The Endocannabinoid System in Neuropsychiatric Disorders: Mechanisms, Dysregulation and Therapeutic Potential

The endocannabinoid system (ECS) is a fundamental regulator of brain and body homeostasis, integrating neural, immune, and stress-related signaling pathways. Dysregulation of ECS components, including cannabinoid receptors (CB1 and CB2), endocannabinoids such as anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and their metabolic enzymes (FAAH and MAGL), has been increasingly implicated in the pathophysiology of neuropsychiatric disorders, including mood, anxiety, psychotic, stress-related, and eating disorders. Altered endocannabinoid signaling contributes to maladaptive stress responses, emotional dysregulation, and impaired synaptic plasticity, highlighting the role of the ECS as a core integrative mechanism. Therapeutic strategies targeting ECS, particularly through FAAH inhibition and the use of plant-derived cannabinoids, such as cannabidiol (CBD), show promise in restoring endogenous homeostasis while minimizing the adverse cognitive and affective effects associated with direct CB1 activation. ECS function and treatment response are further influenced by genetic polymorphisms in CNR1, CNR2, FAAH, and MGLL, as well as epigenetic mechanisms, including DNA methylation, histone modifications, and microRNA regulation. Despite these advances, clinical translation remains limited by interindividual variability, the complexity of ECS interactions, and the relatively small size of existing clinical studies. Future research integrating longitudinal clinical trials with multi-omics approaches is essential to support the development of evidence-based, personalized interventions. Overall, understanding ECS mechanisms and dysregulation provides a valuable framework for the development of targeted therapies in neuropsychiatric disorders.