Long lasting effects of chronic heavy cannabis abuse

Amygdala volume and depression symptoms in young adolescents who use cannabis

INTRODUCTION

Both cannabis use and depressive symptomology increase in prevalence throughout adolescence. Concurrently, the brain is undergoing neurodevelopment in important limbic regions, such as the amygdala. Prior research indicates the amygdala may also be related to cannabis use and depressive symptoms. We aimed to investigate the effects of adolescent cannabis use on amygdala volumes as well as the interaction of cannabis use and amygdala morphometry on depressive symptoms in youth.

METHOD

Two-hundred-twenty-four participants (ages 12-15), balanced by sex assigned at birth, were selected from a sub-sample of the Adolescent Brain Cognitive Development (ABCD) Study based on hair toxicology and self-report measures of cannabis use. Participants positive for cannabinoids in hair and/or self-reported cannabis use were demographically matched to youth with no self-reported or confirmed cannabis use. The guardians of these youth reported depression symptoms on the Child Behavioral Checklist. Linear mixed effect models were run investigating cannabis use group on amygdala volumes bilaterally, controlling for whole brain volume and random effects of scanner type. Additional analyses examined cannabis group status and bilateral amygdala volume on depression symptoms.

RESULTS

Cannabis use was not significantly associated with amygdala volume but was associated with increased depressive symptoms (p<0.01). Cannabis group interacted with amygdala volume, such that individuals with smaller volumes had increased depressive symptoms within the cannabis group (p's<0.01-0.02).

CONCLUSION

Aberrations in amygdala volume based on cannabis use were not found in early adolescence; however, more depressive symptoms were related to cannabis group. Youth who use cannabis and have smaller amygdala volumes were at increased risk for depressive symptomology, suggesting potential neurovulnerabilities to cannabis use.

Potential effects of cannabinoids on audiovestibular function: A narrative review

The growing interest in the development of drugs that target the endocannabinoid system has extended to conditions that affect the audiovestibular pathway. The expression of cannabinoid (CB) receptors in that pathway has been widely demonstrated, indicating a therapeutic potential for drug development at this level. These medications may be beneficial for conditions such as noise-induced hearing loss, ototoxicity, or various forms of vertigo of central or peripheral origin. The therapeutic targets of interest include natural or synthetic compounds that act as CB1/CB2 receptor agonists/antagonists, and inhibitors of the endocannabinoid-degrading enzymes FAAH and MAGL. Furthermore, genetic variations implicated in the response to treatment and the development of related disorders such as epilepsy or migraine have been identified. Direct methods of administering these medications should be examined beyond the systemic strategy.

Preoperative Cannabis Use Associated With an Increased Rate of Reoperation and Postoperative Opioid Use Following Anterior Cervical Decompression and Fusion

Objectives The objective of this retrospective cohort study was to evaluate the associations among preoperative cannabis use, postoperative opioid use, and postoperative outcomes following elective anterior cervical decompression and fusion (ACDF). Methods Patients who underwent one- or two-level ACDF were characterized preoperatively as active cannabis users, former users, or nonusers. Patients were also classified based on history of preoperative opioid use as chronic users, acute users, or nonusers. Groups were compared based on outcomes including the rate of emergency department visits six months postoperatively, rate of readmissions one year postoperatively, rate of reoperation two years postoperatively, and daily postoperative opioid use measured in milligram morphine equivalents (MMEs) at 0-6 months and 6-12 months postoperatively.  Results Of the 198 patients included in this study, 13 (6.6%) were active cannabis users, 11 (5.6%) were former users, and 174 (87.8%) were nonusers. The rate of reoperation within two years was 23.1% for active cannabis users, 0% for former users, and 4.0% for nonusers (p=0.0075). The average daily opioid use in MMEs 6-12 months postoperatively was 49.4 for active cannabis users, 4.1 for former users, and 13.3 for nonusers (p=0.0014). For chronic opioid users, acute users, and nonusers, the average daily opioid use in MMEs 6-12 months postoperatively was 39.9, 18.4, and 5.7, respectively (p<.0001). Conclusions History of cannabis use is associated with increased postoperative opioid use and increased rate of reoperation following elective ACDF.

Medical Students’ Attitudes, Knowledge, and Beliefs about Medical Cannabis: A Qualitative Descriptive Study

Background

There has been increased attention given to understanding the uses of medical cannabis (MC) for symptom management of various medical conditions. Physicians receive minimal training in medical school and rely mostly on anecdotal evidence; by proxy, medical students generally do receive formal training in MC. It is unknown how medical students perceive MC, including its efficacy, appropriateness in medicine, its possible adverse effects, and its value for patients. This study investigated medical students’ perceived knowledge, beliefs, and attitudes toward MC to better understand their knowledge about and attitudes toward MC. 

