Category Archives: Addiction

Testing associations between cannabis use and subcortical volumes in two large population-based samples.

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“Disentangling the putative impact of cannabis on brain morphology from other comorbid substance use is critical. After controlling for the effects of nicotine, alcohol and multi-substance use, this study aimed to determine whether frequent cannabis use is associated with significantly smaller subcortical grey matter volumes.

FINDINGS:

After correcting for multiple testing (p=0.007), cannabis use was unrelated to any subcortical ROI. However, maximum nicotine use was associated with significantly smaller thalamus volumes in middle-age males.

CONCLUSIONS:

In exploratory analyses based on young adult and middle age samples, normal variation in cannabis use is statistically unrelated to individual differences in brain morphology as measured by subcortical volume.”

https://www.ncbi.nlm.nih.gov/pubmed/29691937

https://onlinelibrary.wiley.com/doi/abs/10.1111/add.14252

Prolonged Cannabidiol Treatment Effects on Hippocampal Subfield Volumes in Current Cannabis Users.

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“Chronic cannabis use is associated with neuroanatomical alterations in the hippocampus. While adverse impacts of cannabis use are generally attributed to Δ9-tetrahydrocannabinol, emerging naturalistic evidence suggests cannabidiol (CBD) is neuroprotective and may ameliorate brain harms associated with cannabis use, including protection from hippocampal volume loss. This study examined whether prolonged administration of CBD to regular cannabis users within the community could reverse or reduce the characteristic hippocampal harms associated with chronic cannabis use.

Results: No change was observed in left or right hippocampus as a whole. However, left subicular complex (parasubiculum, presubiculum, and subiculum) volume significantly increased from baseline to post-treatment (p=0.017 uncorrected) by 1.58% (Cohen’s d=0.63; 2.83% in parasubiculum). Heavy cannabis users demonstrated marked growth in the left subicular complex, predominantly within the presubiculum, and right cornu ammonis (CA)1 compared to lighter users. Associations between greater right subicular complex and total hippocampal volume and higher plasma CBD concentration were evident, particularly in heavy users.

Conclusions: Our findings suggest a restorative effect of CBD on the subicular and CA1 subfields in current cannabis users, especially those with greater lifetime exposure to cannabis. While replication is required in a larger, placebo-controlled trial, these findings support a protective role of CBD against brain structural harms conferred by chronic cannabis use. Furthermore, these outcomes suggest that CBD may be a useful adjunct in treatments for cannabis dependence and may be therapeutic for a range of clinical disorders characterized by hippocampal pathology (e.g., schizophrenia, Alzheimer’s disease, and major depressive disorder).”

https://www.ncbi.nlm.nih.gov/pubmed/29682609

“In conclusion, our findings are the first to demonstrate an ameliorating effect of CBD treatment upon brain structural harms characteristic of regular cannabis use. Furthermore, these results speak to the potential for CBD treatment to restore hippocampal pathology in a range of clinical populations (e.g., schizophrenia, Alzheimer’s disease, and major depressive disorder).”

https://www.liebertpub.com/doi/10.1089/can.2017.0047

Crime and the legalization of recreational marijuana

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Journal of Economic Behavior & Organization

“First-pass evidence is provided that the legalization of the cannabis market across US states is inducing a crime drop. We exploit the staggered legalization of recreational marijuana enacted by the adjacent states of Washington (end of 2012) and Oregon (end of 2014). Combining county-level difference-in-differences and spatial regression discontinuity designs, we find that the policy caused a significant reduction in rapes and property crimes on the Washington side of the border in 2013–2014 relative to the Oregon side and relative to the pre-legalization years 2010–2012. The legalization also increased consumption of marijuana and reduced consumption of other drugs and both ordinary and binge alcohol. Four possible mechanisms are discussed: the direct psychotropic effects of cannabis; substitution away from violence-inducing substances; reallocation of police effort; reduced role of criminals in the marijuana business.”

 https://www.sciencedirect.com/science/article/pii/S0167268118300386

“LEGAL POT IS LINKED TO LESS CRIME. A new study suggests it also decreases other types of drug use, including binge drinking.” https://psmag.com/news/it-is-high-time-we-reduced-crime

Accuracy of Patient Opioid Use Reporting at the Time of Medical Cannabis License Renewal.

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“The decision to authorize a patient for continued enrollment in a state-sanctioned medical cannabis program is difficult in part due to the uncertainty in the accuracy of patient symptom reporting and health functioning including any possible effects on other medication use.

We conducted a pragmatic convenience study comparing patient reporting of previous and current prescription opioid usage to the opioid prescription records in the Prescription Monitoring Program (PMP) among 131 chronic pain patients (mean age = 54; 54% male) seeking the first annual renewal of their New Mexico Medical Cannabis Program (NMMCP) license.

Seventy-six percent of the patients reported using prescription opioids prior to enrollment in the NMMCP, however, the PMP records showed that only 49% of the patients were actually prescribed opioids in the six months prior to enrollment.

Of the 64 patients with verifiable opioid prescriptions prior to NMMCP enrollment, 35 (55%) patients reported having eliminated the use of prescription opioids by the time of license renewal.

PMP records showed that 26 patients (63% of patients claiming to have eliminated the use of opioid prescriptions and 41% of all patients with verifiable preenrollment opioid use) showed no prescription opioid activity at their first annual NMMCP renewal visit.”

https://www.ncbi.nlm.nih.gov/pubmed/29623144

https://www.hindawi.com/journals/prm/2018/5704128/

Opioid prescriptions decreased in US states where marijuana was legally accessible

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“American states that permitted legal access to marijuana through medical cannabis laws or legalized its adult recreational use saw falls in opioid prescriptions over a five year period, research has found.

