Cannabis Use and Prospective Long-Term Association with Anxiety: A Systematic Review and Meta-Analysis of Longitudinal Studies: Usage du cannabis et association prospective à long terme avec l'anxiété: une revue systématique et une méta-analyse d'études longitudinales

Disproportionate increase in cannabis use among people with serious psychological distress and associations with psychiatric service use in the United States, 2009-2019

BACKGROUND

Cannabis use is on the rise, but it is unclear how use is changing among individuals with serious psychological distress (SPD) compared to the general population as well as what associations this may have with mental health service use.

METHODS

Retrospective cohort study using the National Survey on Drug Use and Health (NSDUH) 2009-19 public use files of 447,228 adults aged ≥ 18 years. Multivariable logistic regression and predictive margin methods were used to estimate linear time trends in any and greater-than-weekly levels of cannabis use by year and SPD status and rates of psychiatric hospitalization and outpatient mental health care.

FINDINGS

Rates of any and weekly-plus cannabis use increased similarly among individuals with SPD compared to those without from 200 to 2014 but more rapidly in SPD every year from 2015 to 2019 (p < 0.001). Among individuals with SPD, no use was associated with a 4.2 % probability of psychiatric hospitalization, significantly less than less-than-weekly (5.0 %, p = 0.037) and weekly-plus cannabis use (5.1 %, p = 0.028). For outpatient mental health care, no use was associated with a 27.4 % probability (95 % CI 26.7-28.1 %) of any outpatient care, significantly less than less than weekly use (32.6 % probability, p < 0.001) and weekly-plus use (29.9 % probability, p = 0.01).

CONCLUSIONS

Cannabis use is increasing more rapidly among individuals with SPD than the general population, and is associated with increased rates of psychiatric hospitalization and outpatient service use. These findings can inform policy makers looking to tailor regulations on advertising for cannabis and develop public health messaging on cannabis use by people with mental illness.

Effects of Recreational Cannabis Legalization on Mental Health: Scoping Review

OBJECTIVE

Recreational cannabis legalization (RCL) is expanding rapidly. RCL's effects on mental health issues are of particular concern because cannabis use is more frequent among people receiving psychiatric care and is associated with several psychiatric disorders. The authors conducted a scoping review to examine the evidence and discern gaps in the literature concerning the effects of RCL on mental health and to assess the factors responsible for an observed heterogeneity in research results.

METHODS

This scoping literature review followed PRISMA guidelines. Five databases-MEDLINE, CINAHL, Embase, APA PsycInfo, and Web of Science-were searched for English- or French-language reports published between January 1, 2012, and April 30, 2023.

RESULTS

Twenty-eight studies from the United States and Canada were found. The studies were classified by category of the study's data (patients receiving psychiatric care [k=1], death records [k=4], emergency department or hospital records [k=10], and the general population [k=13]) and by the diagnosis (schizophrenia or psychoses, mood disorders, anxiety disorders and symptoms, suicide or suicidal ideation, or other mental health issues) examined. The review findings revealed a paucity of research and indicated mixed and largely inconclusive results of the studies examined. Research gaps were found in the examination of potential changes in cannabis use patterns among people receiving psychiatric care and in the availability of longitudinal studies.

CONCLUSIONS

Clinicians, researchers, and policy makers need to collaborate to address the research gaps and to develop evidence-based policies that reflect a thorough understanding of the effects associated with RCL.

Understanding youth and young adult cannabis use in Canada post-legalization: a scoping review on a public health issue

BACKGROUND

Canada legalized recreational cannabis in 2018, and one of the primary objectives of the Cannabis Act was to protect youth by reducing their access to cannabis and providing public education. Canada has the highest prevalence of cannabis use worldwide, particularly among youth and young adults under the age of 25. Cannabis use is linked with many adverse effects for youth and young adults including psychosis, anxiety, depression, respiratory distress, cannabinoid hyperemesis syndrome, and impaired cognitive performance. Despite the high prevalence of cannabis use and the evolution of policies in Canada and globally, significant knowledge and research gaps remain regarding youth and young adult cannabis use. The aim of this scoping review is to map the extent, nature, and range of evidence available on youth and young adult cannabis use in Canada since its legalization, in order to strengthen policies, services, treatments, training, and public education strategies.

METHODS

Using a scoping review framework developed by Arksey and O'Malley, along with the PRISMA-ScR guidelines, we conducted a rigorous search in five academic databases: MEDLINE, Embase, APA PsycINFO, CINAHL and Web of Science Core Collection. We included empirical studies that collected data in Canada after the legalization of recreational cannabis (October 2018) and focused on youth or young adults < 30. Two reviewers independently screened articles in two stages and extracted relevant information from articles meeting the inclusion criteria.

RESULTS

Of the 47 articles meeting our inclusion criteria, 92% used quantitative methods, 6% were qualitative, and 2% used a mixed-methods approach. Over two-thirds (68%) used secondary data. These studies were categorized into six focus areas: (1) prevalence, patterns, and trends, (2) cannabis-related injuries and emergency department (ED) visits, (3) rates and patterns during the pandemic, (4) perceptions of cannabis use, (5) prevention tools, and (6) cannabis-related offenses. Key findings from the studies reviewed include an increase in cannabis use among 18-24-year-olds post-legalization, with mixed results for youth under 18. ED visits for intentional and unintentional cannabis-related injuries have increased in young children and teens. Perception studies show a mix of concern and normalization of cannabis use. Though limited, prevention studies are promising in raising awareness. A decline in cannabis-related offenses was noted by one study. The review highlights several research gaps, including the need for more qualitative data, disaggregation of demographic data, intervention research, and comprehensive studies on the physical and mental health impacts of cannabis use among youth and young adults.

