Happiness and Attention Deficit/Hyperactivity Disorder Symptoms as Mediated by Subjective Health Conditions: A Nationwide Cross‐Sectional Internet Survey

Objectives There has been limited examination of happiness among individuals with attention‐deficit/hyperactivity disorder (ADHD), despite growing interest in psychiatric comorbidities associated with this disorder. This study aims to fill this gap by exploring the relationship between ADHD symptoms and happiness on the basis of data from the Japan Society and New Tobacco Internet Survey (JASTIS). Method A nationwide, cross‐sectional internet survey was conducted in Japan between January and February 2024. The analytic sample comprised 29 268 individuals aged 16 years and above in Japan. Based on questionnaire responses of the 6‐item short version of the Japanese version of the Adult ADHD Self‐Report Scale (ASRS‐J‐6), the respondents were classified as possible ADHD or not. Information on happiness was collected via a single (10‐point Likert scale) measure. Results Multivariable ordinal logistic regression analysis and a mediation analysis were performed to examine associations. Possible ADHD was associated with increased odds of feeling less happy. Very high somatic symptoms (41.1% mediation), confusion/difficulty to concentrate (37.2%), and depression (14.8%) were important mediators of the association between ADHD and happiness. Conclusions Although the majority of individuals with possible ADHD were classified as having moderate happiness, more than one in four were classified as having low happiness. To increase the happiness of individuals with ADHD, screening and treating for both physical and psychiatric symptoms might be important.