To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Alcohol and other substance use problems are common, and the efficacy of current prevention and intervention programs is limited. Genetics may contribute to differential effectiveness of psychosocial prevention and intervention programs. This paper reviews gene-by-intervention (G×I) studies of alcohol and other substance use, and implications for integrating genetics into prevention science. Systematic review yielded 17 studies for inclusion. Most studies focused on youth substance prevention, alcohol was the most common outcome, and measures of genotype were heterogeneous. All studies reported at least one significant G×I interaction. We discuss these findings in the context of the history and current state of genetics, and provide recommendations for future G×I research. These include the integration of genome-wide polygenic scores into prevention studies, broad outcome measurement, recruitment of underrepresented populations, testing mediators of G×I effects, and addressing ethical implications. Integrating genetic research into prevention science, and training researchers to work fluidly across these fields, will enhance our ability to determine the best intervention for each individual across development. With growing public interest in obtaining personalized genetic information, we anticipate that the integration of genetics and prevention science will become increasingly important as we move into the era of precision medicine.
Many family characteristics were reported to increase the risk of bipolar disorder (BPD). The development of BPD may be mediated through different pathways, involving diverse risk factor profiles. We evaluated the associations of family characteristics to build influential causal-pie models to estimate their contributions on the risk of developing BPD at the population level. We recruited 329 clinically diagnosed BPD patients and 202 healthy controls to collect information in parental psychopathology, parent-child relationship, and conflict within family. Other than logistic regression models, we applied causal-pie models to identify pathways involved with different family factors for BPD. The risk of BPD was significantly increased with parental depression, neurosis, anxiety, paternal substance use problems, and poor relationship with parents. Having a depressed mother further predicted early onset of BPD. Additionally, a greater risk for BPD was observed with higher numbers of paternal/maternal psychopathologies. Three significant risk profiles were identified for BPD, including paternal substance use problems (73.0%), maternal depression (17.6%), and through poor relationship with parents and conflict within the family (6.3%). Our findings demonstrate that different aspects of family characteristics elicit negative impacts on bipolar illness, which can be utilized to target specific factors to design and employ efficient intervention programs.
Personality and its potential role in mediating risk of psychiatric disorders and suicidality are assessed by sexual orientation, using data collected among young Swiss men (n = 5875) recruited while presenting for mandatory military conscription. Mental health outcomes were analyzed by sexual attraction using logistic regression, controlling for five-factor model personality traits and socio-demographics. Homo/bisexual men demonstrated the highest scores for neuroticism-anxiety but the lowest for sociability and sensation seeking, with no differences for aggression-hostility. Among homo/bisexual men, 10.2% fulfilled diagnostic criteria for major depression in the past 2 weeks, 10.8% for ADHD in the past 12 months, 13.8% for lifetime anti-social personality disorder (ASPD), and 6.0% attempted suicide in the past 12 months. Upon adjusting (AOR) for personality traits, their odds ratios (OR) for major depression (OR = 4.78, 95% CI 2.81–8.14; AOR = 1.46, 95% CI 0.80–2.65) and ADHD (OR = 2.17, 95% CI = 1.31–3.58; AOR = 1.00, 95% CI 0.58–1.75) lost statistical significance, and the odds ratio for suicide attempt was halved (OR = 5.10, 95% CI 2.57–10.1; AOR = 2.42, 95% CI 1.16–5.02). There are noteworthy differences in personality traits by sexual orientation, and much of the increased mental morbidity appears to be accounted for by such underlying differences, with important implications for etiology and treatment.
Patients with chronic kidney disease (CKD) have more cognitive impairments. However, the etiologies are not fully clear. Plasma homocysteine levels and vascular burden rise in CKD; meanwhile, high homocysteine levels and vascular factors are known risk factors of dementia in non-CKD patients. Thus, we aimed to investigate the association between homocysteine, vascular burden and cognitive impairment in CKD and to see if the effect of elevated homocysteine on cognitive impairment mediated by vascular factor.
146 patients with CKD and 69 normal comparisons were recruited. Cognitive function was evaluated by comprehensive neuropsychological tests assessing processing speed, executive function, language, visuospatial function, memory, and attention domains. Vascular burden was assessed by Framinghan cardiovascular risk scale (FCRS) which indicates risk of atherosclerotic diseases including stroke.
