Background: While clinical studies have documented sex differences in emotional, behavioral, and cognitive function of children with Attention Deficit and Hyperactive Disorder (ADHD), it is unknown if these sex differences are due to differences in referral and diagnosis or if they can be also seen when we screen a community sample for ADHD. If these sex differences exist in populations with a diagnosis history but cannot be seen in screening, then they are unfair, preventable, and due to gender (social processes in referral and diagnosis) rather than sex.
Aim: Using the data from a community sample of 9-10-year-old healthy developing children, we explored sex differences in the associations between cognitive, emotional, behavioral, and health status with positive screening vs. history of diagnosed ADHD.
Methods: The Adolescent Brain Cognitive Development (ABCD) study included a national sample of 10,171 American children between ages 9 and 10 years old. This sample included 1,488 children with a history of psychiatric diagnosis and 8,683 children without a diagnosis. The two independent variables were screening and history of ADHD. The following variables were outcomes: symptom severity, cognitive function, body mass index (BMI), internalizing, externalizing, and total behavioral disorders. Sex was the moderator, and age, race, ethnicity, education, household income, and family structure were covariates. Mixed-effects regression models were used to adjust for the nested nature of the data.
Results: Positive screening for ADHD and a history of diagnosis were both associated with worse cognitive function, higher internalizing, externalizing, total problem behaviors, higher inattention (ADHD symptoms), and lower BMI. Sex altered the association between history of diagnosis but not positive screening for ADHD with externalizing, and total behavioral problems as well as cognitive function. Sex did not affect the associations between positive screening for ADHD or a history of diagnosis with BMI or ADHD symptoms. Both history of diagnosis and positive screening for ADHD were associated with higher internalizing for boys than girls.
Conclusion: History of diagnosis, but not positive screening for ADHD, is differently associated with behavioral and cognitive performance of males and females. As sex differences are seen in correlates of history of diagnosis but not positive screening, some of the observed sex differences are due to differential referral and diagnosis rather than differential presentation of ADHD in the community. This finding suggests that some of the so-called "sex differences" that are believed to be due to biology and heritable may be "gender differences" and modifiable. This is important because while gender differences are preventable and modifiable, sex differences are not.