Decision-Making Does not Moderate the Association between Cannabis Use and Body Mass Index among Adolescent Cannabis Users

A Review of the Effects of Adolescent Cannabis Use on Physical Health

The current review highlights the available research related to cannabis and indicators of physical health in a variety of domains. Various studies have found associations between cannabis use with pulmonary, cardiovascular, gastrointestinal, and endocrine function as well as body mass index and sleep. At this time, more research is needed to understand the influence of cannabis use on physical health, particularly among adolescent samples.

A Review of the Effects of Adolescent Cannabis Use on Physical Health

The current review highlights the available research related to cannabis and indicators of physical health in a variety of domains. Various studies have found associations between cannabis use with pulmonary, cardiovascular, gastrointestinal, and endocrine function as well as body mass index and sleep. At this time, more research is needed to understand the influence of cannabis use on physical health, particularly among adolescent samples.

The effects of cannabis use on physical health: A co-twin control study

BACKGROUND

Research on the influence of cannabis use on anthropometrics, cardiovascular and pulmonary function, and other indicators of physical health has reported mixed results. We examined whether cannabis frequency is associated with physical health outcomes phenotypically and after controlling for shared genetic and environmental factors via a longitudinal co-twin control design.

METHODS

We tested the phenotypic associations of adolescent, young adult, and adult cannabis frequency with adult physical health. Next, we ran multilevel models to test if significant phenotypic associations remained at the between-family and within-twin pair levels. Participants include 677 individual twins (308 twin pairs) aged 25-35.

RESULTS

At the phenotypic level, adolescent cannabis use was associated with less adult exercise engagement (b = - 0.846 min, p = .000). Adult cannabis use was associated with a lower resting heart rate (HR; b = - 0.170 bpm, p = .001) and more frequent appetite loss (b = 0.018, p = .000). Only between-family effects were significant for adolescent cannabis use and exercise engagement (b = - 1.147 min, p = .000) and adult cannabis use and appetite loss frequency (b = 0.041, p = .002). The total within-twin (b = - 0.184, p = .014), MZ only (b = - 0.304, p = .003), and between-family effects (b = - 0.164, p = .025) were significant between adult cannabis use and a lower resting HR, which persisted after controlling for familial confounds and other substance use.

CONCLUSIONS

The associations between cannabis use with exercise engagement and frequency of appetite loss are explained by familial confounding while the association between cannabis use and resting HR was not. These results do not support a causal association between cannabis use once a week and poorer physical health effects among adults aged 25-35.

Effects of repeated adolescent exposure to cannabis smoke on cognitive outcomes in adulthood

BACKGROUND

Cannabis (marijuana) is the most widely used illicit drug in the USA, and consumption among adolescents is rising. Some animal studies show that adolescent exposure to delta 9-tetrahydrocannabinol or synthetic cannabinoid receptor 1 agonists causes alterations in affect and cognition that can persist into adulthood. It is less clear, however, whether similar alterations result from exposure to cannabis via smoke inhalation, which remains the most frequent route of administration in humans.

AIMS

To begin to address these questions, a rat model was used to determine how cannabis smoke exposure during adolescence affects behavioral and cognitive outcomes in adulthood.

METHODS

Adolescent male Long-Evans rats were assigned to clean air, placebo smoke, or cannabis smoke groups. Clean air or smoke exposure sessions were conducted daily during adolescence (from P29-P49 days of age ) for a total of 21 days, and behavioral testing began on P70.

RESULTS

Compared to clean air and placebo smoke conditions, cannabis smoke significantly attenuated the normal developmental increase in body weight, but had no effects on several measures of either affect/motivation (open field activity, elevated plus maze, instrumental responding under a progressive ratio schedule of reinforcement) or cognition (set shifting, reversal learning, intertemporal choice). Surprisingly, however, in comparison to clean air controls rats exposed to either cannabis or placebo smoke in adolescence exhibited enhanced performance on a delayed response working memory task.

CONCLUSIONS

These findings are consistent with a growing body of evidence for limited long-term adverse cognitive and affective consequences of adolescent exposure to relatively low levels of cannabinoids.

