Sleep Quality Moderates the Relation between Depression Symptoms and Problematic Cannabis Use among Medical Cannabis Users

Objectives: This study sought to extend research on the relation between depression symptoms and problematic cannabis use by evaluating the potential moderating role of perceived sleep quality among medical cannabis users. Methods: This employed a cross-sectional design. The sample consisted of 162 adults (mean age = 42.05 years, SD = 14.8; 22% female), with current recommendations from a doctor for medical cannabis, recruited from a medical cannabis dispensary. Results: Consistent with previous research, individuals with heightened depression symptoms had greater problematic cannabis use. In addition, perceived sleep quality moderated this relation, such that depression symptoms differentially related to problematic cannabis use as a function of perceived quality of sleep (ΔR² = .03, p = .02). Participants with higher levels of depression and good perceived sleep quality had the greatest rates of problematic cannabis use. Conclusions: These results suggest that individuals with heightened depression may have higher rates of problematic cannabis use, in part, because of the beneficial effects of cannabis in terms of perceived sleep quality.     

Dose-dependent cannabis use,depressive symptoms,and FAAH genotype predict sleep quality in emerging adults: a pilot study

ABSTRACT

Background: Cannabis has been shown to affect sleep in humans. Findings from animal studies indicate that higher endocannabinoid levels promote sleep, suggesting that chronic use of cannabis, which downregulates endocannabinoid activity, may disrupt sleep. Objectives: This study sought to determine if past-year cannabis use and genes that regulate endocannabinoid signaling, FAAH rs324420 and CNR1 rs2180619, predicted sleep quality. As depression has been previously associated with both cannabis and sleep, the secondary aim was to determine if depressive symptoms moderated or mediated these relationships. Methods: Data were collected from 41 emerging adult (ages 18–25) cannabis users. Exclusion criteria included Axis I disorders (besides SUD) and medical and neurologic disorders. Relationships were tested using multiple regressions, controlling for demographic variables, past-year substance use, and length of cannabis abstinence. Results: Greater past-year cannabis use and FAAH C/C genotype were associated with poorer sleep quality. CNR1 genotype did not significantly predict sleep quality. Depressive symptoms moderated the relationship between cannabis use and sleep at a nonsignificant trend level, such that participants with the higher cannabis use and depressive symptoms reported the more impaired sleep. Depressive symptoms mediated the relationship between FAAH genotype and sleep quality. Conclusions: This study demonstrates a dose-dependent relationship between chronic cannabis use and reported sleep quality, independent of abstinence length. Furthermore, it provides novel evidence that depressive symptoms mediate the relationship between FAAH genotype and sleep quality in humans. These findings suggest potential targets to impact sleep disruptions in cannabis users.     

Exploring the association between cannabis use and depression

Aim To examine the evidence on the association between cannabis and depression and evaluate competing explanations of the association. Methods A search of Medline, Psychinfo and EMBASE databases was conducted. All references in which the terms ‘cannabis’, ‘marijuana’ or ‘cannabinoid’, and in which the words ‘depression/depressive disorder/depressed’, ‘mood’, ‘mood disorder’ or ‘dysthymia’ were collected. Only research studies were reviewed. Case reports are not discussed. Results There was a modest association between heavy or problematic cannabis use and depression in cohort studies and well‐designed cross‐sectional studies in the general population. Little evidence was found for an association between depression and infrequent cannabis use. A number of studies found a modest association between early‐onset, regular cannabis use and later depression, which persisted after controlling for potential confounding variables. There was little evidence of an increased risk of later cannabis use among people with depression and hence little support for the self‐medication hypothesis. There have been a limited number of studies that have controlled for potential confounding variables in the association between heavy cannabis use and depression. These have found that the risk is much reduced by statistical control but a modest relationship remains. Conclusions Heavy cannabis use and depression are associated and evidence from longitudinal studies suggests that heavy cannabis use may increase depressive symptoms among some users. It is still too early, however, to rule out the hypothesis that the association is due to common social, family and contextual factors that increase risks of both heavy cannabis use and depression. Longitudinal studies and studies of twins discordant for heavy cannabis use and depression are needed to rule out common causes. If the relationship is causal, then on current patterns of cannabis use in the most developed societies cannabis use makes, at most, a modest contribution to the population prevalence of depression.     

