Cannabis and depression: an integrative data analysis of four Australasian cohorts

The Monitoring Illicit Substance Use Consortium: A Study Protocol

Objective

The global impact of substance use, including cannabis, amphetamine, cocaine, ecstasy, hallucinogens, and opioids, is increasing, although the overall prevalence is low. Australia and New Zealand are among the few regions of the world in which use (typically illicit) of these classes of substances remains within the top 10 causes of disease burden. The period of adolescence and young adulthood, during which substance use behaviors accelerate in prevalence, is associated with a particular risk for harm. However, the ability to study each substance class has been limited by their low population prevalence in single population-based cohort studies.

Method

The Monitoring Illicit Substance Use (MISUse) Consortium was established to address this problem by bringing together 4 mature prospective cohort studies across Australia and Zealand: Christchurch Health and Development Study (established 1977; 24 waves; N = 1,265), Australian Temperament Project (established 1983; 16 waves; N = 2,443), Victorian Adolescent Health Cohort Study (established 1992; 11 waves; N = 1,943), and International Youth Development Study (established 2002; 10 waves; N = 2,884).

Conclusion

The MISUse Consortium should enable well-powered studies of the natural history, developmental antecedents, and longer-term consequences of illicit substance use with a focus on identifying modifiable determinants of use that can be targeted in population-level policy and intervention responses.

Perceptions in Orthopedic Surgery on the Use of Cannabis in Treating Pain: A Survey of Musculoskeletal Trauma Patients-Results From the Canadian POSIT Study

OBJECTIVES

To evaluate the patient-reported expectations regarding cannabis for pain following musculoskeletal (MSK) trauma and patients' perceptions and attitudes regarding its use.

METHODS

DESIGN

A cross-sectional retrospective survey-based study.

SETTING

Three orthopaedic clinics in Ontario (Level-1 trauma center, Level-2 trauma center, rehabilitation clinic).

PATIENTS SELECTION CRITERIA

Adult patients presenting to the clinics from January 24, 2018, to March 7, 2018, with traumatic MSK injuries (fractures/dislocations and muscle/tendon/ligament injury) were administered an anonymous questionnaire on cannabis for MSK pain.

OUTCOME MEASURES AND COMPARISONS

Primary outcome measure was the patients' perceived effect of cannabis on MSK pain, reported on a continuous pain scale (0%-100%, 0 being no pain, and 100 unbearable pain). Secondary outcomes included preferences, such as administration route, distribution method, timing, and barriers (lack of knowledge, concerns for side effects/addiction, moral/religious opposition, etc.) regarding cannabis use.

RESULTS

In total, 440 patients were included in this study, 217 (49.3%) of whom were female and 222 (50.5%) were male, with a mean age of 45.6 years (range 18-92 years, standard deviations 15.6). Patients estimated that cannabis could treat 56.5% (95% CI 54.0%-59.0%) of their pain and replace 46.2% (95% CI 42.8%-49.6%) of their current analgesics. Nearly one-third (131/430, 30.5%) reported that they had used medical cannabis and more than one-quarter (123/430, 28.6%) used it in the previous year. Most felt that cannabis may be beneficial to treat pain (304/334, 91.0%) and reduce opioid use (293/331, 88.5%). Not considering using cannabis for their injury (132/350, 37.7%) was the most common reason for not discussing cannabis with physicians. Higher reported pain severity (β = 0.2/point, 95% CI 0.1-0.3, P = 0.005) and previous medical cannabis use were associated with higher perceived pain reduction (β = 11.1, 95% CI 5.4-16.8, P < 0.001).

CONCLUSIONS

One in 3 orthopaedic trauma patients used medical cannabis. Patients considered cannabis could potentially be an effective option for managing traumatic MSK pain and believed that cannabis could reduce opioid usage following acute musculoskeletal trauma. These data will help inform clinicians discussing medical cannabis usage with orthopaedic trauma patients moving forward.

Examining temporal trends in psychological distress and the co-occurrence of common substance use in a population-based sample of grade 7-12 students from 2013 to 2019

PURPOSE

Characterizing trends and correlates of adolescent psychological distress is important due to observed global increases over the last 20 years. Substance use is a commonly discussed correlate, though we lack an understanding about how co-occurrence of these concerns has been changing over time.

METHODS

Data came from repeated, representative, cross-sectional surveys of grade 7-12 students across Ontario, Canada conducted biennially from 2013 to 2019. Poisson regression with robust standard errors was used to examine changes in the joint association between psychological distress (operationalized as Kessler-6 [K6] scores ≥ 13) and substance use over time. Weighted prevalence ratios (PR) and their 99% confidence intervals were estimated, where p < 0.01 denotes statistical significance.

RESULTS

The prevalence of psychological distress doubled between 2013 and 2019, with adjusted increases of about 1.2 times each survey year. This biennial increase did not differ based on sex, perceived social standing, school level, or any substance use. Students using substances consistently reported a higher prevalence of psychological distress (between 1.2 times and 2.7 times higher). There were similarly no differential temporal trends based on substance use for very high distress (K6 ≥ 19) or K6 items explored individually.

CONCLUSION

Psychological distress steeply increased among adolescents and substance use remains important to assess and address alongside distress. However, the magnitude of temporal increases appears to be similar for adolescents reporting and not reporting substance use.

Amyotrophic Lateral Sclerosis and Pain: A Narrative Review from Pain Assessment to Therapy

Amyotrophic lateral sclerosis (ALS) is the most frequent neurodegenerative disease of the motor system that affects upper and lower motor neurons, leading to progressive muscle weakness, spasticity, atrophy, and respiratory failure, with a life expectancy of 2-5 years after symptom onset. In addition to motor symptoms, patients with ALS have a multitude of nonmotor symptoms; in fact, it is currently considered a multisystem disease. The purpose of our narrative review is to evaluate the different types of pain, the correlation between pain and the disease's stages, the pain assessment tools in ALS patients, and the available therapies focusing above all on the benefits of cannabis use. Pain is an underestimated and undertreated symptom that, in the last few years, has received more attention from research because it has a strong impact on the quality of life of these patients. The prevalence of pain is between 15% and 85% of ALS patients, and the studies on the type and intensity of pain are controversial. The absence of pain assessment tools validated in the ALS population and the dissimilar study designs influence the knowledge of ALS pain and consequently the pharmacological therapy. Several studies suggest that ALS is associated with changes in the endocannabinoid system, and the use of cannabis could slow the disease progression due to its neuroprotective action and act on pain, spasticity, cramps, sialorrhea, and depression. Our research has shown high patients' satisfaction with the use of cannabis for the treatment of spasticity and related pain. However, especially due to the ethical problems and the lack of interest of pharmaceutical companies, further studies are needed to ensure the most appropriate care for ALS patients.

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.

Cannabis Use and Its Impact on Mental Health in Youth in Australia and the United States: A Scoping Review

Cannabis is a widely used substance among the youth population, with an estimated 2.8% currently smoking cannabis. Its popularity is growing due to the perception of its harmless nature and lack of dependence. However, this increase in use has been linked to mental health issues, especially since its partial decriminalisation in some part of the United States and Australia. The objective of this scoping review was to investigate the mental health impact of cannabis use among young people in Australia and the United States. A scoping review was conducted according to the Joanna Briggs Institute (JBI) protocol, and articles were searched from ProQuest Central and EBSCO Host (MEDLINE and CINAHL databases). A total of 24 articles were analysed, including systematic reviews, meta-analyses, and cohort, longitudinal, and cross-sectional studies. The findings indicate that cannabis use is associated with depression, psychosis, suicide, cannabis use disorder, dependence, decline in cognitive function, and the development of externalising behaviour, particularly attention deficit hyperactivity disorder. However, the relationship between cannabis use and anxiety is equivocal. Mental health issues were more prevalent with increased frequency, duration, intensity, and type of use. Female, minority, LGBTQI, African American, Aboriginal, and Torres Strait Islander youth and the age of onset of cannabis use were significant factors for the development of mental health problems. The increasing prevalence of cannabis use among high school and college students suggests the need for intervention by teachers, parents, and community health professionals to make them aware of its potential negative mental health outcomes. Moreover, policy-level interventions by the government are required to discourage young people from using cannabis.

