Use of one class of antidepressant drugs, the SSRIs (selective serotonin reuptake inhibitors), may be associated with severe violence in a small number of individuals say the authors of paper published in PLoS Medicine.
David Healy and David Menkes from Cardiff University, and Andrew Herxheimer from the UK Cochrane Centre, used a variety of sources to look at this association.
The sources used were data on paroxetine presented to the UK Committee on Safety of Medicines Expert Working Group by its maker, GlaxoSmithKline; data from United Kingdom Drug Safety Research Unit (DSRU) prescription-event monitoring studies on paroxetine and fluoxetine; legal cases in which the authors have given evidence; and e-mails from 1,374 patients in response to a BBC TV Panorama programme on paroxetine broadcast in 2002.
The association of antidepressant use and self directed violence, such as suicide, is not new. The authors note that "Some regulators, such as the Canadian regulators, have also referred to risks of treatment-induced activation leading to both self-harm and harm to others" and the "United States labels for all antidepressants as of August 2004 note that 'anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, and mania have been reported in adult and pediatric patients being treated with antidepressants for major depressive disorder as well as for other indications, both psychiatric and nonpsychiatric'".
The current paper in PLoS Medicine focuses on the SSRIs, which are claimed to correct a chemical imbalance in the brain involving a lack of serotonin. Of the SSRIs, paroxetine was primarily studied for two reasons. First, the authors had better access to information about illustrative medico-legal cases for this drug than for other antidepressants. Second, the manufacturer of paroxetine, GlaxoSmithKline, has submitted data on "hostile" episodes associated with paroxetine to the British regulatory authorities.
A summary of placebo controlled trials in children and adults showed that 60 of 9219 (0.65%) patients given paroxetine, compared with 20 of 6,455 given placebo (0.31%) had what was called a "hostility event".