The association of cannabis use on inpatient psychiatric hospital outcomes

Background: The associations between cannabis use and psychosis are well documented in numerous studies. There is a need to evaluate the impact of cannabis use on inpatient psychiatric utilization and outcomes. Objectives: To evaluate the impact of cannabis use on psychiatric hospital outcomes. Methods: This study was conducted between April 20, 2015 and October 20, 2015. All patients (n = 120) admitted to Denver Health with psychotic symptoms were administered a urine toxicology screening testing for the presence of 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol (THC-COOH, the active metabolite of cannabis). Patients with positive tests were compared to those with negative tests on several measures, including length of stay, presence or lack of 30-day readmission, Brief Psychotic Rating Scale (BPRS) score, and use of antipsychotics and/or sedatives/anxiolytics. Results: There were 120 patients. Twenty nine were women and 91 were men. Patients testing positive for THC-COOH had a shorter length of stay compared to patients testing negative for THC-COOH, after adjusting for age, prior psychiatric admissions, history of a psychotic-spectrum disorder, and comorbid additional substance use (p = 0.02). There were no differences in 30-day readmissions, 30-day post-discharge presentation to the Denver Health psychiatric emergency department, BPRS scores, and medication administration. Conclusion: Patients presenting with psychotic symptoms and cannabis use require shorter inpatient psychiatric hospitalizations. This study is the first to quantify this observation and highlights the need for future clinical decision-making tools that would ideally correlate cannabis use with the degree of potential need for expensive and scarce mental health resources, such as psychiatric hospitalization.     

Cigarette smoking during an N-acetylcysteine-assisted cannabis cessation trial in adolescents

Background and objectives: Tobacco and cannabis use are both highly prevalent worldwide. Their co-use is also common in adults and adolescents. Despite this frequent co-occurrence, cessation from both substances is rarely addressed in randomized clinical trials. Given evidence that tobacco use may increase during cannabis cessation attempts, and additionally that tobacco users have poorer cannabis cessation outcomes, we explored tobacco outcomes, specifically cigarette smoking, from an adolescent cannabis cessation trial that tested the efficacy of N-acetylesteine (NAC). Methods: Cannabis-dependent adolescents (ages 15–21; n?=?116) interested in cannabis treatment were randomized to NAC (1200?mg bid) or matched placebo for 8 weeks. Participants did not need to be cigarette smokers or be interested in smoking cessation to qualify for inclusion. Results: Approximately 59% of enrolled participants were daily and non-daily cigarette smokers, and only differed from non-smoking participants on the compulsion sub-scale of the Marijuana Craving Questionnaire. Among cigarette smokers who were retained in the study, there was no change in cigarettes per day for either NAC or placebo groups during the eight-week treatment phase. Being a cigarette smoker did not appear to influence the effects of NAC on cannabis abstinence, though there was a trend in the placebo group of poorer cannabis outcomes for cigarette smokers vs. non-smokers. Conclusions: No evidence was found of compensatory cigarette smoking during this cannabis cessation trial in adolescents. Further work assessing interventions to reduce both cannabis and tobacco use in this population is greatly needed.     