Psychiatric comorbidities and concurrent substance use among people who inject drugs: a single-centre hospital-based study

The management of people who inject drugs (PWID) is compounded by the presence of psychiatric comorbidities leading to frequent relapses and poor treatment outcomes. Early identification and treatment of psychiatric comorbidities should be included in the management to enhance treatment outcomes. The objective of this study was to estimate the prevalence of psychiatric comorbidities and concurrent substance use among opioid injectors. This hospital-based, cross-sectional study was conducted from March 2021 to August 2022. This study included opioid injectors of all ages and both sexes. The Mini International Neuropsychiatric Interview-7 (MINI-7) and WHO-ASSIST were used to determine psychiatric comorbidities and concurrent substance use, respectively. Both crude and adjusted odds ratios were calculated to assess associations among demographic variables, concurrent substance use and psychiatric comorbidities. Among the 328 opioid injectors, the overall prevalence of psychiatric comorbidities was 88.1%, with the majority (68.6%) having more than one comorbidity. The most common psychiatric comorbidities were panic disorder (41.2%), social anxiety disorder (40.5%), and antisocial personality disorder (39.3%). Concurrent use of alcoholic beverages doubled the risk of ASPD (odds ratio 2.14 (1.24-3.72)). Cocaine (odds ratio 2.36 (1.10-5.03)) and amphetamines (odds ratio 7.68 (2.21-26.65)) increased the risk of OCD. Daily heroin injections were negatively associated (odds ratio 0.18 (0.03-0.94)) with psychotic disorders. Younger age (adjusted odds ratio 0.20 (0.79-0.53)) and never married status (adjusted odds ratio 2.62 (1.06-6.47)) were the only significant variables in the regression analysis. In conclusion, opioid injectors had a higher prevalence of numerous psychiatric comorbidities. The most common comorbidity was anxiety disorders. Concurrent use of tobacco, cannabis, cocaine, inhalants, etc., greatly increased the risk of psychiatric comorbidities.

Harmonizing Depression Measures Across Studies: a Tutorial for Data Harmonization

There has been increasing interest in applying integrative data analysis (IDA) to analyze data across multiple studies to increase sample size and statistical power. Measures of a construct are frequently not consistent across studies. This article provides a tutorial on the complex decisions that occur when conducting harmonization of measures for an IDA, including item selection, response coding, and modeling decisions. We analyzed caregivers' self-reported data from the ADHD Teen Integrative Data Analysis Longitudinal (ADHD TIDAL) dataset; data from 621 of 854 caregivers were available. We used moderated nonlinear factor analysis (MNLFA) to harmonize items reflecting depressive symptoms. Items were drawn from the Symptom Checklist 90-Revised, the Patient Health Questionnaire-9, and the World Health Organization Quality of Life questionnaire. Conducting IDA often requires more programming skills (e.g., Mplus), statistical knowledge (e.g., IRT framework), and complex decision-making processes than single-study analyses and meta-analyses. Through this paper, we described how we evaluated item characteristics, determined differences across studies, and created a single harmonized factor score that can be used to analyze data across all four studies. We also presented our questions, challenges, and decision-making processes; for example, we explained the thought process and course of actions when models did not converge. This tutorial provides a resource to support prevention scientists to generate harmonized variables accounting for sample and study differences.

The effect of marijuana use on short-term outcomes with bariatric surgery

BACKGROUND

Despite increasing marijuana use nationwide, there are limited data on implications of marijuana use on bariatric surgery outcomes.

OBJECTIVE

We investigated associations between marijuana use and bariatric surgery outcomes.

SETTING

Multicenter statewide study utilizing data from the Michigan Bariatric Surgery Collaborative, a payor-funded consortium including over 40 hospitals and 80 surgeons performing bariatric surgery statewide.

METHODS

We analyzed data from the Michigan Bariatric Surgery Collaborative clinical registry on patients who underwent a laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass between June 2019 and June 2020. Patients were surveyed at baseline and annually on medication use, depression symptoms, and substance use. Regression analysis was performed to compare 30-day and 1-year outcomes between marijuana users and nonusers.

RESULTS

Of 6879 patients, 574 reported baseline marijuana use and 139 reported use at baseline and 1 year. Marijuana users were more likely to be current smokers (14% versus 8%, P < .0001), screen positive for alcohol use disorder (20.0% versus 8.4%, P < .0001), and score higher on the Patient Health Questionnaire-8 (6.1 versus 3.0, P < .0001). There were no statistically significant differences in 30-day outcomes or co-morbidity remission at 1 year. Marijuana users had higher adjusted total mean weight loss (47.6 versus 38.1 kg, P < .0001) and body mass index reduction (17 versus 14 kg/m2, P < .0001).

CONCLUSIONS

Marijuana use is not associated with worse 30-day outcomes or 1-year weight loss outcomes and should not be a barrier to bariatric surgery. However, marijuana use is associated with higher rates of smoking, substance use, and depression. These patients may benefit from additional mental health and substance abuse counseling.

Cannabis Use Associations with Adverse Psychosocial Functioning among North American College Students

Introduction: Adolescent-onset cannabis use (CU) (before age 18) is associated with multiple adverse psychosocial outcomes, but rates of CU peak between the ages of 18 and 22, coinciding with college matriculation. Whether CU among college-enrolled young adults is associated with similar psychosocial outcomes is poorly understood. In the present study, we examined relationships between CU and multiple psychosocial outcomes in North American college students. Methods: Data for this report come from N = 40,250 North American college students ages 18-to-25 years (mean age = 20.7 years, 69% female, 66% Caucasian) who participated in the Healthy Minds Study (HMS) 2016-17. HMS is a web-based annual survey querying multiple mental health, substance use, and psychosocial variables in representative student populations from 53 universities across North America. Student respondents were stratified in two groups based upon their self-report of past 30-day CU and compared on psychosocial variables. Results: Approximately 20% (n = 8,327) of student respondents reported past 30-day CU. After adjusting for socio-demographics, knowledge of campus services, and use of other drugs, the odds of depression (aOR = 1.3), suicidal thoughts and behaviors (aORs ∼1.4-1.7), anxiety (aOR = 1.2), eating disorders (aOR = 1.2), and violence victimization (aOR = 1.4) were all higher for CU students. Additionally, CU students had higher rates of other drug use and lower rates of perceived supportive relationships. Conclusion: Our results indicated that CU is common among North American college students and associated with adverse psychosocial consequences across multiple domains. Based upon these findings, colleges should consider expanding educational, prevention, and early-intervention programs for students who use cannabis.

Medicinal cannabis for psychiatry-related conditions: an overview of current Australian prescribing

Objective: Evidence is accumulating that components of the Cannabis sativa plant may have therapeutic potential in treating psychiatric disorders. Medicinal cannabis (MC) products are legally available for prescription in Australia, primarily through the Therapeutic Goods Administration (TGA) Special Access Scheme B (SAS-B). Here we investigated recent prescribing practices for psychiatric indications under SAS-B by Australian doctors. Methods: The dataset, obtained from the TGA, included information on MC applications made by doctors through the SAS-B process between 1st November 2016 and 30th September 2022 inclusive. Details included the primary conditions treated, patient demographics, prescriber location, product type (e.g., oil, flower or capsule) and the general cannabinoid content of products. The conditions treated were categorized according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR). Trends in prescribing for conditions over time were analyzed via polynomial regression, and relationships between categorical variables determined via correspondence analyses. Results: Approximately 300,000 SAS-B approvals to prescribe MC had been issued in the time period under investigation. This included approvals for 38 different DSM-5-TR defined psychiatric conditions (33.9% of total approvals). The majority of approvals were for anxiety disorders (66.7% of psychiatry-related prescribing), sleep-wake disorders (18.2%), trauma- and stressor-related disorders (5.8%), and neurodevelopmental disorders (4.4%). Oil products were most prescribed (53.0%), followed by flower (31.2%) and other inhaled products (12.4%). CBD-dominant products comprised around 20% of total prescribing and were particularly prevalent in the treatment of autism spectrum disorder. The largest proportion of approvals was for patients aged 25-39 years (46.2% of approvals). Recent dramatic increases in prescribing for attention deficit hyperactivity disorder were identified. Conclusion: A significant proportion of MC prescribing in Australia is for psychiatry-related indications. This prescribing often appears somewhat "experimental", given it involves conditions (e.g., ADHD, depression) for which definitive clinical evidence of MC efficacy is lacking. The high prevalence of THC-containing products being prescribed is of possible concern given the psychiatric problems associated with this drug. Evidence-based clinical guidance around the use of MC products in psychiatry is lacking and would clearly be of benefit to prescribers.