CONCLUSION

Maintaining a public health approach is critical, with a focus on reducing the high prevalence of cannabis use among youth and young adults. This involves implementing prevention strategies to minimize harms, enhancing public education, minimizing commercialization, reducing youth access to cannabis, promoting guidelines for lower-risk cannabis use and harm reduction strategies, and increasing training for healthcare providers.

Cannabis use and its association with psychopathological symptoms in a Swiss adult population: a cross-sectional analysis

Background

As the most commonly used illicit substance, cannabis is gaining global acceptance through increasing legalization efforts. This shift intensifies the need for research to guide policymakers and healthcare providers in harm reduction and treatment strategies. Nonetheless, the relationship between psychopathological symptoms and cannabis use remains inadequately understood.

Methods

A sample of regular cannabis consumers completed self-reported assessments for depression (Patient Health Questionnaire-9), anxiety (General Anxiety Disorder-7), Attention-Deficit/Hyperactivity Disorder (ADHD; Adult ADHD Self-Report Scale V1.1), and psychosis (Early Recognition Inventory based on IRAOS) as well as previous black-market cannabis use patterns. Cannabis Use Disorder Identification Test Revised (CUDIT-R) was used to identify cannabis use disorder (CUD). To understand psychopathological symptom load related to cannabis consumption as well as cannabis use motives, multiple regression models were performed to identify psychopathological variables predicting cannabis use frequency and quantity. Linear regression and correlation analyses were conducted, adjusting for relevant covariates (age, gender, education, alcohol, other substance use).

Results

Three-hundred-sixty regular cannabis users interested in a study on regulated cannabis access in Basel, Switzerland were examined. In bivariate analysis, cannabis use frequency correlated with depressive (r(358) = 0.16, p = 0.003) and anxiety symptom load (r(358) = 0.11, p = 0.034). Cannabis quantity correlated with depressive (r(358) = 0.15, p = 0.005), ADHD (r(358) = 0.14, p = 0.008), and psychosis symptom load (r(358) = 0.16, p = 0.002). However, in the adjusted regression models only depressive and ADHD symptom loads were significantly associated with cannabis use frequency (p = 0.006 and p = 0.034, respectively) and quantity (p = 0.037 and p = 0.019, respectively). No significant correlations between cannabis consumption and anxiety or psychosis remained after adjustment.

Conclusion

ADHD and depressive symptoms correlate with increased cannabis use in a cohort of regular users, suggesting potential self-medication in nonclinical populations. With the rising availability of cannabis worldwide, these results highlight the necessity for longitudinal studies to disentangle the complex dynamics between cannabis consumption and mental health symptoms.

Perceptions, Experiences, and Patterns of Cannabis Use in Individuals with Mood and Anxiety Disorders in the Context of Cannabis Legalization and Medical Cannabis Program in Canada - A Qualitative Study

INTRODUCTION

Perceptions of cannabis as a potential medical treatment for mood and anxiety disorders have been increasing in the context of legalizations, availability, and medical cannabis programs, though current evidence predominately indicates risks and negative effects of cannabis use (CU) on mental health outcomes. This study aims to understand motivations, perceptions, effects, and patterns of CU in individuals with mood and anxiety disorders.

METHODS

Thirty-six adult patients diagnosed with mood or anxiety disorders, obsessive-compulsive disorder, or posttraumatic stress disorder who were currently using cannabis completed an in-depth qualitative interview on individual motivations, perceptions, experiences, effects, and patterns of their CU. The thematic analysis focused on phases of CU and sources of cannabis products and information.

RESULTS

Reported motivations for initiation of CU included curiosity, peer pressure, and dissatisfaction with conventional treatments. Factors such as psychotropic effects and coping with mental health symptoms and insomnia contributed to the continuation of CU. More negative effects, including cognitive dysfunction, worsening of mood, and anxiety symptoms, were acknowledged with ongoing CU. Concerning findings included common initiation of CU before age 18, combined medical and recreational CU, rare consultation of medical professionals on CU, and potential effects and harms.

DISCUSSION

Findings indicate individual complexity of motivations, perceptions, and patterns of CU in the study population. The reported potential beneficial effects of specific cannabis products should be further investigated. Findings emphasize patient-provider dialogue on both CU and conventional treatments. Information from this study can contribute to and inform the development of education, prevention, and intervention strategies.

Nicotine and Alcohol Use as Predictors of Recreational Cannabis Use in Adolescence: A Systematic Review and Narrative Synthesis

Background: The prevalence of recreational cannabis use among adolescents is a growing public health concern due to its link to short- and long-term adverse effects on adolescents' wellbeing, physical health, mental health, and interpersonal behaviors. Method: Five databases were searched from inception to March 17, 2023, for exposure (nicotine product, alcohol) and outcome (recreational cannabis) in adolescents (persons aged 10-19 years). The studies were screened independently by two reviewers, and the quality of the studies was assessed with Newcastle Ottawa and AXIS tool. PRISMA guidelines were employed in this review. Result: Twenty-one (21) studies involving 2,778,406 adolescents were included in the appraisal and heterogeneity was found among these studies. Ascertainment bias was commonly detected in thirteen (13) of the included studies. Among the substances examined as potential exposures, nicotine-product use emerged as a significant factor associated with future cannabis use among adolescents, particularly in mid-adolescence and in places where recreational cannabis use has been legalized. Conclusion: Current evidence suggests an association between nicotine-product use and subsequent recreational cannabis use among adolescents. However, further research is needed to establish causality between exposure to nicotine substances and the use of recreational cannabis within this age demographic. Additionally, there is a need for the development of prevention programs and targeted policies that continuously inform and update this vulnerable sub-population about the risks associated with cannabis use for leisure.