Sociodemographic Characteristics of Cannabis Smokers and the Experience of Cannabis Withdrawal

Background: Cannabis withdrawal can be a negative reinforcer for relapse, but little is known about its association with demographic characteristics. Objectives: Evaluate the association of demographic characteristics with the experience of cannabis withdrawal. Methods: Retrospective self-report of a “serious” cannabis quit attempt without formal treatment in a convenience sample of 104 non-treatment-seeking, adult cannabis smokers (mean age 35 years, 52% white, 78% male) with no other current substance use disorder (except tobacco) or chronic health problems. Reasons for quitting, coping strategies to help quit, and 18 specific withdrawal symptoms were assessed by questionaire. Results: Among withdrawal symptoms, only anxiety, increased sex drive, and craving showed significant associations with age, race, or sex. Women were more likely than men to report a physical withdrawal symptom (OR = 3.2, 95% CI = .99–10.4, p = .05), especially upset stomach. There were few significant demographic associations with coping strategies or reasons for quitting. Conclusions and Scientific Significance: This small study suggests that there are few robust associations between demographic characteristics and cannabis withdrawal. Future studies with larger samples are needed. Attention to physical withdrawal symptoms in women may help promote abstinence.     

Exposure to cannabis in popular music and cannabis use among adolescents

Background Cannabis use is referenced frequently in American popular music, yet it remains uncertain whether exposure to these references is associated with actual cannabis use. We aimed to determine if exposure to cannabis in popular music is associated independently with current cannabis use in a cohort of urban adolescents. Methods We surveyed all 9th grade students at three large US urban high schools. We estimated participants' exposure to lyrics referent to cannabis with overall music exposure and content analyses of their favorite artists' songs. Outcomes included current (past 30 days) and ever use of cannabis. We used multivariable regression to assess independent associations between exposures and outcomes while controlling for important covariates. Results Each of the 959 participants was exposed to an estimated 27 cannabis references per day [correction added on 19 January 2010, after first online publication: 40 has been changed to 27] (standard deviation = 73 [correction added on 19 January 2010, after first online publication: 104 has been changed to 73]). Twelve per cent (n = 108) were current cannabis users and 32% (n = 286) had ever used cannabis. Compared with those in the lowest tertile of total cannabis exposure in music, those in the highest tertile of exposure were almost twice as likely to have used cannabis in the past 30 days (odds ratio = 1.83; 95% confidence interval = 1.04, 3.22), even after adjusting for socio‐demographic variables, personality characteristics and parenting style. As expected, however, there was no significant relationship between our cannabis exposure variable and a sham outcome variable of alcohol use. Conclusions This study supports an independent association between exposure to cannabis in popular music and early cannabis use among urban American adolescents.     

Changes in cannabis use and its consequences over 3 years in a remote indigenous population in northern Australia

Background Few studies describe cannabis use in indigenous populations, and no longitudinal studies are available in Australia. We conducted 3‐year follow‐up interviews and assessments in Aboriginal communities in Arnhem Land (Northern Territory, NT). Methods A randomly selected sample (n = 161; 80 males, 81 females aged 13–36 years) was assessed in October 2001 and then reassessed in September 2004. An opportunistically recruited sample (n = 104; 53 males, 51 females aged 13–36 years) was also interviewed in 2001 and followed‐up in 2004. Cannabis and other substance use were determined by combining proxy assessments by local Aboriginal health workers, medical records and data from interviews. Changes in cannabis use and symptoms of misuse were assessed using McNemar's test for paired proportions and the Wilcoxon signed rank test. Logistic regression assessed associations between clinical presentations and cannabis use at both time‐points. Results Those who used cannabis at both baseline and follow‐up were at greater risk than those who never used it to have suffered: auditory hallucinations; suicidal ideation; and imprisonment. In the randomly selected cohort there were fewer cannabis users at follow‐up than at baseline (P = 0.003). The reduction was evident in females generally (P = 0.008) and older males (aged = 16 at baseline) (P = 0.007). In those interviewed at both baseline and follow‐up we measured no statistically significant reduction in frequency and levels of use, although fewer cannabis users reported symptoms of misuse such as: fragmented thought processes; memory disruption; difficulties controlling use; and auditory and visual hallucinations. Conclusions Modest reductions in cannabis use and its consequences in this population were demonstrated. These may be the result of enhanced supply control and broader socio‐political changes.     

Open-label pilot study of injectable naltrexone for cannabis dependence

Background: There are no FDA-approved pharmacotherapies for cannabis use disorders (CUD), despite the evaluation of numerous medications. Notably, chronic dosing of oral naltrexone decreases self-administration of cannabis in human laboratory studies.

