The impact of decreased environmental reward in predicting depression severity: support for behavioral theories of depression.

Insufficient response-contingent positive reinforcement and decreased environmental reward have been hypothesized to directly contribute to the onset and persistence of depression. The present study examined whether decreased environmental reward was significantly associated with self-reported depression and diagnosed major depression relative to other well-established risk factors that included gender, stressful life events, traumatic life events, childhood maltreatment, and cognitive vulnerability. Based on hierarchical regression analyses, all variables except gender were significantly associated with self-reported depression, and stressful life events, cognitive vulnerability, and decreased environmental reward were associated with diagnosed depression. Of all variables, decreased environmental reward was most strongly related to both self-reported depression and diagnosed clinical depression. The incremental validity of environmental reward in predicting self-reported depression and clinical depression was established, accounting for significant unique variance (12%) in each regression equation. Implications for conceptualizing and treating depression are discussed.