PHQ-9: sensitivity to change over time.

摘要

Malpass et al, in a mixed methods study assessing PHQ-9 scores and patients' experiences, report that patients found the PHQ-9 to be helpful, concurring with other recent qualitative work that suggested that patients viewed such measures as an 'objective adjunct to medical judgement'. Unfortunately, the value of these observations rests entirely on the assumption that the PHQ-9 is a valid measure of depression severity. Considerable doubt attends this premature notion; Indeed, the most recent of these findings is reported by Reddy and colleagues on the pages following Malpass et al's piece. We should not be comforted by the observation that patients' believe their depression is being better assessed by this process until it is shown that this belief matches the evidence.