In controlled analysis, patients with CKD had lower scores in all cognitive domains, and had higher homocysteine levels (18.5±6.4 vs. 9.8±2.9, p< 0.0001) and FCRS(17.0±4.7 vs. 14.0±4.7, p< 0.0001). Among patients with CKD, higher homocysteine levels (p=0.026) were associated with lower score on digit symbol task which is related to processing speed and executive function with controlling for age, sex, education and stage of CKD. The association persisted (p=0.047) after controlling for vascular risks.
Patients with CKD had extensive cognitive impairments. Elevated homocysteine levels may be an risk factor, which is independent of vascular burden, of cognitive impairment on processing speed and executive function. Further studies to investigate if normalization of homocysteine can improve cognitive function will be suggested.
Previous research failed to uncover a replicable structure of dimensions or subtypes underlying the symptoms of depression. One reason might be that research failed to separate co-variation between symptoms due to overall depression severity vs. due to specific symptom profiles.
Objectives and Aims
The study tested the hypothesis that a replicable dimensional structure of depression would be uncovered when depression severity is eliminated from symptom scores. Additionally, the study explored differences in the dimensional structure in general population vs. depressed people-only samples.
The cohort study on substance use risk factors (C-SURF), a large cohort of young Swiss men, and young men from the national health and nutrition survey in the US (NHANES 2009-2012) were analyzed. DSM-IV symptoms of depression were assessed via the Major Depressive Inventory (WHO-MDI) in C-SURF and via the Patient Health Questionnaire 9 (PHQ-9) in NHANES. Dimensionality was examined using principal component analysis in full samples vs. samples of participants with a current depressive episode for raw vs. severity-adjusted symptom scores.
When using severity-adjusted symptom scores, correlations between depressive symptoms largely disappeared and there were no replicable dimensions. When using raw scores in the full samples, one single dimension of depression consistently emerged. When using raw scores in depressed participants, only rudiments of dimensions were found across samples.
It is unlikely that there are stable dimensions underlying the DSM-IV symptoms of depression. The set of symptoms capture the disorder in the general population, but the disorder's manifestation is highly individual.
Studies suggest that alcohol consumption and alcohol use disorders have distinct genetic backgrounds.
We examined whether polygenic risk scores (PRS) for consumption and problem subscales of the Alcohol Use Disorders Identification Test (AUDIT-C, AUDIT-P) in the UK Biobank (UKB; N = 121 630) correlate with alcohol outcomes in four independent samples: an ascertained cohort, the Collaborative Study on the Genetics of Alcoholism (COGA; N = 6850), and population-based cohorts: Avon Longitudinal Study of Parents and Children (ALSPAC; N = 5911), Generation Scotland (GS; N = 17 461), and an independent subset of UKB (N = 245 947). Regression models and survival analyses tested whether the PRS were associated with the alcohol-related outcomes.
In COGA, AUDIT-P PRS was associated with alcohol dependence, AUD symptom count, maximum drinks (R2 = 0.47–0.68%, p = 2.0 × 10−8–1.0 × 10−10), and increased likelihood of onset of alcohol dependence (hazard ratio = 1.15, p = 4.7 × 10−8); AUDIT-C PRS was not an independent predictor of any phenotype. In ALSPAC, the AUDIT-C PRS was associated with alcohol dependence (R2 = 0.96%, p = 4.8 × 10−6). In GS, AUDIT-C PRS was a better predictor of weekly alcohol use (R2 = 0.27%, p = 5.5 × 10−11), while AUDIT-P PRS was more associated with problem drinking (R2 = 0.40%, p = 9.0 × 10−7). Lastly, AUDIT-P PRS was associated with ICD-based alcohol-related disorders in the UKB subset (R2 = 0.18%, p < 2.0 × 10−16).
AUDIT-P PRS was associated with a range of alcohol-related phenotypes across population-based and ascertained cohorts, while AUDIT-C PRS showed less utility in the ascertained cohort. We show that AUDIT-P is genetically correlated with both use and misuse and demonstrate the influence of ascertainment schemes on PRS analyses.
Mental disorders in children are a significant and growing cause of morbidity worldwide. Although interventions to help overcome barriers along the pathway to accessing health care for children with mental disorders exist, there is no overview of randomised controlled trials (RCTs) on these interventions as yet. This study aimed to systematically identify RCTs of interventions to improve access to mental health care for children and synthesise them using a conceptual framework of access to health care.
