Some studies show that the diagnosis of Autism Spectrum Disorder could be considered reliable and stable in children aged 18 to 24 months. Nevertheless, the diagnostic stability of early ASD diagnosis has not yet been fully demonstrated. This observational study examines the one-year diagnostic stability of autism spectrum disorder diagnosis in a clinical sample of 147 children diagnosed between 18 and 48 months of age. The ADOS-2 scores were used in order to stratify children in three levels of symptom severity: Autism (AD; comparison score 5–7), Autism Spectrum Disorder (ASD; comparison score 3–4), and Sub-Threshold Symptoms; (STS; comparison score 1–2). Results: Overall, the largest part of children and toddlers diagnosed with autism spectrum disorder between 18 and 48 months continued to show autistic symptoms at one-year follow-up evaluation. Nevertheless, a significant percentage of children with higher ADOS severity scores exhibited a reduction of symptom severity and, therefore, moved towards a milder severity class one year later. Conversely, the number of subjects of the STS group meaningfully increased. Therefore, at one-year follow-up a statistically significant (χ²(2) = 181.46, p < 0.0001) percentage of subjects (25.2% of the total) who had received a categorical diagnosis of Autistic Disorder or Autism Spectrum Disorder in baseline no longer met the criteria for a categorical diagnosis. Furthermore, children who no longer met the criteria for autism spectrum disorder continue to show delays in one or more neurodevelopmental areas, possibly related to the emergence of other neurodevelopmental/neuropsychiatric disorders. Overall, the comprehensive results of the study account for a high sensibility but a moderate stability of ASD early diagnosis.

Autism spectrum disorder is a neurodevelopmental disorder with a rising prevalence disorder. This high-cost/high-burden condition needs evidence-based behavioral treatments that are able to reduce the impact of symptoms on children’s functioning. This retrospective chart review study compared the impact of different types of early interventions on toddlers diagnosed with an autism spectrum disorder developmental profile. Analyses were conducted on 90 subjects (mean = 27.76 months, range 18–44 months; M:F = 4.29:1), of which 36 children underwent the usual treatment, 13 children underwent an intervention based on early intensive behavioral intervention (EIBI) and 41 children received the Early Start Denver Model, for one year, with the same weekly frequency of about 6 h a week. A significant decrease in the severity of autism symptoms was observed for all children when looking at the Ados-2 severity score (average difference = 3.05, SD = 0.71, p = < 0.001) and the Ados-2 social subscale (average difference = 2.87, SD = 0.59, p < 0.001). Otherwise, for most of the Griffiths subscales, we found a significant improvement only for those children who underwent the Early Start Denver Model intervention (General Quotient average difference = 14.47, SD = 3.22, corrected p < 0.001). Analyzing the influence of age on the investigated scores, we found a significant association with the Eye–hand Coordination Quotient (p = 0.003), Performance Quotient (p = 0.042) and General Quotient (p = 0.006). In all these domains, a mild negative correlation with age was observed, as measured by the Pearson’s correlation coefficient (r = −0.32, p = 0.002; r = −0.21, p = 0.044; r = −0.25, p = 0.019, respectively), suggesting less severe developmental skills at the start of treatment for older children. Our results are consistent with the literature that underlines the importance of early intervention, since prompt diagnosis can reduce the severity of autism symptoms; nevertheless, in toddlers, our study demonstrated that an intervention model based on naturalistic developmental behavioral principles such as the Early Start Denver Model is more effective on children’s developmental profile. Further studies are required to assess the extent of effectiveness of different early intervention models in community settings.

Background and Objectives: Sensory anomalies are a distinctive feature of Autism Spectrum Disorder (ASD) individuals and appear to differ in intensity, frequency, and subtype between male and female subjects. According to the diagnostic framework of the DSM-5-TR, these sensory patterns are key clinical indicators. The objectives of this study were to investigate sensoriality in ASD, to compare sensory profiles in ASD subjects of both sexes and evaluate potential correlations with clinical profiles. Materials and Methods: A total of 94 ASD participants were enrolled at the Children and Adolescents Neuropsychiatry Department of the University of Naples Federico II. The population was assessed through psychometric (cognitive and adaptive levels, and intensity of autism symptoms) and sensory characterization (using the Short Sensory Profile questionnaire). Subsequently, a Mann–Whitney U test was performed to evaluate differences in sensory profiles between males and females. Spearman’s correlation was used to assess significant associations between the sensory profile and cognitive level, adaptive level, and ASD symptom intensity. Subsequently, for the correlations that emerged as significant, an analysis was performed using a General Linear Model (GLM), including age and Intelligence Quotient (IQ) as covariates in the model. Results: No statistically significant differences in the sensory profile emerged between male and female subjects. Sensory anomalies do not appear to be correlated with cognitive level. Although some statistically significant correlations emerged between the sensory profile, the AQ, and the ADOS-2 comparison score, these results were not confirmed after a GLM analysis was performed using the participants’ age and IQ as covariates. Conclusions: The observed results appear partially in line with the existing literature. Following the GLM analysis, it was further observed that variables such as age and IQ play a crucial role in interpreting the functional profile of individuals with ASD. At present, the study has several limitations (the exclusive use of parent-report instruments, an observational design, the lack of a control group) which could affect the robustness of the observed findings. Therefore, further studies are deemed necessary to better define the sex-specific sensory characteristics of ASD individuals.