Cannabis use in adolescents and anxiety symptoms and disorders: a systematic review and meta-analysis

Background: The use of cannabis is highly prevalent during adolescence compared to the general adult population. In addition to the high comorbidity between cannabis use and anxiety disorders, early evidence suggests that cannabis may precede the development of anxiety. Moreover, adolescence represents a major developmental period for both neurobiological and psychological processes, placing these individuals at a heightened vulnerability to the influence of cannabis.Objectives: This systematic review and meta-analysis examined the prospective associations between adolescent cannabis use and subsequent anxiety outcomes (i.e. anxiety disorders and/or symptoms).Methods: Following PRISMA guidelines, a systematic review and meta-analysis were conducted encompassing data from articles published between database inception and September 2022.Results: Six longitudinal studies were identified for quantitative analysis, while twelve non-overlapping longitudinal studies were identified for qualitative review (total N = 18; 33380 subjects). Meta-analytical findings supported an association between adolescent cannabis use and the development of a subsequent anxiety disorder (Odds Ratio = 2.14, 95% CI: 1.37-3.36, p < .01). These findings were consistent with our qualitative synthesis where nine of the twelve longitudinal studies observed a significant relationship between adolescent cannabis use and exacerbation of anxiety symptoms later in life, irrespective of an anxiety disorder diagnosis.Discussion: In summary, the current evidence suggests a prospective association between adolescent cannabis use and later anxiety symptoms and disorders. These findings underscore the importance of refining research methodologies, considering sex-based differences and controlling for confounding factors, as well as implementing educational initiatives and developing clinical interventions to address the mental health risks associated with cannabis use among adolescents.

Long-term Effects of Cannabidiol and/or Fentanyl Exposure in Rats Submitted to Neonatal Pain

The current study aimed to evaluate anxiety behavior, hippocampal ionized calcium-binding adaptor molecule 1 (Iba1) and cannabinoid receptor 1 (CB1) gene expression, and nociceptive response in adulthood after a combination of fentanyl and cannabidiol (CBD) for nociceptive stimuli induced during the first week of life in rats. Complete Freund's adjuvant-induced inflammatory nociceptive insult on postnatal day (PN) 1 and PN3. Both fentanyl and CBD were used alone or in combination from PN1 to PN7. Behavioral and nociceptive tests were performed at PN60 and PN62. The expression of the microglial calcium-binding proteins Iba1 and CB1 was detected in the hippocampus using reverse Quantitative polymerase chain reaction (qPCR) and immunohistochemistry. Our results suggest that the anxiety behavior response and immune activation in adult life depend on the CBD dose combined with fentanyl for the nociceptive stimuli induced during the first week of life. Treatment of neonatal nociceptive insult with CBD and opioids showed significant dose-dependent and male-female differences. The increased gene expression in the hippocampus of the analyzed cannabinoid gene supports this data. In addition, treatment with fentanyl led to an increase in CB1 protein expression. Moreover, the expression of Iba1 varied according to the administered dose of CBD and may or may not be associated with the opioid. A lower dose of CBD during the inflammatory period was associated with enhanced anxiety in adult life. PERSPECTIVE: The treatment of nociceptive stimuli with CBD and opioids during the first week of life demonstrated significant sex differences in adult life on anxiety behavior and supraspinal pain sensitivity.

Associations Between Cannabis Use and Mental Distress in Young People: A Longitudinal Study

PURPOSE

Despite a large number of studies on the relation between cannabis use and mental distress in adolescence, results are inconclusive regarding the nature of this association. The aim of the present study is to expand this body of research by analyzing the within-person association between changes in cannabis use and changes in mental distress among young people.

METHODS

We used longitudinal data from a national sample of young people in Norway. The cohort was assessed in 1992 (T1), 1994 (T2), 1999 (T3), and 2005 (T4). The cumulative response rate was 60%. Respondents who participated in all four waves, aged 11-18 years at T1 (N = 1,988) were analyzed. Within-person association between changes in cannabis use and changes in mental distress in terms of symptoms of depression, anxiety, suicidal ideation, and deliberate self-harm were estimated by applying fixed-effects modeling.

RESULTS

For males, an increase in cannabis use from no use to more than 10 times/year was significantly associated with increased risk for anxiety (relative risk [RR]: 1.72, p = .009), depressed mood (RR: 1.49, p < .001), and suicidal ideation (RR: 3.43, p = .012). For females, the corresponding increase in cannabis use yielded an increased risk for anxiety (RR: 1.38, p = .023) and suicidal ideation (RR: 2.47, p = .002).

DISCUSSION

Increased cannabis use during adolescence and young adulthood seem to increase the risk for symptoms of mental distress. Although the associations appear to be more pronounced among males, it was only for depression that there was a statistically significant gender difference in the association.

