The Endocannabinoid System in PTSD: Molecular Targets for Modulating Fear and Anxiety.

Abstract

Fear and anxiety perform essential protective roles, yet when they become dysregulated, they can trap trauma survivors in persistent hypervigilance and distress. Post-traumatic stress disorder (PTSD) manifests as intrusive memories, avoidance, and heightened arousal long after the precipitating event. Although current pharmacotherapies - including selective serotonin reuptake inhibitors, adrenergic blockers, benzodiazepines, and atypical antipsychotics - provide relief for some, many patients contend with residual symptoms or intolerable adverse effects. Recent discoveries position the endocannabinoid system as a pivotal regulator of fear acquisition, consolidation, and extinction. Clinical observations of altered anandamide levels and cannabinoid receptor CB₁ upregulation in individuals with severe PTSD underscore the therapeutic potential of restoring endocannabinoid tone. Preclinical studies demonstrate that direct CB₁ agonists, fatty acid amide hydrolase (FAAH) inhibitors, and phytocannabinoids such as tetrahydrocannabinol (THC) and cannabidiol (CBD) can facilitate extinction learning and attenuate anxiety-like behaviours. Preliminary human trials report that nabilone alleviates trauma-related nightmares and that acute cannabinoid administration modulates amygdala reactivity to a threat. Yet optimal dosing strategies, sex-specific responses, and ideal THC:CBD ratios remain to be defined. Self-medication with cannabis can offer transient relief but carries a risk of cannabis use disorder and potential worsening of PTSD symptoms. By elucidating molecular targets - including CB₁, CB₂, FAAH, and monoacylglycerol lipase - this review outlines a strategic framework for next-generation cannabinoid-based interventions. Harnessing the endocannabinoid system promises to expand the therapeutic arsenal for PTSD, offering hope for more effective and better-tolerated treatments.