Impact of Cannabis Use on the Development of Psychotic Disorders

Substance-Use Disorders in Critically Ill Patients: A Narrative Review

Substance-use disorders (SUDs) represent a major public health concern. The increased prevalence of SUDs within the general population has led to more patients with SUD being admitted to intensive care units (ICUs) for an SUD-related condition or with SUD as a relevant comorbidity. Multiprofessional providers of critical care should be familiar with these disorders and their impact on critical illness. Management of critically ill patients with SUDs is complicated by both acute exposures leading to intoxication, the associated withdrawal syndrome(s), and the physiologic changes associated with chronic use that can cause, predispose patients to, and worsen the severity of other medical conditions. This article reviews the epidemiology of substance use in critically ill patients, discusses the identification and treatment of common intoxication and withdrawal syndromes, and provides evidence-based recommendations for the management of patients exposed to chronic use.

Ketamine-dependent patients with persistent psychosis have higher neurofilament light chain levels than patients with schizophrenia

OBJECTIVES

Ketamine can induce persisting psychosis in a subset of individuals who use it chronically and heavily. Previously, we found that the psychopathology and cognitive impairments in patients with ketamine dependence (KD) exhibiting persistent psychosis (KPP) bear resemblances with schizophrenia, albeit with less severity in those with no persistent psychosis (KNP). Furthermore, we also showed that patients with KD had higher blood levels of neurofilament light chain (NFL), a biomarker for neuroaxonal injury, compared to healthy controls. In this study, we aimed to investigate the differences in NFL levels between patients with KPP and KNP while comparing the levels of individuals with schizophrenia and healthy controls.

METHODS

We enrolled 64 treatment-seeking ketamine-dependent patients (53 with KNP and 11 with KPP), 37 medication-free patients with schizophrenia, and 80 healthy controls. Blood NFL levels were measured by single molecule array immunoassay.

RESULTS

NFL levels were highest in the KPP subgroup, followed by the KNP subgroup, and then the schizophrenia and control groups (mean ± SD: 24.5 ± 24.7, 12.9 ± 10.9, 9.2 ± 12.2, and 6.2 ± 2.2 pg/mL, respectively), with no significant difference observed between the schizophrenia and control groups.

CONCLUSIONS

We found that KD is associated with higher NFL levels compared to schizophrenia, with the KPP subgroup showing the most consistent alterations. The observation of accentuated neuroaxonal pathology in individuals with KPP implies that this clinical manifestation is associated with a specific neurobiological phenotype, despite prior evidence suggesting syndromal similarity between schizophrenia and KPP.

RETRACTED: Left hemisphere lateralization of the limbic system and frontoparietal network (FPN) correlates with positive and negative symptom improvement following cannabidiol (CBD) administration in psychosis and ultra-high risk (UHR) populations: A voxel-wise meta-analysis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the authors when they discovered and reported to the editors that articles containing population samples drawn from similar cohorts of healthy participants without psychosis were erroneously included in the psychosis subgroup of the meta-analysis. This error in the systematic review processes ultimately affects the findings in the meta-analysis. The authors deeply apologize for this error.

Investigating Cannabis-Use Among Students Attending High Schools Within the Cherokee Nation Reservation 2017 and 2019

Oklahoma's medical cannabis is some of the least restrictive in the US. Previous research suggests that American Indian/Alaska Native (AIAN) have higher rates of cannabis use than other racial or ethnic groups. The goals of this paper are, first, to look at cannabis use among high school students living on the Cherokee Nation Reservation before (2017) and after (2019) medical cannabis because legal in Oklahoma (2018) utilizing the Cherokee Nation Youth Risk Behavior Survey (CNYRBS). Second, to describe the socio-demographic characteristics of youth using cannabis in the Cherokee Nation Reservation. Data were retrieved from the 2017 and 2019 CNYRBS. The data for this study included 1,216 high school students who completed the 2017 and 1,476 who completed the 2019 CNYRBS. After removal of incomplete records, there were 2,602 students whose data was analyzed in this study. Data were weighted to be representative of public-school students attending grades 9-12 within Cherokee Nation Reservation. Despite the legalization of medical cannabis in Oklahoma in 2018, there was no change in cannabis use among youth between 2017 and 2019. There were variations in cannabis use based on demographic factors and other substance uses. AIAN individuals had higher odds of current cannabis use compared to non-Hispanic White students, but there were no differences based on ethnicity. Additionally, the use of cigarettes, e-cigarettes, alcohol, and illegal drugs were associated with increased odds of cannabis use among both current and former users compared to those who had never used it. There was no spike in use among youth at least immediately after the legalization of cannabis in the Cherokee Nation Reservation. There were socio-demographic as well as substance use disparities in the use of cannabis.

Beneficial effects of cannabidiol from Cannabis

Cannabis, traditionally used for recreation due to psychoactive compounds in its leaves, flowers, and seeds, has not been thoroughly explored for potential therapeutic benefits. Δ9-trans-Tetrahydrocannabinol, a key cannabinoid in cannabis, causes hallucinogenic effects and delirium symptoms. In contrast, cannabidiol (CBD) does not induce hallucinations and has shown effectiveness in treating symptoms of various rare, incurable diseases. Cannabis exhibits neuroprotective, anti-inflammatory, anti-thrombotic, anti-bacterial, analgesic, and antiepileptic properties, recently attracting more attention. This review aims to summarize comprehensively the impact of cannabis on human health, focusing on endocannabinoids and their receptors. It also delves into recent CBD research advancements, highlighting the compound’s potential medical applications. Overall, this paper provides valuable insights into the prospective development of medical cannabis, with a particular emphasis on CBD.

Variations of cannabis-related adverse mental health and addiction outcomes across adolescence and adulthood: A scoping review

Introduction

Evidence supporting associations between cannabis use and many health outcomes is growing, however it remains unclear how such associations vary across the lifespan. We therefore aim to answer the following questions: (1) Are the risks of cannabis's adverse effects on mental health and addiction-related outcomes different in adolescents than in adults? (2) What are the relationships between these cannabis's adverse effects and (a) an individual's age at first cannabis use, (b) age at assessment, and (c) duration of cannabis use?

Methods

We searched Medline, Embase, CINAHL, and PsychINFO from inception to 18 October 2021. Two reviewers independently screened studies and descriptively synthesized results.

