Electroencephalographic (EEG) abnormalities are associated with schizophrenia spectrum disorders. Clozapine is an effective medication for individuals with treatment resistant schizophrenia (TRS) with an approximately 30 percent effective rate of improving psychotic symptoms. Psychotropic medications, including clozapine, have been shown to alter neural oscillations. Currently, there are no reliable biomarkers to predict clozapine response. Here, we aim to investigate why some individuals may be more responsive to clozapine treatment and quantify activity related to neural oscillations in hopes of identifying a possible biomarker.
The Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist was used. Two reviewers were used to discuss primary research articles for inclusion and exclusion criteria. Primary research articles were further evaluated using the Joanna Briggs Institute Critical Appraisal Checklist for Quasi-Experimental Studies (non-randomized experimental studies).
A total of seven studies investigating the effects of clozapine on neural oscillations met inclusion criteria. Five studies were identified in our search that reported on power. Two studies reported on coherence measures. Lastly, one study reported on current source density measures employing Low Resolution Electromagnetic Tomography (LORETA).
This review suggests that while clozapine has effects on all neural oscillations, slower oscillations (delta and theta) appear to be consistently increased in power after clozapine administration followed by a typical decrease in faster oscillations such as alpha and beta. Further research is warranted to determine if neural oscillations may be a reliable biomarker for clozapine response.
Live Zoom Session – March 9th
Nicolas Raymond BA, Paulo Lizanoa MD, Phd , Sinead Kellya Phd, Rachal Hegde MA, Brett A. Clementz Phd, Carol A. Tamminga MD, Sarah Keedy Phd, Godfrey D. Pearlson MD, Elliot S. Gershon MD, Matcheri Keshavan, MD
Matcheri Keshavan, MD