BACKGROUND Norplant is a long-acting subdermal implant system that is widely used for contraception. The implant releases a continuous dose of levonorgestrel, a synthetic progestin. Although oral contraceptives are associated with depression and panic disorder, no cases have been reported of psychiatric disorders secondary to the use of Norplant. METHODS Two women, aged 18 and 29 years, are described who developed major depression and panic disorder while using the Norplant system. RESULTS These women who had no prior psychiatric history developed major depression and panic disorder 1 to 2 months after insertion of Norplant system capsules. The symptoms worsened over the course of a year. Following removal of Norplant, the symptoms of depression and anxiety resolved within 1 month. CONCLUSIONS The progesterone content of oral contraceptives has been linked to major depression and panic disorder. Since Norplant is a progestin-only preparation, it is likely that some women will develop these disorders. These cases illustrate the importance of careful follow-up for adolescents and adults who select Norplant for contraception. Patients should be informed about the possible occurrence of psychiatric disorders. When evaluating new onset of depression and panic disorder in adolescent and adult women, it is important to inquire about Norplant insertion.