ADHD News & Research

Study Shows Gender Disparities in ADHD Symptoms of Hyperactivity and Poor Response Inhibition

Girls with ADHD are less physically hyperactive than are boys with the condition, and experience fewer problems with inhibition and cognitive flexibility, according to a new meta-analysis that says more accurate screening tools are needed to recognize the subtler manifestations of ADHD in girls.

June 26, 2020

Attention deficit hyperactivity disorder (ADHD) manifests differently in girls and boys, with two key gender differences: Girls with ADHD are less physically hyperactive than are boys with the condition, and they have fewer motor response inhibition problems. This is the finding of a new meta-analysis published in the Journal of Attention Disorders1, which notably found no significant differences between the genders in terms of working memory or attention. This latter finding is significant because the study also revealed that teachers rate boys as more inattentive and hyperactive-impulsive than girls.

The new meta-analysis, conducted by researchers at the Université du Québec à Montréal, sought to better understand sex differences in primary ADHD symptoms, specifically cognitive flexibility, working memory, and planning among children and adolescents. It reviewed studies published from 1997 to 2017 comparing boys and girls ages 3 to 17 with a valid ADHD diagnosis.

Gender differences in ADHD symptoms and executive and attentional functioning were found using Hedges’ g as an estimator. Effect size was calculated for each individual study using the reported data, and a combined effect size was determined for all the variables using the random-effect model. The findings were as follows:

  • Boys with ADHD were more hyperactive than girls with ADHD
  • Boys with ADHD demonstrated greater deficits in motor response inhibition than did girls with ADHD
  • Though teachers reported more inattention and hyperactive–impulsive behaviors among boys, no significant gender difference was found in the former
  • Girls with ADHD manifested fewer motor response inhibition difficulties than did boys with ADHD, however they experienced similar inattentive and interference control problems
  • Boys with ADHD had more cognitive flexibility problems than did girls, potentially due to later brain development

“The authors demonstrated that the presence of oppositional behaviors increased the ADHD symptoms reported by teachers, but only for boys,” the report reads. “Thus, this tendency might potentially contribute to the sex difference observed, as boys with ADHD are more likely to manifest externalizing behaviors than girls with ADHD are. Teachers might also underestimate symptoms in girls, given that, compared with boys, their symptoms are less disruptive. Indeed, the demands of the school setting might underscore the more disruptive behaviors of boys, such as agitation or opposition, which are known to interfere with classroom management and student learning.”

According to the study, this helps to explain why 5.9% of boys but only 3.04% of girls are diagnosed with ADHD before reaching 18 years old. Researchers also cite the fact that, to date, ADHD has been primarily studied in boys and that most of the hyperactivity-impulsivity criteria in the DSM-5 focus on behaviors more commonly manifested and easily observable in boys. More accurate, gender-specific screening tools are necessary to adequately recognize and treat ADHD in girls.

“These results are important in that, on one hand, they underscore the fact that girls have symptoms that are more subtle and, consequently, less disruptive, which may undermine their chances of being referred clinically,” the report concludes. “These results thus support the idea to the effect that current diagnostic criteria are ill-adapted to properly screen girls with ADHD.”

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1Loyer Carbonneau, M., Demers, M., Bigras, M., & Guay, M.-C. (2020). Meta-Analysis of Sex Differences in ADHD Symptoms and Associated Cognitive Deficits. Journal of Attention Disorders