This systematic review was performed following a predefined protocol registered with PROSPERO (ID: CRD42018081714). We searched the databases MEDLINE, EMBASE, PsycINFO and CENTRAL for RCTs up to 15 May 2019 using terms related to the concepts ‘young people,’ ‘mental disorders’ and ‘help-seeking interventions’ and scanned reference lists from relevant studies. Two reviewers independently screened all identified articles in a two-stage process, extracted results on outcomes of interest (knowledge, attitudes, intentions, help-seeking, accessing care, mental health outcomes and satisfaction), assessed the risk of bias and conducted meta-analyses where deemed appropriate.
After screening 5641 identified articles, 34 RCTs were eligible for inclusion. Eighty per cent of universal school-based interventions measuring knowledge (n = 5) and 67% measuring attitudes (n = 6) reported significantly better results compared with controls on those outcomes, whereas 20% measuring access to care (n = 5) and none measuring mental health outcomes (n = 7) did. In contrast, 71% of interventions targeting at-risk individuals (n = 21) reported better access to care compared with controls, while just 33% (n = 6) did for mental health outcomes. For satisfaction with care, this proportion was 80% (n = 5). Meta-analyses of interventions measuring initial appointment attendance yielded combined odds ratios of 3.11 (2.07–4.67) for appointment reminder interventions and 3.51 (2.02–6.11) for treatment engagement interventions. The outcomes for universal school-based interventions were heterogeneous and could not be summarised quantitatively through meta-analysis.
To have a population-level effect on improving children's access to mental health care, two-stage interventions that identify those in need and then engage them in the health-care system may be necessary. We need more evidence on interventions to target contextual factors such as affordability and infrastructural barriers.
This study proposed the application of a novel immersed boundary method (IBM) for the treatment of irregular geometries using Cartesian computational grids for high speed compressible gas flows modelled using the unsteady Euler equations. Furthermore, the method is accelerated through the use of multiple Graphics Processing Units – specifically using Nvidia’s CUDA together with MPI - due to the computationally intensive nature associated with the numerical solution to multi-dimensional continuity equations. Due to the high degree of locality required for efficient multiple GPU computation, the Split Harten-Lax-van-Leer (SHLL) scheme is employed for vector splitting of fluxes across cell interfaces. NVIDIA visual profiler shows that our proposed method having a computational speed of 98.6 GFLOPS and 61% efficiency based on the Roofline analysis that provides the theoretical computing speed of reaching 160 GLOPS with an average 2.225 operations/byte. To demonstrate the validity of the method, results from several benchmark problems covering both subsonic and supersonic flow regimes are presented. Performance testing using 96 GPU devices demonstrates a speed up of 89 times that of a single GPU (i.e. 92% efficiency) for a benchmark problem employing 48 million cells. Discussions regarding communication overhead and parallel efficiency for varying problem sizes are also presented.
Autism Spectrum Disorder (ASD) and schizophrenia are neurodevelopmental disorders which share substantial overlap in cognitive deficits during adulthood. However, treatment evaluation in ASD and treatment comparisons across ASD and schizophrenia are limited by a dearth of empirical work establishing the validity of a standard cognitive battery across ASD and schizophrenia. Promisingly, the MATRICS Consensus Cognitive Battery (MCCB) has been validated in schizophrenia and encompasses cognitive domains that are impacted in ASD. Thus, this study aimed to establish MCCB's generalizability from schizophrenia to ASD.
Community-residing adults with schizophrenia (N = 100) and ASD (N = 113) underwent MCCB assessment. Using multigroup confirmatory factor analysis, MCCB's transdiagnostic validity was evaluated by examining whether schizophrenia and ASD demonstrate the same configuration, magnitude, and directionality of relationships within and among measures and their underlying cognitive domains.
Across schizophrenia and ASD, the same subsets of MCCB measures inform three cognitive domains: processing speed, attention/working memory, and learning. Except for group means in category fluency, continuous performance, and spatial span, both groups show vastly comparable factor structures and characteristics.
To our knowledge, this study is the first to establish the validity of a standard cognitive battery in adults with ASD and furthermore the first to establish a cognitive battery's comparability across ASD and schizophrenia. Cognitive domain scores can be compared across new samples using weighted sums of MCCB scores resulting from this study. These findings highlight MCCB's applicability to ASD and support its utility for standardizing treatment evaluation of cognitive outcomes across the autism-schizophrenia spectrum.
