The risk-benefit assessment of antidepressant drugs.

Antidepressant drugs in common use are reviewed in terms of their risks and benefits. A simple classification divides these into tricyclic antidepressants, monoamine oxidase inhibitors and second generation antidepressants. Risks may arise from the correct use of an antidepressant, from its incorrect or inappropriate use, or due to its failure to reverse the depression. The greatest risk is to leave the depression untreated. Risks due to adverse drug effects are generally predictable but in some cases are unexpected and have led to the withdrawal of the drug from the market. Assessing the benefits of antidepressant drugs is more difficult. Rating scales can be used in this context and the fact that the majority of antidepressant drugs have a similar degree of efficacy serves to emphasise the importance of making a risk-benefit assessment of each drug. This has been presented for the more widely used drugs. Safety in overdose is a particularly important benefit. The ideal antidepressant should specifically reverse depressive illness without toxic effects. Although no drug at present measures up to this it is clear that antidepressants should be prescribed, as their benefits outweigh their risks.