Autism Spectrum Disorder: A Comprehensive Review of Clinical, Genetic, and Neurobiological Perspectives

Abstract: Autism Spectrum Disorder (ASD) is a lifelong neurodevelopmental condition characterized by persistent difficulties in social interaction, communication, and the presence of repetitive behaviors or restricted interests. Its causes are complex, involving both genetic predisposition and environmental factors that affect early brain development. Recent research has focused on uncovering the biological mechanisms contributing to ASD. In this review, we summarize current findings, emphasizing pathways such as altered GABAergic signaling, oxidative stress, calcium imbalance, and disruptions in mTOR and Wnt signaling. The gut–brain axis, an emerging area of study, is also explored for its potential influence on neurodevelopment and behavior. These interconnected systems help explain how molecular and cellular dysfunctions may result in the behavioral and cognitive features observed in ASD. Diagnostic practices based on DSM-5 criteria are reviewed, including the updated classification of symptom severity. Treatment options are discussed, covering well-established behavioral therapies like Applied Behavior Analysis (ABA) and Cognitive Behavioral Therapy (CBT), along with pharmacological approaches to manage associated symptoms. Despite advancements, current therapies often fall short of meeting the diverse needs of individuals with ASD. Increasing emphasis is being placed on multidisciplinary, personalized care models that integrate medical, psychological, and educational support. By drawing insights from neuroscience, genetics, psychology, and clinical research, this review aims to guide future efforts in improving early diagnosis and developing more targeted, effective interventions to enhance the quality of life for individuals with ASD and their families.