Predictors of methamphetamine use in a longitudinal birth cohort

BACKGROUND

Identifying predictors of methamphetamine use can inform population prevention strategies.

METHODS

Participants (n = 1265) born in Christchurch, New Zealand were followed from birth to age 40. Methamphetamine outcomes (any use since the last interview, and regular use, defined as any period of at least weekly use) were ascertained by self-report at six interviews from age 18 to 40. Predictors with plausible associations with methamphetamine use were extracted from the study database. These were grouped into early predictors (age 0-16), comprising childhood, familial and individual characteristics; and later time-dynamic correlates of methamphetamine use in adulthood (ages 16-40). Generalised estimating equation models were fitted to identify predictors of methamphetamine use outcomes.

RESULTS

In adjusted models, paternal overprotectiveness and childhood anxious / withdrawn behavior were associated with any use of methamphetamine, but not regular use. Conversely, childhood conduct problems and parental illicit drug were associated with regular use but not any use. Male sex, high novelty seeking and deviant peer affiliations were associated with both any use and regular use in adjusted models. The strongest correlates of methamphetamine use in adulthood were unemployment, life stress and other substance use disorders (cannabis, nicotine, and alcohol).

CONCLUSION

Markers of externalizing problems in childhood and adolescence (conduct problems, high novelty seeking, parental illicit substance use, and deviant peer affiliations) are the strongest predictors of regular methamphetamine use in adulthood.

Depression and Suicidal Behavior in Adolescents

Depression commonly onsets in adolescence, affecting approximately 1 in 4 female adolescents and 1 in 10 males in the United States. Adolescent depression is a significant risk factor for suicide, the cause of over a third of all American adolescent deaths. Adolescent depression is introduced alongside its developmental and gendered considerations with a focus on important risk factors of adolescent depression, including nonsuicidal self-injury, adverse childhood experiences, and substance abuse. Protective factors and contemporary special topics of the COVID-19 pandemic and social media use are reviewed. Therapeutic options and clinical barriers are highlighted before a summary of findings and conclusion.

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.

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.

TRPV1: A Common Denominator Mediating Antinociceptive and Antiemetic Effects of Cannabinoids

The most common medicinal claims for cannabis are relief from chronic pain, stimulation of appetite, and as an antiemetic. However, the mechanisms by which cannabis reduces pain and prevents nausea and vomiting are not fully understood. Among more than 450 constituents in cannabis, the most abundant cannabinoids are Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). Cannabinoids either directly or indirectly modulate ion channel function. Transient receptor potential vanilloid 1 (TRPV1) is an ion channel responsible for mediating several modalities of pain, and it is expressed in both the peripheral and the central pain pathways. Activation of TRPV1 in sensory neurons mediates nociception in the ascending pain pathway, while activation of TRPV1 in the central descending pain pathway, which involves the rostral ventral medulla (RVM) and the periaqueductal gray (PAG), mediates antinociception. TRPV1 channels are thought to be implicated in neuropathic/spontaneous pain perception in the setting of impaired descending antinociceptive control. Activation of TRPV1 also can cause the release of calcitonin gene-related peptide (CGRP) and other neuropeptides/neurotransmitters from the peripheral and central nerve terminals, including the vagal nerve terminal innervating the gut that forms central synapses at the nucleus tractus solitarius (NTS). One of the adverse effects of chronic cannabis use is the paradoxical cannabis-induced hyperemesis syndrome (HES), which is becoming more common, perhaps due to the wider availability of cannabis-containing products and the chronic use of products containing higher levels of cannabinoids. Although, the mechanism of HES is unknown, the effective treatment options include hot-water hydrotherapy and the topical application of capsaicin, both activate TRPV1 channels and may involve the vagal-NTS and area postrema (AP) nausea and vomiting pathway. In this review, we will delineate the activation of TRPV1 by cannabinoids and their role in the antinociceptive/nociceptive and antiemetic/emetic effects involving the peripheral, spinal, and supraspinal structures.

Substance use and common contributors to morbidity: A genetics perspective

Excessive substance use and substance use disorders (SUDs) are common, serious and relapsing medical conditions. They frequently co-occur with other diseases that are leading contributors to disability worldwide. While heavy substance use may potentiate the course of some of these illnesses, there is accumulating evidence suggesting common genetic architectures. In this narrative review, we focus on four heritable medical conditions - cardiometabolic disease, chronic pain, depression and COVID-19, which are commonly overlapping with, but not necessarily a direct consequence of, SUDs. We find persuasive evidence of underlying genetic liability that predisposes to both SUDs and chronic pain, depression, and COVID-19. For cardiometabolic disease, there is greater support for a potential causal influence of problematic substance use. Our review encourages de-stigmatization of SUDs and the assessment of substance use in clinical settings. We assert that identifying shared pathways of risk has high translational potential, allowing tailoring of treatments for multiple medical conditions. FUNDING: SSR acknowledges T29KT0526, T32IR5226 and DP1DA054394; RLK acknowledges AA028292; AA acknowledges DA054869 & K02DA032573. The funders had no role in the conceptualization or writing of the paper.

The Use of Cannabis and Its Effects on Postpartum Depression

Cannabis use and depression management have been studied, with a preponderance of exacerbating effects, but there are few studies on postpartum depression (PPD). Depression affects a significant number of women, with a portion of it manifesting as PPD in childbearing women in the United States each year. The pharmacologic management approaches have disadvantages such as side effects, cost-benefit ratio, contraindications, use reluctance, medication adherence, and stigmatization in patients. Anecdotal claims of medical cannabis' therapeutic benefits have led to widespread legalization in several regions, making cannabis and its extracts a possible alternative. Cannabis is widely used during pregnancy and in general. Even though substance use disorders exacerbating depression symptoms have been reported, there are increasing reports and evidence about the therapeutic benefit of dose-dependent cannabis or its extracts in some depression symptoms, such as acute psychosocial stress relief, its purported anxiolytic effect, appetite, and sleep quality, thus stimulating more interest that may be inferred to depression. PPD marijuana use is unclear. This paper reviewed works of literature that claimed cannabis' therapeutic benefit in treating depression and, by extension, PPD. Our findings show the link between cannabis and PPD has not been fully explored. Self-reported studies link marijuana uses to positive mood, anxiety relief, sleep regulation, nausea and vomiting reduction, and appetite stimulation-all PPD symptoms. Others opposed postpartum marijuana use.

Comorbidity and Coaggregation of Major Depressive Disorder and Bipolar Disorder and Cannabis Use Disorder in a Controlled Family Study

IMPORTANCE

Cannabis use disorder (CUD) is increasing in the US. Clarification of the potential mechanisms underlying the comorbidity between mood disorders and CUD may help prevent CUD.

OBJECTIVE

To examine co-occurrence and familial aggregation of CUD and mood disorder subtypes.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional, community-based study in the Washington, DC, metropolitan area, semistructured diagnostic interviews and family history reports assessed lifetime DSM-IV disorders in probands and relatives. Familial aggregation and coaggregation of CUD with mood disorders were estimated via mixed-effects models, adjusting for age, sex, recruitment source, and comorbid mood, anxiety, and other substance use disorders. A total of 586 adult probands (186 with bipolar disorder; 55 with CUD) and 698 first-degree relatives (91 with bipolar disorder; 68 with CUD) were recruited from a community screening of the greater Washington, DC, metropolitan area from May 2004 to August 2020. Inclusion criteria were ability to speak English, and availability and consent to contact at least 2 living first-degree relatives.

