PHQ-9 and PHQ-2 in Western Kenya

Excerpt

To the Editors:—Recently, Monahan et al. concluded that the PHQ-2 and PHQ-9 were “valid/reliable for assessing DSM-IV depressive disorders and depression severity among adults living with HIV/AIDS in Western Kenya”1. However, they did not actually use any accepted assessment tool to diagnose DSM-IV depressive disorders. Instead, they used a “diagnosis” of depression based on the self-report PHQ-9 as their criterion standard. A recent meta-analysis2 found that the PHQ-9 was acceptable for depression screening, but it was not superior to results from other depression screening tools in identifying cases of depression,3 and it was poorly sensitive in some patient groups2. Based on the authors use of the PHQ-9 as a diagnostic criterion, one might conclude that any depression questionnaire could appropriately be substituted for a gold standard structured interview. This is clearly not the case, and the PHQ-9 is not appropriate for that purpose either. …