Youth cannabis use and subsequent health service use for mood and anxiety disorders: A population-based cohort study

Epidemiologic research suggests a modest association between youth cannabis use and mood and anxiety disorders (MADs). However, current evidence is based mostly on cohort studies using data from the 20th century when cannabis was significantly less potent than today. We linked population-based survey data from 2009 to 2012 with administrative records of health services covered under universal healthcare up to 2017. The cohort included youth aged 12 to 24 years at baseline living in Ontario, Canada with no prior MAD health service use (n = 8,252). We conducted a multivariable Cox model to estimate the association between cannabis use frequency (never, Collapse

Key Words

• Anxiety disorders
• Cannabis
• Mood disorders
• Psychiatry
• Youth

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MESH Headings

• Humans
• Adolescent
• Anxiety Disorders/epidemiology
• Anxiety Disorders/therapy
• Cannabis
• Cohort Studies
• Ontario/epidemiology
• Hospitalization
• Patient Acceptance of Health Care

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Affiliation(s)

André J McDonald Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Peter Boris Centre for Addictions Research, St. Joseph's Healthcare Hamilton, Hamilton, Ontario, Canada; Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; Michael G. DeGroote Centre for Medicinal Cannabis Research, McMaster University, Hamilton, Ontario, Canada.
Paul Kurdyak Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; ICES, Toronto, Ontario, Canada; Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
Jürgen Rehm Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Institute of Clinical Psychology and Psychotherapy, Technische Universität Dresden, Dresden, Germany; Department of Psychiatry and Psychotherapy, Centre for Interdisciplinary Addiction Research (ZIS), University Medical Centre Hamburg-Eppendorf, Hamburg, Germany; Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
Michael Roerecke Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
Susan J Bondy Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada

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Unhealthy behaviors associated with mental health disorders: a systematic comparative review of diet quality, sedentary behavior, and cannabis and tobacco use

Background

There are well-established literatures documenting the associations between mental disorders and unhealthy behaviors such as poor diet quality, sedentary behavior, and cannabis and tobacco use. Few studies have attempted to understand the respective findings in light of each other, however.

Objective

The purpose of this review was to assemble comparable data for each behavior-disorder association and assess the associations in terms of their overall strength. The review aimed to include a representative, but not exhaustive, range of studies that would allow for explorative comparisons.

Methods

Eligible studies were identified via Pubmed searches and citation searching, restricted to publications no older than 2015 written in English. To obtain comparable data, only studies that reported findings as odds ratios were included, and risk of bias related to study samples, behavioral measurement disparities, and control variables was assessed via sensitivity analyses. Findings for each disorder were compared on the basis of different measures of central tendency.

Results

From 3,682 records, 294 studies were included. The review found evidence of associations between each of the four unhealthy behaviors and psychosis, depression, anxiety, bipolar disorder, attention-deficit/hyperactivity disorder (ADHD), and post-traumatic stress disorder (PTSD), while personality disorder was only investigated in relation to cannabis and tobacco use. In overall comparison, the associations were generally of similar strength, and only the association between cannabis use and personality disorder was exceptional in terms of being significantly stronger than its counterparts across disorders and across behaviors. Analyses of bias risk identified some influence from behavioral measurement disparities and lack of adequate statistical control, but findings were generally robust across a range of sensitivity analyses.

Conclusion

This explorative and comparative review found that poor diet quality, sedentary behavior, and cannabis and tobacco use are about equally strongly associated with a range of different mental disorders. Given the general nature of these associations, we should probably understand them to reflect a general and shared etiology. However, the findings in this review should be regarded as tentative until confirmed by more comprehensive investigations.

Cannabis Is Not Doping

The World Anti-Doping Agency (WADA) classifies cannabis, all phytocannabinoids, and synthetics as doping, except for CBD. For agency, a method for doping substance must meet two criteria: performance enhancement (ergogenicity), health risk, or violation of the spirit of sports. Cannabis is neither ergogenic nor ergolytic (performance worsens), and the health risks for athletes are overestimated after 20 years of research. The significant problem remains in the complex (and difficult interpretation) definition of the spirit of sports, which transcends the objectives of sports excellence (performance and injury prevention) for moral policing. This perspective presents an evidence-based counterargument recommending the removal of cannabis and phytocannabinoids from the WADA Prohibited List.

Balancing risks and benefits of cannabis use: umbrella review of meta-analyses of randomised controlled trials and observational studies

OBJECTIVE

To systematically assess credibility and certainty of associations between cannabis, cannabinoids, and cannabis based medicines and human health, from observational studies and randomised controlled trials (RCTs).

DESIGN

Umbrella review.

DATA SOURCES

PubMed, PsychInfo, Embase, up to 9 February 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Systematic reviews with meta-analyses of observational studies and RCTs that have reported on the efficacy and safety of cannabis, cannabinoids, or cannabis based medicines were included. Credibility was graded according to convincing, highly suggestive, suggestive, weak, or not significant (observational evidence), and by GRADE (Grading of Recommendations, Assessment, Development and Evaluations) (RCTs). Quality was assessed with AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2). Sensitivity analyses were conducted.