MAIN OUTCOMES AND MEASURES

Lifetime CUD in first-degree relatives.

RESULTS

Of 586 probands, 395 (67.4%) were female; among 698 relatives, 437 (62.6%) were female. The mean (SD) age was 47.5 (15.2) years for probands and 49.6 (18.0) years for relatives. In the proband group, 82 participants (14.0%) self-identified as African American or Black, 467 (79.7%) as White, and 37 (6.3%) as American Indian or Alaska Native, Asian, more than one race, or another race or ethnicity or declined to respond. In the relative group, 53 participants (7.6%) self-identified as African American or Black, 594 (85.1%) as White, and 51 (7.3%) as American Indian or Alaska Native, Asian, more than one race, or another race or ethnicity or declined to respond. These groups were combined to protect privacy owing to small numbers. CUD in probands (55 [9.4%]) was associated with an increase in CUD in relatives (adjusted odds ratio [aOR], 2.64; 95% CI, 1.20-5.79; P = .02). Bipolar disorder II (BP-II) in probands (72 [12.3%]) was also associated with increased risk of CUD in relatives (aOR, 2.57; 95% CI, 1.06-6.23; P = .04). However, bipolar disorder I (114 [19.5%]) and major depressive disorder (192 [32.8%]) in probands were not significantly associated with CUD in relatives. Among relatives, CUD was associated with BP-II (aOR, 4.50; 95% CI, 1.72-11.77; P = .002), major depressive disorder (aOR, 3.64; 95% CI, 1.78-7.45; P < .001), and mean (SD) age (42.7 [12.8] years with CUD vs 50.3 [18.3] years without CUD; aOR, 0.98; 95% CI, 0.96-1.00; P = .02). Familial coaggregation of BP-II with CUD was attenuated by the inclusion of comorbid anxiety disorders. Further, rates of CUD were highest in relatives with both a familial and individual history of BP-II (no familial or individual history of BP-II: 41 [7.2%]; familial history but no individual history of BP-II: 13 [19.1%]; individual history but no familial history of BP-II: 10 [22.2%]; familial and individual history of BP-II: 4 [28.6%]; Fisher exact test, P < .001). The onset of mood disorder subtypes preceded CUD in probands and relatives in most cases.

CONCLUSIONS AND RELEVANCE

The findings confirmed a familial aggregation of CUD. The increase in risk of CUD among relatives of probands with BP-II suggests that CUD may share a common underlying diathesis with BP-II. Taken together with the temporal precedence of depression and mania with respect to CUD onset, these findings highlight a potential role for BP-II intervention as CUD prevention.

Depression and Cognitive Impairment in a Spanish Sample of Psychoactive Substance Users Receiving Mental Health Care

(1) Background: Numerous studies state that the abuse of psychoactive substances produces cognitive, emotional and behavioral disorders. The aim of this study is to analyze the relationship between the consumption of different psychoactive substances with cognitive performance and depression. (2) Methods: The sample was composed of 254 individuals (M = 41.81; SD = 10.74, from 18 to 69; 76% male) who received psychological treatment related to the use of substances. Participants were classified according to the main substance consumed: alcohol (42.9%), cannabis (20.5%), cocaine (15.4%), heroin (13%) and benzodiazepines (8.3%). The Montreal Cognitive Assessment and the Beck's Depression Inventory were administrated. (3) The results indicated no statistically significant differences between levels of depression depending on the substance consumed. Regarding cognitive impairment, it was found that cocaine consumers have the worst level of cognitive impairment, while cannabis consumers have the best level of cognitive functioning. Finally, it was found that participants with severe depression have higher cognitive impairment than those who were diagnosed with moderate depression. (4) Conclusions: Given the high prevalence of depression and cognitive impairment with the abuse of psychoactive substances, early treatment is recommended to avoid a higher cognitive and emotional affectation.

Adult Psychiatric, Substance, and Functional Outcomes of Different Definitions of Early Cannabis Use

OBJECTIVE

Research on associations of early cannabis use with adult functioning reports mixed findings. This may be due, in part, to wide variations in the definitions of early cannabis use. This study aims to compare associations of 4 commonly used definitions of early cannabis use-related to timing, dose, duration, and associated symptoms-with adult outcomes.

METHOD

Analyses were based on a 20⁺-year longitudinal, community-representative study of 1,420 participants. Between ages 9 and 21 years (8,806 observations), participants were assessed for cannabis use and DSM-5 cannabis use disorder. In early adulthood (ages 24-26 and 30; 2,424 observations of 1,266 subjects), participants were also assessed for psychiatric, substance use, and functional outcomes.

RESULTS

All definitions of early use were associated with multiple adult outcomes in models that adjusted for sex and race/ethnicity. In models that also adjusted for childhood psychiatric problems and family adversities, only daily use and a persistent developmental subtype (defined as daily/problematic use that began in adolescence and continued into early adulthood) were associated with later substance use/disorders, poorer functional outcomes, and derailments in the transition to adulthood.

CONCLUSION

Daily, continued-over-time cannabis use beginning on adolescence was most problematic for a range of adult outcomes. Cessation of early use did not fully eliminate later risks; but was associated with fewer negative outcomes, with weaker effect sizes.

Frequent teenage cannabis use: Prevalence across adolescence and associations with young adult psychopathology and functional well-being in an urban cohort

BACKGROUND

Amidst cannabis legalization efforts and laws, we do not fully understand how the youngest frequent cannabis users fare during young adulthood. This study aims to 1) examine the prevalence of cannabis use during adolescence, and 2) investigate links of frequent (i.e., weekly or daily) teenage cannabis use with psychopathology and functional well-being at age 20-compared to no or occasional use.

METHODS

Data came from a prospective-longitudinal cohort study (assessments from 2004 to 2018, from ages 7-20) in an urban setting (N = 1482). Substance use was assessed with self-reports between ages 13 and 20. At age 20, participants reported on psychopathology (psychotic symptoms, problematic substance use, aggression, and internalizing symptoms) and functional well-being (delinquency, financial difficulties, social exclusion, general well-being, and not being in education, employment, or training). Covariates were based on self-, parent-, teacher-, and behavioral measures.

FINDINGS

Almost one in five adolescents had used cannabis frequently between ages 13 and 17 (26.6% of males, 9.8% of females). Adjusting nearly 20 potential confounders, frequent teenage cannabis use was associated with age 20 problematic substance use and poorer functional well-being compared to the no cannabis use and the occasional use groups. Frequent teenage cannabis use was more consistently associated with age 20 functional outcomes compared to frequent teenage nicotine or alcohol use.

CONCLUSIONS

Frequent teenage cannabis use was common and associated with problematic substance use, more delinquency, and poorer functional well-being at age 20. Accordingly, frequent teenage cannabis users could experience increased difficulties in mastering the transitions of young adulthood.

Changes in cannabis use modes among Canadian youth across recreational cannabis legalization: Data from the COMPASS prospective cohort study

INTRODUCTION

Canadian youth consume cannabis in multiple ways, including by smoking, vaping, and eating or drinking. Existing evidence suggests that these behaviours may change after law liberalization, though data regarding youth are scarce. We investigated changes in cannabis modes of use and associated factors across the federal legalization of recreational cannabis use for adults in Canada, among a large sample of underage youth before alternative products were made legally available.

METHODS

Data were available from 2953 longitudinally linked Canadian high school students who reported on their cannabis use during the 2017/2018 and 2018/2019 school years. We explored whether students maintained a single or multiple cannabis use mode(s), contracted, or expanded the number of modes used. We then used generalized estimating equations to analyse associations of baseline characteristics with use mode trajectory.

RESULTS

Expansion of cannabis use modes (42.3%) was more common than maintenance of a single mode (31.3%), maintenance of multiple modes (14.3%), or reduction (12.1%). Students who maintained multiple modes were significantly more likely to have high amounts of weekly spending money (AOR 1.68), to binge drink (AOR 2.25) or vape (AOR 1.99), to use cannabis regularly (AOR 2.67), and to endorse more symptoms of depression (AOR 1.06). School support for quitting tobacco, drug, or alcohol use appeared to have no effect.

