Prozac-type antidepressants reduce the risk of suicide in adults with depression, according to a study published in the July issue of the American Journal of Psychiatry which also found that the lower risk held true for young adults aged 18 to 25.

The finding appears to contradict warnings by some researchers that selective serotonin re-uptake inhibitors may increase patients’ risk of suicide. Acting on such concerns, the US Food and Drug Administration issued a black box warning in 2004 suggesting that SSRI drugs increase the risk of suicidal behaviour in children and adolescents and

an FDA advisory committee recently recommended extending this warning to young adults. The drugs are no longer recommended for under-18s.

In the UK, after pressure from press and TV reports, GlaxoSmithKline finally acknowledged in 2006 “that young adults, particularly those with major depressive disorder, may be at increased risk for suicidal behaviour with Seroxat (paroxetine)”. However, Robert Gibbons, director of the Center for Health Statistics and professor of biostatistics and psychiatry at the University of Illinois at Chicago, said his latest research showed that overall, SSRIs, along with other antidepressants, significantly cut young people’s risk of suicide.

"The risk of suicide attempt among depressed patients treated with SSRI drugs was about one-third that of patients who were not treated with an SSRI," he said. "We would not expect a lower risk in this patient population because patients treated with SSRIs are generally more severely depressed and would have a higher risk of suicide attempt."

His team studied the medical records of 226,866 patients newly diagnosed with depression in 2003 or 2004 at the Veterans Administration healthcare system. They compared risk of suicide in four age groups (ages 18 to 25, 26 to 45, 46 to 65 and older than 65) before and after treatment with SSRI drugs.

All age groups of depressed patients who received SSRIs – the most commonly prescribed antidepressant – showed a significantly lower risk of suicide attempt when compared to those who did not receive antidepressant treatment. Among 82,828 patients, there were 183 suicide attempts before treatment with SSRI drugs and 102 suicide attempts after treatment with SSRI drugs (a rate that fell from 221 to 123 per 100,000 after treatment), leading Prof Gibbons to claim that extending the suicide warning to young adults could further decrease anti-depressant treatment of depression and contribute to higher rates of suicide.

Dr David Brent, a psychiatrist at the University of Pittsburgh School of Medicine, notes that a decade of declining adolescent suicide rates came to an end in 2004 (with an 18% increase in adolescent suicides from the previous year) – and that this coincided with publicity about the link between antidepressant treatment and suicide risk in children and adolescents and a subsequent decline in antidepressant use.

Warning of the dangers of no treatment

Writing in the same issue of the AJP, he said: “The disturbing increase in the suicide rate in adolescents at a time when antidepressant treatment is becoming less frequent in this population should serve as a warning that the consequences of not receiving treatment for depression may be fatal.”

He calls for greater inclusion of high-risk patients in clinical trials in order to clarify the issue. “Only by including depressed patients at significant suicide risk into randomised trials and then systematically assessing the impact of treatment on suicidality and depression will we be able to delineate the effects of antidepressants and psychotherapy on depression and suicide risk,” he said. By Michael Day