High doses of antidepressants 'double chances of suicidal behaviour in teens'

High starting doses of antidepressants such as Prozac have been linked to increased suicidal behaviour in children and young adults, say scientists.

A meta-analysis of various antidepressant drug trials by the US Food and Drug Administration (FDA) found that young people who received antidepressants were twice as likely to have suicidal thoughts or self-harm as those given a placebo.

The study collected data from 162,625 people between the ages of 10 to 64 who had been proscribed antidepressants at modal (the most prescribed on average) or above modal doses, and compared the two groups.

Those aged 24 or younger that started treatment at higher doses was twice as likely to self-harm, with older patients remaining unaffected. The authors of the study suggest that this corresponds to approximately one additional case of self-harm for every 150 patients.

The doctors who conducted the study from the Harvard School of Public Health recommended that doctors should avoid high doses for younger individuals as the benefits are at best “modest”.

A similar study conducted by the British Medical Journal in 2009 also found that young adults taking antidepressants such as SSRIs had double the risk of suicidal thoughts or behaviour when compared to those taking placebos.

SSRIs are a type of antidepressant marketed under many different commercial names including Prozac, Zoloft, Paxil and Seroxat.