Which stressors are associated with which forms of depression in a homogenous sample? An analysis of the effects of lifestyle changes and demands on five subtypes of depression

Background: Although depression is often considered as a single or unitary construct, evidence indicates the existence of several major subtypes of depression, some of which have distinct neurobiological bases and treatment options. Objective: To explore the incidence of five subtypes of depression, and to identify which lifestyle changes and stressor demands are associated with each of five established subtypes of depression, within a homogenous non-clinical sample. Method: 398 Australian university students completed the Effects of University Study on Lifestyle Questionnaire to identify their major stressors, plus the Zung Self-Rating Depression Scale to measure their symptomatology. Regression analysis was used to identify which stressors were most powerful predictors of each depression subtype. Results: The five different subtypes of depression were predicted by a range of different stressors. Incidence of clinically significant scores for the subtypes of depression varied, with some participants experiencing more than one subtype of depression. Conclusions: Different depression subtypes were predicted by different stressors, potentially challenging the clinical validity of depression as a unitary construct. Although restricted in their generalisability to clinical patient samples, these findings suggest further targets for research with depressed patients.