Original ArticlesComorbid personality disorders in manic bipolar I disorder patients is associated with increased use of long-acting injectable antipsychotic treatment and higher rates of rehospitalizationGoren, Yarona,,b; Krivoy, Amira,,b,,c,,d; Gur, Shaya,,b; Valevski, Avia,,b; Weizman, Abrahama,,b,,c; Hochman, Eldara,,b,,cAuthor Information aSackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel bGeha Mental Health Center, Petach-Tikva, Israel cLaboratory of Biological Psychiatry, Felsenstein Medical Research Center, Petach-Tikva, Israel dDepartment of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK Received 31 July 2019 Accepted 2 October 2019 Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's website, www.intclinpsychopharm.com. Correspondence to Yaron Goren, MD, Geha Mental Health Center, P.O. Box 102, Petach Tikva 4910002, Israel, Tel: +972 3 9258310; fax: +972 3 9258388; e-mail: email@example.com. International Clinical Psychopharmacology: March 2020 - Volume 35 - Issue 2 - p 74-80 doi: 10.1097/YIC.0000000000000294 Buy SDC Metrics Abstract Personality disorder comorbidity is considered a poor prognostic factor among bipolar disorder patients. However, an evidence-based pharmacological treatment for this sub-population is lacking, and only few studies investigated the impact of personality disorder on bipolar disorder-I course. Here, we studied the effect of comorbid personality disorder on the administrated psychopharmacotherapy and rehospitalization risk among manic bipolar disorder-I patients. A sample of 340 patients with bipolar disorder-I, who were hospitalized with acute manic episode between 2005 and 2013, were retrospectively followed for a mean duration of 1129 days. Drug treatment at discharge and rehospitalization rates during follow-up time were compared between bipolar disorder-I patients with (n = 55) or without (n = 285) personality disorder comorbidity. Multivariate survival analyses adjusted for covariates were conducted. During the study period, 39.4% of bipolar disorder-I patients were rehospitalized due to a mood episode. Comorbid personality disorder was significantly associated with higher rates of long-acting injectable antipsychotics administration at discharge from hospitalization (adjusted odds ratio 2.66, 95% confidence interval: 1.19–5.94, P = 0.017). Comorbid personality disorder significantly increased the adjusted risk of rehospitalization due to a mood episode (hazard ratio = 2.04, 95% confidence interval: 1.29–3.23, P = 0.002). In conclusion, comorbid personality disorder in manic bipolar disorder-I patients is associated with increased use of long-acting injectable antipsychotics and higher rates of rehospitalization. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.