Medical and non-medical cannabis use and risk of prescription opioid use disorder: Findings from propensity score matching

Neurocognitive Dysfunctions in People with Concurrent Cannabis Use and Opioid Dependence: A Cross-Sectional, Controlled Study

Cannabis and opioid co-dependence is independently associated with cognitive impairments. We examined neurocognitive dysfunctions in people with concurrent opioid dependence with cannabis dependence (OD+CD) or cannabis use (OD+CU) compared to those with only opioid dependence (OD) and healthy controls (HC). We selected adult participants, any sex, who met the diagnosis of OD (N = 268), OD+CU (N = 58), and OD + CD (N = 115). We recruited 68 education-matched HC. We administeredStandard progressive matrices (SPM), Wisconsin card sorting test (WCST), Iowa gambling task (IGT), Trail making tests A and B (TMT), and verbal and visual working memory 1-, 2-backtests. 496 (97.5%) were men, and 13 (2.5%) were women. In WCST, OD and OD+CD had significantly higher non-perseverative errors than HC. OD+CD group completed significantly lesser categories than HC. In verbal working memory 2-back, HC scored significantly fewer errors than OD and OD +CD. All patient groups, OD, OD+CU, and OD+CD, scored higher commission errors than HC in visual working memory 1-back. OD and OD+CD scored higher commission and total errors than the controls. OD+CU showed lesser error score than HC in TMT B. Cannabis and opioid co-dependence contribute to cognitive impairments, especially in working memory and executive functions.

The Role of Medicinal Cannabis as an Emerging Therapy for Opioid Use Disorder

This narrative review explores current insights into the potential use of medicinal cannabis-related products as an emerging therapy for opioid use disorder in the landscape of increasing knowledge about medicinal cannabis-based products, commercialisation and global legalisation. Preclinical studies have provided preliminary insight into the putative neurobiological mechanisms that underpin the potential for medicinal cannabis to be considered a therapeutic in opioid use disorder and addiction. With the progressive legalisation of cannabis in many jurisdictions worldwide, contemporary research has highlighted further evidence that medicinal cannabis may have efficacy in reducing cravings and withdrawal effects, and therefore may be considered as an adjunct or standalone to current medications for opioid use disorder. Despite this potential, the landscape of research in this space draws from a large number of observational studies, with a paucity of rigorous randomised controlled trials to ascertain a true understanding of effect size and safety profile. With current challenges in implementation that arise from political and legal qualms about adopting medicinal cannabis on the background of associated social stigma, significant hurdles remain to be addressed by government, policy-makers, healthcare providers and researchers before medical cannabis can be introduced globally for the treatment of opioid use disorder.

Indirect effects of emotion regulation in the relationship between pain and cannabis use in adults 18-64 years

INTRODUCTION

Individuals with chronic pain often receive prescription opioid medication, and they may use cannabis to treat pain as well, although the risks of cannabis-opioid co-use are significant. This study aimed to investigate whether two transdiagnostic factors, emotion regulation and distress tolerance, had significant indirect effects in the relationship between pain and cannabis use in adults with chronic pain and an opioid prescription.

METHODS

Participants (n = 450; mean age = 38.6 ± 11.09) were recruited using Qualtrics panel service and were 75 % female and 79 % White, non-Hispanic. Participants completed a 30-minute self-report survey capturing three-month cannabis use, the Difficulties in Emotional Regulation Scale (DERS), and the Distress Tolerance Scale (DTS). The Graded Pain Scale (GCPS) assessed pain severity/intensity and disability. Analyses used the SPSS PROCESS macro, with both single (i.e., one transdiagnostic factor) and parallel indirect effects (i.e., both the DERS and DTS) examined.

RESULTS

There were statistically significant indirect effects for both the DERS and DTS in the relationship between pain intensity or disability and three-month cannabis use in single factor models. In the parallel indirect effect model, only the DERS was statistically significant (intensity indirect effect coefficient = 0.0195 % confidence interval [95 %CI] = 0.0065, 0.390; disability indirect effect coefficient = 0.0147, 95 %CI = 0.0055, 0.0274).