Objectives: To test the feasibility of long-acting injectable naltrexone for the treatment of CUD, while obtaining preliminary safety and efficacy data.

Methods: Twelve adult participants (seven male) meeting DSM-IV-TR criteria for cannabis dependence enrolled into an 8-week, open-label pilot study conducted at an academic treatment research clinic. They received 380 mg intramuscular injections of long-acting naltrexone on study day 1 and at the start of study week 5. Outcome measures included percentages of study completers and participants who received the second injection, frequency of adverse events (AEs), and cannabis consumption measured by average daily grams, dollars, and using days per week as measured by timeline follow-back and urine oral delta-9-tetrahydrocannabinol (THC) concentrations.

Results: Of the 12 participants enrolled in the study, 9 completed the study and 6 received the second injection. There were no severe AEs but an unexpected AE led to the addition of supportive medications to the protocol. Number of cannabis use days per week significantly decreased over the course of the study (p = .001). Creatinine-corrected urine THC concentrations and average daily cannabis use per study week in grams and in dollars did not decrease over the course of the study.

Conclusions: Long-acting injectable naltrexone is a feasible intervention for CUD worthy of further study in a placebo-controlled, double-blinded randomized clinical trial.     

Repetitive transcranial magnetic stimulation (rTMS) administration to heavy cannabis users

Background: Cannabis use disorder (CUD) is a common condition with few treatments. Several studies in other substance use disorders have found that applying repetitive transcranial magnetic stimulation (rTMS) to the dorsolateral prefrontal cortex (DLPFC) decreases cue-elicited craving and possibly decreases use. To date, there have been no studies attempting to use rTMS in CUD. Objectives: This study was conducted to determine if rTMS could be feasibly delivered to a group of non-treatment seeking CUD participants. Secondarily, the study aimed to estimate the effect of rTMS on craving. Methods: In a double-blind, sham-controlled, crossover design, a single session of active or sham rTMS (Left DLPFC, 10 Hz, 110% rMT, 4000 pulses) was delivered during a validated cannabis cue paradigm. Participants crossed over to complete the other condition one week later. The feasibility and tolerability were measured by the rate of retention, and the percentage of participants able to tolerate full dose rTMS, respectively. Craving was measured using the Marijuana Craving Questionnaire (MCQ). Results: Eighteen non-treatment seeking CUD participants were recruited from the community; 16 (three women) completed the trial (89% retained for the three study visits). All of the treatment completers tolerated rTMS at full dose without adverse effects. There was not a significant reduction in the total MCQ when participants received active rTMS as compared to sham rTMS. Conclusion: rTMS can be safely and feasibly delivered to CUD participants, and treatment is well tolerated. A single session of rTMS applied to the DLPFC may not reduce cue-elicited craving in heavy cannabis users.     

Genetic and environmental influences on cannabis use initiation and problematic use: a meta‐analysis of twin studies

Background Because cannabis use is associated with social, physical and psychological problems, it is important to know what causes some individuals to initiate cannabis use and a subset of those to become problematic users. Previous twin studies found evidence for both genetic and environmental influences on vulnerability, but due to considerable variation in the results it is difficult to draw clear conclusions regarding the relative magnitude of these influences. Methods A systematic literature search identified 28 twin studies on cannabis use initiation and 24 studies on problematic cannabis use. The proportion of total variance accounted for by genes (A), shared environment (C) and unshared environment (E) in (i) initiation of cannabis use and (ii) problematic cannabis use was calculated by averaging corresponding A, C and E estimates across studies from independent cohorts and weighting by sample size. Results For cannabis use initiation, A, C and E estimates were 48%, 25% and 27% in males and 40%, 39% and 21% in females. For problematic cannabis use A, C and E estimates were 51%, 20% and 29% for males and 59%, 15% and 26% for females. Confidence intervals of these estimates are considerably narrower than those in the source studies. Conclusions Our results indicate that vulnerability to both cannabis use initiation and problematic use was influenced significantly by A, C and E. There was a trend for a greater C and lesser A component for cannabis use initiation compared to problematic use for females.     

