Antidepressants and risk of prostate cancer: a nested case-control study.

Although the association between antidepressant drug use and risk of cancer has received considerable attention in the past years, no work has been done specifically on prostate cancer. We carried out a population-based case-control study to assess the risk of prostate cancer in association with exposure to tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). 7767 prostate cancer cases diagnosed between 1981 and 2000 were accrued through the Saskatchewan Cancer Agency. Saskatchewan Health identified a total of 31,068 male controls who were matched on age and calendar time. Data on exposure to TCAs and SSRIs were compiled from the Saskatchewan outpatient prescription drug database, and covered a period upto 24 years. A positive significant association was found between TCA use and risk of prostate cancer, when exposure took place 2-5 years before diagnosis, with rate ratios of 1.31, 1.58, and 2.42 at the low, medium and high average daily dose levels, respectively. Exposure to SSRIs was not found to be significantly associated with the risk of prostate cancer. TCA use 2-5 years in the past was associated with a small dose-dependent increase in the risk of prostate cancer. Nevertheless, detection bias could have contributed to the observed association.