Neuropsychiatric Sequelae in Adolescents With Acute Synthetic Cannabinoid Toxicity

Reelin Deficiency and Synaptic Impairment in the Adolescent Prefrontal Cortex Following Initial Synthetic Cannabinoid Exposure

Background

Adolescent cannabinoid exposure can have long-lasting effects on the brain, particularly in the prefrontal cortex, where the reelin protein plays a crucial role in neural organization. Chronic cannabinoid exposure leads to reelin deficiency and behavioral abnormalities, but the underlying mechanisms remain unclear. With the increasing use of synthetic cannabinoids (SCs) among young people, understanding these effects is crucial.

Methods

We examined the cellular and synaptic consequences of initial SC exposure in adolescent male mice 1 day after a single in vivo exposure to WIN 55,212-2. Our approach combined immunohistochemistry, Western blots, conditional CB1 receptor (CB1R) knockout mouse lines, quantitative polymerase chain reaction, and ex vivo electrophysiology to investigate the effects of SC on reelin expression and synaptic plasticity. Additionally, single-molecule fluorescent in situ hybridization profiling was used to identify cellular coexpression patterns of reelin and CB1Rs.

Results

Our findings indicate that a single exposure to SC decreased reelin expression in specific prefrontal cortex layers accompanied by disrupted proteolytic fragmentation but not changes in messenger RNA expression. Single-molecule fluorescent in situ hybridization profiling revealed a strong coexpression of CB1R and reelin. Furthermore, our pharmacological and genetic approaches demonstrated that CB1Rs in GABAergic (gamma-aminobutyric acidergic) neurons mediate the SC-induced decrease in reelin. This decrease in reelin results in a reduction in long-term potentiation, phenocopying reelin haploinsufficient mice. Notably, we restored long-term potentiation by infusing reelin bilaterally, establishing a functional link between reelin depletion and synaptic deficits.

Conclusions

These findings provide new insights into the neural consequences of adolescent cannabinoid consumption and highlight the critical role of reelin in the cellular mechanisms associated with SC initiation during adolescence.

Clinical effects of cannabis compared to synthetic cannabinoid receptor agonists (SCRAs): a retrospective cohort study of presentations with acute toxicity to European hospitals between 2013 and 2020

INTRODUCTION

Cannabis is the most common recreational drug worldwide and synthetic cannabinoid receptor agonists are currently the largest group of new psychoactive substances. The aim of this study was to compare the clinical features and outcomes of lone acute cannabis toxicity with lone acute synthetic cannabinoid receptor agonist toxicity in a large series of presentations to European emergency departments between 2013-2020.

METHODS

Self-reported drug exposure, clinical, and outcome data were extracted from the European Drug Emergencies Network Plus which is a surveillance network that records data on drug-related emergency department presentations to 36 centres in 24 European countries. Cannabis exposure was considered the control in all analyses. To compare the lone cannabis and lone synthetic cannabinoid receptor agonist groups, univariate analysis using chi squared testing was used for categorical variables and non-parametric Mann-Whitney U- testing for continuous variables. Statistical significance was defined as a P value of <0.05.

RESULTS

Between 2013-2020 there were 54,314 drug related presentations of which 2,657 were lone cannabis exposures and 503 lone synthetic cannabinoid receptor agonist exposures. Synthetic cannabinoid receptor agonist presentations had statistically significantly higher rates of drowsiness, coma, agitation, seizures and bradycardia at the time of presentation. Cannabis presentations were significantly more likely to have palpitations, chest pain, hypertension, tachycardia, anxiety, vomiting and headache.

DISCUSSION

Emergency department presentations involving lone synthetic cannabinoid receptor agonist exposures were more likely to have neuropsychiatric features and be admitted to a psychiatric ward, and lone cannabis exposures were more likely to have cardiovascular features. Previous studies have shown variability in the acute toxicity of synthetic cannabinoid receptor agonists compared with cannabis but there is little comparative data available on lone exposures. There is limited direct comparison in the current literature between lone synthetic cannabinoid receptor agonist and lone cannabis exposure, with only two previous poison centre series and two clinical series. Whilst this study is limited by self-report being used to identify the drug(s) involved in the presentations, previous studies have demonstrated that self-report is reliable in emergency department presentations with acute drug toxicity.

