Manuscript to be resubmitted to Social Psychiatry and Psychiatric Epidemiology (SPPE)(Attention-deficit/hyperactivity disorder (ADHD), conduct disorder (CD), and oppositional defiant disorder (ODD) are common externalizing disorders of childhood. The common effects of these disorders on substance abuse need further investigation. The current study investigated the joint clusters of childhood/adolescence ADHD, CD, and ODD, and their influence on substance abuse/dependence in a population-based sample of adults.
Methods:The data were drawn from the PsyCoLaus study (n=3720) conducted in Lausanne, Switzerland. The populationbased sample included 238 subjects meeting criteria for ADHD/ODD/CD diagnoses before the age of 15. Latent class analyses (LCA) were performed in order to derive comorbidity subtypes, which were subsequently characterized with respect to psychosocial correlates and substance use.
Results:The best fit in LCAs was achieved with three latent classes: an ADHD subtype (35.7%); an externalizing multimorbid subtype (33.6%) involving ODD, ADHD, and CD; and a third subtype with CD (30.7%). The CD subtype showed the highest association with substance use. Apart from this, the externalizing multimorbid subtype was also significantly linked to substance use. The ADHD subtype had only elevated frequencies for alcohol dependence in comparison with subjects that had no history of ADHD, ODD, and CD during childhood or adolescence. Finally, important interactions between subtypes and sex were observed with regard to substance use.
Conclusions:This study provides evidence showing that subtyping the externalizing disorders, ADHD, ODD and CD, along their comorbidity patterns leads to important differences regarding substance use. This could have implications for the etiology, prevention, and treatment of substance use disorders.
Key words: Attention-deficit/hyperactivity disorder, conduct disorder, oppositional defiant disorder, latent class analysis, epidemiologyExternalizing disorders and substance use Rodgers et al.
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IntroductionAttention deficit hyperactivity disorder (ADHD) is the most common externalizing disorder of childhood, with prevalence rates between 3 and 7.5%, and, with looser definitions, even up to 17% [1]. Subjects with ADHD frequently remain symptomatic into adulthood. This disorder is associated with adverse long-term functional outcomes, such as poor interpersonal relationships and lower educational qualifications, leading to high economic and social burdens [2]. One of the most controversial issues in the research on ADHD is its relation to comorbid disorders such as substance abuse [3]. A recent meta-analysis demonstrated that childhood ADHD was associated with nicotine use in adolescence and with alcohol and drug use disorders in adulthood [4]. These results were confirmed in a large population-based study [5]. Prevalence rates of substance use disorders were shown to be more than two-fold higher than the 8-15% in the general population [6]. In this context, there is still no consensus on th...