Antidepressant medication use and breast

There is epidemiological evidence that antidepressant (AD) medication use may be associated with an increased risk of breast cancer in women,1–5 although findings have been inconsistent, with three studies reporting no association6–8 and five other studies finding an increased risk of breast cancer in women taking tricylic antidepressants (TCA) or selective serotonin reuptake inhibitors (SSRI).1–5 The preponderance of animal studies also indicate that certain antidepressants may promote tumours in experimental models.9–14 The widespread use of antidepressants15–17 and the rise in incidence of breast cancer18,19 have focused interest on whether AD use, a potentially modifiable factor, may be associated with breast cancer risk. We evaluated the association between the use of AD and risk of breast cancer using a population-based case-control study design. Methods Selection of cases and controls Cases were selected based on the following criteria: (1) women diagnosed with breast cancer between June 1996 and May 1998, and reported, via pathology report, to the OCR as a first primary breast cancer, (2) aged 25–74 years at diagnosis, and (3) alive and resident of Ontario. The OCR is a population-based cancer registry and includes all cases of invasive cancer diagnosed among residents of Ontario. Physicians identified i