Subtypes of Personality and 'Locus of Control' in Bariatric Patients and their Effect on Weight Loss, Eating Disorder and Depressive Symptoms, and Quality of Life.

The present study subdivided personality types in a bariatric sample and investigated their impact on weight loss and psychopathology 6 and 12 months after surgery. One hundred thirty participants answered questionnaires on personality (NEO-FFI), 'locus of control' (IPC), depression severity (BDI-II), eating disorder psychopathology (EDE-Q), and health-related quality of life (HRQoL; SF-12). K-means cluster analyses were used to identify subtypes. Two subtypes emerged: an 'emotionally dysregulated/undercontrolled' cluster defined by high neuroticism and external orientation and a 'resilient/high functioning' cluster with the reverse pattern. Prior to surgery, the first subtype reported more eating disorder and depressive symptoms and less HRQoL. Differences persisted regarding depression and mental HRQoL until 12 months after surgery, except in the areas weight loss and eating disorders. Personality seems to influence the improvement or maintenance of psychiatric symptoms after bariatric surgery. Future research could elucidate whether adapted treatment programmes could have an influence on the improvement of procedure outcomes. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.