CONCLUSIONS

When examining parallel indirect effects, only emotional regulation and not distress tolerance mediated the relationship between chronic pain and cannabis use among those with an opioid prescription. Clinically, interventions aimed at improving emotional regulation in individuals with chronic pain can help limit cannabis and opioid co-use.

Evaluation of pre-hospital cannabis exposure and hospital opioid utilization in a trauma population: A retrospective cohort

PURPOSE

Cannabis utilization has increased over time for recreational and medical purposes due to its legalization or decriminalization. The effects of cannabis use on opioid utilization are not well understood. The primary objective was to evaluate the total opioid utilization, measured in morphine milligram equivalents (MME), in hospitalized trauma patients that tested positive for tetrahydrocannabinol (THC) on a urine drug screen (UDS).

METHODS

This was a retrospective, cohort study in a level 1 trauma center between 10/17/17 and 12/31/19. Adult trauma patients (aged 15 years and older) who had a UDS completed within 48 h of hospital arrival were eligible for inclusion. Patients were excluded for a hospitalization >14 days, death within 24 h, severe alcohol withdrawal, prescribed cannabinoids, high daily opioid use prior-to-arrival, or transitioned to hospice or palliative care. Group assignments were determined based on the presence or absence of THC on the UDS.

RESULTS

The analysis included 750 patients with 160 (21 %) THC positive patients. The population were primarily male (64.6 %), median age of 56 years [IQR 35-72], with blunt (93 %) injuries from motor vehicle crash or falls (79 %). The THC group was more likely to have other substances present, including amphetamines, benzodiazepines, opiates, and cocaine. The THC group had a higher median injury severity score (10 [IQR 5-17] vs. 9 [5-14], p = 0.0056), and maximum abbreviated injury score (3 [IQR 2-3] vs. 2 [IQR 2-3], p = 0.0009). The THC group had a total higher median opioid utilization during the hospitalization (155 [IQR 68-367] vs. 62 [IQR 13-175] MME; p < 0.0001), which included higher opioid use in the emergency department, floor, and intensive care unit. There were no significant differences in secondary outcomes except the THC group was more likely to receive an opioid prescription at discharge and more likely to require mechanical ventilation. Based on multivariable regression analyses, other variables were associated with increased opioid utilization.

CONCLUSION

Pre-existing THC exposure may be associated with an increased hospital opioid utilization in a trauma population. However, other variables may also play a role in opioid utilization.

The association between cannabis use and risk of non-medical pain reliever misuse onset among young adults in a legal cannabis context

BACKGROUND

Little is known about the prospective relationship between cannabis use and pain reliever misuse. This study examined associations of non-medical and medical cannabis use with onset of non-medical pain reliever misuse among young adults in Washington State (WA), where non-medical cannabis is legal.

METHODS

Data were from a cohort-sequential study of adults 18-25 residing in WA. Four annual surveys were used from cohorts recruited in 2014, 2015, and 2016. Participants who had not reported non-medical pain reliever misuse at baseline were included in discrete time survival analyses (N = 4,236). Odds ratios (ORs) were estimated for new onset of non-medical pain reliever misuse in any given follow-up year over the course of three years according to baseline non-medical and medical cannabis use.

RESULTS

When included separately in models, non-medical and medical cannabis use at baseline were associated with increased risk of non-medical pain reliever misuse adjusting for demographic characteristics as well as past year cigarette use and alcohol use (non-medical OR = 5.27; 95 % CI: 3.28, 8.48; medical OR = 2.21; 95 % CI: 1.39, 3.52). Including both forms of use in the model, associations of non-medical and medical cannabis use with non-medical pain reliever misuse onset remained (non-medical OR = 4.64; 95 % CI: 2.88, 7.49; medical OR = 1.65; 95 % CI: 1.04, 2.62).