CONCLUSIONS

Multi-modal cannabis use increased among Canadian youth in our sample. Its association with other substance use and depressive symptoms may indicate clustering of additional harms. Screening for this use pattern may assist in identifying high-risk substance use and should be considered in the design of harm reduction programming.

Cannabis, a Miracle Drug with Polyvalent Therapeutic Utility: Preclinical and Clinical-Based Evidence

Cannabis sativa L. is an annual herbaceous dioecious plant which was first cultivated by agricultural human societies in Asia. Over the period of time, various parts of the plant like leaf, flower, and seed were used for recreational as well as therapeutic purposes. The main chemical components of Cannabis sativa are termed as cannabinoids, among them the key psychoactive constituent is Δ-9-tetrahydrocannabinol and cannabidiol (CBD) as active nonpsychotic constituent. Upon doing extensive literature review, it was found that cannabis has been widely studied for a number of disorders. Very recently, a pure CBD formulation, named Epidiolex, got a green flag from both United States Food and Drug Administration and Drug Enforcement Administration for 2 rare types of epilepsies. This laid a milestone in medical cannabis research. This review intends to give a basic and extensive assessment, from past till present, of the ethnological, plant, chemical, pharmacological, and legal aspects of C. sativa. Further, this review contemplates the evidence the studies obtained of cannabis components on Alzheimer's, Parkinson's, amyotrophic lateral sclerosis, multiple sclerosis, emesis, epilepsy, chronic pain, and cancer as a cytotoxic agent as well as a palliative therapy. The assessment in this study was done by reviewing in extensive details from studies on historical importance, ethnopharmacological aspects, and legal grounds of C. sativa from extensive literature available on the scientific databases, with a vision for elevating further pharmaceutical research to investigate its total potential as a therapeutic agent.

Associations between Recent and Cumulative Cannabis Use and Internalizing Problems in Boys from Adolescence to Young Adulthood

This study tested whether increases in recent and cumulative cannabis use were each associated with increases in internalizing problems from adolescence to young adulthood. Participants were boys from a community sample that was assessed annually from ~age 15-26 (N = 506). Boys reported on their cannabis use, depression symptoms, and anxiety/depression problems each year. Exposures were frequency of cannabis use in a given year (no use, < weekly use, weekly or more frequent use) and cumulative prior years of weekly cannabis use. Outcomes were depression symptoms and anxiety/depression problems in a given year. Analyses examined within-person associations between changes in exposures and outcomes over time, which eliminated "fixed" (unchanging) individual differences as potential confounds. Analyses also accounted for time-varying factors as potential confounds (other substance use, externalizing problems, subclinical psychotic symptoms). Results showed that increases in recent cannabis use and cumulative prior years of weekly cannabis use were each associated with increases in depression symptoms and anxiety/depression problems. After controlling for time-varying covariates, increases in cumulative prior years of weekly cannabis use, but not recent cannabis use, remained associated with increases in depression symptoms and anxiety/depression problems. Specifically, each additional year of prior weekly cannabis use was associated with a small increase in depression symptoms (b = 0.012, p = .005) and anxiety/depression problems (b = 0.009, p = .001). Associations did not vary systematically across time. There was also no evidence of reverse causation. As boys engaged in weekly cannabis use for more years, they showed increases in internalizing problems, suggesting the importance of preventing chronic weekly cannabis use.

Association between preconception cannabis use and risk of postpartum depression: Findings from an Australian longitudinal cohort

BACKGROUND AND AIM

Evidence suggests a positive association between cannabis use and depression however whether preconception cannabis use is associated with postpartum depression (PPD) remains unknown. This study examined the association using a longitudinal design.

METHODS

Participants were from the Australian Longitudinal Study on Women's Health (cohort born in 1989-95), a sample broadly representative of similarly aged Australian women. The association of past year cannabis use at 3-15 months prior to pregnancy with PPD at ages 19-24 to 22-27 was examined in 516 women with 570 singleton live births. The associations of chronicity, recency, and initiation of cannabis use before pregnancy with PPD at ages 21-26 to 24-29 were investigated in 538 women with 590 singleton live births. PPD was ascertained from self-report of doctor diagnosis for each birth. Relative risk (RR) and 95 % confidence interval (CI) were used to calculate the associations of interest.

RESULTS

Compared with no cannabis use, any past-year cannabis use at 3-15 months before pregnancy may be associated with an increased risk of PPD (1.50, 0.99-2.28). Compared with no cannabis use in the first three annual surveys before pregnancy, chronic use (a past year user in ≥ 2 surveys) was associated with an 80 % higher risk of incident PPD for births in the following 1-4 years (1.80, 1.22-2.68). Compared to never users at ages 20-25, former users who had no use within the past year had no increased risk; past year users had 73 % higher risk (1.73, 1.07-2.81); and past year users who initiated cannabis use at or after age 18 had twice the risk of incident PPD for births in the following 1-4 years (2.02, 1.17-3.49).

CONCLUSION

This study provides evidence that preconception cannabis use is associated with increased risk of PPD. More studies are warranted to confirm this finding before cannabis cessation policies can be reinforced on reducing the risk of PPD.

A Review of the Potential Use of Pinene and Linalool as Terpene-Based Medicines for Brain Health: Discovering Novel Therapeutics in the Flavours and Fragrances of Cannabis

"Medicinal cannabis" is defined as the use of cannabis-based products for the treatment of an illness. Investigations of cannabis compounds in psychiatric and neurological illnesses primarily focus on the major cannabinoids, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC), which are hypothesised to benefit multiple illnesses manifesting cognitive impairment, neurodegeneration and neuro-inflammation, as well as chronic pain, epilepsy and post-traumatic stress disorder, respectively. The cannabis plant contains >500 compounds, including terpenes responsible for the flavour and fragrance profiles of plants. Recently, research has begun providing evidence on the potential use of certain plant-derived terpenes in modern medicine, demonstrating anti-oxidant, anti-inflammatory, and neuroprotective effects of these compounds. This review examined the effects of two key terpenes, pinene and linalool, on parameters relevant to neurological and psychiatric disorders, highlighting gaps in the literature and recommendations for future research into terpene therapeutics. Overall, evidence is mostly limited to preclinical studies and well-designed clinical trials are lacking. Nevertheless, existing data suggests that pinene and linalool are relevant candidates for further investigation as novel medicines for illnesses, including stroke, ischemia, inflammatory and neuropathic pain (including migraine), cognitive impairment (relevant to Alzheimer's disease and ageing), insomnia, anxiety, and depression. Linalool and pinene influence multiple neurotransmitter, inflammatory and neurotrophic signals as well as behaviour, demonstrating psycho-activity (albeit non-intoxicating). Optimising the phytochemical profile of cannabis chemovars to yield therapeutic levels of beneficial terpenes and cannabinoids, such as linalool, pinene and CBD, could present a unique opportunity to discover novel medicines to treat psychiatric and neurological illnesses; however, further research is needed.

Odds of Anxiety and Depression Symptoms in School-Aged Children From Official Language Minority Communities

Objectives: The aim of this paper is to assess the odds of suffering from anxiety or depression symptoms based on the presence of certain determinants of health for youth living in the province of New Brunswick, Canada, and in two linguistically different Official Language Minority Communities (OLMCs) in the same province.

Methods: With a sample of 22,329 students from grades 7 to 12 in the province of New Brunswick, Canada, logistic regressions were performed to assess each determinant of health's effect on symptoms of anxiety and depression.

Results: Some social determinants, like family support, social support and food insecurity, were identified as important determinants of mental health status regardless of linguistic group membership or community membership, while other determinants, such as alcohol use, cannabis use and natural environment, were more prominent in one OLMC than the other.

Discussion: Social psychology and public health theories are used in an attempt to explain the results. Limitations and recommendations are also brought forward.

