What are the similarities and differences between schizophrenia and schizophrenia-like psychosis of epilepsy? A neuropathological approach to the understanding of schizophrenia spectrum and epilepsy.

Temporal lobe epilepsy (TLE) and psychosis coexist more frequently than chance would predict. In this short review, clinical and neuropathological findings of schizophrenia, TLE, and psychosis of epilepsy are described to enhance our understanding of the noncoincidental association between these conditions. In addition, psychosis of epilepsy was included for the first time in the Diagnostic and Statistical Manual of Mental Disorders (DSM), in the recently launched 5th edition, and improvement in diagnostic criteria was highlighted. Since the hippocampus has long been considered an anatomical area involved in the pathophysiology of TLE and schizophrenia, neuropathological studies of psychoses of epilepsy may contribute to our understanding of the pathophysiology of psychosis in general. The discovery of shared mechanisms and/or affected neurochemicals in TLE and schizophrenia might disclose important clues on the vulnerability of patients with TLE to psychotic symptoms and be an opportunity for new treatment development.