The First "Hit" to the Endocannabinoid System? Associations Between Prenatal Cannabis Exposure and Frontolimbic White Matter Pathways in Children

Prenatal cannabinoid exposure and the developing brain: Evidence of lasting consequences in preclinical rodent models

Cannabis use by people who are pregnant is increasing. Understanding how prenatal cannabinoid exposure (PCE) affects infants and children is of high public health significance. Epidemiological studies have associated PCE with cognitive symptoms, including impaired learning, memory, attention, and executive control, and affective symptoms, including anxiety, emotional dysregulation, and social impairments, in children, adolescents, and young adults. PCE is also associated with neurobiological changes including decreased corticolimbic white matter and functional connectivity; however, the underlying mechanisms for these persisting effects remain unknown. Rodent models are essential for uncovering the effects of PCE on the developing brain. This review summarizes rodent studies focused on the cognitive and affective behavioral and neurobiological outcomes of PCE. Rodent studies have reported cognitive deficits, including impaired learning, memory, attention, and executive control, and affect-related impairments, including anxiety-like behavior, altered stress coping, social impairments, and anhedonia-like behavior, in adolescent and adult offspring. Studies have also demonstrated that PCE affects several underlying neurotransmitter systems, producing dopamine hyperactivity, glutamate and serotonin hypoactivity, and dysregulating GABA and opioid signaling. Evidence further suggests a marked difference in outcomes between males and females, with males being more susceptible to the enduring effects of PCE. However, studies that investigate female-specific outcomes or sex as a biological variable are scarce. Altogether, rodent studies provide corroborating evidence that PCE produces lasting cognitive and affective impairments underpinned by altered neurobiological mechanisms. Research is critically needed to improve our understanding of the risks associated with cannabis use during pregnancy and effects across the lifespan.

Cannabis and psychopathology: 2024 Snapshot of a meandering journey

Background

Cannabis has been associated with psychopathology since ancient times, but controversies continue despite important advances in the field. This article is the fourth one in our decadal series of review articles that have been providing an update snapshot of the meandering journey of the research findings in this area.

Aims

This narrative review of a comprehensive literature search over the past 10 years aims to provide an update and current understanding, while raising unanswered questions for the future, focusing on the following areas: (a) nosological changes in cannabis-related psychiatric syndromes; (b) psychopathology associated with the newer category of synthetic cannabinoids; (c) cannabis withdrawal syndrome); (d) cannabis and psychosis; (e) cannabis and mood disorders; (f) cannabis and suicidality; (g) prenatal cannabis use and psychopathology in the offspring; (h) effect of recent liberal policy overhaul on cannabis control in certain countries/areas on psychopathology and adverse outcomes; (i) cannabis and cognition; and (j) cannabis, psychopathology, and genetics.

Methods

The data search strategies involved a combination of electronic databases and manual hand-searching of relevant publications and cross-references using selected search terms. The primary electronic search focused on Medline and PubMed Central databases but extended to databases such as Google Scholar, PsychINFO, Scopus, and Ovid for specific sections. Key references identified through electronic and manual searches provided additional material. Inclusion criteria for the review spanned studies published between January 2014 and June 2024, with more emphasis placed on recent studies (post-2020) while ensuring historical coverage.

Results

The narrative review aimed to be comprehensive, including a broad range of research without strict methodological exclusions. Strengths and limitations of cited research are discussed when applicable, maintaining consistency with three prior reviews. We focused on psychopathology and psychiatric syndromes, human (rather than animal) studies, and applied (rather than basic) research. We have only focused on policy with reference to psychopathology and not on that entire area because that would be beyond the scope of this article. There are important updates in all the areas covered. There are newer syndromal entities in ICD-11, which also includes synthetic cannabinoids for the first time. Cannabis withdrawal syndrome has been better characterized. The association between cannabis and psychosis has been robustly established especially for very high-potency cannabis and for vulnerable populations, particularly young people. Work is in progress elucidating the causal mechanisms. The links between cannabis and mood disorders as well as suicidality and cognitive impairment are better characterized, though questions remain. Recent liberalizing policies on cannabis have produced newer findings on prenatal and accidental cannabis use (with deleterious effects on the offspring) and on later psychopathology (mixed findings, but a documented increase in emergency visits related to recent cannabis use). This is an area which will require active monitoring for new data.