Targeting the Endocannabinoid CB1 Receptor to Treat Body Weight Disorders: A Preclinical and Clinical Review of the Therapeutic Potential of Past and Present CB1 Drugs

Obesity rates are increasing worldwide and there is a need for novel therapeutic treatment options. The endocannabinoid system has been linked to homeostatic processes, including metabolism, food intake, and the regulation of body weight. Rimonabant, an inverse agonist for the cannabinoid CB1 receptor, was effective at producing weight loss in obese subjects. However, due to adverse psychiatric side effects, rimonabant was removed from the market. More recently, we reported an inverse relationship between cannabis use and BMI, which has now been duplicated by several groups. As those results may appear contradictory, we review here preclinical and clinical studies that have studied the impact on body weight of various cannabinoid CB1 drugs. Notably, we will review the impact of CB1 inverse agonists, agonists, partial agonists, and neutral antagonists. Those findings clearly point out the cannabinoid CB1 as a potential effective target for the treatment of obesity. Recent preclinical studies suggest that ligands targeting the CB1 may retain the therapeutic potential of rimonabant without the negative side effect profile. Such approaches should be tested in clinical trials for validation.

Bidirectional Longitudinal Associations Between Cannabis Use and Body Mass Index Among Adolescents

Introduction: Literature on the association between cannabis use and body mass index (BMI) among adults suggests that greater cannabis use is associated with a lower BMI. However, results are mixed among adolescents, with both cross-sectional and longitudinal studies finding positive, negative, and nonsignificant associations between cannabis use and BMI. This longitudinal study aims to shed light on these associations by prospectively examining the associations between cannabis use and BMI across a 2-year window in a large sample of adolescent cannabis users. Methods: Participants were 401 adolescents ages 14-17 at baseline who were at risk for escalation in their use of cannabis. We conducted a parallel process latent growth curve model to examine associations between the cannabis use intercept, BMI intercept, cannabis use slope, and BMI slope. Results: Results showed that baseline BMI predicted a positive and significant association with cannabis use slope. In addition, there was a significant and negative correlation between the cannabis use slope and the BMI slope. These significant associations remained after controlling for relevant covariates. Conclusions: Results are consistent with the adult literature that reports a negative association between cannabis use and BMI. Future research should focus on uncovering the mechanisms that may drive the association between cannabis use and BMI.

Decision-Making as a Latent Construct and its Measurement Invariance in a Large Sample of Adolescent Cannabis Users

OBJECTIVE

Relative to the vast literature that employs measures of decision-making (DM), rigorous examination of their psychometric properties is sparse. This study aimed to determine whether three measures of DM assess the same construct, and to measure invariance of this construct across relevant covariates.

METHOD

Participants were 372 adolescents at risk of escalation in cannabis use. DM was assessed via four indices from the Cups Task, Game of Dice Task (GDT), and Iowa Gambling Task (IGT). We used confirmatory factor analysis to assess unidimensionality of the DM construct, and moderated nonlinear factor analysis (MNLFA) to examine its measurement invariance.

RESULTS

The unidimensional model of DM demonstrated good fit. MNLFA results revealed that sex influenced mean DM scores, such that boys had lower risk-taking behaviors. There was evidence of differential item functioning (DIF), such that IQ and age moderated the IGT intercept and GDT factor loading, respectively. Significant effects were retained in the final model, which produced participant-specific DM factor scores. These scores showed moderate stability over time.

CONCLUSIONS

Indices from three DM tasks loaded significantly onto a single factor, suggesting that these DM tasks assess a single underlying construct. We suggest that this construct represents the ability to make optimal choices that maximize rewards in the presence of risk. Our final DM factor accounts for DIF caused by covariates, making it comparable across adolescents with different characteristics. (JINS, 2019, 25, 661-667).

Effect of cannabis on weight and metabolism in first-episode non-affective psychosis: Results from a three-year longitudinal study

BACKGROUND

Cannabis smoking is highly prevalent among patients with psychotic disorders. Its use has been found to be related to clinical characteristics and the prognosis of the disorder. Recent evidence indicates a protective effect of cannabis on weight gain and related metabolic alterations. However, there are no previous studies on the long-term longitudinal effects of cannabis on first-episode drug-naïve patients, which would thereby avoid the confounding effects of chronicity and previous treatment exposure. We aimed to explore the effect of cannabis smoking on weight and lipid/glycaemic metabolic measures in a sample of first-episode non-affective psychosis patients.