Results

We included 140 studies. Cannabis effects on mental health and addiction-related outcomes were worse in adolescents, early cannabis initiators and cannabis users who consumed for longest periods. Evidence of worse long-term adverse effects in adolescents was substantial for psychosis, cannabis, and nicotine use disorders; mixed for depression, suicidality, other substance use and disorders; and limited for anxiety. Additionally, acute cannabis exposure had the opposite trend with adults more often reporting adverse effects than adolescents.

Conclusion

The available evidence suggests that cannabis use should be delayed as late as possible in adulthood and shortened in duration across the lifespan to decrease the risk of negative outcomes, while emphasizing the need for adapted harm reduction approaches. This scoping review provides evidence on the role of age and duration of exposure as determinants of cannabis-related adverse effects, which may inform prevention and harm reduction strategies.

Systematic review registration

https://doi.org/10.17605/OSF.IO/BYG72.

Cannabis medicinal: puntos críticos para su uso clínico

El cannabis se ha utilizado desde la antigüedad con fines recreativos y medicinales. Es una fuente muy rica de compuestos químicos, la mayoría denominados fitocannabinoides, que tienen una variedad de efectos fisiológicos, principalmente por su unión a receptores cannabinoides endógenos como el CB1 y CB2, entre otros.El cannabis tiene propiedades terapéuticas potenciales y sus preparaciones se han utilizado como remedios tradicionales para tratar el dolor y la emesis. Los cannabinoides sintéticos se utilizan clínicamente como analgésicos, antiespasmódico, antieméticos y estimulantes del apetito. La toxicidad significativa del cannabis es poco común en los adultos, sin embargo, puede tener múltiples efectos adversos agudos y crónicos. La calidad de la evidencia en este campo se ha visto limitada por la corta duración de los estudios, los reducidos tamaños de las muestras, la falta de grupos de control y la existencia de sesgos en la mayoría de los estudios revisados. En este contexto, son necesarios más estudios de mejor calidad metodológica para apoyar el uso seguro de esta terapia en otras enfermedades. La decisión de incorporar los cannabinoides como terapia en alguna de las condiciones descritas depende de la evidencia, el uso de terapias previas y el tipo de paciente.

Safety and Efficacy of Medical Cannabis in Autism Spectrum Disorder Compared with Commonly Used Medications

Objective: The objective of this study was to evaluate the safety and efficacy of medications commonly used in autism spectrum disorder (ASD) and compare this to what current research has shown regarding medical cannabis use in this population. Methods: Searches were performed to collect information surrounding currently used medications and their safety and efficacy profiles, biologic plausibility of cannabis use for symptoms of ASD, and studies detailing cannabis' safety and efficacy profile for use in the ASD population. Results were used to compare medications to cannabis as a proposed treatment. Results: The heterogeneity of ASD produces great difficulties in finding appropriate treatment, leading to many medication changes or treatment trials throughout a patient's life. Commonly prescribed medications display varying levels of efficacy, safety, and tolerability between patients and symptoms targeted. Some of the most common side effects cited are also considered the most troubling symptoms associated with ASD; aggression, anxiety, irritability, and a negative effect on cognition, leading many patients to discontinue use as the side effects outweigh benefits. Recent case reports and retrospective studies have displayed the potential efficacy, safety, and tolerability of cannabidiol (CBD)-rich medical cannabis use for treating both core symptoms of ASD and many comorbid symptoms such as irritability and sleep problems. Studies have also identified circulating endocannabinoids as a possible biomarker for ASD, providing another possible method of diagnosis. Conclusions: Currently, there are no approved medications for the core symptoms of ASD and only two medications Food and Drug Administration approved for associated irritability. Prescribed medications for symptoms associated with ASD display varying levels of efficacy, safety, and tolerability among the heterogeneous ASD population. At the time of this study there are no published placebo-controlled trials of medical cannabis for ASD and the observational studies have limitations. CBD-rich medical cannabis seems to be an effective, tolerable, and relatively safe option for many symptoms associated with ASD, however, the long-term safety is unknown at this time.

Timing of cannabis exposure relative to prodrome and psychosis onset in a community-based first episode psychosis sample

Cannabis has been implicated as both a potential cause and adverse prognostic factor in psychotic disorders. Investigating the contributory role of cannabis toward the overall burden of psychotic illnesses may represent an important step toward psychosis prevention and treatment. The current study samples consecutive admissions (N = 246) to two community based first-episode psychosis services to characterize timing of cannabis use relative to psychosis and attenuated symptom onset, differences between those with and without cannabis exposure, and the association of age at first cannabis exposure with clinical and demographic variables. Both cannabis exposure (78%) and cannabis use disorders (47%) were highly prevalent at admission. In 94% of participants, cannabis use preceded the onset of both attenuated and full-threshold psychosis symptoms by several years. Earlier age at first exposure to cannabis was associated with younger age at prodrome and psychosis onset, worse premorbid functioning, and greater severity of cannabis use disorder at admission. The timing of first exposure to cannabis may have individual prognostic as well as public health significance. Documenting the prevalence and impact of cannabis use in early psychosis samples, as well as the overall incidence of psychotic disorders, will be of vital public health significance as the United States enacts cannabis legalization and cannabis products become more widely available.

Therapeutic Potential of Cannabis, Cannabidiol, and Cannabinoid-Based Pharmaceuticals

<b><i>Background:</i></b> There is a growing interest in the use of cannabis (and its extracts), as well as CBD oil (hemp extracts containing cannabidiol), for therapeutic purposes. While there is reason to believe that cannabinoids may be efficacious for a number of different diseases and syndromes, there exist limited objective data supporting the use of crude materials (CBD oil, cannabis extracts, and/or cannabis itself). <b><i>Summary:</i></b> In the present review, we examined data for pure cannabinoid compounds (dronabinol, nabilone, and CBD), as well as partially purified medicinal cannabis extracts (nabiximols), to provide guidance on the potential therapeutic uses of high-THC cannabis and CBD oil. In general, data support a role for cannabis/cannabinoids in pain, seizure disorders, appetite stimulation, muscle spasticity, and treatment of nausea/vomiting. Given the biological activities of the cannabinoids, there may be utility in treatment of central nervous system disorders (such as neurodegenerative diseases, PTSD, and addiction) or for the treatment of cancer. However, those data are much less compelling. <b><i>Key Message:</i></b> On balance, there are reasons to support the potential use of medical cannabis and cannabis extract (Δ⁹-THC-dominant or CBD-dominant), but much more careful research is required.

