The impact of gender and development on the clinical, academic and neuropsychological profiles of children with autism spectrum disorder
thesisposted on 2017-02-28, 03:59 authored by May, Tamara
A person’s sex or gender can contribute to the susceptibility of being diagnosed with some psychiatric conditions. For example, in childhood, boys are more frequently diagnosed with learning disorders, speech disorders, Attention Deficit Hyperactivity Disorder (ADHD) and Intellectual Disability, whereas girls are more frequently diagnosed with anxiety disorders such as separation anxiety disorder and selective mutism (American Psychiatric Association, 2000). Autism Spectrum Disorder (ASD) is another condition which affects many more males than females (Fombonne, 2003, 2009). ASD impacts on an individual’s ability to socially relate and communicate and is accompanied by patterns of restricted interests and repetitive behaviours (American Psychiatric Association, 2000). On average four males to every one female are diagnosed with ASD (Fombonne, 2003). Seminal early gender research in ASD found females were more cognitively impaired and had fewer repetitive behaviours than males (Lord, Schopler, & Revicki, 1982; Wing, 1981). Despite these findings there has been limited research on the ASD gender profile with particular gaps in the examination of neuropsychological factors and functional outcomes such as academic achievement. The current thesis therefore presents a series of papers that systematically investigate gender difference in the clinical symptoms, neuropsychological functioning and academic performance of children with ASD and explores inter-relationships between these domains. This was achieved by comparing a group of normally intelligent children aged 7-12 years with ASD (N=64) and typically developing children (N=60); clinically (through use of behavioural rating scales), academically (through the use of standardized individual academic achievement tests) and neuropsychologically (through the use of experimental computerised tasks investigating executive functioning). The children were tested over two time points one year apart to map developmental trajectories. Results from clinical measures indicate gender similarity in core ASD symptoms, with more hyperactive behaviours in boys and more social anxiety in girls, a robust finding across two time points. These findings are presented in Chapter 2 and 3. Chapter 4 further explores the clinical profile of boys and girls by examining sleep behaviour over time and how this may inter-relate with clinical symptoms. Chapters 6 and 7 reveal results from neuropsychological and academic studies where gender similarities in objective tests of reading, mathematics and executive functioning were identified. These chapters also revealed that attention switching difficulties predicted concurrent and also later poorer mathematics attainment in children with ASD. The integrated findings reveal gender similarity across a range of objective academic and neuropsychological tests. Although gender differences in parent-reported hyperactivity and social anxiety were found, these differences were also present in typically developing children and not specific to ASD. These findings have implications for the identification of female cases of ASD in that less hyperactive girls may not be ascertained. These subjectively reported differences in associated symptoms, rather than differences in core ASD symptoms, neuropsychological and academic profiles, may help explain why more males than females are diagnosed with ASD. Findings are explored using a biopsychosocial model considering biological, cognitive-psychological-behavioural, and social factors including gender role stereotypes and gender bias which together might contribute to gender difference in ASD.