METHOD

Anthropometric measurements and glycaemic and lipid parameters were obtained at baseline and three years after initiation of treatment. Patients self-reported their cannabis use at both time points. To explore the longitudinal effect of cannabis, patients were divided into three groups: continuers, discontinuers and non-users.

RESULTS

Cannabis users at baseline presented a lower weight ( F=14.85, p<0.001), body mass index ( F=13.14, p<0.001), total cholesterol ( F=4.85, p=0.028) and low-density lipoprotein-cholesterol ( F=6.26, p=0.013) compared to non-users. These differences were also observed after three years: weight ( F=8.07, p=0.005), body mass index ( F=4.66, p=0.032) and low-density lipoprotein-cholesterol ( F=3.91, p=0.049). Moreover, those patients discontinuing cannabis use presented a higher increase in weight ( F=2.98, p=0.052), body mass index ( F=2.73, p=0.067) and triglyceride-high-density lipoprotein ratio ( F=2.72, p=0.067) than the 'non-users' and 'continuers'.

CONCLUSIONS

The study suggests that cannabis use may produce a protective effect against weight gain and related metabolic alterations in psychosis. However, these results need to be replicated in a larger sample size.

Is Cannabis Use Associated with Sedentary Behavior during Leisure Time? A Study in Canada, 2011-2012

BACKGROUND

Sedentary behavior, defined as lying or sitting, is a global health concern. As researchers continue to identify modern-day risk factors for sedentary behavior, few have explored the role of illicit drug use.

OBJECTIVE

To examine the association between leisure-time sedentary behavior and cannabis use, in adolescents and adults.

METHODS

We conducted a cross-sectional study relating cannabis use to total leisure-time sedentary behavior (hr/wk using the computer, playing video games, watching television or videos, and reading for leisure) using data from the 2011-2012 Canadian Community Health Survey (CCHS), a population-based survey of Canadians age ≥12 years. Analyses were possible for 48,240 respondents in Saskatchewan, Ontario, and Nunavut who reported on sedentary behavior. We used logistic regression modeling to relate frequency of cannabis use (never, occasional, heavy) to high-risk sedentary behavior (<35 versus ≥35 hr/wk) overall and stratified by sex, age, and rural location.

RESULTS

Approximately 80% of respondents were ≥25 years old. In the fully-adjusted model, the odds of ≥35 hr/wk of sedentary behavior were 80% higher for heavy cannabis users versus never users (OR = 1.8, 95% CI: 1.4-2.3); in occasional cannabis users, the odds were 30% higher (OR = 1.3, 95% CI: 1.1-1.5). In stratified analyses, odds ratios were statistically significant among adults age 25-44 years and people living in nonrural settings. Conclusions/Importance: Our findings support dual lifestyle interventions targeting heavy cannabis use and excessive sedentary behavior simultaneously. Moreover, leisure-time sedentary behavior should be considered as a covariate in future epidemiologic models relating cannabis to health.

Transition to drug co-use among adolescent cannabis users: The role of decision-making and mental health

BACKGROUND

Co-use of cannabis and drugs other than cannabis (DOTC) influences the risk of experiencing cannabis disorders. Accordingly, we explored whether speed of transition to drug co-use, the number of DOTC used, and/or being an experimental cannabis-only user, a regular cannabis-only user, or a regular cannabis user who co-uses DOTC (i.e., cannabis-plus user) were associated with decision-making (DM), mental health disorder symptoms, or cannabis use-related characteristics.

METHODS

We analyzed baseline data from a sub-sample of 266 adolescent (ages 14 to 16) cannabis users (CU) participating in an ongoing longitudinal study. Assessments included semi-structured interviews, self-report questionnaires, and measures of drug use, DM (measured via the Iowa Gambling Task), mental health disorders, and cannabis use-related problems.

RESULTS

Endorsing a larger number of mood disorders symptoms was associated with being a regular cannabis-plus user rather than a regular cannabis-only user (AOR = 1.08, C.I.95% 1.01, 1.15). Poorer DM was associated with a faster transition to co-use, such that for each one unit increase in DM performance, the years to onset of drug co-use increased by 1% (p = 0.032). Endorsing a larger number of cannabis use-related problems was positively associated with endorsing a larger number of DOTC used (p = 0.001).

