Antidepressants are widely used to treat not just depression but also obsessive-compulsive disorder, panic attacks, post-traumatic stress disorder and social anxiety. For the most part they are effective and safe but a number of case reports have linked them to bleeding abnormalities. An Italian study of 35,869 people compared different categories of antidepressants to see whether they increased the risk of bleeding problems. None of the depressants had an effect on the overall incidence of bleeding problems and the older antidepressants did not cause an increased risk of gastrointestinal bleeding. But selective-serotonin-reuptake-inhibitor (SSRI) antidepressants caused a minor increase in the incidence of gastrointestinal bleeding and mianserin, mirtazapine, reboxetine, trazodone and venlafaxine led to a statistically-significant increase in the risk of gastrointestinal bleeding.
Barbui, Corrado ... [et al] - Antidepressant drug prescription and risk of abnormal bleeding: a case-control study Journal of Clinical Psychopharmacology February 2009, 29(1), 33-38