A systematic review of neuroimaging and acute cannabis exposure in age-of-risk for psychosis

Acute exposure to cannabis has been associated with an array of cognitive alterations, increased risk for neuropsychiatric illness, and other neuropsychiatric sequelae including the emergence of acute psychotic symptoms. However, the brain alterations associating cannabis use and these behavioral and clinical phenotypes remains disputed. To this end, neuroimaging can be a powerful technique to non-invasively study the impact of cannabis exposure on brain structure and function in both humans and animal models. While chronic exposure studies provide insight into how use may be related to long-term outcomes, acute exposure may reveal interesting information regarding the immediate impact of use and abuse on brain circuits. Understanding these alterations could reveal the connection with symptom dimensions in neuropsychiatric disorders and, more specifically with psychosis. The purpose of the present review is to: 1) provide an update on the findings of pharmacological neuroimaging studies examining the effects of administered cannabinoids and 2) focus the discussion on studies that examine the sensitive window for the emergence of psychosis. Current literature indicates that cannabis exposure has varied effects on the brain, with the principal compounds in cannabis (delta-9-tetrahydrocannabinol and cannabidiol) altering activity across different brain regions. Importantly, we also discovered critical gaps in the literature, particularly regarding sex-dependent responses and long-term effects of chronic exposure. Certain networks often characterized as dysregulated in psychosis, like the default mode network and limbic system, were also impacted by THC exposure, identifying areas of particular interest for future work investigating the potential relationship between the two.

Identifying sensitive periods when changes in parenting and peer factors are associated with changes in adolescent alcohol and marijuana use

PURPOSE

There are well-established associations between parental/peer relationships and adolescent substance use, but few longitudinal studies have examined whether adolescents change their substance use in response to changes in their parents' behavior or peer networks. We employ a within-person change approach to address two key questions: Are changes in parenting and peer factors associated with changes in adolescent marijuana and alcohol use? Are there sensitive periods when changes in parenting and peer factors are more strongly associated with changes in adolescent marijuana and alcohol use?

METHODS

We analyzed longitudinal data collected annually on 503 boys, ages 13-19, recruited from Pittsburgh public schools. Questionnaires regarding parental supervision, negative parenting practices, parental stress, physical punishment, peer delinquency, and peer drug use were administered to adolescents and their caretakers. Alcohol and marijuana use were assessed by a substance use scale adapted from the National Youth Survey.

RESULTS

Reductions in parental supervision and increases in peer drug use and peer delinquency were associated with increases in marijuana frequency, alcohol frequency, and alcohol quantity. Increases in parental stress were associated with increases in marijuana and alcohol frequency. The magnitudes of these relationships were strongest at ages 14-15 and systematically decreased across adolescence. These associations were not due to unmeasured stable confounders or measured time-varying confounders.

CONCLUSIONS

Reducing or mitigating changes in parenting and peer risk factors in early adolescence may be particularly important for preventing substance use problems as adolescents transition into young adulthood.

Global and glucocorticoid receptor gene-specific (NR3C1) DNA methylation analysis in patients with cannabinoid or synthetic cannabinoid use disorder

This study investigates the relationship between cannabinoid use disorder (CUD) or synthetic cannabinoid use disorder (SCUD) and the global methylation, methylation of NR3C1 gene promotor, and NR3C1 BclI polymorphism, considering clinical parameters. Based on the DSM-5 criteria, 172 SCUD patients' and 44 CUD patients' diagnoses were confirmed with a positive urine test; 88 healthy volunteers were also included in the study. Global DNA methylation was measured using a 5-methylcytosine (5-mC) DNA ELISA Kit. Methylation-specific PCR was used to identify the methylation of the NR3C1 gene. The analysis of the BclI polymorphism of the NR3C1 gene was evaluated by using the PCR-RFLP. Our results demonstrated that the mean of 5-mC percentages of SCUD patients differed significantly from those of the control group. When comparing NR3C1 gene methylation and clinical parameters due to NR3C1 genotype distribution in patients, the genotype distribution was significantly different between the groups, due to the former polysubstance abuse. Additionally, there was a significantly positive correlation between the 5-mC percentages of SCUD patients and the reported durations of their disorders. In summary, whereas global DNA methylation may be associated with SCUD, the methylation of the NR3C1 gene and NR3C1 BclI polymorphism were not related to CUD or SCUD.

Association between daily and non-daily cannabis use and depression among United States adult cancer survivors

BACKGROUND

Cancer survivors are vulnerable to Cannabis Use (CU) and at increased risk for depression. Yet, the relationship between CU and depression among cancer survivors is unknown.

PURPOSE

The purpose of this study was to estimate the prevalence of daily/non-daily CU, investigate the association between CU and depression and evaluate CU reasons and methods of administration among cancer survivors.

METHOD

Population-based, nationally representative sample of cancer survivors aged ≥18 (n = 10,799) from 2018 Behavioral Risk Factor Surveillance System Survey was used. Weighted descriptive statistics and multivariate logistic regression were conducted.

FINDINGS

Overall, 4.2% reported daily and 4.1% non-daily CU. Those who self-reported depression had higher prevalence of daily and non-daily CU than those not reporting depression. Daily CU was associated with 120% increased odds of depression (odds ratio = 2.2, 95% confidence interval [1.3, 3.7]) compared with none-users.

DISCUSSION

Efforts to improve open communications and evidence-informed discussions regarding benefits and risks of CU and reasons for using cannabis between clinicians and cancer survivors are imperative.

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.

Cannabis and Depression

There is a growing body of evidence pointing to the co-occurrence of cannabis use and depression. There is also some evidence that the use of cannabis may lead to the onset of depression; however, strong evidence points to the inverse association; i.e. that depression may lead to the onset or increase in cannabis use frequency. Observational and epidemiological studies have not indicated a positive long-term effect of cannabis use on the course and outcome of depression. The association between cannabis use and depression may be stronger among men during adolescence and emerging adulthood and stronger in women during midlife. There is an indication for potential genetic correlation contributing to the comorbidity of cannabis dependence and major depression, namely that serotonin (5-HT) may mediate such association and there is also evidence for specific risk alleles for cannabis addiction. There is preclinical evidence that alteration in the endocannabinoid system could potentially benefit patients suffering from depression. However, the issue of using cannabis as an anti-depressant is at an early stage of examination and there is little evidence to support it. Finally, there has been little support to the notion that selective serotonin reuptake inhibitors (SSRIs) may be effective in decreasing depressive symptoms or rates of substance use in adolescents treated for depression and a co-occurring substance use disorder. In conclusion, despite methodological limitations, research in the past decades has broadened our knowledge on the association between cannabis use and depression from epidemiological, neurological, genetic, and pharmacological perspectives.

Cannabis use, depression and suicidal ideation in adolescence: direction of associations in a population based cohort

BACKGROUND

To clarify the direction of the association between frequency of cannabis use, depressive symptoms and suicidal ideation from 15 to 20 years using cross-lagged analyses.

METHOD

We included 1606 adolescents from the province of Québec followed since 1997 with information on frequency of cannabis use (none/monthly/weekly), depression (defined as being in the top 10% symptoms) and serious suicidal ideation at ages 15, 17 and 20 years.

RESULTS

The prevalence of weekly cannabis use increased from 7.0% at age 15 years to 15.6% by age 20 years. Adolescents who reported using cannabis weekly at one age were 11 to 15 times more likely to continue using cannabis over time. In longitudinal cross-lagged analyses, weekly cannabis use at age 15 was associated with greater odds (OR=2.19, 95% CI=1.04-4.58) of suicidal ideation two years later. However, other substance use (alcohol, tobacco, other drugs) fully explained this association. Further, depression predicted subsequent weekly cannabis use, even after adjusting for comorbid other substance use (eg, for depression at 15 years predicting cannabis use at 17 years: OR=2.30, 95% CI=1.19-4.43).

LIMITATIONS

Quantity of cannabis consumed was not measured.

CONCLUSION

Findings suggest that depressive symptoms in adolescence may represent a risk factor for weekly cannabis consumption, which once initiated is likely to remain chronic. Weekly cannabis use increased risk for suicidal ideation, but not independently from other substance use including alcohol, tobacco and other drugs.

