Critical Windows of Vulnerability: Behavioral Dysregulation After Prenatal vs. Adolescent THC Exposure

This review synthesizes preclinical evidence on the behavioral and neurobiological effects of cannabis exposure during prenatal and adolescent developmental periods, with a focus on anxiety, social behavior, learning and memory, and associated brain changes. Understanding the differential impact of cannabis exposure across these windows is critical, given the increasing prevalence of cannabis use and the rising potency of its primary psychoactive component, delta-9-tetrahydrocannabinol (THC). Both prenatal and adolescent periods represent vulnerable windows for disruption of the endocannabinoid system, which plays a central role in typical neurodevelopment. Exogenous activation of this system via THC can lead to atypical brain maturation and subsequent behavioral impairments. These impairments are associated with region-specific alterations in cortical and subcortical structures and are highly dependent on the timing of exposure. For instance, prenatal exposure may disrupt medial prefrontal cortex development, leading to long-term social deficits while sparing memory function. In contrast, adolescent exposure tends to impair hippocampal function, resulting in learning and memory deficits. The manuscript is organized developmentally, beginning with the effects of prenatal exposure and then discussing consequences of adolescent exposure. By delineating the distinct behavioral and neurobiological outcomes associated with the timing of cannabis exposure, this review highlights the importance of developmental stage in assessing the risks of exogenous cannabinoid use and identifies critical periods for targeted research and intervention.