Methamphetamine use and depression: Longitudinal associations among young adults in the United States

Objective: Methamphetamine use is associated with dire public health outcomes, including increased risk of depression. However, no previous research examines the association between depression and methamphetamine use in a nationally representative sample, and few studies look at the longitudinal association. Given that young adults are the group most prone to use, we examined longitudinal associations between methamphetamine use in young adulthood and depression six years later.

Design: Multivariate regression analyses of prospective cohort data collected for the National Longitudinal Study of Adolescent Health in young adulthood at Wave III (2001-02; ages 18-28) and Wave IV (2007-08; ages 24-34) (N=8,688).

Measurements: Wave III: past year crystal methamphetamine use. Wave IV: Current depression (based on the CES-D scale). Covariates include: age, gender, race/ethnicity, US region, functional poverty, childhood maltreatment, polydrug use, and Wave III depression.

Findings: Methamphetamine use was associated with more than twice the odds of later depression (OR: 2.13, 95% CI: 1.38-3.27); Controlling for covariates, except Wave III depression, revealed methamphetamine use predicts later depression (AOR: 2.04, 95% CI: 1.29-3.21); controlling for covariates and Wave III depression revealed methamphetamine use continues to be a predictor of future depression (AOR: 1.81, 95% CI: 1.12-2.92).

Conclusions: In a nationally representative sample, longitudinal analyses revealed that methamphetamine use is a marker for later depression, and in adjusted analyses, predicted future depression. Evidence that young adult methamphetamine users have an increased risk for depression suggests that screening and treatment for depression among methamphetamine users should be a priority for prevention and treatment providers.