Shifting the Paradigm on Cannabis Safety

The global movement toward legalization of cannabis is resulting in an ever-increasing public perception that cannabis is safe. Cannabis is not the first drug to be available for nonmedical use, nor is it the first to have such an unfounded safety profile. The safety of long-term exposure to phytocannabinoids is misunderstood by, and under reported to, the general public. There is evidence to suggest that long-term use of recreational cannabis may be associated with an increased risk of undesirable side effects. This evidence warrants both appropriate caution from the general public and investment in further research by government and industry sectors that are profiting from the sale of these potent psychoactive agents. There is no doubt that these compounds have medical potential. However, in addition to the medical potential, we must also remain aware of the adverse health effects that are becoming synonymous with recreational cannabis use. This perspective highlights the privileged role that cannabis has as a perceived “safe drug” in society and summarizes some concerning side effects that are becoming associated with regular nonprescribed cannabis use.

Acute neuroradiological, behavioral, and physiological effects of nose-only exposure to vaporized cannabis in C57BL/6 mice

Objective: The rapid increase of cannabis consumption reinforces the need to elucidate the health hazards of this practice. The presence of fine particulate matter in cannabis smoke and vapor poses a major concern, as it may contribute to cardiopulmonary disease. To facilitate the assessment of risks associated with cannabis inhalation, we developed and characterized a method for exposing mice to cannabis in a way that mimics the delivery of the drug to the airways of smokers. Materials and Methods: Cannabis (10.3% THC, 0.05% CBD) was vaporized to generate aerosols with a reproducible particle profile. Aerosols were acutely delivered to male, adult C57BL/6 mice via a nose-only exposure system. Serum THC levels were measured for increasing cannabis doses. Blood pressure and heart rate were recorded at baseline and following exposure. Behavioral response to cannabis inhalation in the open field was documented. Awake neurological activity upon cannabis exposure was monitored using BOLD fMRI.Results and Discussion: Cannabis aerosols contained particles with count median diameter of 243 ± 39 nm and geometric standard deviation of 1.56 ± 0.06. Blood serum THC levels increased linearly with aerosolized mass and peaked at 136 ± 5 ng/mL. Cannabis inhalation decreased heart rate and blood pressure but promoted anxiety-like behavior. Observed differences in BOLD activation volumes linked cannabis to increased awareness to sensory stimuli and reduced behavioral arousal.Conclusions: Quantified physiological, behavioral, and neurological responses served as validation for our mouse model of cannabis inhalation. Animal models of aerosol exposure will be instrumental for uncovering the health outcomes of chronic cannabis use.

Childhood social environmental and behavioural predictors of early adolescent onset cannabis use

INTRODUCTION AND AIMS

This study prospectively investigates behavioural and social antecedents of different patterns of adolescent cannabis use, specifically, early adolescent onset cannabis use and late onset occasional use.

DESIGN AND METHODS

The sample comprised 852 adolescents (53% female) drawn from the Australian arm of the International Youth Development Study. Data were collected via self-report surveys. Risk and protective factors from a modified version of the Communities That Care youth survey were measured in fifth grade (mean [M] = 10.9 years, SD = 0.4). Frequency of cannabis use was measured at six time-points throughout adolescence (ages 12-19 years).

RESULTS

Early adolescent onset cannabis use (10.7% of the sample [n = 91]) was predicted by childhood family-related factors including poor family management, family history of antisocial behaviour and attachment to parents. Cigarette use and drinking until drunk were the strongest predictors of early adolescent onset cannabis use. Cumulative risks associated with community, family, peer/individual environments and early substance use (cigarettes, alcohol) in childhood were predictive of early adolescent onset cannabis use (e.g. relative risk ratio = 2.64; 95% confidence interval 1.40-4.97 for early substance use). Family and early substance use-related cumulative risks were predictive of late adolescent onset occasional cannabis use (n = 231; 27%). Cumulative early substance use risk was the strongest independent predictor of both early adolescent onset and late adolescent onset occasional cannabis use.

DISCUSSION AND CONCLUSIONS

Primary prevention efforts should focus on reducing exposure and access to licit substances during late childhood and delaying the onset of use. Prevention and intervention targeted toward the family environment also appears likely to be important in the prevention of early adolescent onset cannabis use.

Rapid increase in the prevalence of cannabis use among people with depression in the United States, 2005-17: the role of differentially changing risk perceptions

AIMS

To estimate trends in the prevalence of cannabis use and risk perceptions of cannabis use from 2005 to 2017 among United States people with and without depression.

DESIGN

Linear time trends of the prevalence of any, daily and non-daily past 30-day cannabis use and perceived great risk associated with regular cannabis use (outcome variables) among people with and without past-year depression were assessed using logistic regression with survey year as the predictor. All analyses were adjusted for gender, age, race/ethnicity and income; models assessing time trends of cannabis use prevalence were also adjusted for perceived risk.

SETTING

The United States: National Survey on Drug Use and Health, an annual cross-sectional survey, 2005-17 public use data files.

PARTICIPANTS

A total of 728 691 people aged ≥ 12 years.

MEASUREMENTS

Self-report of any, daily and non-daily past 30-day cannabis use and perceived great risk associated with regular cannabis use.

FINDINGS

The prevalence of any, daily and non-daily cannabis use in the past month was higher among those with depression versus those without [e.g. 2017 for any use: 18.94 versus 8.67%; adjusted odds ratio (aOR) = 2.17 (95% confidence interval (CI) = 1.92, 2.45)]. Any, daily and non-daily cannabis use increased among people with and without depression from 2005 to 2017, yet the increase in any (aORs = 1.06 versus 1.05; P = 0.008) and daily (aORs = 1.10 versus 1.07; P = 0.021) cannabis use adjusted for socio-demographic characteristics was more rapid among those with depression. Perception of great risk associated with regular cannabis use was significantly lower among those with depression (P < 0.001) and decreased significantly more rapidly over the study period among people with depression, compared with those without (aORs = 0.89 versus 0.92; P < 0.001).

CONCLUSIONS

The prevalence of cannabis use in the United States increased from 2005 to 2017 among people with and without depression and was approximately twice as common among those with depression. People with depression experienced a more rapid decrease in perception of risk, which may be related to the more rapid increase in any and daily past-month cannabis use in this group.

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.

Genome-wide DNA methylation analysis of heavy cannabis exposure in a New Zealand longitudinal cohort

Cannabis use is of increasing public health interest globally. Here we examined the effect of heavy cannabis use, with and without tobacco, on genome-wide DNA methylation in a longitudinal birth cohort (Christchurch Health and Development Study, CHDS). A total of 48 heavy cannabis users were selected from the CHDS cohort, on the basis of their adult exposure to cannabis and tobacco, and DNA methylation assessed from whole blood samples, collected at approximately age 28. Methylation in heavy cannabis users was assessed, relative to non-users (n = 48 controls) via the Illumina Infinium® MethylationEPIC BeadChip. We found the most differentially methylated sites in cannabis with tobacco users were in the AHRR and F2RL3 genes, replicating previous studies on the effects of tobacco. Cannabis-only users had no evidence of differential methylation in these genes, or at any other loci at the epigenome-wide significance level (P < 10^-7). However, there were 521 sites differentially methylated at P < 0.001 which were enriched for genes involved in neuronal signalling (glutamatergic synapse and long-term potentiation) and cardiomyopathy. Further, the most differentially methylated loci were associated with genes with reported roles in brain function (e.g. TMEM190, MUC3L, CDC20 and SP9). We conclude that the effects of cannabis use on the mature human blood methylome differ from, and are less pronounced than, the effects of tobacco use, and that larger sample sizes are required to investigate this further.

Cannabis use among youth in the United States, 2004-2016: Faster rate of increase among youth with depression

BACKGROUND

Cannabis use has significant negative consequences for youth. Depression is associated with greater cannabis use among adults but less is known about cannabis use and depression among youth. This study investigated whether depression is associated with increased cannabis use among youth in the United States (US), overall and by demographics, and examined trends in cannabis use by depression status among youth from 2004 to 2016.