Many seed quality tests are conducted by first randomly assigning seeds into replicates of a given size. The replicate results are then used to check whether or not any problems occur in the realization of the test. The two main tools developed for this verification are the ratio of the observed variance of the replicate results to a theoretical variance and the tolerance for the range of the results. In this paper, we derive the theoretical distribution and its related properties of the sequence of numbers of seeds with a given quality attribute present in the replicates. From these theoretical results, we revisit the two quality checking tools widely used for the germination test. We show a precaution to be taken when relying on the variance ratio to check for under- or over-dispersion of the replicate results. This has led to the development of tables providing credible intervals of the variance ratio. The International Seed Testing Association tolerance tables for the range of the results are also compared with tolerances computed from the exact theoretical distribution of the range, leading us to recommend a revision of these tables.
Numerous studies have demonstrated that genetic and environmental factors interact to influence alcohol problems. Yet prior research has primarily focused on samples of European descent and little is known about gene–environment interactions in relation to alcohol problems in non-European populations. In this study, we examined whether and how genetic risk for alcohol problems and peer deviance and interpersonal traumatic events independently and interactively influence trajectories of alcohol use disorder symptoms in a sample of African American students across the college years (N = 1,119; Mage = 18.44 years). Data were drawn from the Spit for Science study where participants completed multiple online surveys throughout college and provided a saliva sample for genotyping. Multilevel growth curve analyses indicated that alcohol dependence genome-wide polygenic risk scores did not predict trajectory of alcohol use disorder symptoms, while family history of alcohol problems was associated with alcohol use disorder symptoms at the start of college but not with the rate of change in symptoms over time. Peer deviance and interpersonal traumatic events were associated with more alcohol use disorder symptoms across college years. Neither alcohol dependence genome-wide polygenic risk scores nor family history of alcohol problems moderated the effects of these environmental risk factors on alcohol use disorder symptoms. Our findings indicated that peer deviance and experience of interpersonal traumatic events are salient risk factors that elevate risk for alcohol problems among African American college students. Family history of alcohol problems could be a useful indicator of genetic risk for alcohol problems. Gene identification efforts with much larger samples of African descent are needed to better characterize genetic risk for alcohol use disorders, in order to better understand gene–environment interaction processes in this understudied population.
Genetic predispositions play an important role in the development of internalizing and externalizing behaviors. Understanding the mechanisms through which genetic risk unfolds to influence these developmental outcomes is critical for developing prevention and intervention efforts, capturing key elements of Irv's research agenda and scientific legacy. In this study, we examined the role of parenting and personality in mediating the effect of genetic risk on adolescents’ major depressive disorder and conduct disorder symptoms. Longitudinal data were drawn from a sample of 709 European American adolescents and their mothers from the Collaborative Studies on Genetics of Alcoholism. Results from multivariate path analysis indicated that adolescents’ depressive symptoms genome-wide polygenic scores (DS_GPS) predicted lower parental knowledge, which in turn was associated with more subsequent major depressive disorder and conduct disorder symptoms. Adolescents’ DS_GPS also had indirect effects on these outcomes via personality, with a mediating effect via agreeableness but not via other dimensions of personality. Findings revealed that the pattern of associations was similar across adolescent gender. Our findings emphasize the important role of evocative gene–environment correlation processes and intermediate phenotypes in the pathways of risk from genetic predispositions to complex adolescent outcomes.
Using a large and nationally representative sample, we examined how adolescents’ 5-HTTLPR genotype and perceived parenting quality independently and interactively associated with trajectories of alcohol use from early adolescence to young adulthood and whether/how gender may moderate these associations. The sample for this study included 13,749 adolescents (53.3% female; 56.3% non-Hispanic White, 21.5% Black, 16.0% Hispanic, and 6.1% Asian) followed prospectively from adolescence to young adulthood. Using growth mixture modeling, we identified four distinct trajectories of alcohol use (i.e., persistent heavy alcohol use, developmentally limited alcohol use, late-onset heavy alcohol use, and non/light alcohol use). Results indicated that the short allele of 5-HTTLPR was associated with higher risk of membership in the persistent and the late-onset heavy alcohol use trajectories. Parenting quality was associated with lower likelihoods of following the persistent heavy and the developmentally limited alcohol use trajectories but was not associated with risk of membership for the late-onset heavy drinking trajectory. 5-HTTLPR interacted with parenting quality to predict membership in the persistent heavy alcohol use trajectory for males but not for females. Findings highlighted the importance of considering the heterogeneity in trajectories of alcohol use across development and gender in the study of Gene Environment interactions in alcohol use.
