Summary

A 26-year-old Japanese man was admitted to our unit with exacerbated paranoid schizophrenia. Prior to his admission, daily administration of olanzapine had been sufficient to maintain a partial remission of his schizophrenia, but due to an exacerbation of his delusions, he had then also been prescribed aripiprazole, which had been followed by no improvement in symptoms and a gradual further exacerbation of auditory delusions. Physical examinations, brain MRI and neurophysiological assessment were unremarkable. Blood analysis, however, revealed extremely low thyroid-stimulating hormone (TSH) and prolactin-releasing hormone (PRL) concentration. Interestingly, after aripiprazole discontinuation, he returned to partial remission with an increase in plasma TSH and PRL concentration.