Identifying depression in the general population - A comparison of PHQ-9, PHQ-8 and PHQ-2

Objective: To examine the comparability of depression as defined by PHQ-9, PHQ-8 and PHQ-2 in the German general population. Methods: The PHQ-9 was assessed in a representative sample (N = 2524). Depression diagnosis and depression severity as measured either by PHQ-9, PHQ-8 or PHQ-2 were compared. Results: PHQ-8 and PHQ-9 performed comparably in identifying depressive persons, though there are slight differences in rating depression severity. In comparison, the PHQ-2 showed the best performance in the detection of any depressive disorder. Conclusions: The PHQ-9 should be used in clinical settings, whereas in research and when persons are being approached via telephone/mail/internet the PHQ-8 is preferable. The PHQ-2 is recommended as a very economic and brief screener for depressive disorders.