Risk Factors for Recurrent Major Depressive Disorder in a Nationally Representative Sample

The public use version of the National Comorbidity Survey - Replication (NCS-R) dataset was used (N = 995) to investigate risk factors for recurrent major depressive disorder (MDD) that are evident before recovery from the first major depressive episode (MDE) by comparing persons diagnosed with MDD who experienced a single MDE to persons with recurrent MDD. Multiple logistic regression analyses assessed the independent risk of recurrent MDD for each of the following risk factors: an early age of onset (old), absence of a life stress trigger, chronic first episode, childhood parental loss, parental maltreatment, parental depression, comorbid anxiety disorder, and comorbid substance disorder. The relative excess risk due to interaction (RERI) assessed the risk of recurrent MDD associated with the interaction of an early onset with three childhood-based vulnerabilities: a) parental depression, b) parental loss, and c) parental maltreatment. There was a statistically significant risk of recurrent MDD found for the following risk factors: early onset, stress trigger absent, childhood parental loss, parental maltreatment, parental depression, and anxiety disorder; marginally significant results suggested an increased risk of recurrent MDD for substance disorder. There was a significant increased risk found for the interaction of an early onset with parental depression and similar non-significant trends were found for the interactions of early onset with parental loss and early onset with parental maltreatment. An early onset, the absence of a life stress trigger, and the presence of parental loss, parental maltreatment, parental depression, a comorbid anxiety disorder, and a comorbid substance disorder each confer greater risk of recurrent MDD among persons that have not yet recovered from their first lifetime MDE. The presence of an early onset combined with a childhood-based vulnerability such as parental depression, parental loss, or parental maltreatment, indicate an especially high risk of recurrent MDD. These findings may inform the development of a screening tool to assess risk for recurrent MDD and early intervention to prevent recurrent MDD. Future research should employ a longitudinal research design to replicate and expand upon these findings