Substance use and depression remain common among adolescents and young adults. A recent study attempted to clarify the temporal relationship between substance use and depression, and determine if its directionality varies by sex. This study utilized data from the National Longitudinal Study of Adolescent to Adult Health, a multi-wave study that examined substance use and depression over time. The current study analyzed data collected in the first wave (participants in grades 7-12, collected in 1994-1995) and third wave (participants 18-26yo, collected in 2001) of the study. For females, this study identified a bidirectional relationship. That is, an increase in depressive symptoms in adolescence associated with a later increase in cigarette smoking frequency (predicted an increase in mean monthly smoking by 2 days). The reverse was also significant—an increase in smoking frequency identified in adolescence was associated with a later increase in depressive symptoms. For males, an increase in depressive symptoms in adolescence associated with a later increase in marijuana use frequency (predicted an increase from ½ to 1 day past month use).
Take Away: This study found support that males and females may self-medicate depressive symptoms through substance use (marijuana use and cigarette smoking, respectively). In addition, this study found support for the reverse pathway as well—an increase in smoking frequency in adolescence associated with modest increases in depressive symptoms later in life, with this relationship being stronger for females than males. As a result, the authors encourage prevention programming for teens and young adults to include screenings for both substance use and depressive symptoms.