RESULTS

101 meta-analyses were included (observational=50, RCTs=51) (AMSTAR 2 high 33, moderate 31, low 32, or critically low 5). From RCTs supported by high to moderate certainty, cannabis based medicines increased adverse events related to the central nervous system (equivalent odds ratio 2.84 (95% confidence interval 2.16 to 3.73)), psychological effects (3.07 (1.79 to 5.26)), and vision (3.00 (1.79 to 5.03)) in people with mixed conditions (GRADE=high), improved nausea/vomit, pain, spasticity, but increased psychiatric, gastrointestinal adverse events, and somnolence among others (GRADE=moderate). Cannabidiol improved 50% reduction of seizures (0.59 (0.38 to 0.92)) and seizure events (0.59 (0.36 to 0.96)) (GRADE=high), but increased pneumonia, gastrointestinal adverse events, and somnolence (GRADE=moderate). For chronic pain, cannabis based medicines or cannabinoids reduced pain by 30% (0.59 (0.37 to 0.93), GRADE=high), across different conditions (n=7), but increased psychological distress. For epilepsy, cannabidiol increased risk of diarrhoea (2.25 (1.33 to 3.81)), had no effect on sleep disruption (GRADE=high), reduced seizures across different populations and measures (n=7), improved global impression (n=2), quality of life, and increased risk of somnolence (GRADE=moderate). In the general population, cannabis worsened positive psychotic symptoms (5.21 (3.36 to 8.01)) and total psychiatric symptoms (7.49 (5.31 to 10.42)) (GRADE=high), negative psychotic symptoms, and cognition (n=11) (GRADE=moderate). In healthy people, cannabinoids improved pain threshold (0.74 (0.59 to 0.91)), unpleasantness (0.60 (0.41 to 0.88)) (GRADE=high). For inflammatory bowel disease, cannabinoids improved quality of life (0.34 (0.22 to 0.53) (GRADE=high). For multiple sclerosis, cannabinoids improved spasticity, pain, but increased risk of dizziness, dry mouth, nausea, somnolence (GRADE=moderate). For cancer, cannabinoids improved sleep disruption, but had gastrointestinal adverse events (n=2) (GRADE=moderate). Cannabis based medicines, cannabis, and cannabinoids resulted in poor tolerability across various conditions (GRADE=moderate). Evidence was convincing from observational studies (main and sensitivity analyses) in pregnant women, small for gestational age (1.61 (1.41 to 1.83)), low birth weight (1.43 (1.27 to 1.62)); in drivers, car crash (1.27 (1.21 to 1.34)); and in the general population, psychosis (1.71 (1.47 to 2.00)). Harmful effects were noted for additional neonatal outcomes, outcomes related to car crash, outcomes in the general population including psychotic symptoms, suicide attempt, depression, and mania, and impaired cognition in healthy cannabis users (all suggestive to highly suggestive).

CONCLUSIONS

Convincing or converging evidence supports avoidance of cannabis during adolescence and early adulthood, in people prone to or with mental health disorders, in pregnancy and before and while driving. Cannabidiol is effective in people with epilepsy. Cannabis based medicines are effective in people with multiple sclerosis, chronic pain, inflammatory bowel disease, and in palliative medicine but not without adverse events.

STUDY REGISTRATION

PROSPERO CRD42018093045.

FUNDING

None.

Perceptions of Safety of Daily Cannabis vs Tobacco Smoking and Secondhand Smoke Exposure, 2017-2021

Importance

While rates of cigarette use are declining, more US adults are using cannabis. Perceptions of safety are important drivers of substance use and public policy; however, little is known about the comparative views of US adults on tobacco and cannabis safety.

Objective

To compare public perceptions of safety of cannabis vs tobacco smoke and evaluate how perceptions may be changing over time.

Design, Setting, and Participants

This longitudinal survey study was conducted using a web-based survey administered in 2017, 2020, and 2021. US adults participating in Ipsos KnowledgePanel, a nationally representative, population-based survey panel, were included. Data were analyzed from March 2021 through June 2023.

Main Outcomes and Measures

Two questions directly compared the perception of safety of cannabis vs tobacco in terms of daily smoking and secondhand smoke exposure. Additional questions assessed perceptions of safety of secondhand tobacco smoke for adults, children, and pregnant women, with an analogous set of questions for secondhand cannabis smoke.

Results

A total of 5035 participants (mean [SD] age, 53.4 [16.2] years; 2551 males [50.7%]) completed all 3 surveys and provided responses for tobacco and cannabis risk questions. More than one-third of participants felt that daily smoking of cannabis was safer than tobacco, and their views increasingly favored safety of cannabis vs tobacco over time (1742 participants [36.7%] in 2017 vs 2107 participants [44.3%] in 2021; P < .001). The pattern was similar for secondhand cannabis smoke, with 1668 participants (35.1%) responding that cannabis was safer than tobacco in 2017 vs 1908 participants (40.2%) in 2021 (P < .001). Participants who were younger (adjusted odds ratio [aOR] for ages 18-29 years vs ≥60 years, 1.4 [95% CI, 1.1-1.8]; P = .01) or not married (aOR, 1.2 [95% CI, 1.0-1.4]; P = .01) were more likely to move toward safer views of cannabis use over time, while those who were retired (aOR vs working, 0.8 [95% CI, 0.7-0.9]; P = .01) were less likely to move toward a safer view of cannabis. Participants were also more likely to rate secondhand smoke exposure to cannabis vs tobacco as completely or somewhat safe in adults (629 participants [12.6%] vs. 119 participants [2.4%]; P < .001), children (238 participants [4.8%] vs. 90 participants [1.8%]; P < .001), and pregnant women (264 participants [5.3%] vs. 69 participants [1.4%]; P < .001).

