In 2003, British health authorities declared that most popular anti-depressants might sometimes increase the risk of suicidal behavior in children and teenagers. They declared all but one — Prozac — unsuitable for young people diagnosed with depression, but stopped short of a pediatric ban. In March, the FDA urged close monitoring of patients for suicide warning signs, especially when they first start the pills or change doses. The reason: The drugs may cause agitation, anxiety and hostility in a subset of patients unusually prone to rare side effects.

The FDA and Columbia University psychiatric specialists have re-evaluated 25 studies involving more than 4,000 young people and eight anti-depressants. They found that young anti-depressant users were about 1.8 times more likely to have suicidal thoughts or behaviors than patients given dummy pills.

The FDA plans to hold hearings in September to consider possible changes to the labeling guidelines on how the drugs can be used. The review of the Columbia data confirmed an earlier FDA analysis showing an increased risk between some anti-depressants and suicidal tendencies in children.

The agency commissioned a panel of experts at Columbia early this year to verify potential suicidal-type behavior in the clinical trials, after Andrew Mosholder, an FDA researcher, found that the drugs increased the risk of harmful behavior in children and recommended that they not be used.

Children under 18 years account for about 7% of the usage of the biggest anti-depressants, all but one of which are not approved for use in children. Only Eli Lilly’s Prozac, or fluoxetine, is approved for children, but doctors can prescribe non-approved drugs if they feel it is best for the patient.