Commentary

The introduction of SSRIs and other new antidepressants in the past decade increased the options available for tackling depressive illnesses. But has a major advance occurred in the treatment of this group of disorders so commonly encountered by family practitioners and hospital physicians? Mulrow et al's comprehensive report lends support to the findings of previous high quality systematic reviews that compared newer with older antidepressants.¹ It also examines herbal remedies and psychosocial therapies.

All the meta-analyses have concluded that newer and older antidepressants have equivalent efficacy. Therefore, initial prescribing decisions have to be based on consideration of patient acceptability and cost. Dropout rates in RCTs have been used as the best available proxy measure for tolerability, and Mulrow et al found that tricyclic antidepressants and SSRIs are almost identical in this respect. However, side effect profiles differ, and patients should be informed of these differences so that their wishes can be considered when choosing medicine.

For complementary practitioners and their patients, some evidence exists that St John's wort has antidepressant properties, but more research is required.

Purchasers of health care should re-evaluate their spending on depression. The introduction of SSRIs has prompted a vast increase in spending, which is simply not justified by the available scientific data on efficacy and side effects.

This meticulously done meta-analysis highlights that the evidence does not address all common clinical problems. Insufficient research exists to guide prescribing in mild, severe, treatment resistant, or comorbid depressive illnesses. We cannot depend on the pharmaceutical industry to guide the use of important and widely used medicines; 94% of the antidepressant studies for which a funding source could be identified were industry financed. Health maintenance organisations, insurance companies, and especially governments should take note.