Recent reports that the most popularly prescribed class of antidepressants may be only marginally more effective than a placebo adds a new dimension to the growing controversy over possible links between the drugs and increased risk of suicide.

Researchers at the University of Dundee, UK, have released preliminary findings, which have yet to appear in print, suggesting that although 56 per cent of patients being treated with selective serotonin re-uptake inhibitors (SSRI’s) showed a marked improvement in their condition after just two weeks, so did 43 per cent of those being treated with a placebo. This remarkable finding, if verified by further studies, would indicate that many people may be being misdiagnosed and prescribed drugs they do not need. Reportedly, over 24 million prescriptions for SSRI’s are written every year in the UK alone; an increase of 166 per cent since 1991.

In response to a lawsuit over apparent concealment of clinical data relating to antidepressants, GlaxoSmithKline has chosen to publish results of clinical trials so that all information is publicly available. Eli Lilly has also elected to post clinical results, a decision made just as their latest antidepressant, Cymbalta, receives approval for adult use in the US. Cymbalta has already attracted controversy after a student hanged herself during clinical trials.

A possible link between SSRI therapy and increased suicide risk is hotly debated. When studying this particularly vulnerable patient group it is difficult to assess whether this increased risk is because the treatment is taking time to take effect or because the SSRI’s are directly affecting mood, say researchers.

Vikki Allen