Impersistence of Depression in Youth: Implications for Drug Study Design

Depression persistence and serotonin transporter genotype in adolescents under usual care conditions

OBJECTIVES

Polymorphisms of the serotonin transporter (SERT) gene have been shown to influence the risk for depression. The goal of this study was to investigate a possible effect of SERT polymorphisms on severity and course of depression symptoms in a community sample of adolescents.

METHODS

Community-dwelling adolescents (n=192) ages 13-17 years, who were at risk for depression, were followed for a period of 6 months. Subjects donated a saliva sample for genotyping of the 5-HTTLPR and STin2 VNTR polymorphisms of SERT.

RESULTS

We found no associations between SERT genotype and severity of depressive symptoms at baseline. Depression symptom severity markedly decreased over time. For 5-HTTLPR, we observed a significant interaction between time and genotype, indicating the possibility that heterozygote genotype carriers (s/l) might experience a greater reduction in depression symptoms over time compared with adolescents with the 5-HTTLPR l/l genotype.

CONCLUSIONS

Our study shows that for most community-dwelling adolescents, depressive symptoms decrease over time. A possible interaction effect of time and SERT genotype will require confirmation in larger studies.

Exercise in the Prevention and Treatment of Adolescent Depression: A Promising but Little Researched Intervention

Despite a dramatic increase in the number of treatment studies for adolescent major depressive disorder in the past 15 years, the majority being clinical trials of medications and cognitive behavioral therapy, response rates have been modest and remission rates low. Moreover, most positive responders posttreatment have many residual symptoms, significant functional impairment, and high rates of relapse. There is a need for the development of new, more effective interventions to treat this severe, chronic condition that usually persists into adulthood with poor long-term outcomes. Findings from preliminary treatment studies suggest that exercise may have the potential to be efficacious as a monotherapy or as part of a combined treatment for adolescent major depressive disorder. This review summarizes the findings and analyzes the design flaws of randomized trials of exercise to treat adolescent depression, offering recommendations on how to design more methodologically sound studies with an emphasis on subject selection criteria; issues related to control conditions, types of diagnostic interviews, and measures needed to establish the diagnosis of depression; types of exercise treatments; and appropriate outcome measures. Future studies of exercise to treat and prevent adolescent major depressive disorder need to be comparable to state-of-the-art treatment studies of pharmacotherapy and cognitive behavioral therapy in this population to more accurately determine its efficacy and potential public health benefits.