Cannabis and Mental Health: Adverse Outcomes and Self-Reported Impact of Cannabis Use by Mental Health Status

Background: Cannabis can induce negative outcomes among consumers with mental health conditions. This study examined medical help-seeking behavior, patterns of adverse effects, and perceived impacts of cannabis among consumers with and without mental health conditions. Methods: Data came from the International Cannabis Policy Study, via online surveys conducted in 2018. Respondents included 6,413 past 12-month cannabis consumers aged 16-65, recruited from commercial panels in Canada and the US. Regression models examined differences in adverse health effects and perceived impact of cannabis among those with and without self-reported past 12-month experience of anxiety, depression, PTSD, bipolar disorder, psychosis. Results: Overall, 7% of past 12-month consumers reported seeking medical help for adverse effects of cannabis, including panic, dizziness, nausea. Help-seeking was greater for those with psychosis (13.8%: AOR = 1.78; 1.11-2.87), depression (8.9%: AOR = 1.57; 1.28-1.93), and bipolar disorder (10.1%: AOR = 1.53; 1.44-2.74). Additionally, 54.1% reported using cannabis to manage symptoms of mental health, with higher rates among those with bipolar (90.8%) and PTSD (90.7%). Consumers reporting >1 condition were more likely to perceive positive impacts on friendships, physical/mental health, family life, work, studies, quality of life (all p < .001). Consumers with psychosis were most likely to perceive negative effects across categories. Conclusion: For conditions with substantial evidence suggesting cannabis is harmful, greater help-seeking behaviors and self-perceived negative effects were observed. Consumers with mental health conditions generally perceive cannabis to have a positive impact on their lives. The relationship between cannabis and mental health is disorder specific and may include a combination of perceived benefits and harms.

Cannabis-related emergency department visits by youths and their outcomes in Ontario: a trend analysis

BACKGROUND

Cannabis-related emergency department visits can be an entry point for youths to mental health and substance use care systems. We aimed to examine trends in cannabis-related emergency department visits as a function of youths' age and sex.

METHODS

Using administrative data, we examined all visits to emergency departments in Ontario, Canada, from 2003 to 2017, by youth aged 10-24 years (grouped as 10-13, 14-18 and 19-24 yr) to determine trends in cannabis-related emergency department visits. Cannabis-related visits were identified using International Statistical Classification of Diseases and Related Health Problems, 10th Revision codes for cannabis poisoning and mental disorders due to cannabinoids. We categorized presentations as "less severe" versus "more severe" using scores assigned by nurses at triage.

RESULTS

We examined 14 697 778 emergency department visits. Cannabis-related visits increased from 3.8 per 10 000 youths (95% confidence interval [CI] 3.5-4.0) in 2003 to 17.9 (95% CI 17.4-18.4) in 2017, a 4.8-fold increase (95% CI 4.4-5.1). Rates increased for both sexes and each age group. Males were more likely to have a visit than females (rate ratios ≥ 1.5 in 2003 and 2017). The number of cannabis-related visits in 2017 was 25.0 per 10 000 (95% CI 24.0-25.9) among youth aged 19-24 years, 21.9 per 10 000 (95% CI 20.9-22.9) among those aged 14-18 years, and 0.8 per 10 000 (95% CI 0.5-1.0) among those aged 10-13 years. In 2017, 88.2% (95% CI 87.3%-89.0%) of cannabis-related visits and 58.1% (95% CI 58.0%-58.2%) of non-cannabis-related visits were triaged as "more severe," (rate ratio 1.52, 95% CI 1.50-1.53). Similarly, in 2017, 19.0% (95% CI 18.0%-20.1%) of cannabis-related visits and 5.8% (95% CI 5.7%-5.8%) of non-cannabis-related visits resulted in hospital admission (rate ratio 3.3, 95% CI 3.1-3.5).

INTERPRETATION

Rates of cannabis-related emergency department visit by youths aged 10-24 years increased almost fivefold from 2003 to 2017, with increases in visit severity and hospital admissions. These trends describe an emerging public health problem, and research is needed to identify the causes of this increase and the health and social consequences of cannabis-related visits for these youths.

Cannabis-induced dysphoria/paranoia mediates the link between childhood trauma and psychotic-like experiences in young cannabis users

Childhood trauma (abuse and neglect) is a major risk factor for cannabis use disorder and psychotic-spectrum disorders. Psychotic-like experiences (PLEs) in young people who use cannabis may be an early indicator of psychosis risk following cannabis use. We examined whether (i) childhood trauma moderates the association between cannabis use and PLEs, (ii) the association between childhood trauma and cannabis use is mediated by subjective effects of cannabis (euphoria and dysphoria/paranoia), and (iii) the association between childhood trauma and PLEs is also mediated by these subjective effects. Participants were 2630 cannabis users (aged 16-25) recruited online. They were asked to complete a cross-sectional survey measuring cannabis and other substance use, childhood trauma, PLEs, and the subjective effects of cannabis (euphoria and dysphoria/paranoia). A significant interaction indicated that the effect of cannabis on PLE frequency was stronger for individuals with more severe childhood trauma. Childhood trauma was also associated with greater cannabis use and PLE frequency, both of which were mediated by subjective dysphoria/paranoia when using the drug. This suggests childhood trauma is associated with greater PLEs in young people who use cannabis, which may be linked with an increased susceptibility to the dysphoric/paranoid subjective effects when using the drug. Childhood trauma should be addressed early in young people who use cannabis to mitigate the psychosis-associated harms of the drug.

Form and content of Jamaican cannabis edibles

BACKGROUND

In 2017, the Jamaican government banned the sale of cannabis-infused edibles after reports of over-intoxication in adults and children. There is a general lack of public awareness regarding the risk involved with edible dosage. Vandrey et al. in 2015 reported that random cannabis edibles sampled from dispensaries in California and Washington in the USA failed to meet the basic labeling standards for pharmaceuticals (Vandrey et al.; JAMA 2015). This study aims to measure the levels of THC and CBD in a variety of edibles available locally in order to establish current cannabinoid content and to report on safety and packaging. This study is deemed necessary as no such study has been done to measure the potency levels of edibles and to raise awareness of the potential risk to children.

