There are differences in efficacy of commonly prescribed anti-depressants. Escitalopram, sertraline, venlafaxine and mirtazapine (‘the four’) were the most effective.

To compare the efficacy of ‘the four’ with other anti-depressant monotherapies prescribed either for the treatment of unipolar depression or other indications, using discharge rates as the outcome measure.

We studied all patients on an antidepressant monotherapy in Bedford hospital (206 in total). We examined the clinical notes for each patient prescribed antidepressants to assess whether they were discharged from the out-patient clinic. Hence we calculated rates of discharge for ‘the four’ and other antidepressant monotherapies for patients with unipolar depression or another psychiatric condition.

For patients with unipolar depression, discharge rates were higher for ‘The four’. For patients with other indications, discharge rates were higher for other antidepressant monotherapies. A greater percentage of patients with unipolar depression were discharged from clinic compared with people treated for other indications

This suggests that indication for which the antidepressant monotherapy is prescribed will affect the efficacy of treatment, as measured by discharge rates. The fact that a greater percentage of patients with unipolar depression were discharged from clinic compared with people treated for other indications may suggest that people with ‘treatment resistant depression’ may really have another disorder, for example borderline personality disorder, bipolar disorder or PTSD.

This audit suggests that ‘the four’ are more effective for the treatment of unipolar depression compared with other indications, using discharge rates as the outcome measure.