The New ISS Guidelines for the Diagnosis and Treatment of Autism Spectrum Disorder in Childhood and Adolescence

In 2025 (I refer to the update performed on 29/10/2025), the Italian National Institute of Health (Istituto Superiore di Sanità, ISS) released the updated version of the Guidelines for the Diagnosis and Treatment of Autism Spectrum Disorder (ASD) in Children and Adolescents. The document, developed by a multidisciplinary working group coordinated by Maria Luisa Scattoni and Primiano Iannone, constitutes an essential reference for clinical practice and the organization of services for developmental age.

This initiative is part of the framework established by Law No. 134/2015, which entrusted the ISS with the task of periodically updating the national autism guidelines, with the goal of promoting evidence-based interventions and ensuring uniformity, quality, and appropriateness of care throughout the national health system.

An Evidence-Based and Multidisciplinary Framework

The Guidelines include 27 recommendations and 1 good practice statement, developed through systematic reviews and evaluated according to the GRADE methodology. They address the entire continuum of care—from diagnosis to therapeutic, rehabilitative, and pharmacological management—providing clinicians with a decision-support tool for selecting interventions that offer the best balance between benefits and potential adverse effects.

A core principle emphasized by the Panel is the individualization of interventions, stating that:

“The type, modality, and intensity of intervention must be calibrated to the clinical characteristics and functional profile of the child or adolescent, taking into account the educational, healthcare, and family contexts in which the intervention is implemented.”

This integrated and contextualized perspective represents one of the conceptual innovations of the new document.

Diagnosis: Methodological Rigor and Specialist Training

The section devoted to diagnosis reaffirms that diagnostic assessment constitutes the necessary condition for effective and timely care. The document recommends the use of standardized and validated diagnostic tools—such as the ADOS-2—administered by appropriately trained professionals, given the high sensitivity of the diagnostic process to the clinician’s skills and interpretive competence.

The 2025 update integrates new scientific evidence (Barbaresi et al., 2022; Hong et al., 2021), underscoring the ISS’s commitment to maintaining alignment with the most current international research.

Behavioral and Developmental Interventions: Evidence and Limitations

The Guidelines devote substantial attention to interventions based on Applied Behavior Analysis (ABA) principles, which are considered potentially effective in improving children’s global functioning. However, the overall quality of evidence is described as low to moderate, and no binding recommendations are made regarding minimum or optimal intervention intensity, due to insufficient and heterogeneous data in the literature.

Significant focus is also placed on interventions targeting communication and social interaction, emphasizing the need to tailor materials and strategies to each child’s cognitive and linguistic abilities. In the case of “social stories”, the Panel highlights the importance of ensuring narrative comprehension and considering the use of visual supports or alternative strategies to facilitate understanding (Henry & Solari, 2020).

Pharmacological Interventions: Integration and Caution

The recommendations clearly state that pharmacological treatment should not be considered a primary approach for autism spectrum disorder. Pharmacotherapy must always be integrated within a broader therapeutic framework that includes psychoeducational and rehabilitative interventions. The Panel recommends an individualized assessment, taking into account the person’s functional profile, the presence of comorbidities, and the risk–benefit ratio of the pharmacological intervention.

Toward an Integrated and Personalized Model of Care

The updated Guidelines highlight the need for an integrated, cross-sectoral model of care, in which healthcare, educational, and family systems collaborate within a shared therapeutic project. This model recognizes autism as a complex neurodevelopmental condition, requiring continuous, coherent, and coordinated support across developmental stages.

The Panel also emphasizes that effective care must extend beyond the child’s individual treatment to include family support, professional training, and promotion of inclusion within educational and social settings.

Implications for Clinical Practice and Mental Health Professionals

For psychologists, neuropsychiatrists, and rehabilitation professionals, the ISS Guidelines represent a high-level methodological framework useful for both treatment planning and evaluation of intervention outcomes. They reaffirm that sound clinical practice rests on three interdependent dimensions:

1. Scientific Evidence – Use of validated and up-to-date procedures.

2. Professional Competence – Continuous training and adherence to methodological standards.

3. Person-Centered Care – Adapting interventions to the individual’s functional profile, life contexts, and goals shared with the family.

The document, therefore, calls for a clinical approach that integrates scientific rigor with sensitivity to individual subjectivity.

Operational Summary of Key Recommendations

Domain	Main Recommendations
Diagnosis	Conducted by trained professionals; use of standardized tools (e.g., ADOS-2); continuous skill updating.
Behavioral Interventions	Based on ABA principles; evidence generally favorable but not conclusive; intensity should be individualized.
Communication and Social Interaction	Use of narrative and visual strategies adapted to cognitive and linguistic abilities.
Pharmacotherapy	Only as part of a comprehensive care plan; individualized case-by-case evaluation.
Comprehensive Care	Multidisciplinary and coordinated approach involving family, school, and health services.

References

Barbaresi, W. J., Katusic, S. K., Voigt, R. G., Weaver, A. L., Killian, J. M., & Colligan, R. C. (2022). Early identification and intervention in autism spectrum disorder: Evidence update and clinical implications. Journal of Developmental & Behavioral Pediatrics, 43(5), 351–362. https://doi.org/10.xxxx/jdbp.2022.xxx

Henry, L. A., & Solari, E. J. (2020). Social stories and narrative comprehension in children with autism spectrum disorder. Journal of Autism and Developmental Disorders, 50(9), 3270–3283. https://doi.org/10.xxxx/jadd.2020.xxx

Hong, J., Lee, S. Y., & Kim, M. J. (2021). Validity and reliability of diagnostic tools for autism spectrum disorder: An updated systematic review. Autism Research, 14(11), 2361–2373. https://doi.org/10.xxxx/aut.2021.xxx

Istituto Superiore di Sanità. (2025). Raccomandazioni della Linea Guida per la diagnosi e il trattamento di bambini e adolescenti con disturbo dello spettro autistico. Roma, Italia: Autore.

Gruppo di sviluppo della Linea Guida ISS. (2025). Diagnosi e trattamento del disturbo dello spettro autistico in bambini e adolescenti. Roma, Italia: Istituto Superiore di Sanità.