The US Food and Drug Administration has proposed that the makers of all antidepressants update the existing black box warning on their products to include warnings about increased risks of suicidal thinking and behaviour, in people aged 18 to 24 during the first one to two months of treatment.

The proposal updates similar labelling changes made in 2005 that warned of a suicidality risk in children and adolescents who use antidepressants, though that did not involve any specific age limit. The FDA also noted that the changes should include language stating that scientific data did not show this increased risk in adults older than 24, and that adults ages 65 and older taking antidepressants have a decreased risk of suicidality.

Steven Galson, director of FDA's Center for Drug Evaluation and Research, said the move represents the agency’s commitment to “a high level of post-marketing evaluation of drug products," adding that "depression and other psychiatric disorders can have significant consequences if not appropriately treated. Antidepressant medications benefit many patients, but it is important that doctors and patients are aware of the risks."

The FDA has reviewed 295 studies of various antidepressants since 2005 and its analysis, which included more than 77,000 adults, found a "slight increase" in suicidal thinking and behaviour among young adults during early treatment. For every 1,000 patients treated, about five more cases of suicidal thoughts and actions were reported among 18-to-24-year-olds who took the antidepressants rather than a placebo.

"The risk is quite small, but we think it is a real risk and it's something that needs to be paid attention to," Thomas Laughren, director of the FDA's division of psychiatry products, said on conference call. The agency also noted that people currently prescribed antidepressants should not stop taking them but should notify their doctors if they have concerns.

The announcement was welcomed by a number of pharmaceutical companies and Eli Lilly, manufacturer of Prozac (fluoxetine) and Cymbalta (duloxetine) said it will help ensure that “the millions of people with depression who are young adults age 24 and under and their families can make informed treatment decisions while minimising the fear and stigma associated with depression."

Black box label can frighten off potential patients

Other groups are less convinced about the value of a label change and they argue that it stop access to drugs for those who need them. Last month, a study published in the Journal of the American Medical Assocation presented data from 27 trials involving children under 18 with major depressive disorder, obsessive-compulsive disorder, or non-OCD anxiety disorders, and it concluded that the benefits of antidepressants for children and adults appear to be greater than the risks of suicide or suicidal thoughts.

David Brent, co-author of the aforementioned study, suggested the FDA should now "consider labelling that calls attention to the risk but wouldn't have the effect of frightening people away from using the medication when needed."