Conclusions and Relevance

This study found that US adults increasingly perceived daily smoking and secondhand exposure to cannabis smoke as safer than tobacco smoke from 2017 to 2021. Given that these views do not reflect the existing science on cannabis and tobacco smoke, the findings may have important implications for public health and policy as the legalization and use of cannabis increase.

Youth cannabis use in Canada post-legalization: service providers' perceptions, practices, and recommendations

BACKGROUND

In 2018, Canada legalized recreational cannabis use with the purpose of protecting youth and restricting access. However, concerns have been raised that this objective has not been met as rates of cannabis use among youth aged 16-24 have not declined. Youth cannabis use is associated with various adverse effects including psychosis, anxiety, depression, suicidality, respiratory distress, cannabinoid hyperemesis syndrome, and intoxications. Service providers play a crucial role in addressing youth cannabis use. This study aimed to understand Ontario service providers' perceptions, practices, and recommendations on youth cannabis use.

METHODS

This mixed method study included a survey and two focus groups. The survey was distributed to mental health service providers serving youth aged 16-24 across Ontario who were given the option to participate in a focus group. The survey included closed and open-ended questions regarding perceptions, practices, and recommendations, while the focus groups explored these categories in greater depth. Descriptive statistics were used to analyze close-ended questions and interpretative content analysis was applied for open-ended questions. Focus group data were analyzed using thematic analysis.

RESULTS

The survey was completed by 160 service providers and 12 participated in two focus groups. Regarding perceptions, 60% of survey participants agreed with legalization, 26% had a strong understanding of medical versus recreational cannabis, 84% believed that cannabis has physical and mental health risks, and 49% perceived stigmatization. Less than half of the survey participants reported screening or assessing cannabis use, 16% stated they are highly familiar with treating cannabis use, and 67% reported that they rarely work with families. Subthemes identified in the focus groups under perceptions included normalization and stigmatization, harms for youth, and stigma, racism, and discrimination. Subthemes under practice included cannabis not being the primary focus, challenges with screening, assessment, and intervention, and referral to specialized services. Both the survey and focus group participants recommended increasing public education, enhancing service provider training, improving regulation and policies, reducing stigma and minimization, improving service access, and providing more culturally responsive services.

CONCLUSION

Youth cannabis use in Canada remains a significant public health concern, necessitating a more comprehensive plan to protect Ontario youth and reduce associated harms.

[Anxiety and substance abuse disorders-Focus on alcohol and cannabis]

Anxiety disorders are frequent, with a 12-month prevalence of 14%, tend to be chronic, and display a high comorbidity with substance abuse disorders. Anxiety and substance abuse disorders are associated with a pronounced individual as well as socioeconomic burden. This article reviews the epidemiological, etiological, and clinical aspects of the dual diagnosis of anxiety and substance abuse disorders, with a particular focus on alcohol and cannabis. The treatment comprises nonpharmacological strategies, mainly cognitive behavioral therapy combined with elements of motivational interviewing (MI) and pharmacological management with antidepressants; however, the use of selective serotonin reuptake inhibitors (SSRI)/serotonin and noradrenaline reuptake inhibitors (SNRI) is not unreservedly recommended. The use of gabapentinoids requires careful risk-benefit consideration because of their potential for abuse and dependence in substance abuse disorders. Benzodiazepines are reserved exclusively for crisis management. Rapid diagnosis and treatment initiation targeting both disorders are essential for successful treatment of comorbid anxiety and substance abuse disorders.

Cannabis-Induced Anxiety Disorder in the Emergency Department

BACKGROUND

In December 2018, Michigan became the 10th state to legalize marijuana for adults. Since this law took effect, increased availability and use of cannabis in Michigan have led to increased emergency department (ED) visits associated with the drug's psychiatric effects.

OBJECTIVES

To describe cannabis-induced anxiety disorder's prevalence, clinical features, and disposition in a community-based study.

METHODS

This was a retrospective cohort analysis of consecutive patients diagnosed with acute toxicity related to cannabis use (ICD-10 code F12). Patients were seen at seven EDs over a 24-month study period. Data collected included demographics, clinical features, and treatment outcomes in ED patients who met the criteria for cannabis-induced anxiety disorder. This group was compared to a cohort experiencing other forms of acute cannabis toxicity. Chi-squared and t-tests were used to compare these two groups across key demographic and outcome variables.

RESULTS

During the study period, 1135 patients were evaluated for acute cannabis toxicity. A total of 196 patients (17.3%) had a chief complaint of anxiety, and 939 (82.7%) experienced other forms of acute cannabis toxicity, predominantly symptoms of intoxication or cannabis hyperemesis syndrome. Patients with anxiety symptoms had panic attacks (11.7%), aggression or manic behavior (9.2%), and hallucinations (6.1%). Compared to patients presenting with other forms of cannabis toxicity, those with anxiety were likelier to be younger, ingested edible cannabis, had psychiatric comorbidities, or had a history of polysubstance abuse.

CONCLUSIONS

Cannabis-induced anxiety occurred in 17.3% of ED patients in this community-based study. Clinicians must be adept in recognizing, evaluating, managing, and counseling these patients following cannabis exposure.

