# Successful Challenge With Brexpiprazole for Idiopathic Hypersomnia in a Patient With Bipolar Disorder: A Case Report

## TL;DR

A patient with bipolar disorder and idiopathic hypersomnia improved with brexpiprazole after methylphenidate caused psychosis.

## Contribution

Shows brexpiprazole's potential to treat both manic symptoms and idiopathic hypersomnia.

## Key findings

- Methylphenidate caused psychosis in a manic patient with hypersomnia.
- Brexpiprazole improved both manic symptoms and hypersomnolence.
- Idiopathic hypersomnia was confirmed after methylphenidate was stopped.

## Abstract

We describe a 32-year-old Japanese female with hypersomnia and bipolar disorder. She had developed hypersomnia and sleep attacks in her teens. She was misdiagnosed with narcolepsy at a neurology department and then received methylphenidate (MPH) for many years. After giving birth, she developed postpartum depression and suffered from mood swings and irritability. Following 10-year treatment with methylphenidate, she experienced MPH-induced psychosis when she was in a manic state. Her psychosis improved rapidly with the cessation of methylphenidate. Furthermore, brexpiprazole treatment ameliorated her manic symptoms and hypersomnolence. Post-discharge, she was diagnosed with idiopathic hypersomnia based on nocturnal polysomnography and a multiple sleep latency test. This case indicates that brexpiprazole as a serotonin dopamine activity modulator might provide therapeutic effects against not only the patient's manic symptoms but also idiopathic hypersomnia.