Summary

We report the case of a 19-year-old male student with a Kleine-Levin syndrome who was referred to our sleep laboratory during an episode of hypersomnia, hypersexuality, cognitive impairment and bizarre behaviour. Owing to similar clinical symptoms, he had been misdiagnosed with schizophrenia. This had led to a placement in a facility for persons with chronic schizophrenia, antipsychotic pharmacotherapy for 4 years and side effects, including substantial weight gain and hypertension. After cessation of the antipsychotic medication, the weight and blood pressure normalised. We started a prophylactic treatment with lithium under which the patient had become asymptomatic and had been able to begin a vocational training since treatment.