Psychotic depressive subtype and white mater hyperintensities do not predict cognitive side effects in ECT A systematic review of pretreatment predictors

Background: Most studies regarding cognitive side-effects following ECT for treating depression report transient forms of cognitive disturbances. However, a growing number of studies also report considerable differences among individual patients. Objective: The aim of this systematic review was to identify pretreatment patient characteristics for predicting the risk of developing cognitive side-effects following ECT. Methods: Online databases PubMed/Medline, Embase, and PsycINFO were searched for articles published from 2002 through May 2019, using the following relevant search terms: #cognitive deficits AND #Electro Convulsive Therapy. Inclusion and exclusion criteria were applied for full-text inclusion. PRISMA guidelines were used. Results: Our initial search yielded 2155 publications; 16 studies were included. A total of 16 possible predictive factors were identified. Two factors, psychotic features and white matter hyperintensities, were conclusively found to not predict cognitive side-effects following ECT; the remaining 14 factors were inconclusive. Conclusions: There is robust evidence that psychotic features and white matter hyperintensities are not predictive of cognitive side-effects following ECT. None of the other 14 factors examined were predictive, however these levels of evidence were weak and therefore inconclusive. Additional studies focusing primarily on pretreatment patient characteristics for predicting cognitive side-effects following ECT are needed, including demographic, clinical, physiological, neurobiological, and genetic factors. Finally, we provide suggestions for future research.