Young people taking antidepressants such as Prozac and Seroxat are significantly more likely to commit violent crimes when they are on the medication, but taking higher doses of the drugs appears to reduce that risk, scientists said Tuesday.

In research published in the PLoS Medicine journal, the scientists said that while their finding of a link does not prove that such drugs cause people to be more violent, further studies should be conducted and extra warnings may be needed in future when they are prescribed to people aged 15 to 24.

Selective Serotonin Re-uptake Inhibitors (SSRIs) are a class of widely prescribed drugs, including fluoxetine, branded by Eli Lilly as Prozac, and GlaxoSmithKline's paroxetine, branded as Paxil or Seroxat, designed to ease symptoms of anxiety and depression.