The relationship between epilepsy and psychiatric illness are well documented, as epilepsy patients have a high prevalence of psychiatric disorders, including psychosis. This linkage may be reflected in various ways, as shared pathophisiological mechanisms, genetic, psychosocial and iatrogenic factors.

The authors report a case study in which they describe a young adult with an epilepsy resistant to treatment that developed a psychosis episode, questioning the possible underlying causes and mechanisms. A review of literature concerning the comorbidity between epilepsy and psychosis is taken.

A case report is presented in sequential detail and a literature review of the theme is shortly surveyed.

The case report is about a 31 years old young man who have been referred to psychiatric yard with initial delusions of reference that later evolved to grandiose and religious delusions with the changing in the antiepileptic treatment. He also presented aggressiveness and impairment in his daily activities and functioning, worsening his epileptic clinical picture. The literature points out the role of generalized epilepsy, intellectual function and family history as factors that may contribute to development of psychosis in epileptic patients, particularly in the case of the temporal lobe epilepsy.

The treatment in epilepsy goes far beyond seizures control, once the psychiatric comorbidity may appear any time during the evolution and create great clinical impact. Clinicians should be aware of psychiatric symptoms in order to optimize care and treatment.