Prevalence of attention deficit/hyperactivity disorder among adults in obesity treatment

BACKGROUND Bariatric patients showing poor "focus" during treatment more often failed to lose weight or maintain reduced weight. Evaluation of these patients identified a number having attention deficit/hyperactivity disorder (ADHD), evidently a potent factor limiting successful weight control. After searches found no published reports describing comorbid ADHD and obesity, this report was conceived to begin exploring the prevalence and characteristics of these patients. METHOD Clinical records of 215 patients receiving obesity treatment during 2000 were reviewed. Data collected and analyzed included age, sex, beginning and ending body mass index (BMI), number of clinic visits, months of treatment, and diagnostic category (ADHD, some ADHD symptoms, non-ADHD). DSM-IV criteria were used, except age of onset was modified to <= 12 years. RESULTS Whole sample ADHD prevalence was 27.4% (CI:21.1,32.9), but 42.6% (CI: 36.3% to 48.9%) for BMI >= 40. Mean weight loss among obese patients with ADHD (OB+ADHD) was 2.6 BMI (kg/m2) vs. 4.0 for non-ADHD (NAD) (p < 0.002). For BMI >= 40, OB+ADHD had BMI loss 2.9 vs. 7.0 (NAD) (p < 0.004). OB+ADHD had more clinic visits, with a trend toward longer treatment duration. CONCLUSIONS ADHD was highly prevalent among obese patients and highest in those with extreme obesity. Comorbid obesity and ADHD symptoms rendered treatment less successful compared to NAD counterparts. Reasons for the comorbidity are unknown, but may involve brain dopamine or insulin receptor activity. If replicated in further studies, these findings have important implications for treatment of severe and extreme obesity.