Method

Using a semi-structured interview guide, eight focus groups were conducted with 83 medical students via Zoom virtual meeting platform (Zoom Video Communications, Inc., San Jose, California, United States) in June 2022. The interviews were guided by the following content areas: (1) beliefs about cannabis' therapeutic utility, (2) perceived knowledge about MC, (3) the role of the physician regarding MC, (4) concern for cannabis’ adverse effects, and (5) MC education in the school curriculum. Data were analyzed using thematic analysis, an iterative, systematic process of coding patterns, and emerged themes in the interview data to explore medical students’ perceptions about MC. Themes were validated based on whether each theme captured distinct parts of the interview data and whether their content cohered meaningfully.

Results

Four themes emerged from the focus group interviews investigating medical students’ perceptions of MC: (1) erroneous beliefs about MC, (2) unreliable sources of information, (3) mixed attitudes toward legalization, and (4) desire for MC education while in medical school. Attitudes regarding MC in general, including legalization, varied by United States state of origin of the student and exposure to MC (e.g., use by family member). 

Conclusion

MC seems to be a significant issue for medical trainees who might be required to recommend it to patients and manage coexisting therapies. Cultivating new knowledge about students’ perceptions and perceived knowledge about medicinal options and dosing of MC is critical for medical educators as they design undergraduate curricular initiatives for future physicians.

Self-reported marijuana use and its effects on overall approval in potential living kidney donors

BACKGROUND

Past and present substance use is an important part of the psychosocial evaluation of potential living kidney donors (LKDs). Increasing state legalizations and social acceptance of marijuana (MJ) use can create challenges for transplant centers.

METHODS

We investigated the frequency of reporting MJ use, and its effect on the LKD evaluation. A retrospective chart review was performed on all living donor candidates from December 2016 to December 2019 for reports of MJ use, both on an electronic intake form and during clinic evaluation with a licensed social worker (SW).Active MJ use was defined as current use or use within one year of evaluation. Baseline characteristics between MJ users and non-users were compared at each step of donor evaluation. We explored variables associated with MJ use including additional consults and testing during the donor evaluation. Overall approval and donation rates for living donors with active MJ use were compared to non-users. Additionally, 1-year donor follow up was compared between the two groups. Results Of 1,818 living donor candidates who completed the intake form, 132 admitted to active MJ use. Compared to non-users, MJ users were more likely to be younger, male, single, renting a home, and with a lower level of education. 33 of 338 candidates who completed a social work evaluation reported MJ use. Compared to non-users, MJ users were more frequently classified as moderate or high risk on SW evaluation, and often required a toxicology screen or psychiatry visit for clearance to donate. 24.2% of MJ users vs 9.5% of non-users discontinued their evaluation (P<0.01). 42.4% of MJ users vs 56.1% of non-users donated their kidney (P = 0.13). For those who donated, MJ users were less likely than non-users to follow up at 1 year (57.1% vs 83.0, p-value 0.02).

CONCLUSION

MJ users were often asked to complete additional steps in their evaluation before an approval decision was made, which may have led to the higher rate of donor drop out observed in this group. Further research is needed to assess the effects of MJ use on living donor candidacy, as well as any effects of MJ use on long-term donor outcomes. This article is protected by copyright. All rights reserved.

A perspective review of cannabis use and sexual offenses

Substance abuse is an established risk factor for crime and violence, including sexual violence. Nevertheless, the link between cannabis use and sexual offenses remains poorly understood. Cannabis use has a broad effect on sexual functioning and can have both acute and lasting adverse effects on psychological functioning, which in turn can elevate the risk of sexual offending behavior. Yet there is a scarcity of studies that have examined the link between cannabis use and sexual offending. To help fill the gap, this perspective review investigates the link between substance use and crime with a particular emphasis on cannabis use and its effects on sexual and psychological functioning. It then explores how these mechanisms may contribute to sexual offenses and recidivism, with a final discussion on how cannabis use should be conceptualized as a risk factor for sexual violence.

Relationship Between Cannabis Use and Erectile Dysfunction: A Systematic Review and Meta-Analysis

Globally, there is increasing usage and legalization of cannabis. In addition to its reported therapeutic effects, cannabis has several health risks which are not clearly defined. Erectile dysfunction (ED) is the most common male sexual disorder and there are plausible mechanisms linking cannabis use to ED. No attempt has been made to collate the literature on this topic. The aim of this review was to summarize the prevalence and risk of ED in cannabis users compared to controls.

A systematic review of major databases from inception to January 1, 2019, without language restriction, was undertaken to identify studies investigating cannabis use and presence of ED. The analysis compared the prevalence of ED in cannabis users versus controls. Consequently, the odds ratio (OR) with 95% confidence intervals (CI) was calculated, applying a random-effect model.

Five case–control studies were included with data from 3,395 healthy men, 1,035 using cannabis (smoking) and 2,360 nonusers. The overall prevalence of ED in cannabis users was 69.1% (95% CI: 38.0–89.1), whilst the correspondent figure in controls was 34.7% (95% CI: 20.3–52.7). The OR of ED in cannabis users was almost four times that of controls (OR = 3.83; 95% CI: 1.30–11.28; p = .02), even if characterized by high heterogeneity (I² = 90%) and the prediction intervals overlapped 1.00 (95% CI: 0.35–7.26).

