Associations between subtypes of major depressive episodes and substance use disorders

The goal of this study was to examine whether certain subtypes of major depressive episodes (MDEs)-defined by their particular constellations of symptoms-were more strongly associated with substance use disorders (SUDs), compared to other subtypes of MDEs. Participants were adults in the National Comorbidity Survey-Replication sample who met DSM criteria for at least one lifetime MDE (n = 1829). Diagnostic assessments were conducted using structured interviews. The following MDE subtypes were examined: atypical, psychomotor agitation, psychomotor retardation, melancholic, and suicidal. The results indicated that: (1) suicidal MDEs were associated with increased risk for all SUDs; (2) melancholic MDEs were associated with increased risk for alcohol use disorders; and (3) psychomotor agitation was associated with increased risk for alcohol dependence. These associations did not differ significantly by gender. Adjusting for age, the severity of the MDE, the age of onset of the first MDE, and psychiatric comorbidity did not substantially change the results. Supplemental analyses examining only diagnoses that occurred in the year prior to the assessment demonstrated a similar pattern (with MDEs characterized by psychomotor agitation being associated with drug use disorders as well). Exploratory order of onset analyses indicated that participants with lifetime MDEs and SUDs tended to report an MDE onset prior to the SUD onset, and those who experienced a suicidal MDE at some time in their lives were particularly likely to have had their first MDE prior to developing a SUD. Therefore, risk for lifetime SUDs differs according to the particular set of symptoms experienced during MDEs.