Schizophrenia is a chronic
psychiatric disorder that may lead to
epilepsy. However, there are limited findings on the issues. This narrative review aimed to provide a practical perspective on
epilepsy in patients with
schizophrenia using the current treatment systems for
epilepsy. While there has been a debate on the relationship between
epilepsy and
schizophrenia, i.e., antagonism, affinity, and coincidence, recent large cohort studies have revealed a high frequency of
epilepsy in patients with
schizophrenia (4-5 times higher than that of general population). The high incidence observed is likely to be due to the bidirectionality between
epilepsy and
schizophrenia and additional
schizophrenia-related conditions, e.g.,
antipsychotic drugs (APD),
substance abuse, and
head injury. As for symptomatology of
epilepsy, only one small-size study showed that
seizures of patients with
schizophrenia are equivalent to those of patients without
schizophrenia. Patients with
schizophrenia exhibit the first seizure in their twenties or later, which are mostly
focal seizures. Most of
seizures in patients with
schizophrenia can be controlled with conventional
antiepileptic drugs. Few patients with
schizophrenia develop treatment-resistant
epilepsy. However, since drug interactions can be more complicated due to multiple conditions, such as pre-existing
polypharmacy, heavy smoking, irregular eating, and comorbid metabolic disorders, cautious monitoring for clinical symptoms is required. To improve seizure control and adherence, non-pharmacological approaches are also recommended. Thus far, for seizure treatments in patients with
schizophrenia, we have to use many empirical findings or substitute certain findings from population without
schizophrenia because evidence is insufficient. The accumulation of clinical findings may contribute to the development of efficient treatment systems.