Conclusion

The field of cannabis use and psychopathology continues to collect new data and settle some old controversies while raising new questions, which are important to address in view of the wide use of cannabis worldwide and its implications for public health.

Prenatal cannabis exposure in the clinic and laboratory: What do we know and where do we need to go?

Coincident with the legalisation of cannabis in many nations, rates of cannabis use during pregnancy have increased. Like prior investigations on smoking and alcohol, understanding how prenatal cannabis exposure (PCE) impacts offspring outcomes across the lifespan will be critical for informing choices for pregnant people, clinicians, and policy makers alike. A thorough characterization of the life-long impacts is especially urgent for supporting all of these stakeholders in the decision-making process. While studies in humans bring forth the most direct information, it can be difficult to parse the impact of PCE from confounding variables. Laboratory studies in animal models can provide experimental designs that allow for causal inferences to be drawn, however there can be challenges in designing experiments with external validity in mirroring real-world exposure, as well as challenges translating results from the laboratory back to the clinic. In this literature review, we first highlight what is known about patterns of cannabis use during pregnancy. We then seek to lay out updates to the current understanding of the impact of PCE on offspring development informed by both human and nonhuman animal experiments. Finally we highlight opportunities for information exchange among the laboratory, clinic, and policy, identifying gaps to be filled by future research.

Endocannabinoid dysregulation and PTSD in urban adolescents: Associations with anandamide concentrations and FAAH genotype

BACKGROUND

The endocannabinoid system, which regulates fear- and anxiety-related behaviors, is dysregulated in adults with posttraumatic stress disorder (PTSD), as indicated by higher circulating anandamide (AEA) concentrations. The C385A (rs324420) polymorphism in the fatty acid amide hydrolase (FAAH) gene, which catabolizes AEA, is linked to higher AEA concentrations and greater PTSD symptoms in adults. Given that adolescence is a critical period during which trauma and psychiatric disorders emerge, understanding this relationship in youth is essential. This study examines PTSD symptoms, AEA concentrations, and FAAH genotype in a diverse adolescent sample.

METHODS

This study included 102 Detroit-area adolescents (M ± SD = 13.33 ± 2.21 years, 54.9% female) and their parents/guardians. The sample consisted of 40.2% White Non-Hispanic, 34.3% Black Non-Hispanic, 6.9% White Hispanic, 4.9% Asian/Pacific Islander, and 12.7% Biracial adolescents. Trauma exposure and PTSD symptoms were assessed using the UCLA PTSD Reaction Index for DSM-5. Plasma concentrations of AEA were measured by liquid chromatography-tandem mass spectrometry, and FAAH genotype was determined from saliva samples and high-throughput screening.

RESULTS

The majority (90%) of adolescents reported trauma exposure, and 20% met PTSD criteria. Higher AEA concentrations were associated with more severe PTSD symptoms (p = 0.009), especially hyperarousal. The FAAH A-allele (present in 52.5% of participants) was associated with higher AEA concentrations (2.11 ± 0.69 pmol/ml, p = 0.013) and greater PTSD severity (22.65 ± 15.931, p = 0.027), particularly those with the reexperiencing cluster, compared to the CC genotype (1.79 ± 0.66 pmol/ml and 15.87 ±+ 13.043, respectively).

CONCLUSION

Elevated AEA concentrations and the FAAH A-allele were associated with greater PTSD symptom severity in urban adolescents. These findings suggest endocannabinoid dysregulation may play a role in adolescent PTSD, highlighting the need for further research and targeted interventions.