Impact of Depression and Bipolar Disorders on Functional and Quality of Life Outcomes in Patients Undergoing Surgery for Degenerative Cervical Myelopathy: Analysis of a Combined Prospective Dataset

STUDY DESIGN.Analysis of a combined prospective dataset. OBJECTIVE.To compare clinical outcomes in patients with and without preexisting depression or bipolar disorder undergoing surgery for degenerative cervical myelopathy (DCM). SUMMARY OF BACKGROUND DATA.Psychiatric co-morbidities, including depression, have been associated with worse clinical outcomes following lumbar spine surgery; however, it is unclear whether these psychiatric disorders are also predictive of outcomes in patients undergoing surgery for the treatment of DCM. METHODS.Four hundred and one patients with symptomatic DCM were enrolled in the prospective AOSpine International or North America study at twelve North American sites. Patients were evaluated preoperatively and at 6-, 12- and 24-months using the modified Japanese Orthopedic Association scale (mJOA), Nurick score, Neck Disability Index (NDI), and Short- Form 36v2 (SF-36) Health Survey. A mixed model analytic approach was used to evaluate differences in outcomes at 24-months between patients with and without psychiatric disorders, while controlling for relevant baseline characteristics and surgical factors. RESULTS.Ninety-seven patients (24.19%) were diagnosed with preexisting depression or bipolar disorder. There were more females (65.98%) with these psychiatric disorders than males (34.02%) (p