Editor—I welcome Gunnell and Ashby's timely review on the risks versus benefits of selective serotonin reuptake inhibitors (SSRIs),1 but I am not sure how much this article clears the air.
The authors take adverse “suicide related event” data reported by the Medicines and Healthcare Products Regulatory Agency (largely over-arousal, suicidal thoughts, and self harm) explicitly to mean completed suicide. Although no actual suicides occurred in the agency's data, the authors multiply an estimate of completed suicides per year in those taking antidepressants by the relative risk (incorrectly stated as “odds ratio” in table 1) of suicide related events to calculate what is claimed to be an excess number of completed suicides attributable to antidepressants. Even if both figures that they quote were correct, the final figure would be the excess of deliberate self harm in the worst case and over-arousal in the best case (but more likely a heterogeneous composite effect). Of course there is a link between deliberate self harm and suicide but it is not 1:1. The study with the longest follow up showed a 13% rate of suicide after deliberate self harm over 37 years.2 This would translate into an excess of 30 possible cases, not 233 in men and 20 cases in women. Of course, even this smaller number would be a concern if real and not likely to be outweighed by beneficial effects in the long term (in terms of both treating the depressive syndrome and reducing complications therein).3
Calculating how much of the risk of a complex outcome such as suicide is attributable to one factor such as antidepressants is a difficult task, but any such calculation must be based on actual data and not estimates if one is to keep a balanced perspective on this debate. Just such a calculation has been performed for deliberate self harm with the finding that suicidal behaviour (deliberate self harm) is increased in the first one to nine days after starting an antidepressant but without major differences between individual antidepressants.4 Clearly more research evidence is needed about the benefits and risks of SSRIs but it may be sobering to remember that less than one in 10 patients who are depressed in the community receive adequate doses of antidepressants of any type, regardless of their suicide risk.5
Competing interests: None declared.
References
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