CONCLUSIONS

Despite claims that cannabis use may reduce opioid use and related harms, findings suggest that cannabis use, including medical use, may not be protective, but instead may increase risk for non-medical pain reliever misuse.

Cannabis Use Does Not Increase Risk of Perioperative Complications Following Primary Total Hip Arthroplasty: A Cohort-Matched Comparison

Introduction: Cannabis use among arthroplasty patients has dramatically increased throughout the United States. Despite this trend, knowledge remains particularly limited regarding the effects of cannabis use on perioperative outcomes in total hip arthroplasty (THA). Therefore, the goal of this research was to investigate how cannabis use affects risk of perioperative outcomes, cost and length of stay (LOS) after THA. Materials and Methods: The National Inpatient Sample was used to identify 331,825 patients who underwent primary THA between 2010 and 2014 using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) procedure code 81.51. Patients with an ICD-9 diagnosis code correlating to history of thromboembolic events, cardiac events, or active substance use other than cannabis were eliminated. The ICD-9 diagnosis codes for cannabis use (304.3-304.32, 305.2-305.22) were used to identify 538 patients with active use. Cannabis users were matched 1:1 to nonusers on age, sex, tobacco use, and comorbidities. The chi-square test was used to determine risk of major and minor complications, whereas the Kruskal-Wallis H test was used to compare hospital charges and LOS. Results: A total of 534 (99.3%) patients with cannabis use were successfully matched with 534 patients without cannabis use. Risk of major complications among cannabis users (25, 4.68%) was similar to that of nonusers (20, 3.74%, p=0.446). Minor complications also occurred at similar rates between cannabis users (77, 14.4%) and nonusers (87, 16.3%, p=0.396). LOS for cannabis users (3.07±2.40) did not differ from nonusers (3.10±1.45, p=0.488). Mean hospital charges were higher for cannabis users ($17,847±10,024) compared with nonusers ($16,284±7025, p<0.001). Conclusion: Utilizing statistically matched cohorts within a nationally representative database demonstrated that cannabis use is not associated with increased risk of complications or prolonged LOS after primary THA. However, cannabis use is associated with higher hospital charges.

ASRA Pain Medicine consensus guidelines on the management of the perioperative patient on cannabis and cannabinoids

BACKGROUND

The past two decades have seen an increase in cannabis use due to both regulatory changes and an interest in potential therapeutic effects of the substance, yet many aspects of the substance and their health implications remain controversial or unclear.

METHODS

In November 2020, the American Society of Regional Anesthesia and Pain Medicine charged the Cannabis Working Group to develop guidelines for the perioperative use of cannabis. The Perioperative Use of Cannabis and Cannabinoids Guidelines Committee was charged with drafting responses to the nine key questions using a modified Delphi method with the overall goal of producing a document focused on the safe management of surgical patients using cannabinoids. A consensus recommendation required ≥75% agreement.

RESULTS

Nine questions were selected, with 100% consensus achieved on third-round voting. Topics addressed included perioperative screening, postponement of elective surgery, concomitant use of opioid and cannabis perioperatively, implications for parturients, adjustment in anesthetic and analgesics intraoperatively, postoperative monitoring, cannabis use disorder, and postoperative concerns. Surgical patients using cannabinoids are at potential increased risk for negative perioperative outcomes.

CONCLUSIONS

Specific clinical recommendations for perioperative management of cannabis and cannabinoids were successfully created.

