Antidepressants and the risk of breast cancer

Background: A recent national newspaper article highlighted 2 published research papers that suggest an association between antidepressants and an increased risk of breast cancer. The authors of the 2 papers recommend switching or avoiding the antidepressants implicated in their studies. Method: We critically review these papers and, based on our review, consider what clinical practices, if any, should be modified as a result of their findings. Results: Both articles are based upon case-control studies. In the first paper, the authors examine the relation between tricyclic antidepressants (TCAs) and an increased risk of breast cancer. The study upon which the paper is based has several design strengths, and the paper presents findings that have biological plausibility. However, the conclusions are weakened by the lack of accounting for potential confounding factors and multiple statistical comparisons. In the second paper, the authors combined survey and administrative data to examine the association between antidepressant use and breast cancer risk. The press article notwithstanding, the second paper does not find a significant association between specific antidepressants and an increased risk of breast cancer, after adjusting for potential confounders. There are significant methodological limitations to the research upon which the paper is based. Conclusions: The finding of an association between TCA use and increased risk of breast cancer merits further testing using stronger research designs. However, because of the methodological concerns described, the 2 papers we review provide insufficient evidence to guide practitioners to change clinical practice.