Purpose of review: Dysthymic disorder and other chronic depressive disorders have recently been merged in DSM-5 into a ‘persistent depressive disorder’ category. As its introduction in DSM-III, the validity of dysthymic disorder has long been challenged, posing concerns regarding the validity of its successor – persistent depressive disorder. This review aims to present recent findings regarding the validity and utility of dysthymic disorder.
Recent findings: Several recent studies raise questions regarding the validity of dysthymic disorder, namely, results indicating a significant overlap between dysthymic disorder and other mood and/or anxiety disorders, failure of such a diagnosis to predict illness outcome and the lack of any validation strategy identifying that it is a depressive entity or subtype.
Summary: Research findings indicate that dysthymic disorder is a heterogeneous diagnosis encompassing many different depressive (and anxiety or personality weighted) conditions, and without clear evidence of its validity as a diagnostic entity. As dysthymic disorder is a key component of DSM-defined persistent depressive disorder – the latter is at similar risk of providing a heterogeneous domain diagnosis, and thus limiting identification of specific causative factors and preferential treatment modality.