Attention-Deficit Hyperactivity Disorder and Obesity - A National Study of 1.1 Million Israeli Adolescents.

Purpose The incidences of obesity and attention-deficit/hyperactivity disorder (ADHD) have increased in parallel over recent decades. We assessed the association between obesity and ADHD in a national sample of adolescents. Method In a nationwide population-based study of 1,118,315 adolescents (57% males; mean age 17 years), risks of obesity were compared between individuals with severe and mild ADHD, and those without ADHD. Diagnoses of ADHD were confirmed by specialists in either neurology or psychiatry. Adolescents requiring regular and continuous treatment with stimulants with no improvement of symptoms under treatment were classified as having severe ADHD; data were available from 2004 to 2019. During 2015-2019, the diagnosis of ADHD was defined and 65,118 (16.76%) of 388,543 adolescents with mild symptoms who required medications only for learning or who used stimulants irregularly were defined as having mild ADHD. Results The prevalence of severe ADHD was 0.3% and of mild ADHD 20.1%. Obesity was more prevalent among adolescents with severe ADHD than among those without ADHD (13.5% vs. 7.5%). In the mild ADHD group 12.6% of males and 8.4% of females were diagnosed with obesity compared to 9.7% and 6.4%, respectively, in the non-ADHD group. The adjusted odds of severe ADHD for males and females with obesity were 1.77(1.56-2.02) and 2.09 (1.63-2.66) times the odds for low-normal BMI males and females, respectively, and 1.42 (1.37-1.48) and 1.42 (1.34-1.50) for males and females with mild ADHD. The elevated risk persisted in several sensitivity analyses. Conclusions Both adolescents with severe and mild ADHD are at increased risk for obesity.