Abstract
Findings regarding sex differences in autism spectrum disorder (ASD), as far as core symptoms and psychiatric comorbidities (PC) are concerned, are inconsistent, inconclusive, or conflicting among studies. The lower prevalence of ASD in females than in males and the age and intelligence quotient (IQ) heterogeneity among samples made it difficult to investigate these differences. This case–control study tries to deepen the impact of sex differences on core symptoms of autism and PC in 214 preschoolers with ASD (mean age, 45.26) without impairment in non-verbal IQ (nvIQ ≥70). A total of 107 ASD females (mean age, 44.51 ± 13.79 months) were matched one by one with 107 males (mean age, 46.01 ± 13.42 months) for chronological age (±6 months) and nvIQ (±6 points). We used the Autism Diagnostic Observation Schedule 2 (ADOS-2) and the Child Behavior Checklist (CBCL) 1.5–5 to explore autism severity and PC. The results highlight that ASD females did not significantly differ from ASD males regarding the severity of autism. Statistically significant lower levels of emotionally reactive (p = 0.005, η2 = 0.04), anxious-depressed (p = 0.001, η2 = 0.05), internalizing problems (p = 0.04, η2 = 0.02), and DSM-Oriented Scales anxiety problems (p = 0.02, η2 = 0.04) in ASD females than in ASD males were also detected. Our findings of no difference in the autism severity and lower internalizing problems in females than males with ASD extend the knowledge of autism in females during preschool years. Compared to other similar studies on this topic, we can state that these results are not supported by differences in nvIQ between sexes nor by the presence of cognitive impairment. It confirms the need for clinicians to consider sex differences when describing autism psychopathology.
Highlights
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by persistent deficits in social communication and social interaction and repetitive, restricted interests or behaviors (American Psychiatric Association, 2013)
Considering the whole sample, we found a statistically significant difference in restricted repetitive behaviors (RRB)-Calibrated Severity Score (CSS), where males showed higher mean scores than females with ASD
Contradictory or inconsistent results depending on the criteria adopted for a comorbid diagnosis [e.g., an additional diagnosis of attention-deficit hyperactivity disorder (ADHD) in subjects with ASD was not allowed in the DSM-IV and the DSM-IV-TR (American Psychiatric Association, 1994)], the inclusion of cognitively/functionally different subjects (Lai et al, 2011; Mandy et al, 2012), the broad age ranges examined (Worley and Matson, 2011), and the lack of quite large samples of females (Nasca et al, 2019) have been reported, possibly obscuring the ASD female phenotype and sex differences in ASD
Summary
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by persistent deficits in social communication and social interaction and repetitive, restricted interests or behaviors (American Psychiatric Association, 2013). Previous studies have shown a prevalence rate higher than 1% in Italy (Narzisi et al, 2018), with a male-to-female ratio close to 3:1, according to a recent systematic review and meta-analysis (Loomes et al, 2017). This sex imbalance remains a matter of debate, genetic, and/or sex-related hormone pathogenesis are thought to play a considerable role (Werling, 2016). Different biological characteristics seem to distinguish females from males with ASD (Lai et al, 2015a,b). The higher rates of psychiatric comorbidity (PC) often reported in females with ASD have been linked to diagnosis delays
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
