Pharmacological Interventions in Autism Spectrum Disorder: A Comprehensive Review of Mechanisms and Efficacy

Background and Objectives: Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental condition characterized by social communication deficits, restricted interests, and repetitive behaviors. At present, there is no pharmacological intervention that reliably targets the core symptoms of ASD; instead, medications are primarily used to manage associated or concurrent symptoms such as irritability, aggression, anxiety, attention difficulties, and sleep disturbances. This review summarizes the current evidence for pharmacological treatments in ASD, emphasizing how these interventions are used in a symptom-focused, adjunctive manner, and highlighting efficacy, mechanisms, limitations, and emerging therapeutic targets. Methods: A comprehensive literature review was conducted across PubMed, Cochrane Library, and Embase to identify clinical trials, systematic reviews, meta-analyses, and preclinical studies on pharmacological interventions for ASD. Seventy-seven references were integrated to reflect the current state of evidence. Results: Established pharmacological strategies include atypical antipsychotics for severe irritability and aggression, as well as antidepressants, stimulants and non-stimulant agents, mood stabilizers, and anxiolytics for selected comorbid symptoms, although efficacy is often modest and variable, and side effects can be significant. Adjunctive and investigational approaches targeting glutamatergic and GABAergic neurotransmission, monoaminergic systems, and neuroinflammatory and oxidative stress pathways show preliminary promise but remain experimental. Across all categories, pharmacological treatments are most effective when embedded in individualized, multimodal care plans that integrate behavioral, rehabilitative, and psychological interventions. Conclusions: This review maps pharmacologic strategies in ASD onto their underlying neurobiological mechanisms and clarifies how evidence strength differs across drug classes and symptom domains. Ongoing advances in genetics, synaptic and circuit-level neuroscience, and neuroimmune signaling are expected to yield more specific, mechanism-based pharmacological approaches for autistic behaviors, with the potential to improve long-term functioning and quality of life when combined with comprehensive psychosocial care.