Original ArticlesClinical outcomes after clozapine discontinuation in responders versus nonresponders: a retrospective chart reviewWatanabe, Maikoa; Misawa, Fuminaria; Miura, Gentarob; Fujii, Yasuoa; Takeuchi, Hiroyoshia,,cAuthor Information aYamanashi Prefectural Kita Hospital, Yamanashi bOizumi Hospital cDepartment of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan Received 4 November 2020 Accepted 16 March 2021 Correspondence to Hiroyoshi Takeuchi, MD, PhD, Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan, Tel: +81 3 3353 1211 x 62454; fax: +81 3 5379 0187; e-mail: [email protected] International Clinical Psychopharmacology: July 2021 - Volume 36 - Issue 4 - p 188-192 doi: 10.1097/YIC.0000000000000361 Buy Metrics Abstract No studies have compared clinical outcomes after discontinuation of clozapine between patients who responded to clozapine and those who did not. Therefore, we examined 1-year clinical outcomes after clozapine discontinuation in responders and nonresponders. We reviewed data on patients who discontinued clozapine and retrospectively followed them for 1 year. Clinical information was collected from medical records starting at the initiation of clozapine administration, at discontinuation and at 1 year after discontinuation. In addition, clinical status was assessed using the Clinical Global Impression – Severity (CGI-S) and Clinical Global Impression – Improvement (CGI-I) scales. We classified the patients into clozapine responder and nonresponder groups according to the CGI-I score. Thirty-nine patients were enrolled in this study. Olanzapine was the most common antipsychotic prescribed after clozapine discontinuation in both the responder and nonresponder groups. The mean CGI-S score significantly increased 1 year after clozapine discontinuation in the responder group and significantly decreased in the nonresponder group; there was a significant difference in changes in the CGI-S scores between the groups. The difference remained significant after controlling for clozapine dose and duration of treatment. The findings suggest that clinicians may consider continuing and discontinuing clozapine treatment for patients who responded to clozapine and those who did not, respectively. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.