METHODS

Forty-five cannabis-infused edible items were collected as convenience samples over a 4-year period (2014-2018) and analyzed. The QuEChERS technique (modified) was used to extract cannabinoids from each item. The extracts were then derivatized with MSTFA prior to analysis by gas chromatography-mass spectrometry (GC-MS). The descriptive statistics were calculated using the Statistical Package for Social Sciences-SPSS Software. Descriptive statistics presented include the mean, median, standard deviation, and range for each product category. The distribution of data with a box and whisker plot and frequency of THC to CBD ratios with a histogram was also presented.

RESULTS

Edibles on the Jamaican market comprise baked goods, candies, frozen foods, and beverages. Eighty-six percent of samples were poorly labeled and failed to meet basic labeling requirements. None of the packages were observed to be child-proof. THC levels ranged from 0.01 to 99.9 mg per product while CBD levels ranged from 0.001 to 69.2 mg per product. The highest THC and CBD levels were detected in cookies and brownies. Thirty percent of the samples had THC levels greater than the recommended 10 mg THC per serving.

CONCLUSION

The lack of proper labeling and the wide range of THC levels in cannabis edibles raises public health concerns for all consumers including inexperienced persons who may be at a greater risk of overdosing. Concern must also be raised over the possibility that the attractive and tasty ways in which the drug is being presented might tempt young children and teens to take cannabis. Impact statement It is hoped that this information will raise public awareness of the current potential danger these edibles pose to children and inexperienced users and that policymakers will see the need for the imposition of suitable regulations.

Cannabis: A Toxin-Producing Plant with Potential Therapeutic Uses

For thousands of years, Cannabis sativa has been utilized as a medicine and for recreational and spiritual purposes. Phytocannabinoids are a family of compounds that are found in the cannabis plant, which is known for its psychotogenic and euphoric effects; the main psychotropic constituent of cannabis is Δ9-tetrahydrocannabinol (Δ9-THC). The pharmacological effects of cannabinoids are a result of interactions between those compounds and cannabinoid receptors, CB1 and CB2, located in many parts of the human body. Cannabis is used as a therapeutic agent for treating pain and emesis. Some cannabinoids are clinically applied for treating chronic pain, particularly cancer and multiple sclerosis-associated pain, for appetite stimulation and anti-emesis in HIV/AIDS and cancer patients, and for spasticity treatment in multiple sclerosis and epilepsy patients. Medical cannabis varies from recreational cannabis in the chemical content of THC and cannabidiol (CBD), modes of administration, and safety. Despite the therapeutic effects of cannabis, exposure to high concentrations of THC, the main compound that is responsible for most of the intoxicating effects experienced by users, could lead to psychological events and adverse effects that affect almost all body systems, such as neurological (dizziness, drowsiness, seizures, coma, and others), ophthalmological (mydriasis and conjunctival hyperemia), cardiovascular (tachycardia and arterial hypertension), and gastrointestinal (nausea, vomiting, and thirst), mainly associated with recreational use. Cannabis toxicity in children is more concerning and can cause serious adverse effects such as acute neurological symptoms (stupor), lethargy, seizures, and even coma. More countries are legalizing the commercial production and sale of cannabis for medicinal use, and some for recreational use as well. Liberalization of cannabis laws has led to increased incidence of toxicity, hyperemesis syndrome, lung disease cardiovascular disease, reduced fertility, tolerance, and dependence with chronic prolonged use. This review focuses on the potential therapeutic effects of cannabis and cannabinoids, as well as the acute and chronic toxic effects of cannabis use on various body systems.

Adolescent Gender Identity, Sexual Orientation, and Cannabis Use: Potential Mediations by Internalizing Disorder Risk

BACKGROUND/AIMS

Adolescents who identify as nonbinary gender or as not heterosexual report higher levels of mental illness than their counterparts. Cannabis use is a commonly employed strategy to cope with mental illness symptoms among adolescents; however, cannabis use can have many deleterious health consequences for youth. Within the frame of minority stress theory, this study investigates the relationships between gender identity and sexual orientation, internalizing disorder symptoms, and cannabis use among adolescents.

METHOD

A national cross-sectional survey of a generalizable sample of high school students in Canada from the 2017 wave (N = 15,191) of the Cancer Risk Assessment in Youth Survey was analyzed in spring 2019. Mediation analyses were completed to examine risk of internalizing disorder symptoms as a potential mediator of the association between (1) gender identity and (2) sexual orientation, and cannabis use.

RESULTS

Indirect effects in all models show significantly higher levels of reported internalizing disorder symptoms for female (OR = 3.44, 95% CI [2.84, 4.18]) and nonbinary gender (OR = 3.75, 95% CI [2.16, 6.51]) compared with male students. Sexual minority adolescents had higher odds of internalizing disorder risk relative to non-sexual minority adolescents (OR = 3.13, 95% CI [2.63, 3.74]). Students who reported higher rates of internalizing disorder symptoms were more likely to have ever used cannabis. Patterns of partial mediation are also present among all groups.

DISCUSSION/CONCLUSIONS

Findings can be used to better inform mental health interventions for adolescents. Future study should explore specific mental health stressors of vulnerable adolescent groups with respect to cannabis use as a coping mechanism.

Patterns of brain function associated with cannabis cue-reactivity in regular cannabis users: a systematic review of fMRI studies

RATIONALE

Regular cannabis use (i.e. ≥ monthly) is highly prevalent, with past year use being reported by ~ 200 million people globally.High reactivity to cannabis cues is a key feature of regular cannabis use and has been ascribed to greater cannabis exposure and craving, but the underlying neurobiology is yet to be systematically integrated.

OBJECTIVES

We aim to systematically summarise the findings from fMRI studies which examined brain function in cannabis users while exposed to cannabis vs neutral stimuli during a cue-reactivity fMRI task.

METHODS

A systematic search of PsycINFO, PubMed and Scopus databases was pre-registered in PROSPERO (CRD42020171750) and conducted following PRISMA guidelines. Eighteen studies met inclusion/exclusion criteria. Samples comprised 918 participants (340 female) aged 16-38 years. Of these, 603 were regular cannabis users, and 315 were controls.

