ADHD News & Research

Study: Comorbid Conditions More Prevalent in Women with ADHD

Women and girls diagnosed with ADHD are more likely than their male counterparts to also have one or more comorbid conditions including autism spectrum disorder, schizophrenia, and suicidal behavior, according to a new study of ADD gender differences.

April 19, 2019

Individuals with attention deficit disorder (ADHD or ADD) are more likely than people without the disorder to have one or more comorbid conditions as well; at least 60% of patients with ADHD have another diagnosis. However, a new study published in the Journal of the American Academy of Child and Adolescent Psychiatry1 finds that women with ADHD are at an even greater risk for several specific comorbid disorders including autism spectrum disorder, oppositional defiant disorder (ODD), intellectual disability, personality disorders, schizophrenia, substance use disorders (SUD), and suicidal behavior.

Researchers from Denmark’s Aarhus University investigating ADHD gender differences studied 1,665,729 children born in Denmark to Danish-born parents from 1918 through 2013. Variables selected as covariates included birth characteristics, socioeconomic status, familial psychiatry history, and diagnosis of ADHD and comorbid disorders.

The 12 comorbid disorders assessed along with ADHD were anxiety, autism spectrum disorder (ASD), bipolar disorder, depression, eating disorder, intellectual disability, ODD, conduct disorder, personality disorder, SUD, suicidal behavior, tic disorder, and schizophrenia spectrum disorders. Risks for the disorders for males and females were calculated using incidence rates and adjusted hazard ratios with 95% confidence indexes (the range of the CI indicates how precise, or confident, the data is).

While all individuals with ADHD had significant absolute and relative risk for all 12 of the comorbid disorders, the increased risk for female individuals suggests they are a more vulnerable population. This vulnerability is heightened by the fact that, since more boys than girls are diagnosed with ADHD, fewer clinical studies include large samples of females with ADHD.


Cæcilie Ottosen et al. Sex Differences in Comorbidity Patterns of Attention-Deficit/Hyperactivity Disorder. Journal of the American Academy of Child & Adolescent Psychiatry. Vol. 58, 4. (Apr. 2019)