A review of the published literature into cannabis withdrawal symptoms in human users

Recent experimental papers have been published suggesting the appearance of withdrawal symptoms upon the cessation of cannabis use in human users and proposing the introduction of a diagnostic category for such symptoms. Research also continues to be published into the physiological effects of cannabis on animals via self-administration paradigms and the use of cannabinoid antagonists. Animal research does not provide a clear picture of a consistent withdrawal effect. The literature on withdrawal symptoms appearing in human users following the cessation of cannabis is investigated in this paper to clarify this issue further and enhance the scientific and lay debate on the status of the drug. Methodological weaknesses in the literature are highlighted. These include variable levels of drug-dose administered in laboratory conditions, lack of controlled studies and the absence of definitions of the withdrawal syndrome sought. It is suggested that the studies conducted to date do not provide a strong evidence base for the drawing of any conclusions as to the existence of a cannabis withdrawal syndrome in human users, or as to the cause of symptoms reported by those abstaining from the drug. On the basis of current research cannabis cannot be said to provide as clear a withdrawal pattern as other drugs of abuse, such as opiates. However, cannabis also highlights the need for a further defining of withdrawal, in particular the position that rebound effects occupy in this phenomenon. It is concluded that more controlled research might uncover a diagnosable withdrawal syndrome in human users and that there may be a precedent for the introduction of a cannabis withdrawal syndrome before the exact root of it is known.     

Treatment of cannabis dependence using escitalopram in combination with cognitive-behavior therapy: a double-blind placebo-controlled study

Background: Cannabis is the most frequently used illegal substance in the United States and Europe. There is a dramatic increase in the demand for treatment for cannabis dependence. Cannabis users frequently have co-morbid mood symptoms, especially depression and anxiety, and regular cannabis users may self-medicate for such symptoms. Objectives: We report a double-blind, placebo-controlled treatment study, for the prevention of cannabis use in cannabis-dependent individuals. Method: Regular cannabis-dependent users (n?=?52) were treated for 9 weeks with weekly cognitive-behavior and motivation-enhancement therapy sessions together with escitalopram 10?mg/day. Urine samples were collected to monitor delta-9 tetrahydrocannabinol (THC) during treatment and questionnaires were administered to assess anxiety and depression. Results: We observed a high rate of dropout (50%) during the 9-week treatment program. Fifty-two patients were included in the intention-to-treat analysis. Of these, ten (19%) remained abstinent after 9 weeks of treatment as indicated by negative urine samples for THC. Escitalopram provided no advantage over placebo in either abstinence rates from cannabis or anxiety and depression scores during the withdrawal and abstinent periods. Conclusions: Escitalopram treatment does not provide an additional benefit either for achieving abstinence, or for the treatment of the cannabis withdrawal syndrome. Due to limitations of our study, namely, a high dropout rate and effects of low abstinence rates on measures of anxiety, depression and withdrawal, it is premature to conclude that selective serotonin reuptake inhibitors are not effective for treatment of the cannabis withdrawal syndrome.     

A flicker paradigm for inducing change blindness reveals alcohol and cannabis information processing biases in social users

Aim To apply a new paradigm using transient changes to visual scenes to explore information processing biases relating to ‘social’ levels of alcohol and cannabis use. Participants Male and female student volunteers (n = 200) not self‐reporting substance‐related problems. Setting Quiet testing areas throughout the university campus. Design A flicker paradigm, for inducing change blindness with lighter and heavier social users of alcohol (experiment 1, n= 100) and social users and non‐users of cannabis (experiment 2, n= 100), explored the associations between habitual level of use and the latency to detection of a single substance‐related or neutral change made to a scene of grouped substance‐related and neutral objects. Measurements Alcohol use was measured as the number of units of the heaviest drinking day from the previous week; cannabis use as the number of months of use in previous 12. Change–detection latency comparisons were used to evaluate processing biases. Findings In both experiments, (i) heavier social users detected substance‐related changes quicker than lighter and non‐users; (ii) lighter and non‐users detected substance‐neutral changes quicker than heavier users; (iii) heavier social users detected substance‐related quicker than substance‐neutral changes; and (iv) lighter and non‐users detected substance‐neutral changes quicker than substance‐related changes. Conclusions Alcohol and cannabis processing biases are found at levels of social use, have the potential to influence future consumption and for this reason merit further research.     

