Chronic, low-grade depression in a nonclinical sample: depressive personality or dysthymia?

Depressive personality disorder (DPD) is being considered for inclusion in future editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM). However, there is substantial conceptual and empirical overlap between DPD and dysthymic disorder (Dysthymia) criteria, suggesting that these two constructs may not be distinct. Confirmatory factor analysis of the DPD traits and dysthymia symptoms in a large, nonclinical sample (N = 368) indicated that a two-factor model was a better fit than a one-factor model. However, binary diagnostic analysis revealed that over half of the individuals meeting criteria for DPD also met criteria for dysthymia and that the best-fitting model allowed the psychological symptoms of dysthymia to load on both DPD and dysthymia latent factors. All of the individuals with DPD alone failed to meet criteria for dysthymia because they did not report chronic depressed mood. Our results suggest that although DPD is not synonymous with Dysthymia, it may be a milder subtype.