Antidepressant medication use and breast cancer risk

Experimental and epidemiologic studies suggest that antidepressant medicati on use may be associated with breast cancer risk. This hypothesis was inves tigated using a population-based case-control study; cases diagnosed in 199 5-1996 were identified using the Ontario Cancer Registry, and controls were randomly sampled from an Ontario Ministry of Finance database. Data were c ollected using a self-administered questionnaire, and multivariate logistic regression was used to estimate odds ratios and 95% confidence intervals. Adjusted odds ratio estimates ranged from 0.7 to 0.8 and were not statistic ally significant for "ever" use of antidepressants, tricyclics, and selecti ve serotonin reuptake inhibitors, Compared with no antidepressant use, use of tricyclic antidepressants for greater than 2 years' duration was associa ted with an elevated risk of breast cancer (odds ratio (OR) = 2.1, 95% conf idence interval (CI): 0.9, 5.0), Of the six most commonly reported antidepr essant medications, only paroxetine use was associated with an increase in breast cancer risk (OR = 7.2, 95% CI: 0.9, 58.3), Results from this study d o not support the hypothesis that "ever" use of any antidepressant medicati ons is associated with breast cancer risk. Use of tricyclic medications for greater than 2 years, however, may be associated with a twofold elevation, and use of paroxetine may be associated with a substantial increase in bre ast cancer risk.