METHODS

Data were from the 2004-2016 National Survey on Drug Use and Health (NSDUH), annual cross-sectional national samples of US persons 12 and older. The analytic sample included respondents aged 12-17 (total combined n=204,102). First, the prevalence of past-month cannabis use by past-year depression status among youth was examined, overall and by demographic subgroups, using pooled data from 2004-2016. Next, linear time trends of past-month cannabis use were assessed by depression status from 2004 to 2016 using logistic regression models with continuous year as the predictor. Models with year-by-depression status interaction terms assessed differential time trends for those with and without depression.

RESULTS

From 2004-2016, cannabis use increased both among youth with and without depression. Cannabis use increased significantly more rapidly among youth with (8.45% to 11.65%), compared to without, depression (4.28% to 4.71%). Youth with depression were more than twice as likely to report cannabis use (12.86% versus 6.40%), relative to those without depression.

CONCLUSIONS

Cannabis use was more than twice as common and increased more rapidly from 2004 to 2016 among youth with depression compared to youth without depression.

Cannabis use, depression and self-harm: phenotypic and genetic relationships

BACKGROUND AND AIMS

The use of cannabis has previously been linked to both depression and self-harm; however, the role of genetics in this relationship is unclear. This study aimed to estimate the phenotypic and genetic associations between cannabis use and depression and self-harm.

DESIGN

Cross-sectional data collected through UK Biobank were used to test the phenotypic association between cannabis use, depression and self-harm. UK Biobank genetic data were then combined with consortia genome-wide association study summary statistics to further test the genetic relationships between these traits using LD score regression, polygenic risk scoring and Mendelian randomization methods.

SETTING

United Kingdom, with additional international consortia data.

PARTICIPANTS

A total of 126 291 British adults aged between 40 and 70 years, recruited into UK Biobank.

MEASUREMENTS

Phenotypic outcomes were life-time history of cannabis use (including initial and continued cannabis use), depression (including single-episode and recurrent depression) and self-harm. Genome-wide genetic data were used and assessment centre, batch and the first six principal components were included as key covariates when handling genetic data.

FINDINGS

In UK Biobank, cannabis use is associated with an increased likelihood of depression [odds ratio (OR) = 1.64, 95% confidence interval (CI) = 1.59-1.70] and self-harm (OR = 2.85, 95% CI = 2.69-3.01). The strength of this phenotypic association is stronger when more severe trait definitions of cannabis use and depression are considered. Using consortia genome-wide summary statistics, significant genetic correlations are seen between cannabis use and depression [rg = 0.289, standard error (SE) = 0.036]. Polygenic risk scores for cannabis use and depression explain a small but significant proportion of variance in cannabis use, depression and self-harm within a UK Biobank target sample. However, two-sample Mendelian randomization analyses were not significant.

CONCLUSIONS

Cannabis use appeared to be both phenotypically and genetically associated with depression and self-harm. Limitations in statistical power mean that conclusions could not be made on the direction of causality between these traits.

The relationship between psychological health and social support: Evidence from physicians in China

BACKGROUND

The psychological health (PH) of doctors affects the quality of medical service and is related to the safety of patients. The serious problems with the doctor-patient relationship in China can lead to long-term imbalances in doctor PH, and the poor PH status of doctors has raised scholars' concern. Current research mainly focuses on how factors such as social support and the impact of the residential environment correlate with individual PH. We continue this direction of research to see how the mechanism of social support impacts physician PH, also investigating the moderating effect of demographic indicators on physician PH.

METHODS

Based on a survey of 399 physicians, a descriptive analysis of measured data was done using SPSS 19.0. Pearson correlation coefficient analysis was used to examine the correlations between PH and the social support rating scale (SSRS) and the demographic variables. KMO and Bartlett methods were used to examine the correlations between PH and SDS (a scale to measure depression) and between PH and SAS (a scale to measure anxiety). The method of factor analysis was used for multicollinearity tests, and multiple stepwise regression analysis was used to explore the demographic factors correlated with PH and SSRS. Two-way interactions in moderated multiple regression were used to test the moderating effect of education level and title on SSRS, SDS, and SAS.

RESULTS

Our results indicate that the level of PH is influenced by the age, education, and title of a doctor. A physician's title is significantly and positively correlated with PH, but age and education are significantly negatively related. Age, education, and title also affect the level of SSRS in physicians. SSRS is positively correlated with age, education, and title, and SSRS positively influences PH. Education and title had significant effects on the moderating influences of SSRS, SDS, SAS, and PH.

CONCLUSION

The factors directly affecting PH include SSRS, age, and title, while education was found to be an indirect influencing factor. To meet goals expressed in Chinese government policy related to these issues, we suggest strengthening the guidance of the media, introducing laws and regulations on doctor-patient risk management and control, reforming the review mechanism of hospital job titles, improving the education level of doctors, building a comprehensive evaluation system of "practice performance + doctor-patient satisfaction", and strengthening doctor-patient empathy. Through such measures, the level of PH in physicians will improve.

A Comprehensive Examination of the Links between Cannabis Use and Motivation

Background: Cannabis use is widely perceived to produce an "amotivational syndrome" characterized by reduced desire to work or compete, passivity, and lower achievement orientation. The notion that cannabis diminishes motivation has been perpetuated in popular culture, despite the equivocal results of past research. Moreover, previous literature has largely failed to consider the potentially confounding influences of depression, other substance use, and personality, despite known relationships between these variables and cannabis use.Purpose: The purpose of this study was to elucidate the nature of the relationships between specific aspects of motivation and cannabis use/misuse. Moreover, we sought to determine whether depression, alcohol and other substance use, and/or personality could account for these relationships.Method: A total of 1,168 participants completed a survey comprising self-report measures of motivation (self-efficacy, apathy, goal orientation, reward-sensitivity, and behavioral inhibition/approach systems) and cannabis use/misuse (cannabis use status, cannabis use frequency, quantity, age of onset of cannabis use, symptoms of cannabis use disorder, problematic cannabis use).Results: The results revealed small (r < .30) but significant correlations between various aspects of cannabis use and motivation, which were largely accounted for by cannabis-related differences in depression, alcohol and other substance use, and personality. However, relationships between cannabis misuse and apathy remained statistically significant after controlling for confounds, indicating that individuals who misuse cannabis may demonstrate higher levels of apathy specifically.Conclusion: Collectively, these results suggest that differences in depression, substance use, and personality between cannabis users and non-users largely explain differences in motivation between these groups.

Cannabis Use and the Risk for Psychosis and Affective Disorders

Objective: This review discusses the relationship between cannabis use and psychotic, bipolar, depressive, and anxiety disorders, as well as suicide. It summarizes epidemiological evidence from cross-sectional and long-term prospective studies and considers possible etiological mechanisms. Methods: Systematic reviews and methodologically robust studies in the field (from inception to February 2019) were identified using a comprehensive search of Medline, PsychINFO, and Embase and summarized using a narrative synthesis. Results: Consistent evidence, both from observational and experimental studies, has confirmed the important role of cannabis use in the initiation and persistence of psychotic disorders. The size of the effect is related to the extent of cannabis use, with greater risk for early cannabis use and use of high-potency varieties and synthetic cannabinoids. Accumulating evidence suggests that frequent cannabis use also increases the risk for mania as well as for suicide. However, the effect on depression is less clear and findings on anxiety are contradictory with only a few methodologically robust studies. Furthermore, the relationship with common mental disorders may involve reverse causality, as depression and anxiety are reported to lead to greater cannabis consumption in some studies. Pathogenetic mechanisms focus on the effect of tetrahydrocannabinol (THC, the main psychoactive ingredient of cannabis) interacting with genetic predisposition and perhaps other environmental risk factors. Cannabidiol (CBD), the other important ingredient of traditional cannabis, ameliorates the psychotogenic effects of THC but is absent from the high-potency varieties that are increasingly available. Conclusions: The evidence that heavy use of high-THC/low-CBD types of cannabis increases the risk of psychosis is sufficiently strong to merit public health education. Evidence of similar but smaller effects in mania and suicide is growing, but is not convincing for depression and anxiety. There is much current interest in the possibility that CBD may be therapeutically useful.