CONCLUSION

This study directly compares presentations with acute drug toxicity related to the lone use of cannabis or synthetic cannabinoid receptor agonists. It supports previous findings of increased neuropsychiatric toxicity from synthetic cannabinoid receptor agonists compared to cannabis and provides further data on cardiovascular toxicity in lone cannabis use.

Reduced fetal cerebral blood flow predicts perinatal mortality in a mouse model of prenatal alcohol and cannabinoid exposure

BACKGROUND

Children exposed prenatally to alcohol or cannabinoids individually can exhibit growth deficits and increased risk for adverse birth outcomes. However, these drugs are often co-consumed and their combined effects on early brain development are virtually unknown. The blood vessels of the fetal brain emerge and mature during the neurogenic period to support nutritional needs of the rapidly growing brain, and teratogenic exposure during this gestational window may therefore impair fetal cerebrovascular development.

STUDY DESIGN

To determine whether prenatal polysubstance exposure confers additional risk for impaired fetal-directed blood flow, we performed high resolution in vivo ultrasound imaging in C57Bl/6J pregnant mice. After pregnancy confirmation, dams were randomly assigned to one of four groups: drug-free control, alcohol-exposed, cannabinoid-exposed or alcohol-and-cannabinoid-exposed. Drug exposure occurred daily between Gestational Days 12-15, equivalent to the transition between the first and second trimesters in humans. Dams first received an intraperitoneal injection of either cannabinoid agonist CP-55,940 (750 µg/kg) or volume-equivalent vehicle. Then, dams were placed in vapor chambers for 30 min of inhalation of either ethanol or room air. Dams underwent ultrasound imaging on three days of pregnancy: Gestational Day 11 (pre-exposure), Gestational Day 13.5 (peri-exposure) and Gestational Day 16 (post-exposure).

RESULTS

All drug exposures decreased fetal cranial blood flow 24-hours after the final exposure episode, though combined alcohol and cannabinoid co-exposure reduced internal carotid artery blood flow relative to all other exposures. Umbilical artery metrics were not affected by drug exposure, indicating a specific vulnerability of fetal cranial circulation. Cannabinoid exposure significantly reduced cerebroplacental ratios, mirroring prior findings in cannabis-exposed human fetuses. Post-exposure cerebroplacental ratios significantly predicted subsequent perinatal mortality (p = 0.019, area under the curve, 0.772; sensitivity, 81%; specificity, 85.70%) and retroactively diagnosed prior drug exposure (p = 0.005; AUC, 0.861; sensitivity, 86.40%; specificity, 66.7%).

CONCLUSIONS

Fetal cerebrovasculature is significantly impaired by exposure to alcohol or cannabinoids, and co-exposure confers additional risk for adverse birth outcomes. Considering the rising potency and global availability of cannabis products, there is an imperative for research to explore translational models of prenatal drug exposure, including polysubstance models, to inform appropriate strategies for treatment and care in pregnancies affected by drug exposure.

Association of cannabis, cannabidiol and synthetic cannabinoid use with mental health in UK adolescents

BACKGROUND

Cannabis has been associated with poorer mental health, but little is known of the effect of synthetic cannabinoids or cannabidiol (often referred to as CBD).

AIMS

To investigate associations of cannabis, synthetic cannabinoids and cannabidiol with mental health in adolescence.

METHOD

We conducted a cross-sectional analysis with 13- to 14-year-old adolescents across England and Wales in 2019-2020. Multilevel logistic regression was used to examine the association of lifetime use of cannabis, synthetic cannabinoids and cannabidiol with self-reported symptoms of probable depression, anxiety, conduct disorder and auditory hallucinations.

