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. 2021 Dec;144(6):635-646.
doi: 10.1111/acps.13368. Epub 2021 Sep 20.

Male to female ratios in autism spectrum disorders by age, intellectual disability and attention-deficit/hyperactivity disorder

Maj-Britt Posserud  1   2 , Berit Skretting Solberg  3   4   5 , Anders Engeland  4   6 , Jan Haavik  1   3 , Kari Klungsøyr  4   6
Affiliations

Male to female ratios in autism spectrum disorders by age, intellectual disability and attention-deficit/hyperactivity disorder

Maj-Britt Posserud et al. Acta Psychiatr Scand. 2021 Dec.

Abstract

Objective: To examine the gender distribution in ASD in adults compared with children and the impact of comorbid intellectual disability (ID) and attention-deficit/hyperactivity disorder (ADHD) on the male to female ratio (MFR).

Methods: We estimated the MFR and the male prevalence ratio (PR) for ASD in adults and children using the Medical Birth Registry of Norway, including all individuals born during 1967-2011. We examined variation with age, comorbid ID and ADHD as defined by diagnoses in the Norwegian Patient Registry during 2008-2015 and/or a dispensed prescription for ADHD medication.

Results: The sample included 1,701,206 adults and 804,146 children, including 8,995 (0.5%) adults and 8,056 (1.0%) children with ASD, 53,822 (3.2%) adults and 26,967 (3.4%) children with ADHD and 9,178 (0.5%) adults and 5,038 (0.6%) children with ID. The MFR for ASD was 3.67 in children and 2.57 in adults, corresponding to a male PR in ASD of 1.54 (95% CI 1.53-1.56) and 1.41 (1.39-1.24), respectively. Comorbid ID decreased the MFR and the male PR in both adults and children, whereas comorbid ADHD significantly increased the male PR in children. The MFR and the population prevalence of ASD, ADHD and ID decreased from children to younger adults and yet further to older adults.

Conclusion: We found a lower MFR and male PR in adults than in children. Findings suggest the strong male predominance seen in childhood/clinical studies of ASD diminishes in adult samples, possibly reflecting the influence of non-aetiological factors such as later diagnosis in females, diagnostic biases and diagnostic trends.

Keywords: attention deficit disorder with hyperactivity; autism spectrum disorder; intellectual disability; male to female ratio; prevalence.

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References

REFERENCES

    1. Loomes R, Hull L, Mandy WPL. What is the male-to-female ratio in autism spectrum disorder? A systematic review and meta-analysis. J Am Acad Child Adolesc Psychiatry. 2017;56(6):466-474.
    1. Roman-Urrestarazu A, et al. Association of race/Ethnicity and social disadvantage with autism prevalence in 7 million school children in England. JAMA Pediatr. 2021;175(6):e210054.
    1. Tan DW, et al. Perceived gender ratings for high and low scorers on the autism-spectrum quotient consistent with the extreme male Brain Account of Autism. PLoS One. 2015;10(7):e0131780.
    1. Constantino JN, Todd RD. Autistic traits in the general population: a twin study. Arch Gen Psychiatry. 2003;60(5):524-530.
    1. Fombonne E, et al. Autism and associated medical disorders in a French epidemiological survey. J Am Acad Child Adolesc Psychiatry. 1997;36(11):1561-1569.

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