Category: Comorbidity - Substance Use and Other
Childhood attention deficit hyperactivity disorder (ADHD) has been established as a significant predictor of substance use in adolescence and adulthood. While it is clear that adolescents with ADHD are more likely to abuse substances, less is known about the impact that co-occurring ADHD and substance use has on adolescents. The current study examined the effect of levels of substance use and ADHD symptoms on substance use outcomes and consequences in the context of a school-based, motivational interviewing (MI) substance use intervention. A quadrant model was utilized to classify participants based on severity of substance use and ADHD symptoms. The quadrant comprised (1) Low substance use and low ADHD symptoms, (2) Low substance use and high ADHD symptoms, (3) High substance use and low ADHD symptoms, and (4) High substance use and high ADHD symptoms. These quadrants were compared on outcomes of post-treatment substance use and related consequences. We hypothesized that adolescents with comorbid ADHD symptoms and substance use at varying severities would differ in key concomitants of substance use including context of use, motivation to change, and school legal problems. Specifically, we believe adolescents with high ADHD symptoms co-occurring with severe substance use symptoms would exhibit the most problematic behaviors. Third, co-occurring patterns of ADHD symptoms and substance use severity would result in differential substance use outcomes at post-treatment follow up. Participants (N = 296) were adolescents (ages 12-18, mean = 16) from the greater Seattle area receiving a school-based substance use intervention, Project READY. A majority of the participants were male (57%). Assessments were administered at intake, post-treatment, and one month follow-up sessions. We found that all participants significantly reduced their substance use over time. A one-way ANOVA showed group quadrant classification differences between groups across all domains (e.g. legal problems, early age of onset, days skipping school, depression symptoms). We also found in support of our hypothesis that quadrant four had more legal problems, more school absences, and more depression symptoms. We tested outcomes using repeated measures ANOVA and found the intervention effectiveness varied by co-occurring quadrant classification with alcohol use showing a larger reduction for adolescents in quadrant four. No difference in marijuana use among quadrants was found in outcomes. This effect is due in part to quadrant four adolescents having a much higher average alcohol use at intake but showing the same reduced level of use as the other quadrants by eight week follow up. The results of the current study support the value of using a quadrant model for examining the comorbid relationship between adolescent substance use and ADHD symptoms. These findings support the effectiveness of a brief MI intervention despite differences in initial presentation of comorbid ADHD and substance use symptoms. Implications for the unique benefits of MI and school-based interventions for adolescents with ADHD symptoms will be discussed.
Elizabeth Lehinger– Graduate Student, Seattle Pacific University, Seattle, Washington
Malini Varma– Graduate Student, Seattle Pacific University, Seattle, Washington
Lindsay Moore– Graduate Student, Seattle Pacific University
Ashley Estoup– Graduate Student, Seattle Pacific University, Seattle, Washington
David Stewart– Seattle Pacific University