RESULTS

The literature consistently reported greater brain activity in cannabis users while exposed to cannabis vs neutral stimuli in three key brain areas: the striatum, the prefrontal (anterior cingulate, middle frontal) and the parietal cortex (posterior cingulate/precuneus) and additional brain regions (hippocampus, amygdala, thalamus, occipital cortex). Preliminary correlations emerged between cannabis craving and the function of partially overlapping regions (amygdala, striatum, orbitofrontal cortex ).

CONCLUSIONS

Exposure to cannabis-cues may elicit greater brain function and thus trigger cravings in regular cannabis users and thus trigger cannabis craving. Standardised and longitudinal assessments of cannabis use and related problems are required to profile with greater precision the neurobiology of cannabis cue-reactivity, and its role in predicting  cravings and relapse.

The Behavioral Sequelae of Cannabis Use in Healthy People: A Systematic Review

Background: Cannabis is known to have a broad range of effects on behavior, including experiencing a "high" and tranquility/relaxation. However, there are several adverse behavioral sequalae that can arise from cannabis use, depending on frequency of use, potency (e.g., THC content), age of onset, and cumulative exposure. This systematic review examined evidence for cannabis-related adverse behavioral sequalae in otherwise healthy human subjects. Methods: Following PRISMA guidelines, we conducted a systematic review of cross-sectional and longitudinal studies from 1990 to 2020 that identified cannabis-related adverse behavioral outcomes in subjects without psychiatric and medical co-morbidities from PubMed and PsychInfo searches. Key search terms included "cannabis" OR "tetrahydrocannabinol" OR "cannabidiol" OR "marijuana" AND "anxiety" OR "depression" OR "psychosis" OR "schizophrenia" "OR "IQ" OR "memory" OR "attention" OR "impulsivity" OR "cognition" OR "education" OR "occupation". Results: Our search detected a total of 2,870 studies, from which we extracted 124 relevant studies from the literature on cannabis effects in the non-clinical population. Effects of cannabis on several behavioral sequelae including cognition, motivation, impulsivity, mood, anxiety, psychosis intelligence, and psychosocial functioning were identified. The preponderance of the evidence suggests that frequency of cannabis use, THC (but not CBD) content, age of onset, and cumulative cannabis exposure can all contribute to these adverse outcomes in individuals without a pre-existing medical condition or psychiatric disorder. The strongest evidence for the negative effects of cannabis are for psychosis and psychosocial functioning. Conclusions: Although more research is needed to determine risk factors for development of adverse behavioral sequelae of cannabis use, these findings underline the importance of understanding vulnerability to the adverse effects of cannabis, which has implications for prevention and treatment of problematic cannabis use.

Prospects for the Use of Cannabinoids in Psychiatric Disorders

Increasing evidence suggests an essential role of the endocannabinoid system in modulating cognitive abilities, mood, stress, and sleep. The psychoactive effects of cannabis are described as euphoric, calming, anxiolytic, and sleep-inducing and positively affect the mood, but can also adversely affect therapy. The responses to cannabinoid medications depend on the patient's endocannabinoid system activity, the proportion of phytocannabinoids, the terpenoid composition, and the dose used. There is some evidence for a therapeutic use of phytocannabinoids in psychiatric conditions. THC and CBD may have opposing effects on anxiety. Current guidelines recommend caution in using THC in patients with anxiety or mood disorders. In a small number of clinical trials, cannabinoids used to treat cancer, HIV, multiple sclerosis, hepatitis C, Crohn's disease, and chronic neuropathic pain report decreases in anxiety or depression symptoms and presented sedative and anxiolytic effects. Several studies have investigated the influence of potential genetic factors on psychosis and schizophrenia development after cannabis use. THC may increase the risk of psychosis, especially in young patients with an immature central nervous system. There is limited evidence from clinical trials that cannabinoids are effective therapy for sleep disorders associated with concomitant conditions. There is evidence for a possible role of cannabis as a substitute for alcohol and drugs, also in the context of the risks of opioid use (e.g., opioid-related mortality). In this narrative review of the recent evidence, we discuss the prospects of using the psychoactive effects of cannabinoids in treating mental and psychiatric disorders. However, this evidence is weak for some clinical conditions and well-designed randomized controlled trials are currently lacking. Furthermore, some disorders may be worsened by cannabis use.

Do the Transmissible Liability Index (TLI) and Adolescent Cannabis Use Predict Paranoid and Schizotypal Symptoms at Young Adulthood?

Background: Adolescent cannabis use is an established risk factor for the development of psychosis, but the premorbid vulnerability factors and specificity versus generality of the psychotic symptom domains affected in cannabis-psychosis relationships remain incompletely understood. To improve our understanding of these relationships, we used longitudinal data to examine the individual and interactive effects of preadolescent transmissible liability to substance use disorders (SUD), measured via the transmissible liability index (TLI), and adolescent cannabis use on the development of two distinct psychotic symptom domains, paranoid and schizotypal personality traits in young adulthood. Methods: We performed secondary analysis of data from the Center for Education and Drug Abuse (CEDAR) study, which longitudinally assessed offspring of men with (N = 211) and without (N = 237) lifetime history of SUD at ages 10-12, and across adolescence as they transitioned to young adulthood. TLI scores were calculated at age 10-12, self-reported cannabis use was assessed at age 16, and paranoid and schizotypal symptoms were assessed at age 19. Results: Cannabis use at age 16 and family history of SUD were significantly associated with paranoid and schizotypal symptoms at age 19, but TLI scores were not. The interactive effect of TLI x cannabis use was also not significant. Paranoid and schizotypal symptoms showed different dose-dependent sensitivities to cannabis exposure at age 16. Conclusions: These findings indicate that adolescent cannabis use and family history of SUD differentially contribute to the development of paranoid and schizotypal personality traits through mechanisms that do not include behavioral disinhibition.

Psychotic experiences from preadolescence to adolescence: when should we be worried about adolescent risk behaviors?

