Suicide risk with antidepressants is age dependent
Recent studies by the US Food and Drug Administration (FDA) have revealed that people under the age of 25 who take antidepressants have a higher risk of suicide.
The FDA analysis conducted by Dr Marc Stone, Dr Thomas Laughren and their colleagues involved a review of 372 trials involving nearly 100,000 people who took antidepressants. The study, published in the British Medical Journal, showed that antidepressant drugs increase the risk for suicide in people younger than 25, have no effect in those 25 to 64, and reduce risk in those 65 and older. Hence, they found the risk of suicide was strongly age dependent.
Since 2003, US and European regulators have raised alarm bells on the use of antidepressants after studies from a clinical trial showed that antidepressants increased the risk of suicidal thoughts and behaviours in those aged under 18.
The FDA studies showed an increased risk of suicide attempts or suicide-related behaviour among children and adolescents taking the widely used selective serotonin reuptake inhibitors (SSRIs), such as Zoloft, Celexa and Prozac.
In 2005, the FDA added a so-called black box warning – the agency’s strongest warning – so that health care providers would be alert to any indication of suicide-related behaviour in young children and teens. In May 2007, the warnings were extended to young adults aged 18 to 24.
The researchers support the Food and Drug Administration’s warnings on antidepressant drug labelling for people under 25, and they also support the notion that antidepressant drugs can have two distinct effects. In some patients, they can promote suicidal thoughts or behaviour but this risk appears to diminish with age. In other patients, the drugs provide relief from depression thereby reducing the risk of suicide.
The report was criticised by John Geddes, Professor of Epidemiological Psychiatry, at the University of Oxford who said: “One of the things that we need to be clear about is that we can’t rely on placebo-control trials of new medications done by the industry. They can’t answer all the clinical questions. We need more active comparison trials which don’t have placebo in them and larger trials aimed at antidepressants in clinical practice.”
According to Geddes, the study did make clear differences in risks among specific antidepressants. For example, the odds of suicidal behaviour by people taking Pfizer Inc’s Zoloft, or sertraline, were around half of those who took the placebo. By comparison, Forest Laboratories Inc’s Celexa, or citalopram, and Lexapro, or escitalopram, “seem to increase the risk of suicidal events” according to Geddes.
Currently, there are no age-related warnings on antidepressant labels in Australia. Australian psychiatrist, Professor Bernhard Baune of James Cook University, calls for further research into the long-term impact of antidepressants. Professor Baune said that such research may help clinicians choose the antidepressant with the lowest suicide risk for the individual they are prescribing for.
Reference: Antidepressant risk ‘worse for young’, ABC News, 12/08/09