Predictors of perceived symptom change with acute cannabis use for mental health conditions in a naturalistic sample: A machine learning approach

BACKGROUND

Despite limited clinical evidence of its efficacy, cannabis use has been commonly reported for the management of various mental health concerns in naturalistic field studies. The aim of the current study was to use machine learning methods to investigate predictors of perceived symptom change across various mental health symptoms with acute cannabis use in a large naturalistic sample.

METHODS

Data from 68,819 unique observations of cannabis use from 1307 individuals using cannabis to manage mental health symptoms were analyzed. Data were extracted from Strainprint®, a mobile app that allows users to monitor their cannabis use for therapeutic purposes. Machine learning models were employed to predict self-perceived symptom change after cannabis use, and SHapley Additive exPlanations (SHAP) value plots were used to assess feature importance of individual predictors in the model. Interaction effects of symptom severity pre-scores of anxiety, depression, insomnia, and gender were also examined.

RESULTS

The factors that were most strongly associated with perceived symptom change following acute cannabis use were pre-symptom severity, age, gender, and the ratio of CBD to THC. Further examination on the impact of baseline severity for the most commonly reported symptoms revealed distinct responses, with cannabis being reported to more likely benefit individuals with lower pre-symptom severity for depression, and higher pre-symptom severity for insomnia. Responses to cannabis use also differed between genders.

CONCLUSIONS

Findings from this study highlight the importance of several factors in predicting perceived symptom change with acute cannabis use for mental health symptom management. Mental health profiles and baseline symptom severity may play a large role in perceived responses to cannabis. Distinct response patterns were also noted across commonly reported mental health symptoms, emphasizing the need for placebo-controlled cannabis trials for specific user profiles.

Interventions for generalized anxiety disorder

PURPOSE OF REVIEW

To provide an overview of recently published work on anxiety, focusing on generalized anxiety disorder (GAD) and its treatment.

RECENT FINDINGS

Self-reported anxiety symptoms were highly prevalent during the COVID-19 global pandemic in both the general population and in selected groups. There remains divided opinion about whether internet-based cognitive behavioural therapy (CBT) is noninferior to face-to-face CBT for GAD. A systematic review of drug treatment for GAD showed efficacy for selective serotonin reuptake inhibitors (SNRIs), agomelatine, and quetiapine. There may be a place for repetitive transcranial magnetic stimulation in the treatment of GAD. There was some evidence of efficacy for complementary therapies, including physical exercise, yoga, acupuncture, and Withania somnifera (ashwagandha). However, a systematic review of cannabidiol and tetrahydrocannabinol found insufficient evidence of efficacy in anxiety disorders.

SUMMARY

Antidepressants and quetiapine show efficacy in the treatment of GAD. Internet-based psychological interventions have a place in the treatment of GAD when face-to-face treatment is inaccessible. There is increasing evidence for the use of physical exercise in the management of GAD. Some other complementary therapies, including cannabinoids, require further, methodologically sound, research.

A Case of Panic Attacks Developing After 10 Years of Chronic Cannabis Use in a Patient With No Prior Psychiatric History

Cannabis use for medical and recreational purposes is increasing. Inhibitory activity of cannabinoids (CB) at the CB1 and CB2 receptors centrally and peripherally mediate the therapeutic effects that are wielded for palliation of pain, anxiety, inflammation, and nausea in indicated conditions. Cannabis dependence is also associated with anxiety; however, the direction of causality is unknown, such as whether anxiety disorders lead to cannabis use, or whether cannabis contributes to the development of anxiety disorder. The evidence hints that both may have validity. Here we present a case of cannabis-associated panic attacks following 10 years of chronic cannabis dependence in an individual with no prior psychiatric history. The patient is a 32-year-old male with no significant past medical history who presented complaining of five-minute episodes of palpitations, dyspnea, upper extremity paresthesia, subjective tachycardia, and cold diaphoresis occurring in a variety of circumstances for the past two years. His social history was significant for 10 years of smoking marijuana multiple times daily, which he had quit over two years ago. The patient denied past psychiatric history or known anxiety problems. Symptoms were unrelated to activity and only relieved with deep breathing. The episodes were not associated with chest pain, syncope, headache, or emotional triggers. The patient had no family history of cardiac disease or sudden death. The episodes were refractory to the elimination of caffeine, alcohol, or other sugary beverages. The patient had already stopped smoking marijuana when the episodes began. Due to the unpredictable nature of the episodes, the patient reported a growing fear of being in public. On laboratory workup, metabolic and blood panels were within normal limits, as well as thyroid studies. Electrocardiogram showed normal sinus rhythm, and continuous cardiac monitoring revealed no arrhythmias or abnormalities despite the patient indicating multiple triggered events within the duration of monitoring. Echocardiography also showed no abnormalities. With organic cardiac causes of the subjective palpitation episodes ruled out, a psychogenic etiology of the episodes was presumed, and the patient was referred to behavioral health services. In conclusion, cannabis-induced anxiety or panic disorders should be considered in patients with no prior psychiatric history presenting with anxiety-like attacks following a period of cannabis dependence or current use. These patients should be advised to cease cannabis use and referred to behavioral medicine.

The CannTeen Study: Cannabis use disorder, depression, anxiety, and psychotic-like symptoms in adolescent and adult cannabis users and age-matched controls

BACKGROUND

Adolescence is characterised by psychological and neural development. Cannabis harms may be accentuated during adolescence. We hypothesised that adolescents would be more vulnerable to the associations between cannabis use and mental health and addiction problems than adults.

