Objectives/aims The objective of this paper is to present a case report of a patient with what we believe to be topiramate-induced psychosis. We also aim to persuade the reader to consider such a diagnosis in the differential of patients like ours. We present a comprehensive literature review of other similar cases, as well as a possible mechanism by which topiramate causes psychosis.

Methods We reviewed the patient‘s chart in our electronic medical record and we conducted review of current case reports documenting associations between antiepileptic medications and psychosis. We used the PubMed database, using search terms ‘psychotic disorders,’ ‘hallucinations,’ ‘delusions,’ ‘psychosis’ in conjunction with ‘topiramate,’ ‘Topamax,’ ‘anti-seizure medication,’ ‘anti-epileptic medication.’

Results We present the case of a 66 year old woman admitted to the psychiatric inpatient unit for management of severe, recent onset psychotic delusions and hallucinations. Prior to this psychotic episode, she had no known psychiatric history and had functioned independently at home. The patient was recently transitioned to topiramate 100 mg BID for migraines and seizures, the latter of which had started after traumatic subdural hematoma 9 years prior. The patient had an extensive medical work-up on the inpatient psychiatry unit, including head imaging, EEG, and lab tests, all of which were non-contributory. She was started on risperidone and showed little improvement. At the recommendation of neurology, topiramate was discontinued in favor of an alternative antiepileptic. With discontinuation of topiramate, the patient had almost complete resolution of psychotic symptoms. She was discharged home.

Conclusion Topiramate-induced psychosis should be considered in patients being treated with topiramate who present with psychosis. Special consideration of this diagnosis should be made in patients like ours, in whom older age of onset makes primary psychotic illness less likely. Continued study in this area will be necessary to definitely establish a causal relationship and identify the mechanism of this phenomenon.