The Prevalence of Somatic Diseases in Swedish Adolescents with and without Attention-Deficit/Hyperactivity Disorder: A Cross-Sectional Study

Abstract Background Attention-deficit/hyperactivity disorder (ADHD) often exists alongside psychiatric comorbidities, but the prevalence of somatic diseases in adolescents with ADHD remains understudied. Method This study aimed to examine the prevalence rates of specific somatic diseases in adolescents with ADHD and compare them to those in adolescents without any psychiatric conditions. A cross-sectional study was conducted among Swedish upper secondary high school students aged 15–19 years. Data were collected using an electronic version of the “Mental and Somatic Health without borders” survey. In 2020, 1608 Swedish adolescents completed the survey, thereby providing information on their psychiatric and somatic diagnoses. Results Among the sample of Swedish adolescents, 5.5% reported ADHD diagnoses. The most common somatic diseases in the group with ADHD were allergy (43.4%), asthma (24.7%), and skin diseases (16.7%). Statistically significant differences in the prevalence of these diseases were found between the ADHD group and the comparison group, but the effect sizes of these differences were negligible (allergy p = 0.002, Cramer’s V = 0.08; asthma p = 0.041, Cramer’s V = 0.06; skin diseases p = 0.007, Cramer’s V = 0.08). Compared to adolescents without any diagnosed psychiatric conditions, those with ADHD reported significantly higher rates of uncertainty regarding the existence of asthma, diabetes, and rheumatoid and thyroid diseases. Conclusions Adolescents with ADHD reportedly experienced more somatic diseases and more uncertainty about whether they had such diseases than those without ADHD. Further research is needed to explore the underlying physiological mechanisms of ADHD and somatic comorbidities. The growing body of evidence regarding somatic difficulties in children and adolescents with ADHD prompts us to contemplate the design of treatment guidelines for somatic conditions that are tailored to the unique needs of adolescents with ADHD.