Psychotic experiences (PE), below the threshold of psychotic disorder, are common in the general population. PE are associated with risk behaviors such as suicidality, non-suicidal self-injury (NSSI) and substance use. However, PE as specific or causal phenomena of these risk behaviors are still debated. We aimed to examine the longitudinal trajectories of PE from preadolescence to adolescence and their associated risk behaviors in adolescence. A total of 1138 adolescents from the Copenhagen Child Cohort 2000 were assessed for PE and risk behaviors (NSSI, suicide ideation and -attempts and substance use) at age 11 and 16 years, along with measures of general psychopathology and depressive symptoms specifically. Self-reported impact of general psychopathology tended to be associated with more PE persistence. PE were associated with all risk behaviors in cross section at both follow-ups. Persistent PE from ages 11 to 16 and incident PE at age 16 were associated with risk behaviors at age 16, whereas remitting PE from age 11 to 16 were not. After adjustment for co-occurring depressive symptoms and general psychopathology, all associations were markedly reduced. After exclusion of preadolescents who already had expressed risk behavior at age 11, PE in preadolescence did not stand out as an independent predictor of incident adolescent risk behaviors. The current study suggests that PE in preadolescence and adolescence may not play a direct causal role regarding NSSI, suicidality, and substance use. However, PE are still useful clinical markers of severity of psychopathology and associated risk behaviors.

Possible therapeutic applications of cannabis in the neuropsychopharmacology field

Cannabis use induces a plethora of actions on the CNS via its active chemical ingredients, the so-called phytocannabinoids. These compounds have been frequently associated with the intoxicating properties of cannabis preparations. However, not all phytocannabinoids are psychotropic, and, irrespective of whether they are psychotropic or not, they have also shown numerous therapeutic properties. These properties are mostly associated with their ability to modulate the activity of an intercellular communication system, the so-called endocannabinoid system, which is highly active in the CNS and has been found altered in many neurological disorders. Specifically, this includes the neuropsychopharmacology field, with diseases such as schizophrenia and related psychoses, anxiety-related disorders, mood disorders, addiction, sleep disorders, post-traumatic stress disorder, anorexia nervosa and other feeding-related disorders, dementia, epileptic syndromes, as well as autism, fragile X syndrome and other neurodevelopment-related disorders. Here, we gather, from a pharmacological and biochemical standpoint, the recent advances in the study of the therapeutic relevance of the endocannabinoid system in the CNS, with especial emphasis on the neuropsychopharmacology field. We also illustrate the efforts that are currently being made to investigate at the clinical level the potential therapeutic benefits derived from elevating or inhibiting endocannabinoid signaling in animal models of neuropsychiatric disorders.

Cannabis use among U.S. adolescents in the era of marijuana legalization: a review of changing use patterns, comorbidity, and health correlates

Decriminalization, medicalization, and legalization of cannabis use by a majority of U.S. states over the past 25 years have dramatically shifted societal perceptions and use patterns among Americans. How marijuana policy changes have affected population-wide health of U.S. youth and what the downstream public health implications of marijuana legalization are topics of significant debate. Cannabis remains the most commonly used federally illicit psychoactive drug by U.S. adolescents and is the main drug for which U.S. youth present for substance use treatment. Converging evidence indicates that adolescent-onset cannabis exposure is associated with short- and possibly long-term impairments in cognition, worse academic/vocational outcomes, and increased prevalence of psychotic, mood, and addictive disorders. Odds of negative developmental outcomes are increased in youth with early-onset, persistent, high frequency, and high-potency Δ-9-THC cannabis use, suggesting dose-dependent relationships. Cannabis use disorders are treatable conditions with clear childhood antecedents that respond to targeted prevention and early intervention strategies. This review indicates that marijuana policy changes have had mixed effects on U.S. adolescent health including potential benefits from decriminalization and negative health outcomes evidenced by increases in cannabis-related motor vehicle accidents, emergency department visits, and hospitalizations. Federal and state legislatures should apply a public health framework and consider the possible downstream effects of marijuana policy change on paediatric health.

Cannabis Surveillance With Twitter Data: Emerging Topics and Social Bots

Objectives. To use publicly accessible data from people who post to Twitter to rapidly capture and describe the public's recent experiences with cannabis.Methods. We obtained Twitter posts containing cannabis-related terms from May 1, 2018, to December 31, 2018. We used methods to distinguish between posts from social bots and nonbots. We used text classifiers to identify topics in posts (n = 60 861).Results. Prevalent topics of posts included using cannabis with mentions of cannabis initiation, processed cannabis products, and health and medical with posts suggesting that cannabis could help with cancer, sleep, pain, anxiety, depression, trauma, and posttraumatic stress disorder. Polysubstance use was a common topic with mentions of cocaine, heroin, ecstasy, LSD, meth, mushrooms, and Xanax along with cannabis. Social bots regularly made health claims about cannabis.Conclusions. Findings suggest that processed cannabis products, unsubstantiated health claims about cannabis products, and the co-use of cannabis with legal and illicit substances warrant considerations by public health researchers in the future.

First Episode Psychosis Medical Workup: Evidence-Informed Recommendations and Introduction to a Clinically Guided Approach

Evaluating the patient with first episode psychosis (FEP) requires a careful assessment that includes a thorough history, examination, and workup. This begins with a thoughtful consideration of the differential diagnoses and is followed and supported by laboratory, encephalographic, and imaging studies where appropriate. This article presents some of the diagnostic considerations for a patient presenting with psychosis with an emphasis on the secondary causes and proposes a tiered approach to the workup of FEP that is clinically guided.

[Cannabis use in subjects at ultra high risk for psychosis]

Cannabis use is widespread among people at ultra-high risk (UHR) for psychosis. The causal link as well as the temporal link between cannabis use and further occurrence of psychosis in UHR people remain inconclusive. Current science data supported an increased risk of transition to psychosis in cannabis users who are genetically predisposed to psychosis. This risk would be even greater in the presence of a family history of psychosis, in case of a strong use and an early onset use. Several models have been cited to explain the link between cannabis use and the subsequent onset of psychosis or prepsychotic states: cannabis-induced modifications of some brain structures, a dysregulation of the hypothalamic-pituitary axis and an alteration of normal neurological development via the endocannabinoid system. Cannabis represents a modifiable risk for psychosis. Current interventions aim to reduce or stop the cannabis use in order to reduce the risk of transition to psychosis.