RESULTS

Of the 6672 adolescents who participated, 5.2% reported using of cannabis, 1.9% reported using cannabidiol and 0.6% reported using synthetic cannabinoids. After correction for multiple testing, adolescents who had used these substances were significantly more likely to report a probable depressive, anxiety or conduct disorder, as well as auditory hallucinations, than those who had not. Adjustment for socioeconomic disadvantage had little effect on associations, but weekly tobacco use resulted in marked attenuation of associations. The association of cannabis use with probable anxiety and depressive disorders was weaker in those who reported using cannabidiol than those who did not. There was little evidence of an interaction between synthetic cannabinoids and cannabidiol.

CONCLUSIONS

To our knowledge, this study provides the first general population evidence that synthetic cannabinoids and cannabidiol are associated with probable mental health disorders in adolescence. These associations require replication, ideally with prospective cohorts and stronger study designs.

Potential neonatal toxicity of new psychoactive substances

Cannabis, cocaine, 3,4-methylenedioxymethamphetamine, and lysergic acid diethylamide are psychoactive substances with a significant increase in consumption during the 21st century due to their popularity in medicinal and recreational use. New psychoactive substances (NPSs) mimic established psychoactive substances. NPSs are known as being natural and safe to consumers; however, they are neither natural nor safe, causing severe adverse reactions, including seizures, nephrotoxicity, and sometimes death. Synthetic cannabinoids, synthetic cathinones, phenethylamines, and piperazines are all examples of NPSs. As of January 2020, nearly 1000 NPSs have become documented. Due to their low cost, ease of availability, and difficulty of detection, misuse of NPSs has become a familiar and growing problem, especially in adolescents and young adults in the past decade. The use of NPSs is associated with higher risks of unplanned sexual intercourse and pregnancy. As many as 4 in 100 women seeking treatment for substance abuse are pregnant or nursing. Animal studies and human clinical case reports have shown that exposure to certain NPSs during lactation periods has toxic effects on neonates, increasing various risks, including brain damage. Nevertheless, neonatal toxicity effects of NPSs are usually unrecognized and overlooked by healthcare professionals. In this review article, we introduce and discuss the potential neonatal toxicity of NPSs, emphasizing synthetic cannabinoids. Utilizing the established prediction models, we identify synthetic cannabinoids and their highly accumulative metabolites in breast milk.

Synthetic cannabinoid-associated acute interstitial nephritis: An emerging cause of pediatric acute kidney injury?

Synthetic cannabinoid (SCB) usage among children is a rapidly emerging public health concern in the United States. Acute kidney injury (AKI) is an uncommon manifestation of SCB usage, with acute tubular necrosis (ATN) as the predominant histology. Here we describe a 16-year-old adolescent who sustained severe non-oliguric AKI in association with SCB usage. Emesis, right flank pain, and hypertension were the presenting clinical features. There was no uveitis, skin rash, joint pains, or eosinophilia. Urinalysis showed absence of proteinuria or hematuria. Urine toxicology was negative. Renal sonogram showed bilateral echogenic kidneys. Renal biopsy demonstrated severe acute interstitial nephritis (AIN), mild tubulitis, and absence of ATN. AIN responded with pulse steroid followed by oral steroid. Renal replacement therapy was not required. Although the exact pathophysiology of SCB-associated AIN is not known, immune response elicited by the renal tubulointerstitial cells against the antigens present in the SCB is the most likely mechanism. A high index of suspicion for SCB-induced AKI is necessary in adolescents who present with AKI of unclear etiology.

Effect of new legislation in Germany on prevalence and harm of synthetic cannabinoids

CONTEXT

New psychoactive substances (NPS) have become an ongoing threat to public health. To prevent the emergence and spread of NPS, a new German law, the 'NpSG' took effect in November 2016. This study presents an overview of analytically confirmed synthetic cannabinoid (SC) intoxications from January 2015 to December 2018. In order to demonstrate effects of the NpSG, the results of 23 month before and 25 month after the introduction of the law were compared.

METHODS

Within the scope of a prospective observational study blood and urine samples were collected from emergency patients with suspected NPS intoxication. Comprehensive drug analyses were performed by LC-MS/MS analysis.