CONCLUSIONS

This study provides new evidence on the process of drug co-use among CU. Specifically, mood disorder symptoms were associated with use of DOTC among regular CU. Furthermore, poorer DM was associated with a faster transition to drug co-use. Poorer DM and mood disorder symptoms may aggravate or accelerate the onset of adverse consequences among adolescent CU.

Effects of cannabis use on body mass, fasting glucose and lipids during the first 12 months of treatment in schizophrenia spectrum disorders

While acute cannabis use stimulates appetite, general population studies suggest that chronic use is associated with reduced risk of obesity and other cardiometabolic risk factors. In this study we investigated changes in body mass index (BMI), fasting blood glucose and lipids, and rates of metabolic syndrome risk factors in cannabis users vs. non-users in 109 minimally treated patients with first-episode schizophrenia, schizophreniform or schizo-affective disorder who were treated according to a standardized treatment regime with depot antipsychotic medication over 12 months. Participants underwent repeated urine toxicology tests for cannabis and those testing positive at any time during the study (n = 40), were compared with those who tested negative at all time points (n = 69). There was a significant group*time interaction effect (p = 0.002) with the cannabis negative group showing a greater increase in BMI than the cannabis positive group, after adjusting for age, sex, methamphetamine use and modal dose of antipsychotic. There were no group*time interaction effects for fasting blood glucose or lipids. Post hoc tests indicated significant increases in fasting blood glucose and triglycerides and a decrease in high-density lipoprotein cholesterol for the cannabis negative group, with no significant changes in the cannabis positive group. Rates of metabolic syndrome did not differ significantly between groups, although more cannabis negative patients had elevated waist-circumference at endpoint (p = 0.003). It may be that chronic cannabis use directly suppresses appetite, thereby preventing weight gain in users. However, other indirect effects such as dietary neglect and smoking may be contributory and could explain our findings.

Identifying Inhibitory Subcomponents Associated with Changes in Binge Drinking Behavior: A 6-Month Longitudinal Design

BACKGROUND

Links between response inhibition and young adult problematic drinking (e.g., binge drinking) have been established, but only to an extent. Considering the presence of some inconsistent findings associated with these 2 variables, this study proposes the need to investigate the extent in which different inhibitory subcomponents are associated with binge drinking behaviors of the same sample.

METHODS

Through the use of a 6-month longitudinal design, changes in Alcohol Use Questionnaire (AUQ) binge score of 163 college students (50.3% female) with a mean age of 21.06 years (SD = 1.83) were correlated with performance on 3 different inhibitory control tasks. Each task was selected to assess separate inhibitory subcomponents: Stop Signal Task (e.g., cancellation of a response), Go/No-Go Task (e.g., withholding of a response), and Simon Task (e.g., inhibiting response interference). Response inhibition was also compared between 2 groups, those who had a substantial increase in AUQ binge score during participation (inAUQ) and those who had a substantial decrease in AUQ binge score (deAUQ).

RESULTS

A significant correlation was found with a change in AUQ binge score and stop signal reaction time among females only, where an increase in binge drinking score positively correlated with a reduced ability to cancel an already-initiated inhibitory response. Differences in inhibitory performance, where inAUQ performed worse than deAUQ, approached significance.

CONCLUSIONS

The results suggest that the cancellation of a prepotent response, as opposed to the withholding of response or interference inhibition, is a more sensitive inhibitory measure associated with increases in binge drinking behavior among female young adult college students. Further exploration of inhibitory subcomponents relative to substance use is greatly needed (e.g., more extensive longitudinal designs and neuroimaging techniques).

Executive and Reward-Related Function in Pediatric Obesity: A Meta-Analysis

OBJECTIVE

This study examined the effect of pediatric obesity on executive function and reward-related decision-making, cognitive processes that are relevant to obesogenic behaviors, and evaluated their association with sample (e.g., age, gender, intelligence, and socioeconomic status, SES) and study/task (e.g., categorical/continuous variable, food stimuli) characteristics.

