Antidepressant medication use and breast cancer risk

grantor: University of TorontoPrevious research suggests antidepressant medication use may be associated with breast cancer risk. This hypothesis was investigated using a population-based case-control study. Cases were identified using the Ontario Cancer Registry and controls were randomly sampled from the Ontario Ministry of Finance assessment rolls. Data were collected using a self administered questionnaire, and multivariate logistic regression was used to estimate odds ratios (ORs). Adjusted OR estimates ranged from 0.7-0.8 and were not statistically significant for 'ever' use of any antidepressants, tricyclics, and selective serotonin re-uptake inhibitors. Use of tricyclic antidepressants for greater than 2 years duration was associated with an elevated risk of breast cancer (OR = 2.1, 95% CI: 0.9, 5.0). Of the six most commonly antidepressant medications, only 'ever' use of paroxetine was associated with an increase in breast cancer risk (OR = 7.2, 95% CI: 0.9, 58.3). Results from this study do not support the hypothesis that 'ever' use of antidepressant medications is associated with breast cancer risk However, use of tricyclic medications; for greater than two years was associated with a 2-fold elevation in breast cancer risk, and 'ever' use of paroxetine was associated with a substantial increase in breast cancer risk.Ph.D