Detecting recurrent major depressive disorder within primary care rapidly and reliably using short questionnaire measures.

BACKGROUND Major depressive disorder (MDD) is often a chronic disorder with relapses usually detected and managed in primary care using a validated depression symptom questionnaire. However, for individuals with recurrent depression the choice of which questionnaire to use and whether a shorter measure could suffice is not established. AIM To compare the nine-item Patient Health Questionnaire (PHQ-9), the Beck Depression Inventory, and the Hospital Anxiety and Depression Scale against shorter PHQ-derived measures for detecting episodes of DSM-IV major depression in primary care patients with recurrent MDD. DESIGN AND SETTING Diagnostic accuracy study of adults with recurrent depression in primary care predominantly from Wales METHOD Scores on each of the depression questionnaire measures were compared with the results of a semi-structured clinical diagnostic interview using Receiver Operating Characteristic curve analysis for 337 adults with recurrent MDD. RESULTS Concurrent questionnaire and interview data were available for 272 participants. The one-month prevalence rate of depression was 22.2%. The area under the curve (AUC) and positive predictive value (PPV) at the derived optimal cut-off value for the three longer questionnaires were comparable (AUC = 0.86-0.90, PPV = 49.4-58.4%) but the AUC for the PHQ-9 was significantly greater than for the PHQ-2. However, by supplementing the PHQ-2 score with items on problems concentrating and feeling slowed down or restless, the AUC (0.91) and the PPV (55.3%) were comparable with those for the PHQ-9. CONCLUSION A novel four-item PHQ-based questionnaire measure of depression performs equivalently to three longer depression questionnaires in identifying depression relapse in patients with recurrent MDD.