Symptoms of depression are more frequent in non-surgical patients with left lateralization of Temporal Lobe Epilepsy: A systematic review

Objective: Considering that the side of epileptogenic focus is a factor that could contribute to depressive and anxiety symptoms, we propose a systematic review searching for the prevalence of depression in TLE in non-surgical patients. Methods: We performed a literature search in PubMed/Medline, Web of Science and PsycNET for data from inception until January 2019. Results: After screening titles and abstracts, only 32 articles met the inclusion criteria. DSM/SCID is the main method utilized to psychiatric diagnosis. The majority of the studies did not perform neuropsychological evaluation. From 24 studies, most clinic cases of lateralization of epileptic focus depression symptoms showed lateralization in the left hemisphere. Nine studies were evaluated for individual depressive diagnosis, therefore, the analyzed data does not present statistical significance between right and left hemispheres. Significance: This study shows mood disorders are prevalent in epileptic patients undergoing clinical treatment. However, to date there is no correlation between lateralization of epilepsy and the prevalence of mood disorders or cognitive impairment. Well-conducted studies are needed to establish the correlation between the epilepsy lateralization and mood disorders.