Cannabis Consumption in People Living with HIV: Reasons for Use, Secondary Effects, and Opportunities for Health Education

Introduction: Rates of cannabis consumption range from 40% to 74% among people living with HIV (PLWH). Little is known about the reasons for cannabis use, related modes of administration, effectiveness for symptom relief, or undesirable effects in the modern antiretroviral therapy (ART) era. Our aim was to conduct an exploratory study to identify potential areas for further evaluation and intervention. Materials and Methods: From January to June 2018, health care providers at the Chronic Viral Illness Service in Montreal, Canada, asked their patients about cannabis use during routine visits. Patients reporting cannabis use were invited to complete a 20-min coordinator-administered questionnaire. Questions related to patterns of use, modes of administration, reasons for use, secondary effects, and HIV health-related factors (e.g., adherence to ART). Results: One hundred and four PLWH reporting cannabis use participated. Median age was 54 years (interquartile range [IQR] 46-59), 13% were female, and 42% were HIV-Hepatitis C co-infected. Median CD4 count was 590 cells/mm³ (IQR 390-821), 95% of participants were on ART, and 88% had suppressed viral loads. Reported cannabis use was more than once daily (32%); daily (25%); weekly (22%); monthly (17%); and rarely (twice to thrice per year; 6%). The majority of participants (97%) smoked dry plant cannabis. Other modes included vaping (12%), capsules (2%), edibles (21%), and oils (12%). Common reasons for cannabis use were for pleasure (68%) and to reduce anxiety (57%), stress (55%), and pain (57%). Many participants found cannabis "quite effective" or "extremely effective" (45%) for symptom relief. Secondary effects included feeling high (74%), increased cough (45%), paranoia (22%), palpitations (20%), and increased anxiety (21%). Over two-thirds of participants indicated that secondary effects were not bothersome at all. Most participants (68%) rarely missed doses of their ART, while 27% missed occasionally (once to twice per month). The most commonly accessed sources of information about cannabis were friends (77%) and the internet (55%). Conclusion: The most common reasons for cannabis use in our population were for pleasure, followed by reduction of stress/anxiety and symptoms associated with a medical condition. Most smoke cannabis and rate cannabis as quite effective for symptom relief. While many participants experience secondary effects, most are not bothered by these symptoms. Amid widespread changes in the regulatory landscape of recreational cannabis, health care providers should be prepared to answer questions about cannabis.

What are the psychological effects of using synthetic cannabinoids? A systematic review

BACKGROUND

Synthetic cannabinoids are, typically, full agonists at the cannabinoid CB1 receptor, and therefore considerably more potent than natural cannabis and may have correspondingly more serious psychological effects. Despite government sanctions against their production they continue to be available in ever-increasing varieties over the Internet. The psychological consequences of synthetic cannabinoid use are relatively unknown.

AIM

The purpose of this study was to synthesise the available research on the psychological consequences of synthetic cannabinoid use.

METHOD

A literature search of three databases was conducted in February 2018, including the following keywords: Spice, synthetic cannabis, cognition, affect, behaviour, psychosis, depression and anxiety.

RESULTS

Seventeen studies involving a variety of participants were eligible for inclusion: one controlled administration study, seven cross-sectional studies, five Internet surveys and four qualitative studies. The controlled administration study showed that, compared to placebo, synthetic cannabinoids acutely affected some aspects of cognitive functioning and subjective psychological ratings. Non-controlled, cross-sectional studies generally showed that synthetic cannabinoid users had lower performance on cognitive tasks and showed elevated symptomatology (e.g. paranoia) compared to both natural cannabis and non-cannabis users. Methodological limitations were noted across different study designs. There is limited research on how doses, frequency or type of synthetic cannabinoid influence outcomes.

CONCLUSIONS

Acute synthetic cannabinoid use can result in a range of psychological outcomes and, when non-intoxicated, synthetic cannabinoid users appear to differ from natural cannabis and non-users on various affective and cognitive domains. As synthetic cannabinoid use is increasing in at-risk populations there is an urgent need for more and better research to inform users, professionals and policymakers.

Cannabis for refractory epilepsy in children: A review focusing on CDKL5 Deficiency Disorder

Severe paediatric epilepsies such as CDKL5 Deficiency Disorder (CDD) are extremely debilitating, largely due to the early-onset and refractory nature of the seizures. Existing treatment options are often ineffective and associated with a host of adverse effects, causing those that are affected to seek alternative treatments. Cannabis based products have attracted significant attention over recent years, primarily driven by reports of miraculous cures and a renewed public preference for 'natural' therapies, thus placing intense pressure on health professionals and the government for regulatory change. This study provides a comprehensive overview of the potential role for cannabis in the treatment of CDD. Key areas discussed include the history, mechanism of action, efficacy and safety of cannabis based preparations as well as the burden related to CDD. The evidence supports the use of cannabinoids, especially cannabidiol, in similar forms of refractory epilepsy including Dravet and Lennox-Gastaut syndromes. Evidence for cannabinoids specifically in CDD is limited but growing, with multiple anecdotal reports and an open-label trial showing cannabidiol to be associated with a significant reduction in seizure activity. This review provides the first comprehensive overview of the potential role for cannabis based preparations in the treatment of CDD and provides justification for further clinical and observational research.

Oral Cannabidiol Use in Children With Autism Spectrum Disorder to Treat Related Symptoms and Co-morbidities

Objective: Children with autism spectrum disorder (ASD) commonly exhibit comorbid symptoms such as aggression, hyperactivity and anxiety. Several studies are being conducted worldwide on cannabidiol use in ASD; however, these studies are still ongoing, and data on the effects of its use is very limited. In this study we aimed to report the experience of parents who administer, under supervision, oral cannabinoids to their children with ASD.

Methods: After obtaining a license from the Israeli Ministry of Health, parents of children with ASD were instructed by a nurse practitioner how to administer oral drops of cannabidiol oil. Information on comorbid symptoms and safety was prospectively recorded biweekly during follow-up interviews. An independent group of specialists analyzed these data for changes in ASD symptoms and drug safety.

Results: 53 children at a median age of 11 (4–22) year received cannabidiol for a median duration of 66 days (30–588). Self-injury and rage attacks (n = 34) improved in 67.6% and worsened in 8.8%. Hyperactivity symptoms (n = 38) improved in 68.4%, did not change in 28.9% and worsened in 2.6%. Sleep problems (n = 21) improved in 71.4% and worsened in 4.7%. Anxiety (n = 17) improved in 47.1% and worsened in 23.5%. Adverse effects, mostly somnolence and change in appetite were mild.

