight, and physical energy capacity. Main outcomes were criminal convictions (any, violent, and non-violent) from the National Crime Register. Secondary outcome was unintentional injuries requiring medical treatment or causing death. We used survival analyses to test for associations between predictors and outcomes. RESULTS: Low RHR, relative to high RHR, was associated with an increased risk of any criminal conviction, non-violent criminal convictions, and unintentional injuries. Low SBP, relative to high SBP, was associated with an increased risk of violent criminal convictions. CONCLUSIONS: Results support lower autonomic arousal, particularly lower RHR, as a correlate of criminal offending among women that warrants further examination, as the reported findings have potential implications for the prediction of future female crime.

Background: Over the last decades, the prevalence of Attention-deficit/hyperactivity disorder (ADHD) has increased. However, the underlying explanation for this increase remains unclear. We aimed to assess whether there has been a secular change in how parents perceive the impairment conferred by ADHD symptomatology. Methods: Data for this study were obtained from the Child and Adolescent Twin Study in Sweden, involving 27,240 individuals whose parents answered a questionnaire when the children were 9 years old. We assessed the relationship between parentally perceived impairment caused by ADHD symptoms scores over time. The analysis was performed separately for five different birth cohorts, spanning three-year periods from 1995 to 2009 and for ADHD inattention and hyperactivity/impulsivity dimensions. Results: We found a consistent upward trend of parents reporting impairment in relation to ADHD symptomatology across birth cohorts. Over a 12-year period, comparing those born 2007–2009 (assessed 2016–2018) with those born 1995–1997 (assessed 2004–2006), impairment scores increased by 27% at clinically relevant levels of ADHD symptomatology. Notably, when specifically evaluating the hyperactivity/impulsivity dimension, the disparity was even more striking, with an increase of up to 77%. Conclusions: This study revealed a significant secular change in parental perception of impairment attributed to ADHD symptomatology over recent decades, providing new insights into the increased prevalence of ADHD. It underscores the need to better understand the factors that have contributed to the increased perception of impairment related to ADHD symptoms.