The influence of different relapse criteria on the assessment of long-term efficacy of sertraline.

The treatment of depression with antidepressant agents must be continued beyond the acute phase, until the response is complete. The precise length of this continuation phase is still debated, but most authors estimate that it should last for between 4-6 months after apparent recovery. If antidepressants are withdrawn sooner, the original depression will return (relapse) in a proportion of patients. Relapse rates on placebo are high, whether patients are first-time or recurrent depressives. Most depressions are recurrent and long-term treatment therefore ensures that the changes of a new episode of illness developing are reduced. The importance of this aspect of efficacy is recognized and new antidepressants are being tested in long-term prophylactic studies. A long-term efficacy study has shown that sertraline was significantly more effective than placebo in preventing both relapse and recurrence.