Effects of testosterone therapy on bipolar disorder with Klinefelter syndrome.

Klinefelter syndrome (KS) is widely associated with cognitive impairment and language problems. KS patients may also exhibit psychiatric symptoms. We present the case of an 18-year-old man with KS who experienced rapidly repeating relapses of manic episodes. He was unresponsive to the usual pharmacotherapies for bipolar disorders such as mood stabilizers and second-generation antipsychotics. Mood was eventually improved with testosterone therapy in addition to pharmacotherapy, with no relapse of manic episodes for 3 years after discharge. Testosterone therapy may prevent relapsing manic episodes of bipolar disorder in patients with KS.