PurposeSubjects with obesity, especially those seeking bariatric surgery, exhibit high rates of mental disorders and marked psychopathological traits. The primary objective of this prospective, non-interventional study was to investigate whether the presence of different psychiatric disorders, attention deficit/hyperactivity disorder (ADHD) symptomatology and emotional dysregulation influenced weight loss at 1-year follow-up after surgery.MethodsSubjects consecutively referred for pre-surgical evaluation at the Obesity Center of Pisa University Hospital were recruited. Psychiatric diagnoses were made through the Mini-International Neuropsychiatric Interview (MINI) and ADHD symptomatology was assessed with the Wender–Reimherr Adult Attention Deficit Disorder Scale (WRAADDS). Emotional dysregulation was investigated through the WRAADDS and self-report questionnaires. After surgery, weight and obesity-related comorbidities were monitored during follow-up.ResultsOf the 99 participants recruited, 76 underwent surgery and 65 could be reevaluated 1 year after surgery. Subjects with insufficient weight loss (excess body mass index loss ≤ 53%,n= 15) had more frequent lifetime binge eating disorder (BED) and BED-mood disorders comorbidity than subjects with favorable post-surgical outcome. Additionally, they scored higher on both physician-administered and self-report scales assessing emotional dysregulation, which represents a nuclear symptom of ADHD in adults. At the logistic regression analysis, older age, higher preoperative excess body mass index and greater affective instability were predictors of reduced weight loss at 1-year follow-up.ConclusionEmotional dysregulation seems to be associated with a worse outcome after bariatric surgery. Further studies with larger samples and longer follow-up are needed to confirm the influence of different psychiatric disorders and psychopathological traits on post-surgical outcome.Level of evidenceV, prospective descriptive study.