PRL and breast cancer: Compared with 8173 matched controls, the odds of breast cancer increased in women with prior exposure to prolactin-increasing antipsychotics for 1–4 years (adjusted odds ratio [aOR] = 1.20, 95% confidence interval [CI] = 1.03–1.41), and for ≥ 5 years (aOR = 1.47, 95%CI = 1.26–1.71).