In our attempt to investigate the basic active galactic nucleus (AGN) paradigm requiring a centrally located supermassive black hole (SMBH), a close to Keplerian accretion disk and a jet perpendicular to its plane, we have searched for radio continuum in galaxies with H2O megamasers in their disks. We observed 18 such galaxies with the Very Large Baseline Array in C band (5 GHz, ~2 mas resolution) and we detected 5 galaxies at 8 σ or higher levels. For those sources for which the maser data is available, the positions of masers and those of the 5 GHz radio continuum sources coincide within the uncertainties, and the radio continuum is perpendicular to the maser disk’s orientation within the position angle uncertainties.
Introduction: In 2015, there were 476 apparent illicit drug overdose deaths, prompting BC’s Provincial Health Officer to declare a public health emergency on 14 Apr 2016. Paramedics of BC’s Ambulance Service (BCAS) are on the front lines in this crisis. Here we examine recent trends in the number of suspected overdose events attended by the BCAS and the use of naloxone, an opioid antagonist, by BCAS paramedics. Methods: The BC Centre for Disease Control receives a weekly data feed from BC Emergency Health Services that includes all records from the BCAS Patient Care Record where: naloxone was administered by paramedics; the primary impression code indicates poisoning or overdose; or, the originating call is associated with ingestion poisoning (‘card 23’). Here, we report a descriptive analysis of these data for suspected drug overdose events during the period January 1, 2010 to September 30, 2016. Results: Between January 2010 and September 2016 BCAS paramedics attended 164,227 suspected overdose events; 12% of these events (n=16,944) included naloxone administration by BCAS paramedics. Paralleling the rise in illicit drug overdose deaths in BC, naloxone administration by paramedics has been increasing rapidly, doubling from approximately 180/month in 2014, to 370/month in 2016. When naloxone was administered by paramedics, 90% of these patients were transported, whereas 77% were transported when naloxone was not administered. Administrations occurred most frequently on Friday and Saturday evenings. Almost half (46%) of all naloxone administrations by paramedics were recorded as being in a home or residence; 18% were recorded as occurring on a street or highway. The proportion of naloxone administrations among males has increased yearly. In 2010, 58% of naloxone administrations were in males compared to 69% in 2016. Conclusion: The number of overdose deaths in BC has risen drastically in recent years and the proportion of ambulance calls requiring administration of naloxone by BCAS has climbed correspondingly. The vast majority of overdose cases-especially those requiring naloxone-are transported to the emergency department. With the overdose crisis showing little sign of abating, the administration of naloxone by BC paramedics will continue to be a critical element of the provincial response.
Previous research failed to uncover a replicable dimensional structure underlying the symptoms of depression. We aimed to examine two neglected methodological issues in this research: (a) adjusting symptom correlations for overall depression severity; and (b) analysing general population samples v. subsamples of currently depressed individuals.
Using population-based cross-sectional and longitudinal data from two nations (Switzerland, 5883 young men; USA, 2174 young men and 2244 young women) we assessed the dimensions of the nine DSM-IV depression symptoms in young adults. In each general-population sample and each subsample of currently depressed participants, we conducted a standardised process of three analytical steps, based on exploratory and confirmatory factor and bifactor analysis, to reveal any replicable dimensional structure underlying symptom correlations while controlling for overall depression severity.
We found no evidence of a replicable dimensional structure across samples when adjusting symptom correlations for overall depression severity. In the general-population samples, symptoms correlated strongly and a single dimension of depression severity was revealed. Among depressed participants, symptom correlations were surprisingly weak and no replicable dimensions were identified, regardless of severity-adjustment.
First, caution is warranted when considering studies assessing dimensions of depression because general population-based studies and studies of depressed individuals generate different data that can lead to different conclusions. This problem likely generalises to other models based on the symptoms’ inter-relationships such as network models. Second, whereas the overall severity aligns individuals on a continuum of disorder intensity that allows non-affected individuals to be distinguished from affected individuals, the clinical evaluation and treatment of depressed individuals should focus directly on each individual's symptom profile.
Exposure to trauma was found to increase later violent behaviours in youth but the underlying psychopathological mechanisms are unclear. This study aimed to test whether posttraumatic stress disorder (PTSD) is related to violent behaviours and whether PTSD symptoms mediate the relationship between the number of trauma experiences and violent behaviours in adolescents.
