To the top

Page Manager: Webmaster
Last update: 9/11/2012 3:13 PM

Tell a friend about this page
Print version

Is There a Female Protect… - University of Gothenburg, Sweden Till startsida
To content Read more about how we use cookies on

Is There a Female Protective Effect Against Attention-Deficit/Hyperactivity Disorder? Evidence From Two Representative Twin Samples

Journal article
Authors M. J. Taylor
P. Lichtenstein
H. Larsson
Henrik Anckarsäter
C. U. Greven
A. Ronald
Published in Journal of the American Academy of Child and Adolescent Psychiatry
Volume 55
Issue 6
Pages 504-512
ISSN 0890-8567
Publication year 2016
Published at Centre for Ethics, Law, and Mental Health
Pages 504-512
Language en
Keywords ADHD, sex differences, genetics, twin study, deficit hyperactivity disorder, neurodevelopmental symptoms, telephone, interview, early adolescence, sex-differences, adhd symptoms, rating-scale, birth-weight, autism-tics, a-tac, Psychology, Pediatrics, Psychiatry
Subject categories Medical Genetics


Objective: Attention-deficit/hyperactivity disorder (ADHD) is more frequent in males than in females. The "female protective effect" posits that females undergo greater exposure to etiological factors than males in order to develop ADHD, leading to the prediction that relatives of females with ADHD will display more ADHD behaviors. We thus tested whether cotwins of females displaying extreme ADHD traits would display more ADHD traits than cotwins of males displaying extreme ADHD traits. Method: Parents of approximately 7,000 pairs of nonidentical twins in Sweden, and approximately 4,000 pairs of twins in England and Wales, completed dimensional assessments of ADHD traits. Probands were selected on the basis of scoring within the highest 10% of the distribution in each sample. Dimensional scores of cotwins of probands, as well as the categorical recurrence rate, were investigated by proband sex. Results: Cotwins of female probands displayed higher mean ADHD trait scores (mean = 0.62-0.79) than cotwins of male probands (mean = 0.38-0.55) in both samples. This trend was significant in the Swedish sample (p <.01) and when the 2 samples were merged into a single, larger sample (p <.001). When the samples were merged, there was also a significant association between proband sex and cotwin's categorical status, with more cotwins of female probands also being probands than cotwins of male probands. Conclusion: These findings support a female protective effect against ADHD behaviors, suggesting that females require greater exposure to genetic and environmental factors associated with ADHD in order to develop the condition.

Page Manager: Webmaster|Last update: 9/11/2012

The University of Gothenburg uses cookies to provide you with the best possible user experience. By continuing on this website, you approve of our use of cookies.  What are cookies?