Attention-deficit/hyperactivity disorder subtypes in adolescents with comorbid substance-use disorder.
Little is known about the relationship between attention-deficit/hyperactivity disorder (ADHD) subtypes and substance-use disorder (SUD). As there is literature suggesting different subtype phenotypes, there may be subtype differences in regard to the risk for developing SUD and substance treatment response. The purpose of this study was to characterize the sample in a National Drug Abuse Treatment Clinical Trials Network (CTN) study (protocol CTN-0029, “A Pilot Study of Osmotic-Release Methylphenidate in Initiating and Maintaining Abstinence in Smokers with ADHD”), according to ADHD subtypes and baseline psychosocial and substance-use characteristics and to compare subtypes on response to treatment. Secondary analyses were performed on data collected from adolescents diagnosed with ADHD and SUD (non-nicotine) and treated with stimulant medication or placebo and cognitive behavioral therapy for substance abuse. Participants were characterized as inattentive or combined ADHD subtype and compared on baseline characteristics and treatment outcome. Results found that the combined subtype presented with more severe SUDs and higher rates of conduct disorder. There were a greater proportion of boys with inattentive subtype, and the inattentive subtype also appeared less ready for treatment with poorer coping skills at baseline. However, the two subtypes responded equally to treatment even after controlled for baseline differences.
Conclusions: Findings from this large community sample indicate that there were no subtype differences in treatment response, although there were differences in terms of substance use, antisocial behavior, readiness for treatment, and gender prior to treatment. This study is the first to report on subtype differences for treatment response for non-nicotine substance use disorder in a comorbid ADHD-SUD population. Despite some baseline differences, the fact both subtypes responded equally to treatment suggests that subtype designation may not be relevant when assessing treatment needs for an adolescent with comorbid ADHD-SUD.
Related protocols: CTN-0028