The Impact of Comorbid Mental Health Disorders on Complications Following Adult Spinal Deformity Surgery With Minimum 2-Year Surveillance Bassel G. Diebo, MD,  Joshua D. Lavian, BS,  Daniel P. Murray, BA,  Shian Liu, MD, y Neil V. Shah, MD, MS,  George A. Beyer, MS,  Frank A. Segreto, BS,  Lee Bloom, MD,  Dennis Vasquez-Montes, MS, z Louis M. Day, MD,  Douglas A. Hollern, MD,  Samantha R. Horn, BA, z Qais Naziri, MD, MBA,  Daniel Cukor, PhD, § Peter G. Passias, MD, z and Carl B. Paulino, MD  Study Design. Retrospective analysis. Objective. To compare long-term outcomes between patients with and without mental health comorbidities who are undergo- ing surgery for adult spinal deformity (ASD). Summary of Background Data. Recent literature reveals that one in three patients admitted for surgical treatment for ASD has comorbid mental health disorder. Currently, impacts of baseline mental health status on long-term outcomes following ASD surgery have not been thoroughly investigated. Methods. Patients admitted from 2009 to 2013 with diagnoses of ASD who underwent more than or equal to 4-level thoraco- lumbar fusion with minimum 2-year follow-up were retrospec- tively reviewed using New York State’s Statewide Planning and Research Cooperative System (SPARCS). Patients were stratified by fusion length (short: 4–8-level; long: 9 level). Patients with comorbid mental health disorder (MHD) at time of admission were selected for analysis (MHD) and compared against those without MHD (no-MHD). Univariate analysis compared demo- graphics, complications, readmissions, and revisions between cohorts for each fusion length. Multivariate binary logistic regression models identified independent predictors of outcomes (covariates: fusion length, age, female sex, and Deyo score). Results. Six thousand twenty patients (MHD: n ¼ 1631; no- MHD: n ¼ 4389) met inclusion criteria. Mental health diagnoses included disorders of depression (59.0%), sleep (28.0%), anxiety (24.0%), and stress (2.3%). At 2-year follow-up, MHD patients with short fusion had significantly higher complication rates (P ¼ 0.001). MHD patients with short or long fusion also had significantly higher rates of any readmission and revision (all P  0.002). Regression modeling revealed that comorbid MHD was a significant predictor of any complication (odds ratio [OR]: 1.17, P ¼ 0.01) and readmission (OR: 1.32, P < 0.001). MHD was the strongest predictor of any revision (OR: 1.56, P < 0.001). Long fusion most strongly predicted any complica- tion (OR: 1.87, P < 0.001). Conclusion. ASD patients with comorbid depressive, sleep, anxiety, and stress disorders were more likely to experience surgical complications and revision at minimum of 2 years following spinal fusion surgery. Proper patient counseling and psychological screening/support is recommended to complement ASD treatment. Key words: adult spinal deformity, comorbidity, mental health disorder, patient outcomes, postoperative complications, preoperative risk stratification, spinal surgery. Level of Evidence: 3 Spine 2018;43:1176–1183 A dult spinal deformity (ASD) represents a complex spectrum of spinal diseases, including adult degen- erative scoliosis, sagittal and coronal malalignment, and iatrogenic deformity (with or without associated spinal stenosis). 1 Spinal malalignment and prevalence of ASD increases with age, and the growing geriatric population From the  Department of Orthopaedic Surgery, State University of New York Downstate Medical Center, Brooklyn, New York; y Headquarters Battalion, 1st Marine Division, Camp Pendleton, California; z Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, NYU Langone Medical Center, New York, New York; and § Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, New York. Acknowledgment date: July 13, 2017. First revision date: October 30, 2017. Acceptance date: January 10, 2018. The manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. Relevant financial activities outside the submitted work: board membership, grants, payment for lecture. Address correspondence and reprint requests to Bassel G. Diebo, MD, Orthopaedic Surgery Resident, 450 Clarkson Ave., Box #30, Brooklyn, NY 11203; E-mail: dr.basseldiebo@gmail.com DOI: 10.1097/BRS.0000000000002583 1176 www.spinejournal.com September 2018 SPINE Volume 43, Number 17, pp 1176–1183 ß 2018 Wolters Kluwer Health, Inc. All rights reserved. DEFORMITY Copyright © 2018 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.