Sex Differences in Children Referred for Assessment: Utilizing the Autism Mental Status Exam (AMSE)

Background:

Several studies have noted that female diagnosed with ASD exhibit a higher severity of symptoms than males (e.g. Øien et al. 2016). One suggestion for this difference is that females with the same levels of autistic traits as males might fail to meet diagnostic criteria due to sex-specific differences in trait expression (Dworozynski et al. 2012). Recently, we have found that female toddlers with ASD express a relative strength in joint attention, but a relative weakness in imitation compared to male toddlers with ASD (Øien et al., 2016). In the present study we address sex differences in observed behavioral symptoms utilizing the Autism Mental Status Exam (AMSE). The AMSE is a free (brief) standardized diagnostic assessment that structures the observation and documentation of eight items comprising social, communicative, and behavioral signs and symptoms of ASD that typically emerge throughout a neuro- developmental evaluation (Grodberg, Weinger, Kolevzon, Soorya, & Buxbaum, 2012; Øien, Weinger, Kolevzon & Grodberg 2016).

Objectives:

To evaluate sex differences in parent and clinician reported ASD specific symptoms in a sample of children referred to clinic for ASD assessment.

Methods:

The source population for this study included all patients receiving comprehensive autism-focused diagnostic evaluations, as part of the Assessment Core protocol at the Seaver Autism Center for Research and Treatment from September 2013 through December 2014. The total sample comprised of N=123 children with a mean age of 5.74 years (S.D.= 2.88). Sixty-two males and 23 females received a DSM-5 guided consensus diagnosis of ASD. The AMSE was administered in children first, before they were administered the reference standard (ADOS, ADI-R). ANOVA was used to compare the proportion of total scores on the AMSE between males and females in the groups. Mann-Whitney U non-parametric tests were used to analyse which items most frequently failed by males and females receiving an ASD diagnosis.

Results:

A one-way ANOVA revealed no differences on total AMSE score between males and females. Mann-Whitney U tests were conducted to ascertain differences on item level between male and female toddlers receiving an ASD diagnosis. The analysis revealed that ASD females performed worse than males on language (P=.005). Furthermore, the analysis showed that ASD females had fewer problems related to oversensitivity than ASD males (P=.025)

Conclusions:

The present study found that females performed worse than males on language, and thus it may be the case that females with the same level of general language difficulty as male peers fall under the diagnostic thresholds for ASD due to the presence of fewer sensory issues disrupting social interaction. It is important to stress that this viewpoint is still highly theoretical, and that nuanced patterns of behavioural differences are present in girls with ASD as compared to males through childhood. Results suggest that nuanced patterns of behavioral differences are present in girls with ASD as compared to boys with ASD through childhood.