Patients on antidepressant drugs like Prozac and Paxil are prone to suicidal tendencies when they are first put on antidepressants, according to a study published in Wednesday’s issue of Journal of the American Medical Association.

The study, by Drs. Herschel and Susan Jick and James Kaye at Boston University, looked at Prozac, Paxil, amitriptyline and dothiepin and found that suicidal thoughts or attempts is increased in the first months after starting treatment, especially during the first ten days.

Researchers looked at 2,791 British adults and children, ages 10 to 69, who were first-time users of any of the four drugs from 1993 to 1999. In their analysis, they found no substantial difference in effect of the four drugs on people aged 10 to 19 years.

Suicidal impulses were 29 percent more common among Paxil users than among dothiepin users studied, reports The Associated Press. “Kaye said that finding was statistically insignificant and could reflect doctors’ tendency to prescribe the newest drug for more serious cases. Still, he said it ‘doesn’t exclude the possibility’ that Paxil is more risky.”.

(via The Associated Press)