ObjectiveThe aim of this study was to validate the psychotic depression assessment scale (PDAS), which includes the six-item melancholia subscale from the Hamilton depression rating scale (HAMD-6) and the five-item psychosis subscale from the brief psychiatric rating scale (BPRS-5). Data from the Clinical Research Center for Depression (CRESCEND) study, which is a 52-week naturalistic trial, were analyzed.MethodsFifty-two patients with psychotic depression from the CRESCEND study met our inclusion criteria. The patients underwent the following psychometric assessments: the PDAS, including HAMD-6 and BPRS-5, the clinical global impression scales, the HAMD, the positive symptom subscale, and the negative symptom subscale. Assessments were performed at the baseline and then at weeks 1, 2, 4, 8, 12, 24, and 52. Spearman correlation analyses were used to assess the clinical validity and responsiveness of the PDAS.ResultsThe clinical validity and responsiveness of the PDAS, including HAMD-6 and BPRS-5, were acceptable, with the exception of the clinical responsiveness of the PDAS for positive symptoms and the clinical responsiveness of BPRS-5 for negative symptoms.ConclusionThe clinical relevance of the PDAS has been confirmed and this clinical validation will enhance its clinical utility and availability.