Gender Differences in Obsessive and Compulsive Symptomatology Among Children with ASD

Background:

Gender differences have been found in young children with Autistic Spectrum Disorders (ASDs). Two consistent findings have shown that; ASDs are more common in males than females and females tend to score lower on intelligence tests than males. Research into gender differences in core autistic symptomatology is less consistent when focused on older children and adults. Recent evidence has shown differences with respect to the core autistic symptomatology of older male and female children, which showed that males exhibited greater levels of repetitive stereotypic behaviours than females. There is also some evidence that females with ASD exhibit greater internalising difficulties than males, although the extent and precise nature of this difference is poorly understood. In particular, whilst ASD is a risk factor for developing Obsessive Compulsive Disorder (OCD), little is known about any OCD gender differences in this population.

Objectives:

To investigate whether females with ASDs exhibit higher levels of OCD symptomatology compared to age and IQ equivalent males with ASD.

Methods:

Participants (N = 116, 21 females; aged 3–18 years) received a clinic consensus diagnosis of ASD (based on 3Di and ADOS assessment) at a national clinic for children with high-functioning ASD. All participants were equivalent on age, IQ and symptom severity. All participants were in mainstream school and had fluent language. Male and female participants were compared on parent and self-report OCD symptoms scores. In addition parent and teacher report for internalizing difficulties on the Strengths and Difficulties Questionnaire (SDQ) were available.

Results:

Parents reported that females with ASD exhibited significantly higher levels of OCD symptomatology when compared to males (p= 0.031). Using SDQ scores on the emotional subscale both parents and teachers also reported higher levels of internalizing difficulties in females than males. Teachers report of internalizing difficulties was statistically significant (p=0.03) and parent report scores were non-significant but displayed a similar trend (p=0.07). Linear regression was then used to ascertain whether the significant gender difference in OCD symptomatology remained after controlling for general internalizing difficulties. Females were reported to exhibit clinically significant levels of OCD symptomatology even after controlling for the effects of general internalizing difficulties in females (p=0.04).

Conclusions:

In this study, females with ASDs were shown to exhibit significantly higher levels of OCD symptomatology, when compared to males with ASDs. As clinical experience suggests, females are more likely to display higher levels of internalizing, emotional difficulties than males although this does not fully explain their higher levels of OCD symptomatology. These findings are of research and clinical interest. If females with ASDs are more disposed toward higher levels of OCD symptomatology then clinically, this could be an area for routine assessment of females at the point of an ASD diagnosis. In addition OCD symptoms in females with ASDs could represent the manifestation of repetitive and rigidity behaviours in a more ‘cognitive’ than behavioural domain than in the male dominated RSB diagnostic subscale. Future ASD gender difference research should therefore distinguish between the cognitive and behavioural manifestations of OCD.