Depression is unfortunately a very common illness; it is extremely unpleasant for sufferers and for their relatives and friends, and is associated with a substantial morbidity and mortality. The lifetime risk of developing depression was estimated by Boyd & Weissman (1981) as between 8% and 12% for men and between 20% and 26% for women. Estimates of point-prevalence vary, but a review of published studies suggests a level of 8.4% for men and 14.8% for women. A difference in prevalence of depression between men and women, with a twofold increase in women, appears to be well established. Recent evidence suggests, however, that the incidence of depression in men is rather more common than was previously thought: some apparent sex differences in frequency may be accounted for by a difference in coping with, and expression of, depressive symptoms (Angst & Dobler-Mikola, 1984). What is clear from the epidemiological studies in ‘normal’ populations is that much depressive illness remains untreated.
All existing treatments for depression, in particular the tricyclic antidepressants (TCAs), have drawbacks. Since the TCAs, for example, are associated with rather unpleasant and sometimes dangerous side-effects, which reduce compliance and compromise treatment, the search for new antidepressants with less unwanted effects and if possible greater efficacy remains an important goal. A recent trend in antidepressant research has been to develop compounds with specific pharmacological actions, which are selective for one of the amine systems. Currently, a number of specific 5-HT reuptake inhibitors are being developed, and some of these are now in clinical use.