Author's reply

Professor Malt feels that his study of the use of antidepressants establishes the utility of antidepressants in mild or moderate depression in primary care and contradicts the notion that unblinding may have biased results. He reports that there was no difference in rates of side-effects in any of the treatment groups. However, patients may be able to guess whether they are taking active drugs without necessarily reporting side-effects. Taking an active drug may lead to a physiological experience, which reveals the nature of the treatment but may not be construed as unpleasant, and therefore may not be reported as a side-effect. Without specifically asking patients to guess whether they are taking active drugs or placebo it is not possible to know whether or not this effect may be occurring. In addition, the fact that Professor Malt reports that the active drugs were substantially more effective than placebo for insomnia suggests that the drugs had a sedative effect which may have been independent of the proposed antidepressant effect and may have suggested to patients that they were taking an active medication.

It is also worth pointing out that although this trial found statistically significant differences between active drugs and placebo, these differences were very small and of doubtful clinical relevance. The difference in the reduction of scores on the Montgomery—Åsberg Depression Rating Scale (MADRS) between the active drugs and placebo consisted of a maximum of 3 points. The MADRS scale has a total of 60 points and mean baseline values in this study were 27. In subjects in whom depression was characterised as severe or major depression, the differences were smaller still, and were not statistically significant.

It is arguable that treatment of mild depression in primary care with anti-depressants is the worst case of the inappropriate medicalisation of misery and social problems. This may be harmful to the individuals concerned by encouraging reliance on physical treatments, and to society by masking the social conditions that are the sources of modern discontent.