Patterns and correlates of cannabis use among individuals with HIV/AIDS in Maritime Canada

BACKGROUND:

The prevalence of cannabis use in HIV-infected individuals is high and its long-term effects are unclear.

METHODS:

The prevalence, perceived benefits and consequences, and predictors of cannabis use were studied using a cross-sectional survey in two immunodeficiency clinics in Maritime Canada.

RESULTS:

Current cannabis use was identified in 38.5% (87 of 226) of participants. Almost all cannabis users (85 of 87 [97.7%]) acknowledged its use for recreational purposes, with 21.8% (19 of 87) reporting medicinal cannabis use. The majority of patients enrolled in the present study reported mild or no symptoms related to HIV (n=179). Overall, 80.5% (70 of 87) of the cannabis-using participants reported a symptom-relieving benefit, mostly for relief of stress, anorexia or pain. Participants consumed a mean (± SD) of 18.3±21.1 g of cannabis per month and spent an average of $105.15±109.87 on cannabis per month. Cannabis use was associated with rural residence, lower income level, driving under the influence of a substance, and consumption of ecstasy and tobacco. Income level, ecstasy use and tobacco use were retained as significant predictors in regression modelling. Cannabis use was not associated with adverse psychological outcomes.

DISCUSSION:

Prolonged previous cannabis consumption and the substantial overlap between recreational and medicinal cannabis use highlight the challenges in obtaining a tenable definition of medicinal cannabis therapy.     

Cannabis and social welfare assistance: a longitudinal study

Aims To investigate associations between cannabis use and subsequent receipt of social welfare assistance. Design, setting and participants The Young in Norway Longitudinal Study. A population‐based Norwegian sample (n = 2606) was followed‐up from adolescence to late 20s. Self‐report data were merged with data from national registers. Measurements Data were extracted on the use of alcohol, tobacco and cannabis and other illegal substances. Information was also retrieved on socio‐demographic and family factors, academic achievement, conduct problems and mental health. National registers provided data on social welfare assistance, educational level and crime statistics. Findings We observed prospective bivariate associations between increasing levels of cannabis use and subsequent social welfare assistance (P < 0.0001). The associations were reduced after adjusting for a range of potentially confounding factors, but remained significant. Frequent cannabis users were at highly increased risk for subsequently receiving social welfare assistance. At 28 years, those with 50+ times cannabis use during the previous 12 months and had an odds ratio of 9.3 (95% confidence interval: 4.3–20.1) for receiving social welfare assistance in the following 2‐year span. Users of cannabis also had longer periods of receiving social welfare assistance than others (P < 0.0001) and were less likely to leave the welfare assistance system (P < 0.0001). Conclusions In Norway the use of cannabis is linked with subsequent receipt of social welfare assistance whether the consequences are related to use of the substance per se, or to cultural factors and the illegal status of the cannabis. Future research should attempt to understand the interactions of factors behind these associations.     

Leveraging user perspectives for insight into cannabis concentrates

Background: The US has seen an increase in the popularity of highly concentrated forms of cannabis (hereafter concentrates) and too little is known about the potential risks associated with their use.

Objectives: The present study aims to better understand the patterns and outcomes of concentrates use through the perspectives of young adult users.

Methods: Participants (N = 234, 27.9% female) aged 18–35 years were recruited using SurveyMonkey Audience® and had ingested concentrates at least once in the past 6 months. They were queried on concentrates use patterns (e.g., frequency, medical/recreational) and the effects experienced after using concentrates (e.g., physiological/psychological, strength/duration).