The impact of recreational cannabis markets on motor vehicle accident, suicide, and opioid overdose fatalities

In the U.S., an increasing number of states are legalizing regulated commercial markets for recreational cannabis, which allows private industry to produce, distribute, and sell marijuana to those 21 and older. The health impacts of these markets are not fully understood. Preliminary evidence suggests recreational markets may be associated with increased use among adults, which indicates there may be downstream health impacts on outcomes related to cannabis use. Three causes of death that are linked to cannabis use are motor vehicle accidents, suicide, and opioid overdose. Drawing on data from U.S. death certificates from 2009 to 2019, we conducted a difference-in-differences analysis to estimate the impact of recreational markets on fatalities from motor vehicle accidents, suicide, and opioid overdose in seven states: Colorado, Washington, Oregon, Alaska, Nevada, California, and Massachusetts. States with comprehensive medical cannabis programs with similar pre-trends in deaths were used as comparisons. For each outcome, a pooled estimate was generated with a meta-analysis using random effects models. The results revealed substantial increases in crash fatalities in Colorado, Oregon, Alaska, and California of 16%, 22%, 20%, and 14%, respectively. Based on estimates from all seven states, recreational markets were associated with a 10% increase in motor vehicle accident deaths, on average. This study found no evidence that recreational markets impacted suicides. Most states saw a relative reduction in opioid overdose death that ranged between 3 and 28%. On average, recreational markets were associated with an 11% reduction in opioid overdose fatalities.

Recreational cannabis legalization and transitions in cannabis use: findings from a nationally representative longitudinal cohort in the United States

AIMS

This study estimated the likelihoods of individuals transitioning to different cannabis use status following recreational cannabis legalization (RCL) in the United States.

DESIGN

Secondary analysis of a nationally representative longitudinal cohort in the United States. We used propensity score matching to balance individual characteristics between RCL and comparison states and generalized mixed regressions to estimate behavioral transitions in matched samples.

PARTICIPANTS

A longitudinal cohort of 21 863 individuals (6925 youths and 14 938 adults) participating in the Population Assessment of Tobacco and Health waves 3 and 4.

SETTING

Four RCL states that implemented RCL between waves 3 and 4 (California, Massachusetts, Nevada and Maine) and comparison states in the United States.

MEASUREMENTS

Transitions in cannabis use over the two waves: (1) from non-users to users; (2) from non-users to weekly users; (3) from users to non-users. Individuals in RCL states were compared with matched individuals in (1) states with medical cannabis legalization (MCL), (2) states not legalizing cannabis (non-legalizing) and (3) MCL and non-legalizing states combined.

FINDINGS

Among youths, the association between RCL and greater odds of transition from non-users to users was seen in comparison with non-legalizing states [odds ratio (OR) = 2.18, 95% confidence interval (CI) = 1.37-3.45] and combined states (OR = 1.73, 95% CI = 1.23-2.42). Evidence was lacking regarding the associations between RCL and transitions from non-users to weekly users and from users to non-users. Among adults, RCL was associated with greater odds of transitions from non-users to users and non-users to weekly users if RCL states were compared with non-legalizing states (OR = 1.68, 95% CI = 1.15-2.46; OR = 1.82, 95% CI = 1.00-3.31, respectively) or combined states (OR = 1.51, 95% CI = 1.11-2.07; OR = 2.09, 95% CI = 1.19-3.66, respectively). RCL was also associated with lower odds of transition from users to non-users if RCL states were compared with non-legalizing states (OR = 0.54, 95% CI = 0.35-0.81).

CONCLUSIONS

There appears to be some evidence that recreational cannabis legalization in the United States is associated with elevated odds of transition to cannabis use among both youths and adults.

Nationwide Population-Based Study About Patterns of Prescription Opioid Use and Misuse Among Young Adults in Spain

Objective: Prescription opioid misuse has become one of the most common ways drugs are consumed among young adults. The objective of our study was to describe the prevalence and factors associated with prescription opioid use and misuse among young adults living in Spain.

Methods: A nationwide, cross-sectional epidemiological study on the use and misuse of prescription opioids in Spanish Youngers. We used individualized secondary data provided by the Household Survey on Alcohol and Drugs in Spain 2017–2018.

Results: Prevalence of prescription opioid use among young adults was 4.89%. Misuse among this population reached prevalence values of 13.4%, with higher values observed among women . The variables associated with a greater probability of prescription opioid use and misuse were misuse of tranquilizers, sedatives, and sleeping pills, along with using cannabis and other illicit psychoactive drugs (aOR = 2.99; 95% CI: 1.10–8.15).

