Watchful waiting for minor depression, full dose treatment for major depression

This week's BMJ includes three studies of the use of antidepressant drugs in general practice. MacDonald et al (p 860) looked at patient specific dispensed prescribing and hospitalisations for possible adverse effects, using a record linkage database covering Tayside, Scotland.1 They found prescribing of tricyclic antidepressants to be generally safe: the drugs were rarely used in the presence of contraindications and did not lead to an excess of hospitalisations for adverse cardiovascular effects. The authors say, however, that this may have been because about three quarters of prescriptions were for less than the recommended dose for major depression (125 mg of amitriptyline or equivalent a day2) and most were for less than 60 days.

These findings are not new: studies going back more than 20 years have consistently found that tricyclic antidepressants are usually prescribed at low doses for short periods in general practice.3 4 5 So why do practitioners continue to prescribe in such a way, and are they really wrong to do so?

Low dose tricyclic antidepressants for migraine prophylaxis, neuralgia, and nocturnal enuresis account for only a small proportion of prescriptions; most are used for a diagnosis of depression. …