Results: A total of 27.8% of participants reported frequent use of concentrates (≥10 days in past month). Those who used for medical purposes or lived in states where use is legal were more likely to use concentrates frequently. While most (64.2%) did not report experiencing potentially serious side effects, some reported a sense of altered reality/confusion (23.3%), rapid heartbeat (11.2%), lung pain (9.9%) and severe paranoia (6.9%). Among those who used concentrates in the past month (N = 168), 72.6% used concentrates with other cannabis forms, 57.7% used along with alcohol, and 22.6% used with other drugs.

Conclusion: Continued research on concentrates use in the US is needed. Research-informed policies that foster safe and responsible use of concentrates are necessary to protect users, especially those who use concentrates frequently, from potential negative side effects.     

Altered resting-state connectivity in adolescent cannabis users

Abstract

Background: Cannabis is the most commonly used illicit drug in adolescence. Heavy use is associated with deficits on a broad range of cognitive functions and heavy use during adolescence may impact development of gray and white matter. Objectives: To examine differences in intrinsic brain activity and connectivity associated with cannabis dependence in adolescence using whole-brain voxelwise approaches. Methods: Adolescents admitted to a drug-treatment facility for cannabis dependence (n?=?17) and age-matched controls (n?=?18) were compared on a measure of oscillations in the low-frequency blood oxygen level-dependent signal at rest (the fractional amplitude of low-frequency fluctuations fALFF, 0.01–0.1?Hz) and interhemispheric resting-state functional connectivity (RSFC) using voxel-mirrored homotopic connectivity. Results: The cannabis-dependent population showed increased fALFF activity compared to the control group in right hemisphere regions including the superior parietal gyrus, superior frontal gyrus, inferior frontal gyrus, inferior semilunar lobe of the cerebellum and the inferior temporal gyrus. Post-hoc analyses revealed stronger intra-hemispheric functional connectivity between these functionally defined regions of interest (ROIs) in the cannabis-dependent population than in the controls. Reduced interhemispheric connectivity was observed in the cannabis users compared to controls in the pyramis of the cerebellum and the superior frontal gyrus. Controls showed reduced interhemispheric connectivity compared to users in the supramarginal gyrus. Conclusions: The reduced interhemispheric RSFC in adolescent cannabis users complements previous reports of white matter deficits associated with cannabis use. The evidence of elevated connectivity within the right hemisphere may reflect a compensatory mechanism. Combined, the results suggest that altered intrinsic connectivity may be characteristic of adolescent cannabis dependence.     

Sustained cannabis use does not predispose clinical hypertension: Findings from a national survey

Cannabis is among the most used recreational and medicinal drugs in the United States. The effects of chronic use on hypertension remain poorly understood. Our study retrospectively evaluated data collected by the National Health and Nutrition Examination Survey from 2017 to 2018. Cannabis use was measured with five metrics: (1) sustained use at any point in the past, (2) sustained use within the past year, (3) frequency of use, (4) age of first cannabis use, and (5) current use. Hypertension status was determined by individuals reporting having been diagnosed in the past. Multivariable logistic regressions were performed, controlling for age, race, and gender. A total of 4565 respondents were identified, of which 867 (19.0%) reported sustained cannabis use in the past. Participants who reported past sustained cannabis use did not have statistically different odds of having hypertension (OR: 1.12; 95% CI: .66–1.91; p = .6). Moderate (OR: 1.08; 95% CI: .36–3.25; p = .8) and highly-frequent users (OR: 1.30; 95% CI: .56–3.03; p = .4) did not have different odds of having hypertension than infrequent users. No relationship between the age of first cannabis use and hypertension was observed. The recency of sustained cannabis use was not associated with hypertension status. Current cannabis users had similar odds of hypertension as past users (OR: 1.03; 95% CI: .59–1.79; p = .9). The findings of this study indicate that neither past nor current cannabis use is associated with clinical hypertension.