METHOD

As part of the 'CannTeen' study, we conducted a cross-sectional analysis. There were 274 participants: split into groups of adolescent users (n = 76; 16-17 years old) and controls (n = 63), and adult users (n = 71; 26-29 years old) and controls (n = 64). Among users, cannabis use frequency ranged from 1 to 7 days/week, while controls had 0-10 lifetime exposures to cannabis. Adolescent and adult cannabis users were matched on cannabis use frequency (mean=4 days/week). We measured Diagnostic and Statistical Manual (DSM-5) Cannabis Use Disorder (CUD), Beck Depression Inventory, Beck Anxiety Inventory and Psychotomimetic States Inventory-adapted.

RESULTS

After adjustment for covariates, adolescent users were more likely to have severe CUD than adult users (odd ratio = 3.474, 95% confidence interval (CI) = 1.501-8.036). Users reported greater psychotic-like symptoms than controls (b = 6.004, 95% CI = 1.211-10.796) and adolescents reported greater psychotic-like symptoms than adults (b = 5.509, 95% CI = 1.070-9.947). User-group was not associated with depression or anxiety. No significant interactions between age-group and user-group were identified. Exploratory analyses suggested that cannabis users with severe CUD had greater depression and anxiety levels than cannabis users without severe CUD.

CONCLUSION

Adolescent cannabis users are more likely than adult cannabis users to have severe CUD. Adolescent cannabis users have greater psychotic-like symptoms than adult cannabis users and adolescent controls, through an additive effect. There was no evidence of an amplified vulnerability to cannabis-related increases in subclinical depression, anxiety or psychotic-like symptoms in adolescence. However, poorer mental health was associated with the presence of severe CUD.

Association of cannabis potency with mental ill health and addiction: a systematic review

Cannabis potency, defined as the concentration of Δ⁹-tetrahydrocannabinol (THC), has increased internationally, which could increase the risk of adverse health outcomes for cannabis users. We present, to our knowledge, the first systematic review of the association of cannabis potency with mental health and addiction (PROSPERO, CRD42021226447). We searched Embase, PsycINFO, and MEDLINE (from database inception to Jan 14, 2021). Included studies were observational studies of human participants comparing the association of high-potency cannabis (products with a higher concentration of THC) and low-potency cannabis (products with a lower concentration of THC), as defined by the studies included, with depression, anxiety, psychosis, or cannabis use disorder (CUD). Of 4171 articles screened, 20 met the eligibility criteria: eight studies focused on psychosis, eight on anxiety, seven on depression, and six on CUD. Overall, use of higher potency cannabis, relative to lower potency cannabis, was associated with an increased risk of psychosis and CUD. Evidence varied for depression and anxiety. The association of cannabis potency with CUD and psychosis highlights its relevance in health-care settings, and for public health guidelines and policies on cannabis sales. Standardisation of exposure measures and longitudinal designs are needed to strengthen the evidence of this association.

Cannabis use among youth in Canada: a scoping review protocol

INTRODUCTION

Canadian youth (aged 15-24) have the highest rates of cannabis use globally. There are increasing concerns about the adverse effects of cannabis use on youth physical and mental health. However, there are gaps in our understanding of risks and harms to youth. This scoping review will synthesise the literature related to youth cannabis use in Canada. We will examine the relationship between youth cannabis use and physical and mental health, and the relationship with use of other substances. We will also examine prevention strategies for youth cannabis use in Canada and how the literature addresses social determinants of health.

METHODS AND ANALYSIS

Using a scoping review framework developed by Arksey and O'Malley, we will conduct our search in five academic databases: MEDLINE, Embase, APA PsycInfo, CINAHL and Web of Science's Core Collection. We will include articles published between 2000 and 2021, and articles meeting the inclusion criteria will be charted to extract relevant themes and analysed using a qualitative thematic analysis approach.

ETHICS AND DISSEMINATION

This review will provide relevant information about youth cannabis use and generate recommendations and gaps in the literature. Updated research will inform policies, public education strategies and evidence-based programming. Results will be disseminated through an infographic, peer-reviewed publication and presentation at a mental health and addiction conference. Ethics approval is not required for this scoping review.

Impact of Acute and Chronic Cannabis Use on Stress Response Regulation: Challenging the Belief That Cannabis Is an Effective Method for Coping

Although research has only recently started to examine the impact of cannabis use on stress response, there is some evidence that indicates acute and chronic impacts of cannabis on these processes. In this paper, we review processes involved in regulating the stress response and we review the influence of acute and chronic exposure to cannabis on patterns and regulation of the stress response. We also highlight the role of stress as a risk factor for initiation and maintenance of cannabis use. In this context, we examine moderating variables, including sex and life adversity. In light of recent observations indicating increasing prevalence of cannabis use during pregnancy, we provide additional focus on cannabis use in this vulnerable population, including how acute and chronic stress may predispose some individuals to use cannabis during pregnancy. While this line of research is in its infancy, we review available articles that focus on the perinatal period and that examined the association between cannabis use and various life stressors, including partner violence, job loss, and lack of housing. We also review psychiatric co-morbidities (e.g., post-traumatic stress disorder, anxiety). A better understanding of the way stress and cannabis use relate within the general population, as well as within certain subgroups that may be at a greater risk of using and/or at greater risk for adverse outcomes of use, may lead to the development of novel prevention and intervention approaches.