Data suggest that ED is twice as high in cannabis users compared to controls. Future longitudinal research is needed to confirm/refute this and explore if a dose–response relationship between cannabis and ED may be evident.

A review of bioanalytical techniques for evaluation of cannabis (Marijuana, weed, Hashish) in human hair

Cannabis products (marijuana, weed, hashish) are among the most widely abused psychoactive drugs in the world, due to their euphorigenic and anxiolytic properties. Recently, hair analysis is of great interest in analytical, clinical, and forensic sciences due to its non-invasiveness, negligible risk of infection and tampering, facile storage, and a wider window of detection. Hair analysis is now widely accepted as evidence in courts around the world. Hair analysis is very feasible to complement saliva, blood tests, and urinalysis. In this review, we have focused on state of the art in hair analysis of cannabis with particular attention to hair sample preparation for cannabis analysis involving pulverization, extraction and screening techniques followed by confirmatory tests (e.g., GC–MS and LC–MS/MS). We have reviewed the literature for the past 10 years’ period with special emphasis on cannabis quantification using mass spectrometry. The pros and cons of all the published methods have also been discussed along with the prospective future of cannabis analysis.

Cannabinoid drugs: will they relieve or exacerbate tinnitus?

PURPOSE OF REVIEW

Recent enthusiasm for cannabinoid drugs for the treatment of chronic pain and some forms of epilepsy, raises the question of whether they could be useful for other disorders associated with abnormal neuronal activity in the brain, such as subjective tinnitus. Indeed, there is evidence to indicate that some tinnitus sufferers self-medicate using Cannabis. The aim of this review is to critically evaluate the available evidence relating to the effects of cannabinoids on tinnitus.

RECENT FINDINGS

Despite the fact that cannabinoids have been shown to decrease neuronal hyperactivity in many parts of the brain, the current evidence suggests that in auditory brain regions such as the dorsal cochlear nucleus, they have the potential to facilitate neuronal hyperactivity and exacerbate tinnitus. All of the available experimental evidence from animal studies suggests that cannabinoid CB1 receptor agonists will either have no effect on tinnitus or will worsen it.

SUMMARY

In our opinion, the use of the available cannabinoid drugs to alleviate tinnitus, based on their alleged efficacy for neuropathic pain conditions and some forms of epilepsy, is premature and not supported by the available evidence.

Motor Adaptation Impairment in Chronic Cannabis Users Assessed by a Visuomotor Rotation Task

Background—The cerebellum has been recently suggested as an important player in the addiction brain circuit. Cannabis is one of the most used drugs worldwide, and its long-term effects on the central nervous system are not fully understood. No valid clinical evaluations of cannabis impact on the brain are available today. The cerebellum is expected to be one of the brain structures that are highly affected by prolonged exposure to cannabis, due to its high density in endocannabinoid receptors. We aim to use a motor adaptation paradigm to indirectly assess cerebellar function in chronic cannabis users (CCUs). Methods—We used a visuomotor rotation (VMR) task that probes a putatively-cerebellar implicit motor adaptation process together with the learning and execution of an explicit aiming rule. We conducted a case-control study, recruiting 18 CCUs and 18 age-matched healthy controls. Our main measure was the angular aiming error. Results—Our results show that CCUs have impaired implicit motor adaptation, as they showed a smaller rate of adaptation compared with healthy controls (drift rate: 19.3 +/− 6.8° vs. 27.4 +/− 11.6°; t(26) = −2.1, p = 0.048, Cohen’s d = −0.8, 95% CI = (−1.7, −0.15)). Conclusions—We suggest that a visuomotor rotation task might be the first step towards developing a useful tool for the detection of alterations in implicit learning among cannabis users.

Detection of cannabinoids in hair after cosmetic application of hemp oil

The detection of cannabis constituents and metabolites in hair is an established procedure to provide evidence of exposure to cannabis. We present the first known evidence to suggest that applying hemp oil to hair, as cosmetic treatment, may result in the incorporation of Δ⁹-tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD) and in one instance, the metabolite 11-hydroxy-Δ⁹-tetrahydrocannabinol (THC-OH). 10 volunteers treated their head hair daily with commercially available hemp oil for a period of 6 weeks. Head hair samples were collected before and after the application period. Hair samples were washed with methanol and subjected to clean up via liquid/liquid and solid phase extraction procedures, and then GC-MS/MS for the analysis of THC, CBN, CBD, THC-OH and THC-COOH. Application of hemp oil to hair resulted in the incorporation of one or more cannabis constituents in 89% of volunteers, and 33% of the group tested positive for the three major constituents, THC, CBN and CBD. One volunteer showed low levels of the metabolite THC-OH. We suggest that cosmetic use of hemp oil should be recorded when sampling head hair for analysis, and that the interpretative value of cannabinoid hair measurements from people reporting application of hemp oil is treated with caution in both criminology and public health.