RESULTS

In the period considered, 138 patients were included. Within these, SC intake was verified in 65 patients (73%) in the period before the law change, and in 30 patients (61%) after. The median age increased significantly from 19.5 to 26 years. Seizures and admission to the ICU were reported significantly less frequently (seizures 29% versus 6.7%, p = 0.0283; ICU admission 42% versus 13%, p = 0.0089). 34 different SCs were detected, including four SCs (Cumyl-PEGACLONE, 5 F-MDMB-P7AICA, EG-018, 5 F-Cumyl-P7AICA) not covered by the NpSG at the time of detection. In the first period the most prevalent SC was MDMB-CHMICA (n = 24). 5 F-ADB was the most prevalent SC overall, detected in 7 patients (11%) in the first, and in 24 patients (80%) in the second period.

CONCLUSION

The number of SC intoxications decreased overall after the implementation of the NpSG. The shift in the detected SCs can be considered a direct effect of the NpSG but unfortunately the market supply does not appear to have been reduced. Although changes in the age distribution and in the severity of intoxications may be seen as secondary effects of the law, the main objectives of the new law to prevent the emergence and spread of further chemical variations of known scheduled drugs, have apparently not been achieved from the perspective of this study.

Behavioral and Molecular Responses to Exogenous Cannabinoids During Pentylenetetrazol-Induced Convulsions in Male and Female Rats

Epilepsy is a disabling, chronic brain disease,affecting ~1% of the World’s population, characterized by recurrent seizures (sudden, uncontrolled brain activity), which may manifest with motor symptoms (e.g., convulsions) or non-motor symptoms. Temporal lobe epilepsies (TLE) compromising the hippocampus are the most common form of focal epilepsies. Resistance in ~1/3 of epileptic patients to the first line of treatment, i.e., antiepileptic drugs (AEDs), has been an important motivation to seek alternative treatments. Among these, the plant Cannabis sativa (commonly known as marihuana) or compounds extracted from it (cannabinoids) have gained widespread popularity. Moreover, sex differences have been proposed in epilepsy syndromes and in cannabinoid action. In the hippocampus, cannabinoids interact with the CB1R receptor whose membrane levels are regulated by β-Arrestin2, a protein that promotes its endocytosis and causes its downregulation. In this article, we evaluate the modulatory role of WIN 55,212-2 (WIN), a synthetic exogenous cannabinoid on behavioral convulsions and on the levels of CB1R and β-Arrestin2 in female and male adolescent rats after a single injection of the proconvulsant pentylenetetrazol (PTZ). As epilepsies can have a considerable impact on synaptic proteins that regulate neuronal toxicity, plasticity, and cognition, we also measured the levels of key proteins markers of excitatory synapses, in order to examine whether exogenous cannabinoids may prevent such pathologic changes after acute seizures. We found that the exogenous administration of WIN prevented convulsions of medium severity in females and males and increased the levels of phosphorylated CaMKII in the hippocampus. Furthermore, we observed a higher degree of colocalization between CB1R and β-Arrestin2 in the granule cell layer.

The Potential Proconvulsant Effects of Cannabis: a Scoping Review

INTRODUCTION

Cannabis' effect on seizure activity is an emerging topic that remains without consensus and merits further investigation. We therefore performed a scoping review to identify the available evidence and knowledge gaps within the existing literature on cannabis product exposures as a potential cause of seizures in humans.

METHODS

A scoping review was conducted in accordance with the PRISMA Extension for Scoping Reviews guidelines. The PubMed and Scopus databases were searched over a 20-year period from the date of the database query (12/21/2020). Inclusion criteria were (1) English language original research articles, (2) inclusion of human subjects, and (3) either investigation of seizures as a part of recreational cannabinoid use OR of exogenous cannabinoids as a cause of seizures.

