August 12, 2009

Suicide Risk Among Antidepressant Users Varies By Age

Researchers from the U.S. Food and Drug Administration released an analysis on Tuesday that showed people under age 25 who take antidepressants have a higher risk of suicide, but adults older than that do not, Reuters reported.

The new data supports the agency's age-related warnings on the drugs' labeling.

Clinical trials from 2003 showed the use of antidepressant drugs increased the risk of suicidal thoughts and behaviors in those under age 18, leading regulators from the U.S. and Europe to sound alarms over their safety for young people.

The FDA added a so-called black box warning in February 2005 concerning the use of all antidepressants in young children and teens in an attempt to draw attention to the possible risks of these medications.

The warnings were then extended to young adults aged 18 to 24 in May 2007.

However, some psychiatrists say the warnings scare people away from effective treatment for depression and cite recent studies that have suggested the warnings triggered an 8 percent rise in suicide among youth and teens in 2004 -- the biggest one-year gain in 15 years.

Meanwhile, the FDA's decision to impose black box warnings for children and young adults had a spillover effect on depression care in older adults, resulting in a lasting decline in depression diagnosis and treatment, according to a study published in June in the journal Archives of General Psychiatry.

Researchers have since asked the FDA to revise its policy.

The FDA analysis involved a review of data from eight drug makers on 372 clinical trials involving nearly 100,000 adults.

The studies leaders, Dr. Marc Stone and Dr. Thomas Laughren, found that the overall risk of suicide was "strongly age-dependent," with higher risks in people under 25, no difference among those 25 to 64, and lower risks in people 65 and older.

The findings support the agency's warnings on antidepressant drug labeling for people under 25, and they also support the notion that antidepressant drugs can have two distinct effects, the researchers said on the British Medical Journal website.

Antidepressants can promote suicidal thoughts or behavior in some patients, but the risk appears to diminish with age. However, the drugs provide relief from depression in others and reduce the risk of suicide.

More research is needed to understand these differences, they added.

But a commentary suggested the findings were not new and noted that the trials studied by the FDA excluded sicker patients. The study did, however, make clear differences in risks among specific antidepressants, according to John Geddes from the University of Oxford and colleagues.

More commonly used drugs called selective serotonin reuptake inhibitors, or SSRIs, were noted to have specific differences.

Studies showed that the chance of suicidal behavior by people taking Pfizer's Zoloft, or sertraline, were around half of those who took placebo.

But Geddes and colleagues wrote that Forest Laboratories' Celexa, or citalopram, and Lexapro, or escitalopram, seem to increase the risk of suicidal events, adding that increased risk is probably restricted to younger people and varies greatly between individual medicines.


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