Introduction: Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by marked etiological and clinical heterogeneity. In recent years, there has been growing recognition of the need to investigate integrative approaches that consider its potential multisystem nature. From the perspective of complex systems theory, effective interventions should necessarily be multidimensional and adaptive.
Case Presentation: An 18-month-old boy of Mexican nationality was evaluated for early socio-communicative regression. Independent external assessments identified a clinical suspicion of ASD and a significant global developmental delay (Battelle Developmental Quotient: 69).
Intervention: An individualized Complex Naturopathic Intervention (CNI) was implemented over 24 months. In accordance with minimal intervention protocols due to the patient’s young age, it was progressively structured into three core components: (1) trophology and strict dietary exclusion (month 0); (2) ongoing parental coaching; and (3) individualized naturopathic supplementation, introduced following laboratory confirmation at month 13.
Results: A reduction in symptom severity was observed (ATEC baseline score of 56, decreasing to 10 after 24 months of intervention). The participant experienced an episode of acute regression at 5 years of age, triggered by the discontinuation of immunonutrition guidelines (trophology), which fully remitted within 4 months following reinstatement of the intervention. External reassessments revealed methodological discrepancies: a blinded clinical evaluation at 5 years of age identified only ADHD, without detecting the autistic phenotype, with above-average cognitive performance (Full-Scale IQ: 113), whereas a final non-blinded evaluation at 7 years of age established a diagnosis of ASD level 1 with co-occurring ADHD.
Conclusiones: The early application of the CNI was associated with a profound reorganization of the system, in line with complex systems models, and consistent with functional remission (optimal outcome), transitioning toward residual high-functioning neurodivergence. The case suggests a functional association between biological determinants of behavior (gut–brain axis) and illustrates successful mechanisms of functional masking, documenting a phenomenon of diagnostic overshadowing conditioned by evaluator blinding.
Keywords: autism spectrum disorder, functional remission, diagnostic overshadowing, naturopathic intervention, case study