Conclusion: Prescription opioid use and misuse in Youngers has important implications for the Spanish public health system, because, even though not currently comparable to the situation in other countries, this drug use could be on the verge of creating similar problems.

Strategies aimed at preventing long-term opioid use in trauma and orthopaedic surgery: a scoping review

BACKGROUND

Long-term opioid use, which may have significant individual and societal impacts, has been documented in up to 20% of patients after trauma or orthopaedic surgery. The objectives of this scoping review were to systematically map the research on strategies aiming to prevent chronic opioid use in these populations and to identify knowledge gaps in this area.

METHODS

This scoping review is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Checklist. We searched seven databases and websites of relevant organizations. Selected studies and guidelines were published between January 2008 and September 2021. Preventive strategies were categorized as: system-based, pharmacological, educational, multimodal, and others. We summarized findings using measures of central tendency and frequency along with p-values. We also reported the level of evidence and the strength of recommendations presented in clinical guidelines.

RESULTS

A total of 391 studies met the inclusion criteria after initial screening from which 66 studies and 20 guidelines were selected. Studies mainly focused on orthopaedic surgery (62,1%), trauma (30.3%) and spine surgery (7.6%). Among system-based strategies, hospital-based individualized opioid tapering protocols, and regulation initiatives limiting the prescription of opioids were associated with statistically significant decreases in morphine equivalent doses (MEDs) at 1 to 3 months following trauma and orthopaedic surgery. Among pharmacological strategies, only the use of non-steroidal anti-inflammatory drugs and beta blockers led to a significant reduction in MEDs up to 12 months after orthopaedic surgery. Most studies on educational strategies, multimodal strategies and psychological strategies were associated with significant reductions in MEDs beyond 1 month. The majority of recommendations from clinical practice guidelines were of low level of evidence.

CONCLUSIONS

This scoping review advances knowledge on existing strategies to prevent long-term opioid use in trauma and orthopaedic surgery patients. We observed that system-based, educational, multimodal and psychological strategies are the most promising. Future research should focus on determining which strategies should be implemented particularly in trauma patients at high risk for long-term use, testing those that can promote a judicious prescription of opioids while preventing an illicit use, and evaluating their effects on relevant patient-reported and social outcomes.

Abuse-deterrent extended-release oxycodone and risk of opioid-related harm

AIM

To establish and quantify the association between abuse-deterrent formulation (ADF) oxycodone and 1-year risk of opioid-related harm.

DESIGN

Propensity score-matched cohort study of electronic medical records for years 2014-18, with patients followed up for 1 year after their index health-care visit.

SETTING

More than 70 million patients from 56 US health-care organizations.

PARTICIPANTS

Patients aged 18-64 years at index health-care visit with any indication for an oral opioid analgesic, with no past 12-month history of oral oxycodone use or substance use disorder, and who were alive at the end of the 1-year follow-up (new episode of prescription oral ADF oxycodone [OxyContin], n = 45 045; new episode of non-ADF oxycodone opioid preparation, n = 1 377 359).

MEASUREMENTS

International Classification of Diseases diagnoses of any opioid-related disorder or non-fatal opioid poisoning within 1 year of the index health-care visit. Pooled odds ratios (OR) with 95% confidence intervals (95% CI).

FINDINGS

After propensity score matching, 89 802 patients with a mean age of 44 [standard deviation (SD) = 11] years (62% women, 68% white) were included. During 1-year follow-up, 1445 diagnoses of opioid use disorder or opioid poisoning occurred in the ADF oxycodone cohort (34.8/1000 person-years) and 765 occurred in the non-ADF oxycodone cohort (18.2/1000 person-years). The odds of opioid-related adverse outcomes were increased in the ADF oxycodone cohort compared with the non-ADF oxycodone opioid cohort, including for opioid use disorders (OR = 2.02; 95% CI = 1.83, 2.23) and opioid poisoning (OR = 1.64 95% CI = 1.35, 1.99).