METHODS

A random-effects meta-analysis was conducted using Hedge's g effect sizes of published studies from 1960 to 2016, limited to children younger than the age of 21 years without medical comorbidities. Analysis included estimation of heterogeneity (τ²), publication bias (funnel-plot symmetry and fail-safe N), and sensitivity analyses for sample and study/task characteristics.

RESULTS

Across 68 studies with 70 samples, obesity was associated with worse functioning overall (-0.24; 95CI: -0.30 to -0.19; p < 0.001) and for each component process (attention, switching, inhibition, interference, working memory, reward, delay of gratification: -0.19 to -0.38; p's < 0.017), except trait impulsivity (-0.06; 95CI: -0.18 to 0.07). Deficits increased with age and female composition of the sample for inhibition (p = 0.002). No other characteristics moderated effect of obesity.

CONCLUSIONS

Small-to-moderate negative associations with obesity were observed for executive and reward-related performance, but not on reported impulsivity in studies with children younger than the age of 21 years. These results were not moderated by IQ, SES, and study/task characteristics. Age and gender moderated association with inhibition, with a larger obesity-related deficit in older and predominantly female samples. These results suggest cognitive and demographic intervention targets for prevention and mitigation of obesogenic behavior.

The association between adolescent cannabis use and anxiety: A parallel process analysis

INTRODUCTION

Associations between anxiety symptoms and cannabis use have been previously explored, yet the directionality of these associations remains highly debatable. The present study aims to prospectively examine patterns of cannabis use and anxiety during adolescence focusing on their co-development and bidirectional influences.

METHODS

Adolescents (n=250) of predominantly Hispanic ethnicity, aged 14-17 at baseline, exposed to drugs, alcohol, or cigarettes completed three (bi-annual) assessments across a 1-year period. Latent growth curve modeling (LGCM) and parallel process growth curves were conducted to examine potential associations in the joint development of anxiety and cannabis use.

RESULTS

Our results suggest that, during adolescence, early cannabis use has a greater influence on prospective reports of anxiety, than vice versa. Specifically, adolescents exhibiting higher initial levels of cannabis use displayed more persisting self-reported anxiety across time, as compared to those with less frequent use (b=0.28, p=0.024). In contrast, early levels of anxiety were not found to influence rates of change in cannabis use. These analyses considered concurrent depression, alcohol, and nicotine use.

CONCLUSIONS

Our findings suggest that prevention and targeted intervention programs for cannabis use in adolescence would benefit from anxiety management strategies; in order to reduce subsequent anxiety associated with cannabis use. Future studies should continue to employ longitudinal designs across larger time periods and aim to replicate these findings with more diverse samples.

Cannabis use in people with Parkinson's disease and Multiple Sclerosis: A web-based investigation

OBJECTIVES

Cannabis has been used for medicinal purpose for thousands of years; however the positive and negative effects of cannabis use in Parkinson's disease (PD) and Multiple Sclerosis (MS) are mostly unknown. Our aim was to assess cannabis use in PD and MS and compare results of self-reported assessments of neurological disability between current cannabis users and non-users.

METHODS

An anonymous web-based survey was hosted on the Michael J. Fox Foundation and the National Multiple Sclerosis Society webpages from 15 February to 15 October 2016. The survey collected demographic and cannabis use information, and used standardized questionnaires to assess neurological function, fatigue, balance, and physical activity participation. Analysis of variance and chi-square tests were used for the analysis.

RESULTS

The survey was viewed 801 times, and 595 participants were in the final data set. Seventy-six percent and 24% of the respondents reported PD and MS respectively. Current users reported high efficacy of cannabis, 6.4 (SD 1.8) on a scale from 0 to 7 and 59% reported reducing prescription medication since beginning cannabis use. Current cannabis users were younger and less likely to be classified as obese (P < 0.035). Cannabis users reported lower levels of disability, specifically in domains of mood, memory, and fatigue (P<0.040).

CONCLUSIONS

Cannabis may have positive impacts on mood, memory, fatigue, and obesity status in people with PD and MS. Further studies using clinically and longitudinally assessed measurements of these domains are needed to establish if these associations are causal and determine the long-term benefits and consequences of cannabis use in people with PD and MS.