Should we adjust substance use disorder treatment for depressed adolescents?

Although depression and substance use disorders commonly co-occur in adolescents, little is known about how depression influences adolescent substance use disorder treatment retention and outcomes. With this issue in mind, a team of American researchers reviewed the available scientific literature and suggested four important considerations to maximize the clinical impact of future research regarding adolescent depression symptoms and substance use. Their review is published in the newest special issue of Substance Abuse journal.

In the review, the researchers noted the mixed results of a total of thirteen quantitative studies investigating whether and how depression is associated with substance-related outcomes. "Our review highlights that studies to date varied widely in hypotheses and research methods, suggesting that the field needs to develop more standardized methods to allow for a clearer understanding of the role of comorbid depression among adolescents in substance abuse treatment," wrote the researchers in a joint statement.

To avoid future ambiguities within clinical research, the researchers provide four considerations to inform study design. First, researchers must consider the time frame for assessing symptoms of depression, such as measuring symptoms at both the beginning and end of treatment and distinguishing between lifetime versus current symptoms. A second consideration pertains to the debate about whether to address comorbid depression within substance abuse treatment, and if so, how. Measuring comorbid symptoms at the beginning and end of treatment even when depression is not specifically addressed during treatment would help to answer this question. Third, it is also important to assess comorbidity both dimensionally (i.e., severity level) and categorically (i.e., meets criteria for a disorder) in order to fully understand the effects of depression on treatment success. Fourth, researchers should consider the timing of comorbid symptoms relative to the substance use disorder since substance use disorders can occur before, after, or simultaneously with the onset of depression.

"Clarification based on rigorous research studies will permit researchers to identify the conditions under which depression can influence substance abuse treatment retention and outcomes, which in turn will help to specify when depression needs to be directly addressed with this population of young people," explained the researchers.