CONCLUSIONS

Patients with a new prescription of abuse-deterrent formulation oxycodone may be at increased risk of opioid-related harm.

Prevalence and correlates of non-fatal overdose among people who use drugs: findings from rapid assessments in Massachusetts, 2017-2019

BACKGROUND

People who experience non-fatal overdose (NFOD) are at high risk of subsequent overdose. With unprecedented increases in fentanyl in the US drug supply, many Massachusetts (MA) communities have seen a surge in opioid-related overdoses. The objective of this study was to determine factors associated with lifetime and past year NFOD in at-risk MA communities.

METHODS

We conducted multiple rapid assessments among people who use drugs (PWUD) in eight MA communities using non-probability sampling (purposive, chain referral, respondent-driven) methods. We collected sociodemographic, substance use, overdose history, substance use treatment, and harm reduction services utilization data. We examined the prevalence of NFOD (lifetime and past year) and identified factors associated with NFOD through multivariable logistic regression analyses in a subset of 469 study participants between 2017 and 2019.

RESULTS

The prevalence of lifetime and last year non-fatal opioid overdose was 62.5% and 36.9%, respectively. Many of the study participants reported heroin (64%) and fentanyl (45%) use during the 30 days preceding the survey. Nonprescription buprenorphine and fentanyl use were independently associated with higher odds of lifetime NFOD, while marijuana use was associated with lower odds of lifetime NFOD (p < 0.05). Injection as the route of administration, benzodiazepine, nonprescription buprenorphine, heroin, and fentanyl use were independently associated with higher odds, while methadone use was associated with lower odds of past year NFOD (p < 0.05).

CONCLUSION

We documented a high prevalence of past year and lifetime NFOD among PWUD in MA. Our findings provide indicators that can help inform interventions to prevent overdoses among PWUD, including overdose prevention, medication treatment, and naloxone distribution.

Positive Toxicology Results Are Not Associated with Emergency Physicians' Opioid Prescribing Behavior

Introduction

Given the general lack of literature on opioid and naloxone prescribing guidelines for patients with substance use disorder, we aimed to explore how a physician’s behavior and prescribing habits are altered by knowledge of the patient’s concomitant use of psychotropic compounds as evident on urine and serum toxicology screens.

Methods

We conducted a retrospective chart review study at a tertiary, academic, Level I trauma center between November 2017–October 2018 that included 358 patients who were discharged from the emergency department (ED) with a diagnosis of fracture, dislocation, or amputation and received an opioid prescription upon discharge. We extracted urine and serum toxicology results, number and amount of prescription opioids upon discharge, and the presence of a naloxone script.

Results

The study population was divided into five subgroups that included the following: negative urine and serum toxicology screen; depressants; stimulants; mixed; and no toxicology screens. When comparing the 103 patients in which toxicology screens were obtained to the 255 patients without toxicology screens, we found no statistically significant differences in the total prescribed morphine milligram equivalent (75.0 and 75.0, respectively) or in the number of pills prescribed (15.0 and 13.5, respectively). Notably, none of the 103 patients who had toxicology screens were prescribed naloxone upon discharge.

Conclusion

Our study found no association between positive urine toxicology results for psychotropically active substances and the rates of opioid prescribing within a single-center, academic ED. Notably, none of the 103 patients who had toxicology screens were prescribed naloxone upon discharge. More research on the associations between illicit drug use, opioids, and naloxone prescriptions is necessary to help establish guidelines for high-risk patients.

Association between county level cannabis dispensary counts and opioid related mortality rates in the United States: panel data study

OBJECTIVE

To examine county level associations between the prevalence of medical and recreational cannabis stores (referred to as dispensaries) and opioid related mortality rates.

DESIGN

Panel regression methods.

