Sex differences in adults with attention-deficit/hyperactivity disorder: A population-based study

Abstract

Attention-deficit/hyperactivity disorder; Psychiatric comorbidities; Sex differences

Trastorno por déficit de atención e hiperactividad; Comorbilidades psiquiátricas; Diferencias sexuales

Trastorn per dèficit d'atenció i hiperactivitat; Comorbiditats psiquiàtriques; Diferències sexuals

Background: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that often persists into adulthood, significantly impacting daily functioning and quality of life. Sex differences influence ADHD presentation, with females experiencing delayed diagnosis and distinct patterns of severity and comorbidities. Exploring these differences is essential for improving diagnostic accuracy and developing tailored interventions. This study examines ADHD severity, psychiatric comorbidities, and functional impairment by ADHD subtype and sex. Methods: This population-based study included 900 adults diagnosed with ADHD. ADHD severity, comorbidities, and functional outcomes were assessed using validated tools. Bivariate analyses and General Linear Models (GLMs) were applied to examine sex- and subtype-specific effects and their interactions. Results: Females exhibited greater ADHD severity (p < 0.001), higher levels of depression (p = 0.003) and anxiety (p < 0.001), lower substance use (p < 0.001), poorer functioning (p = 0.039), and greater disability (p = 0.001) than males. No significant sex differences were found in ADHD subtype distribution or age of symptom onset; however, females were diagnosed with ADHD later than males (p < 0.001). The combined ADHD subtype was associated with greater clinical severity, higher levels of depression, anxiety, and impulsive symptoms, increased substance use, and greater disability. A significant interaction between sex and subtype was observed only for disability, with females in the combined subtype exhibiting the most pronounced impairment. Conclusions: ADHD presents differently across sexes and subtypes, with specific interactions influencing disability. These findings emphasize the importance of considering sex and ADHD subtype independently to enhance diagnostic accuracy and develop targeted treatment strategies.

Dr. Amoretti has been supported by the Sara Borrell doctoral program (CD20/00177) and the M-AES mobility fellowship (MV22/00002), from the Instituto de Salud Carlos III (ISCIII), and co-funded by European Social Fund “Investing in your future” and La Marató-TV3 Foundation grants 202234-32. Dr. Amoretti (PI24/00671) and Dr. Torrent (PI20/00344; PI24/00407) thank the support of the Spanish Ministry of Innovation and Science, funded by the Instituto de Salud Carlos III and cofinanced by the European Union (FEDER) “Una manera de hacer Europa.” The funding sources had no role in the design or conduct of the study; the collection, management, analysis, and interpretation of the data; the preparation, review, or approval of the manuscript; or the decision to submit the manuscript for publication.