Potential Gender Differences in Older Children and Adolescents with Autism Spectrum Disorder

Background:

A limited number of studies have examined gender differences within Autism Spectrum Disorder (ASD). Research indicates that girls compared to boys within the ASD population are more impaired in social competence, communication, cognitive abilities, and demonstrate more anxious or depressed affect (Hartley & Sikora, 2009; Carter et al., 2007; Holtman, et al, 2007), although some studies have found no significant differences (McLennan, 2003).  The majority of these studies have focused on either toddlerhood/preschool or spanned a large age range.  Adolescence is a crucial developmental stage requiring further examination in the ASD population because of great advances in social and cognitive abilities that have been found to be impaired in ASD.  Additionally, adolescent gender differences in depression have been found in a typically developing (TD) population (Nolen-Hoeksema & Girgus, 1993), but investigation in the ASD population is scarce.

Objectives:

The current study examined gender differences across multiple domains, including social abilities, communication, and depression in higher functioning individuals during late childhood and adolescence.

Methods:

Participants consisted of older children and adolescents ranging from 10.1 to 17.8 (M=14.94, SD=1.85) years. Theory of Mind (ToM) was assessed using Happé’s strange stories (Happé et al., 1994), and the Erickson Flanker Task (Eriksen & Schultz, 1979) measured inhibitory control.  Verbal and non-verbal abilities were measured using the Kaufman Brief Intelligence Test-Second Edition (KBIT-2) (Kaufman & Kaufman, 1990) and autistic traits were measured using the Autism-Spectrum Quotient - Adolescent Version (AQ; Baron-Cohen et al., 2006).

Results:

To examine group and gender differences in depression, we used a univariate analyses of variance (ANOVA) with group (TD vs. ASD) and gender (Male vs. Female) as fixed factors, and depression as the dependent variable. This analysis revealed a main effect of group, F(1,68) = 6.40 , p =.01, such that the ASD group (M= 15.95, SE= 1.40) scored significantly higher on depression than the TD group (M= 11.11, SE= 1.31).  In addition, we found a marginally significant gender by group interaction, F(1,68)= 3.45 ,  p= .07, with ASD males (M= 17.40, SE= 1.85) scoring highest , then ASD females (M= 14.50, SE= 2.15), followed by TD females (M=13.21, SE= 1.85), and with TD males (M= 9.00, SE= 1.85) scoring the lowest.

Regarding ToM, an ANOVA revealed a main effect of group, F(1,63) = 4.95 , p=.03, such that the ASD group (M =11.41, SE= 0.40) scored significantly worse on the ToM task than the TD group (M =12.65, SE= 0.38).

A two-way MANOVA with group and gender as the fixed factors, and the five AQ subscales as the dependent variables revealed a significant multivariate main effect of gender, Wilks’ Λ= .35, F(5,66)= 24.48, p < .001. Univariate tests indicated a significant effect of all five subscales (p< .01), such that the ASD group showed greater impairments than the TD group.

Conclusions:

The ASD group showed more autistic traits and depression, as well as worse ToM than the TD group. Further, a gender by group interaction suggested that ASD males have greater depressive symptoms than TD males.