Antidepressants

Recent years have seen a large increase in the prescription of antidepressants in the UK. This is a field in which both research and clinical practice are developing rapidly. A new generation of 'designer drugs' has largely replaced the tricyclic antidepressants and monoamine oxidase inhibitors, on grounds of safety and tolerability rather than improved efficacy. Drugs have been developed on the basis of the monoamine theory of depression, although the biological changes that are responsible for the development of depressive symptoms have yet to be clearly established. All of the antidepressants currently available act by enhancing the activity of monoamine neurotransmitters, either by reuptake inhibition, enzyme inhibition or activity at pre- or postsynaptic receptors. This contribution describes the pharmacology of the different classes of antidepressants, puts this in a context of clinical prescribing and current practice guidelines and considers likely future developments in the field.