RESULTS

A total of 3104 unique articles were screened, of which 68 underwent full-text review, and 13 met inclusion/exclusion criteria. Ten of 11 studies evaluating acute cannabis exposures reported a higher seizure incidence than would be expected based on the prevalence of epilepsy in the general and pediatric populations (range 0.7-1.2% and 0.3-0.5% respectively). The remaining two studies demonstrated increased seizure frequency and/or seizure-related hospitalization in recreational cannabis users and those with cannabis use disorder.

CONCLUSIONS

This scoping review demonstrates that a body of literature describing seizures in the setting of cannabis exposure exists, but it has several limitations. Ten identified studies showed a higher than expected incidence of seizures in populations exposed to cannabis products. Based on the Bradford Hill criteria, delta-9 tetrahydrocannabinol (THC) may be the causative xenobiotic for this phenomenon.

Metabolic Profiles of 5F-MDMB-PICA in Human Urine, Serum, and Hair Samples Using LC-Q Exactive HF MS

In 2020, 5F-MDMB-PICA (5F-MDMB-2201) was one of the most common synthetic cannabinoids (SCs) identified in drugs seized by the Beijing Drug Control Agency and it was categorized as Schedule II by the United Nations Office on Drugs and Crime (UNODC) in March 2020. It is difficult to detect 5F-MDMB-PICA in biological matrices due to its fast metabolic rate in vivo. In this work, 5F-MDMB-PICA metabolic profiles were investigated by liquid chromatography-Q Exactive HF Hybrid Quadrupole-Orbitrap mass spectrometry (LC-QE-HF-MS), with accurate mass measurements in human urine, serum, and pubic hair. To obtain intact metabolites, solid-phase extraction (SPE) for urine and serum and direct ultrasonic extraction for pubic hair were applied to clean the samples without enzymatic hydrolysis. The differences in 5F-MDMB-PICA metabolism in the three different matrices were compared for the first time to determine the best detection biomarkers for monitoring 5F-MDMB-PICA misuse. Urine samples were determined to be the preferred biological material for identifying 5F-MDMB-PICA abuse. Forty-seven intact metabolites were detected in human urine, the ester-hydrolyzed with glucuronidated metabolite in urine samples can be used as the primary biomarker to identify drug misuse. Fifteen metabolites were found in serum samples. Ester hydrolysis was considered to be the major metabolic pathway, and a large number of metabolites were involved with it. Zero metabolites apart from the parent drug were detected in pubic hair samples. Twenty-eight new metabolites and their metabolic pathways were characterized and tentatively identified by LC-QE-HF-MS, and a new potential biomarker (M5 Ester hydrolysis + propionic acid) was also identified.

Chronic cannabinoid exposure produces tolerance to the dopamine releasing effects of WIN 55,212-2 and heroin in adult male rats

Synthetic cannabinoids were introduced into recreational drug culture in 2008 and quickly became one of the most commonly abused drugs in the United States. The neurobiological consequences resulting from synthetic cannabinoid repeated exposure remain poorly understood. It is possible that a blunted dopamine (DA) response may lead drug users to consume larger quantities to compensate for this form of neurochemical tolerance. Because the endogenous cannabinoid and opioid systems exhibit considerable cross-talk and cross-tolerance frequently develops following repeated exposure to either opioids or cannabinoids, there is interest in investigating whether a history of synthetic cannabinoid exposure influences the ability of heroin to increase DA release. To test the effects of chronic cannabinoid exposure on cannabinoid- and heroin-evoked DA release, male adult rats were treated with either vehicle or a synthetic cannabinoid (WIN55-212-2; WIN) using an intravenous (IV) dose escalation regimen (0.2-0.8 mg/kg IV over 9 treatments). As predicted, WIN-treated rats showed a rightward shift in the dose-response relationship across all behavioral/physiological measures when compared to vehicle-treated controls. Then, using fast-scan cyclic voltammetry to measure changes in the frequency of transient DA events in the nucleus accumbens shell of awake and freely-moving rats, it was observed that the DA releasing effects of both WIN and heroin were significantly reduced in male rats with a pharmacological history of cannabinoid exposure. These results demonstrate that repeated exposure to the synthetic cannabinoid WIN can produce tolerance to its DA releasing effects and cross-tolerance to the DA releasing effects of heroin.

