Results on ASD Diagnosis Levels and Autism Symptoms
The analysis shows a consistent alignment between DSM-5 ASD levels (1: requiring support, 2: requiring substantial support, 3: requiring very substantial support) and symptom severity in verbal communication, social deficits, repetitive behaviors, and sensory hypo-reactivity.
In the sample, 62.1% of participants came from mothers under 35, while 17.3% came from mothers 35 or older. Although previous studies link advanced maternal age with higher autism risk (Myat et al., 2025), this study suggests a weak correlation between maternal age and ASD level, possibly due to skewed maternal age distribution.
Verbal ability strongly correlated with ASD level 3; 68% of level 3 individuals did not speak. Levels 1 and 2 showed wide variation, indicating a weaker correlation. These patterns may reflect the ASD level spread in the dataset.
Social deficits aligned with ASD levels. Among level 1 participants, 90.7% showed mild or moderate deficits. Level 2 participants showed 87.2% moderate or severe, while level 3 showed 80% in those same categories. A large gap exists between levels 1 and 2, with less distinction between levels 2 and 3.
Repetitive behaviors occurred across all levels. Every level 3 participant exhibited them. Among level 2 participants, 78.9% showed repetitive behaviors, compared to 67.7% of level 1 participants. These results suggest stronger ties between repetitive behaviors and ASD diagnosis than between ASD and other symptoms.
Not to confuse with hyper-reactivity, sensory hypo-reactivity refers to an atypical under-reaction to the sensory environment, such as “not addressing a loud sound.” Sensory hypo-reactivity can “interfere with self-care skills” and “academic progress.” The “prevalence of sensory symptoms in people with autism spectrum disorder (ASD) ranges from 69% to 93% in children and adults” (Savarese, G. et al., 2025). Most participants in the current study experienced sensory hypo-reactivity. Among level 3, 100% showed moderate to severe hypo-reactivity. Levels 2 and 1 showed 69.2% and 56.4% respectively. These patterns align with DSM-5 criteria and current literature.
The most common behaviors prompting an autism spectrum disorder diagnosis include lack of communication, hyperactivity, repetitive behavior, and lack of social interaction. However, this varied among different genders.
Gender and Autism Results
Girls and women often receive delayed or missed psychiatric diagnoses due to more internalized symptoms (Craddock, 2024). By age 4, 87.8% of males and 64.3% of females in the study had an ASD diagnosis. If we consider a diagnosis as late starting by age 12 or later, 3.6% of females and 1.5% of males received late diagnoses, aligning with research on diagnostic delays in females. These findings highlight the need for increased awareness and understanding of autism in females to ensure timely and accurate diagnoses.
The current study reveals that the most common behaviors that prompted parents, guardians, and caregivers to seek assessment for an ASD diagnosis slightly differed between females and males. Nearly half (46.4%) of females exhibited either a lack of communication or hyperactivity, compared to 31.8% of males. In males, 30.4% exhibited repetitive behavior or lack of social interaction, compared to 21.4% of females. These trends may reflect gendered perceptions rather than true behavioral differences.
Past research suggests that “females with ASD may be more socially oriented than males and are better at masking their autism symptoms” (Zack, D. et al., 2025). In the current study, those with a mild social deficit level included 35.7% of females and 22.1% of males, and those with a moderate to severe social deficit included 64.3% of females and 77.9% of males. Though not statistically significant, these results support prior research suggesting greater social masking in females.
Repetitive behaviors occurred in 86.3% of females and 72.3% of males. Although this study showed that repetitive behavior prompted an ASD diagnosis about 60% more often in males than females, more females exhibited repetitive behavior in general, suggesting gender-based recognition bias despite higher prevalence in females.
Moderate to severe sensory hypo-reactivity occurred in 75% of females and 67.1% of males. Gender differences did not reach statistical significance.
Autism Comorbidity Results
ADHD and learning disorders appeared as the most common comorbidities, with over half of participants with ADHD and over a quarter with a learning disorder, with little difference in prevalence between females and males. Anxiety and learning disorders show stronger links to moderate-severe social deficits. Females were over twice as likely than males to have an anxiety disorder, while males were over twice as likely than females to have epilepsy.
Autism and ADHD Comorbidity Results
Among participants with both autism spectrum disorder and ADHD, 71.7% of females and 74.3% of males showed moderate to severe social deficit levels, 85.7% of females and 75.7% of males exhibited repetitive behaviors, and 64.3% of females and 68.6% of males experienced moderate to severe sensory hypo-reactivity.
Although the ASD and ADHD group consisted of 28.6% females and 71.4% males, the social deficit levels, repetitive behaviors, and sensory hypo-reactivity showed minimal statistical significance between females and males. Gender differences did not show statistical significance, suggesting symptom similarity across genders in comorbid ASD and ADHD, whereas a diagnosis of only autism spectrum disorder sees more gendered variation in symptom profiles.
Autism and Learning Disorder Comorbidity Results
Among those with both ASD and a learning disorder, 25.9% were female and 32.8% male. Diagnosis levels included 39.1% level 1, 47.8% level 2, and 13% level 3. These numbers suggest lower ASD levels more often accompany learning disorders, though inaccessibility to traditional education for level 3 may skew results. Within this group, 71.4% spoke few words or none, indicating a strong correlation between limited verbal ability and ASD-learning disorder comorbidity. Moderate to severe social deficits appeared in 67.9% of this group, similar to the overall ASD population, suggesting no major difference linked to co-occurring learning disorders.
Implications
The current findings strengthen the practical utility of DSM-5 ASD-level classifications in clinical assessment and individualized support planning. Clear patterns between ASD levels and symptom severity—particularly in verbal ability, social deficits, repetitive behaviors, and sensory hypo-reactivity—demonstrate how symptom-based stratification supports accurate identification of support needs. These trends highlight the importance of comprehensive behavioral evaluations in early childhood and reinforce the need for diagnostic tools that capture symptom nuance rather than relying solely on age or stereotypical traits.
The analysis reveals multiple implications regarding ASD symptom patterns, maternal age, and gender differences. Symptom alignment across DSM-5 ASD levels shows consistency for social deficits and sensory hypo-reactivity, especially at level 3, while verbal ability and repetitive behaviors vary more widely at levels 1 and 2. While prior studies connect advanced maternal age with autism prevalence, this study found minimal linkage between maternal age and ASD severity. This discrepancy may stem from sample distribution, but it also raises questions about maternal age's role in outcome prediction. Gender discrepancies in diagnosis timing and symptom expression emphasize ongoing gaps in early identification for females, particularly due to differences in observed versus actual behaviors as well as gendered diagnostic bias. Higher rates of repetitive behaviors among females challenge traditional diagnostic biases that overlook subtle presentations. Comorbidity analysis shows strong overlap in symptom profiles among those with both ASD and ADHD, regardless of gender, while individuals with both ASD and learning disorders exhibit lower verbal communication, suggesting that communication challenges may increase with cognitive comorbidities. Together, these findings support the need for more tailored diagnostic tools that account for gender, communication profiles, and the interaction of co-occurring conditions.
Limitations
The study used a dataset with a sample size of 99 participants, which may not provide enough statistical power to detect a moderation effect. The study focused on exploratory data analysis and descriptive patterns, rather than inferential statistics. Future work may use a larger sample and incorporate inferential statistical methods to assess potential confounds. In addition, reliance on parent-reported data may introduce bias based on recall, interpretation, or access to diagnostic services. Still, the depth of open-ended responses and the detailed categorization of developmental characteristics provided a valuable foundation for exploratory analysis.