Conclusion: Parents’ reports suggest that cannabidiol may improve ASD comorbidity symptoms; however, the long-term effects should be evaluated in large scale studies.

First-Episode Psychosis from the Perspective of Family Members

The purpose of the current study was to explore family members' perceptions of the causes of first-episode psychosis (FEP). A qualitative study with 68 family members of patients with FEP was performed. Data were collected through semi-structured interviews and submitted for thematic analysis. The attributions for FEP were: use of psychoactive substances as a trigger; influence of genetic and personal factors; exposure to stressful life events; and lack of previous health care and knowledge about psychotic symptoms. Knowledge of possible attributions for the onset of psychosis may be valuable in optimizing early identification of individuals with FEP. [Journal of Psychosocial Nursing and Mental Health Services, 57(1), 34-42.].

Astrocytic Mechanisms Involving Kynurenic Acid Control Δ9-Tetrahydrocannabinol-Induced Increases in Glutamate Release in Brain Reward-Processing Areas

The reinforcing effects of Δ⁹-tetrahydrocannabinol (THC) in rats and monkeys, and the reinforcement-related dopamine-releasing effects of THC in rats, can be attenuated by increasing endogenous levels of kynurenic acid (KYNA) through systemic administration of the kynurenine 3-monooxygenase inhibitor, Ro 61-8048. KYNA is a negative allosteric modulator of α7 nicotinic acetylcholine receptors (α7nAChRs) and is synthesized and released by astroglia, which express functional α7nAChRs and cannabinoid CB1 receptors (CB1Rs). Here, we tested whether these presumed KYNA autoreceptors (α7nAChRs) and CB1Rs regulate glutamate release. We used in vivo microdialysis and electrophysiology in rats, RNAscope in situ hybridization in brain slices, and primary culture of rat cortical astrocytes. Acute systemic administration of THC increased extracellular levels of glutamate in the nucleus accumbens shell (NAcS), ventral tegmental area (VTA), and medial prefrontal cortex (mPFC). THC also reduced extracellular levels of KYNA in the NAcS. These THC effects were prevented by administration of Ro 61-8048 or the CB1R antagonist, rimonabant. THC increased the firing activity of glutamatergic pyramidal neurons projecting from the mPFC to the NAcS or to the VTA in vivo. These effects were averted by pretreatment with Ro 61-8048. In vitro, THC elicited glutamate release from cortical astrocytes (on which we demonstrated co-localization of the CB1Rs and α7nAChR mRNAs), and this effect was prevented by KYNA and rimonabant. These results suggest a key role of astrocytes in interactions between the endocannabinoid system, kynurenine pathway, and glutamatergic neurotransmission, with ramifications for the pathophysiology and treatment of psychiatric and neurodegenerative diseases.

A review of Indian research on co-occurring cannabis use disorders& psychiatric disorders

BACKGROUND & OBJECTIVES

Cannabis is a widely used illicit drug and its use is often associated with co-occurring psychiatric disorders. This systematic review was aimed to provide information on the published Indian studies on co-occurring cannabis use disorders and psychiatric disorders.

METHODS

An electronic search of available Indian literature using relevant search terms was carried out in May 2015 and 52 articles in English language published from India were included in the current review.

RESULTS

Studies on cannabis and associated psychotic disorders (n=16) chiefly described acute episodes with predominant positive symptoms, following cannabis use. Some studies (n=6) observed an overall increased prevalence of all psychiatric disorders and symptoms owing to cannabis use, while others (n=14) elaborated on high rates of substance use in those with psychiatric disorders. The effect of cannabis use on cognitive function was the focus of some of the Indian studies (n=7). All these studies barring one had all male subjects, and a single study described the service delivery model for those with dual diagnosis disorders in India. Most of the research used cross-sectional observational design and focussed on treatment-seeking population.

INTERPRETATION & CONCLUSIONS

A review of Indian literature on cannabis use and its association with psychiatric disorders indicates a high co-prevalence of psychotic disorders, especially in vulnerable individuals as well as high rates of co-occurrence of other psychiatric comorbidities. However, there is limited focus on exploring the aetiological association between cannabis use and psychiatric disorders; understanding the neurobiology of this association and management-related issues.

Interactions between cannabis and schizophrenia in humans and rodents

In this review, we provide an overview of the relationship between cannabis use and the development of schizophrenia, using both animal and human studies. We further discuss the potential neural mechanism that may mediate the relationship between cannabis use and schizophrenia symptoms. We finally provide clinical implications and future studies that can further elucidate the relationship between cannabis and schizophrenia.

Adolescent THC exposure in female rats leads to cognitive deficits through a mechanism involving chromatin modifications in the prefrontal cortex

BACKGROUND

Increasing cannabis consumption among adolescents, studies that link its early use with mental illnesses, and the political debate on cannabis legalization together call for an urgent need to study molecular underpinnings of adolescent brain vulnerability. The emerging role of epigenetic mechanisms in psychiatric diseases led us to hypothesize that epigenetic alterations could play a role in causes and subsequent development of the depressive/psychotic-like phenotype induced by adolescent, but not adult, Δ9-tetrahydrocannabinol (THC) exposure in female rats.

METHODS

We performed a time-course analysis of histone modifications, chromatin remodelling enzymes and gene expression in the prefrontal cortex of female rats after adolescent and adult THC exposure. We also administered a specific epigenetic drug (chaetocin) with THC to investigate its impact on THC-induced behavioural alterations.

RESULTS

Adolescent THC exposure induced alterations of selective histone modifications (mainly H3K9me3), impacting the expression of genes closely associated with synaptic plasticity. Changes in both histone modifications and gene expression were more widespread and intense after adolescent treatment, suggesting specific adolescent susceptibility. Adolescent THC exposure significantly increased Suv39H1 levels, which could account for the enhanced H3K9me3. Pharmacological blockade of H3K9me3 during adolescent THC treatment prevented THC-induced cognitive deficits, suggesting the relevant role played by H3K9me3 in THC-induced effects.

LIMITATIONS

Only female rats were investigated, and the expression studies were limited to a specific subset of genes.

CONCLUSION

Through a mechanism involving SUV39H1, THC modifies histone modifications and, thereby, expression of plasticity genes. This pathway appears to be relevant for the development of cognitive deficits.