The present study is based on a nationally representative sample of 9th grade students with 3434 boys (mean age = 15.5 years) and 3194 girls (mean age = 15.5 years) in Switzerland. Lifetime exposure to traumatic events and current PTSD were assessed by the use of the University of California at Los Angeles Posttraumatic Stress Disorder Reaction Index (UCLA-RI). Logistic regression was used to assess associations between PTSD and violent behaviours, and structural equation modelling (SEM) was used to examine the meditation effects of PTSD.
PTSD (boys: OR = 7.9; girls: OR = 5.5) was strongly related to violent behaviours. PTSD symptoms partially mediated the association between trauma exposure and violent behaviours in boys but not in girls. PTSD symptoms of dysphoric arousal were positively related to violent behaviours in both genders. Anxious arousal symptoms were negatively related to violent behaviours in boys but not in girls.
In addition to trauma, posttraumatic stress is related to violent outcomes. However, specific symptom clusters of PTSD seem differently related to violent behaviours and they do not fully explain a trauma-violence link. Specific interventions to improve emotion regulation skills may be useful particularly in boys with elevated PTSD dysphoric arousal in order to break up the cycle of violence.
Eating disorders (EDs) have long-term physical and mental impacts on those affected. However, few population-based studies have estimated the prevalence of EDs. We aimed to estimate the lifetime and 12-month prevalence rates of EDs using DSM-IV criteria, and to examine differences against the DSM-5 criteria for anorexia.
A nationally representative sample of 10 038 residents in Switzerland was interviewed, and prevalence rates for anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED) were assessed using WHO Composite International Diagnostic Interviews (WHO-CIDI).
The lifetime prevalence rate for any ED was found to be 3.5%. Lifetime prevalence estimates for AN, BN, and/or BED were 1.2%, 2.4%, and 2.4%, respectively, among women and 0.2%, 0.9%, and 0.7%, respectively, among men. Utilizing the DSM-5 criteria, the prevalence of AN in women increased by more than 50%, from 1.2% to 1.9%. Among those meeting the criteria for any ED, only 49.4% of men and 67.9% of women had ever sought professional help about their problems with eating or weight.
The higher prevalence of BN we detected relative to other studies should prompt further monitoring for a possible increasing trend. The female v. male ratios, especially for bulimia and BED, are decreasing. Given that more than half of those affected have never consulted any professional about their problems with eating or weight, routine inquiries about eating and weight by clinicians, school teachers/psychologists, and family members may help those who are at risk, especially among men.
Functional and mental health impairments that adults with attention-deficit/hyperactivity disorder (ADHD) experience may be exacerbated by regular substance use and co-morbidity with substance use disorders (SUD). This may be especially true during young adulthood, which represents a critical stage of life associated with increased substance use and associated problems. However, previous studies investigating the association between ADHD and substance use and SUD have demonstrated inconsistent results, probably due to methodological limitations (e.g., small and non-representative samples). Thus, the relationship of ADHD with substance use and related disorders remains unclear. The aim of the present study was to examine the association between ADHD and both the use of licit and illicit substances and the presence of SUD in a large, representative sample of young men.
The sample included 5677 Swiss men (mean age 20 ± 1.23 years) who participated in the Cohort Study on Substance Use Risk Factors (C-SURF). ADHD was assessed using the adult ADHD Self Report Screener (ASRS). The association between ADHD and substance use and SUD was assessed for alcohol, nicotine, cannabis and other illicit drugs, while controlling for socio-demographic variables and co-morbid psychiatric disorders (i.e., major depression (MD) and anti-social personality disorder (ASPD)).
Men with ADHD were more likely to report having used nicotine, cannabis and other illicit drugs at some time in their life, but not alcohol. ADHD was positively associated with early initiation of alcohol, nicotine and cannabis use, the risky use of these substances, and the presence of alcohol use disorders, and nicotine and cannabis dependence. Additionally, our analyses revealed that these patterns are also highly associated with ASPD. After adjusting for this disorder, the association between ADHD and licit and illicit substance use and the presence of SUDs was reduced, but remained significant.
Our findings suggest that adult ADHD is significantly associated with a propensity to experiment with licit and illicit substances, especially at earlier ages, to exhibit risky substance use patterns, and to subsequently develop SUDs. Preventive strategies that include early intervention and addressing co-morbidity with ASPD may be crucial to reducing substance use and the development of pathological substance use patterns in young men affected by ADHD and, thus, helping to prevent further illness burden later in life.