Hormonal birth control that suppresses ovulation is effective in the treatment of premenstrual dysphoric disorder (PMDD). Combined birth control pills containing drospirenone are approved for the treatment of PMDD and may be particularly beneficial due to the antimineralocorticoid activity of drospirenone. Studies on the influence of hormonal birth control on mood in women with existing mood disorders or polycystic ovary syndrome are limited and mixed. Women with underlying mood disorders may be more likely to experience mood changes with hormonal birth control. A 2016 systematic review found based on limited evidence from 6 studies that hormonal birth control, including combined birth control pills, depot medroxyprogesterone acetate, and levonorgestrel-containing intrauterine devices, was not associated with worse outcomes compared to non-use in women with depressive or bipolar disorders. A 2008 Cochrane review found a greater likelihood of postpartum depression in women given norethisterone enanthate as a form of progestogen-only injectable birth control, and recommended caution on the use of progestogen-only birth control in the postpartum period.