Do doctors know best? Comments on a failed trial.

A randomised controlled trial was planned to compare two different treatment strategies--structured problem solving and selective serotonin reuptake inhibitor (SSRI) medication--for patients with mild to moderate major depression. The trial was to be conducted in the primary care setting with all treatment given by general practitioners. When no patients had been recruited into the study after six months, we performed an audit of all patients with depressive symptoms attending the doctors' practices over three weeks. Exclusion criteria were changed to ease entry into the trial, but still no patients were recruited over the following six months. What went wrong?