Sertraline is a selective inhibitor of central serotonin reuptake. Thus, it enhances serotoninergic transmission--a property which appears to explain its antidepressant activity. Its elimination half-life (approximately 26 hours) makes it suitable for once daily administration. Although clinical experience with sertraline is limited, it appears to possess antidepressant efficacy similar to that of amitriptyline and dothiepin, marginally better than imipramine, and significantly better than placebo. Additionally, sertraline is the only antidepressant licensed in the UK for the prevention of recurrence of depression, and preliminary findings suggest that the drug may also be effective in the treatment of obsessive-compulsive disorder. Sertraline and other serotonin reuptake inhibitors possess tolerability advantages over tricyclic antidepressants. Sertraline has minimal anticholinergic activity, is essentially devoid of cardiovascular effects, has a wide therapeutic index and may be administered to elderly patients or those with underlying cardiovascular disorders. However, as with other serotonin reuptake inhibitors, sertraline has been associated with gastrointestinal disturbances (nausea, diarrhoea/loose stools) and male sexual dysfunction (primarily ejaculatory disturbance), although each of these effects is usually mild and transient, decreasing in frequency with continued treatment. As a drug class, serotonin reuptake inhibitors such as sertraline appear to provide significant advantages compared with the more established antidepressant agents, particularly in terms of tolerability. Although much broader clinical experience is required before sertraline's full therapeutic potential can be realised, if future studies confirm the encouraging initial findings, sertraline will undoubtedly become an important option in the treatment of depression.