Commentary

The reviews by Bacaltchuk et al are laudable for the rigour of the data analyses, but they rightly generate more questions than answers. Bacaltchuk and Hay have comprehensively reviewed 16 published RCTs of antidepressant treatments for BN. Although modest effectiveness is shown, high dropout rates among patients limit the clinical application of these data, and the authors comment on the need for more studies of tolerability and cost effectiveness. The studies included were generally of short duration in young adult women who did not have any substantial psychiatric comorbid conditions. The results therefore cannot be generalised to the substantial minority of bulimic patients with comorbid “multi-impulsive” personality characteristics¹ or substance abuse or to adolescents.

Pharmacological treatment trials of BN are dominated by the reported reduction in bulimic symptoms, but clinicians and their patients are more interested in remission of symptoms. The emphasis of this review on remission is therefore of greater clinical application than the emphasis of its sources. The review discusses the limitations of outcome measures and is right to conclude that the use of antidepressants as sole treatment “does not seem sufficient to effectively treat these patients”.

Bacaltchuk et al review a scant number of studies comparing combined antidepressant medication and psychotherapy with each treatment alone. In clinical practice, cognitive behavioural therapy (CBT), which is limited by its availability, is generally regarded as the treatment of choice for BN, with antidepressant medication as an adjunct. This review supports that approach by using restricted data from fairly small studies. However, the clinical risk associated with a pharmacological approach to BN seems to be a higher dropout rate than with CBT and, again, the results cannot necessarily be generalised beyond young adult women who have no substantial comorbid illness.

The UK Department of Health's National Service Framework for Mental Health has stressed the importance of managing such eating disorders as BN in primary care,² noting that “antidepressants can reduce purging and bingeing whether or not the person is also depressed”. Although this statement is true in the short term, it would seem an optimistic reading of the literature. Prescription of antidepressants may appear to be the easiest route in a primary care setting, but the clinical implication of Bacaltchuk et al's review is that the easiest route may not be the most effective, cost effective, or acceptable for clinicians and their patients.

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However, in the busy world of primary care, the treatment of BN will continue to be driven by available resources. CBT for BN is generally preferred by the family doctor when specialists with such training are available. But the Royal College of Psychiatrists, in collaboration with the Consumers' Association, has recently reported the dearth of specialist eating disorder services beyond southeastern England.³ Thus, in the more likely scenario of limited eating disorder services, use of antidepressant medication may seem more attractive. These 2 reviews agree with that approach and suggest that antidepressant medication will produce positive short term results; however, BN is not a short term illness. Relapse prevention deserves greater scrutiny for patients with BN and anorexia nervosa, and longer term follow up studies should drive the next generation of treatment intervention studies.

Regarding treatment of BN in particular, a pressing need exists for longer term studies examining relapse rates, health economics, and comparisons of classes of antidepressants for treatment concordance.