Synthesis and in Vitro Cannabinoid Receptor 1 Activity of Recently Detected Synthetic Cannabinoids 4F-MDMB-BICA, 5F-MPP-PICA, MMB-4en-PICA, CUMYL-CBMICA, ADB-BINACA, APP-BINACA, 4F-MDMB-BINACA, MDMB-4en-PINACA, A-CHMINACA, 5F-AB-P7AICA, 5F-MDMB-P7AICA, and 5F-AP7AICA

Synthetic cannabinoid receptor agonists (SCRAs) are an evolving class of new psychoactive substances (NPS) with structurally diverse compounds emerging each year. Due to the rapid pace at which these drugs enter the market, there is often little or nil information regarding the pharmacology of these substances despite widespread human use. In this study, 12 recently emerged SCRAs (reported between 2018 and 2020) were synthesized, analytically characterized, and pharmacologically evaluated using a live cell-based nanoluciferase complementation reporter assay that monitors in vitro cannabinoid receptor type 1 (CB1) activation via its interaction with β-arrestin 2 (βarr2). All synthesized SCRAs acted as agonists of CB1, although differences in potency (EC₅₀ = 2.33-5475 nM) and efficacy (E_max = 37-378%) were noted, and several structure-activity relationships were identified. SCRAs featuring indazole cores (EC₅₀ = 2.33-159 nM) were generally of equal or greater potency than indole analogues (EC₅₀ = 32.9-330 nM) or 7-azaindole derivatives (EC₅₀ = 64.0-5475 nM). Interestingly, with the exception of APP-BINACA (E_max = 75.7%) and 5F-A-P7AICA (E_max = 37.4%), all SCRAs showed greater efficacy than the historical SCRA JWH-018 to which responses were normalized (E_max = 142-378%). The most potent CB1 agonists in the study were ADB-BINACA (EC₅₀ = 6.36 nM), 4F-MDMB-BINACA (EC₅₀ = 7.39 nM), and MDMB-4en-PINACA (EC₅₀ = 2.33 nM). Notably, all of these SCRAs featured an indazole core as well as a "bulky" tert-butyl moiety in the pendant amino acid side chain. This study confirms that recently detected SCRAs 4F-MDMB-BICA, 5F-MPP-PICA, MMB-4en-PICA, CUMYL-CBMICA, ADB-BINACA, APP-BINACA, 4F-MDMB-BINACA, MDMB-4en-PINACA, A-CHMINACA, 5F-AB-P7AICA, 5F-MDMB-P7AICA, and 5F-AP7AICA were all able to activate the CB1 receptor in vitro, albeit to different extents, and are potentially psychoactive in vivo. These results indicate that further evaluation of these widely used NPS is warranted to better understand the risks associated with human consumption of these drugs.

The other side of the leaf: Seizures associated with synthetic cannabinoid use

There has recently been a marked rise in the medicinal use of cannabis for epilepsy and multiple other conditions. While seizures have been reported in association with synthetic cannabinoids, the clinical features and prognosis have not been studied. Thirty patients with a history of seizures occurring within 24 h of synthetic cannabinoid use were identified from a first seizure clinic database in Perth, Western Australia between 2011 and 2016. Eight had a prior history of seizures, three related to synthetic cannabinoid use, with an additional three patients having risk factors for seizures. The presenting event was a tonic-clonic seizure in 27 patients (90%). "Kronic" was the synthetic cannabinoid used by 16 patients. Absorption was via smoking in all cases, with seizures occurring within 30 min of inhalation in 14 patients (46%). Electroencephalography (EEG) showed epileptiform abnormalities in 11%, and neuroimaging revealed epileptogenic lesions in 12%. Nine of 24 patients with follow-up had subsequent seizures, occurring in the setting of further synthetic cannabinoid use in two patients. This seizure recurrence rate is similar to seizures provoked by other acute systemic insults. In conclusion, smoking of some synthetic cannabinoids is associated with seizures, and this may relate to an intrinsic proconvulsant effect.