Researchers from the University of Georgia conducted longitudinal analysis of Medicare Part D records from 2010 to 2015. Their findings, published in JAMA Internal Medicine,1 showed a significant 14.4% average reduction in opioid prescriptions in states that allowed medical marijuana dispensaries. The effect was particularly pronounced in hydrocodone and morphine use.”

https://www.ncbi.nlm.nih.gov/pubmed/29618464

https://www.bmj.com/content/361/bmj.k1514.full

Cannabidiol regulates behavioural alterations and gene expression changes induced by spontaneous cannabinoid withdrawal.

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“Cannabidiol (CBD) represents a promising therapeutic tool for treating cannabis use disorder (CUD).

This study aimed to evaluate the effects of CBD on the behavioural and gene expression alterations induced by spontaneous cannabinoid withdrawal.

CONCLUSION AND IMPLICATIONS:

The results suggest that CBD alleviates spontaneous cannabinoid withdrawal and normalises associated gene expression changes. Future studies are needed to determine the relevance of CBD as a potential therapeutic tool for treating CUD.”

https://www.ncbi.nlm.nih.gov/pubmed/29624642

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14226

The Role of Cannabis Legalization in the Opioid Crisis

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“The United States remains gripped by the opioid crisis. Each day, 90 Americans die from opioid overdoses. Owing to the incredible reach of the opioid crisis—it has affected people of every race, sex, and age across our country—many stakeholders are trying to combat the crisis using multipronged approaches emphasizing prevention, treatment, and law enforcement.

In this issue of JAMA Internal Medicine, Bradford et al and Wen and Hockenberry report results suggesting that cannabis legalization may play a beneficial role in the opioid crisis.”

https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2676997

Association of Medical and Adult-Use Marijuana Laws With Opioid Prescribing for Medicaid Enrollees

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“In this population-based, cross-sectional study using the all-capture Medicaid prescription data for 2011 to 2016, medical marijuana laws and adult-use marijuana laws were associated with lower opioid prescribing rates (5.88% and 6.38% lower, respectively).

Medical and adult-use marijuana laws have the potential to lower opioid prescribing for Medicaid enrollees, a high-risk population for chronic pain, opioid use disorder, and opioid overdose, and marijuana liberalization may serve as a component of a comprehensive package to tackle the opioid epidemic.

These findings suggest that medical and adult-use marijuana laws have the potential to reduce opioid prescribing for Medicaid enrollees, a segment of population with disproportionately high risk for chronic pain, opioid use disorder, and opioid overdose.

Marijuana is one of the potential nonopioid alternatives that can relieve pain at a relatively lower risk of addiction and virtually no risk of overdose.”

https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2677000

“Medicare, Medicaid Opioid Scripts Decline in Medical Marijuana States”  https://www.medpagetoday.com/neurology/opioids/72105

Association Between US State Medical Cannabis Laws and Opioid Prescribing in the Medicare Part D Population

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“In this study, we investigated whether medical cannabis access was associated with prescription opioid prescribing in Medicare Part D. We found that overall opioid prescribing in Part D was lower when states permit access to medical cannabis. When examining data by individual drug classes, we found that prescriptions for hydrocodone and morphine had statistically significant negative associations with medical cannabis access via dispensaries; while not statistically significant, there were also negative associations between dispensary MCLs and fentanyl and “other opioid” use. Combined with previously published studies suggesting cannabis laws are associated with lower opioid mortality, these findings further strengthen arguments in favor of considering medical applications of cannabis as one tool in the policy arsenal that can be used to diminish the harm of prescription opioids.”

https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2676999

“Rise of medical marijuana eases abuse of opioids, study says”   https://www.ajc.com/news/rise-medical-marijuana-eases-abuse-opioids-study-says/uyXDks4G81MMIsrmq2mkeL/

Therapeutic Effects of Prolonged Cannabidiol Treatment on Psychological Symptoms and Cognitive Function in Regular Cannabis Users: A Pragmatic Open-Label Clinical Trial.

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“Chronic cannabis use has been associated with impaired cognition and elevated psychological symptoms, particularly psychotic-like experiences. While Δ9-tetrahydrocannabinol (THC) is thought to be primarily responsible for these deleterious effects, cannabidiol (CBD) is purported to have antipsychotic properties and to ameliorate cognitive, symptomatic, and brain harms in cannabis users. However, this has never been tested in a prolonged administration trial in otherwise healthy cannabis users. Here, we report the first study of prolonged CBD administration to a community sample of regular cannabis users in a pragmatic trial investigating potential restorative effects of CBD on psychological symptoms and cognition.

Results: CBD was well tolerated with no reported side effects; however, participants retrospectively reported reduced euphoria when smoking cannabis. No impairments to cognition were found, nor were there deleterious effects on psychological function. Importantly, participants reported significantly fewer depressive and psychotic-like symptoms at PT relative to BL, and exhibited improvements in attentional switching, verbal learning, and memory. Increased plasma CBD concentrations were associated with improvements in attentional control and beneficial changes in psychological symptoms. Greater benefits were observed in dependent than in nondependent cannabis users.

Conclusions:Prolonged CBD treatment appears to have promising therapeutic effects for improving psychological symptoms and cognition in regular cannabis users. Our findings require replication given the lack of a placebo control in this pragmatic trial, but suggest that CBD may be a useful adjunct treatment for cannabis dependence.”

 https://www.ncbi.nlm.nih.gov/pubmed/29607408
https://www.liebertpub.com/doi/10.1089/can.2017.0043