SETTING

812 counties in the United States in the 23 states that allowed legal forms of cannabis dispensaries to operate by the end of 2017.

PARTICIPANTS

The study used US mortality data from the Centers for Disease Control and Prevention combined with US census data and data from Weedmaps.com on storefront dispensary operations. Data were analyzed at the county level by using panel regression methods.

MAIN OUTCOME MEASURE

The main outcome measures were the log transformed, age adjusted mortality rates associated with all opioid types combined, and with subcategories of prescription opioids, heroin, and synthetic opioids other than methadone. The associations of medical dispensary and recreational dispensary counts with age adjusted mortality rates were also analyzed.

RESULTS

County level dispensary count (natural logarithm) is negatively related to the log transformed, age adjusted mortality rate associated with all opioid types (β=-0.17, 95% confidence interval -0.23 to -0.11). According to this estimate, an increase from one to two storefront dispensaries in a county is associated with an estimated 17% reduction in all opioid related mortality rates. Dispensary count has a particularly strong negative association with deaths caused by synthetic opioids other than methadone (β=-0.21, 95% confidence interval -0.27 to -0.14), with an estimated 21% reduction in mortality rates associated with an increase from one to two dispensaries. Similar associations were found for medical versus recreational storefront dispensary counts on synthetic (non-methadone) opioid related mortality rates.

CONCLUSIONS

Higher medical and recreational storefront dispensary counts are associated with reduced opioid related death rates, particularly deaths associated with synthetic opioids such as fentanyl. While the associations documented cannot be assumed to be causal, they suggest a potential association between increased prevalence of medical and recreational cannabis dispensaries and reduced opioid related mortality rates. This study highlights the importance of considering the complex supply side of related drug markets and how this shapes opioid use and misuse.

The associations of medical marijuana policies with opioid-related health care utilization

OBJECTIVE

To examine the associations between medical marijuana policies and opioid-related hospitalizations and emergency department visits.

DATA SOURCES

We utilized quarterly rates of hospital discharge data from the Healthcare Cost and Utilization Project's (HCUP) Fast Stats Database from 2005 to 2016 along with state-level sociodemographic data from US Census Bureau and Bureau of Labor Statistics and opioid-related state health policy data from publicly available sources for the analysis.

STUDY DESIGN

Analyses were carried out using a difference-in-differences regression approach. We estimate heterogeneous effects of medical marijuana policies such as initial policy, presence of active dispensary, and home cultivation on opioid-related hospitalizations and emergency department visits related to opioids.

DATA COLLECTION/EXTRACTION METHODS

Publicly available secondary data were collected, linked, and analyzed. Observations with missing values for explanatory variables were excluded from the analysis.

PRINCIPAL FINDINGS

Regression results indicate that type of medical marijuana policy has varying effects on opioid-related hospitalizations and emergency department visits. States that allow home cultivation of medical marijuana experienced significant positive associations with opioid-related hospitalizations and emergency department visits, while no effect was observed with medical marijuana dispensaries. Moreover, recreational marijuana policies were positively associated with opioid-related hospitalizations.

CONCLUSIONS

The findings indicate that the effects of medical marijuana policies on opioid-related hospitalizations and emergency department visits vary depending on the type of medical marijuana policy. Our findings indicate that the implementation of home cultivation of marijuana is positively associated with hospitalizations and emergency department visits related to opioids, suggesting that easier access to marijuana among opioid users may result in adverse health conditions that need treatment.

Cannabis Use, Cannabis Use Disorder, and Comorbid Psychiatric Illness: A Narrative Review

BACKGROUND

The landscape of attitudes, legal status and patterns of use of cannabis is rapidly changing in the United States and elsewhere. Therefore, the primary aim of this narrative review is to provide a concise overview of the literature on the comorbidity of cannabis use and cannabis use disorder (CUD) with other substance use and psychiatric disorders, and to use this information to accurately guide future directions for the field.

METHODS

A literature review of PubMed was conducted for studies relating to cannabis use, CUD, and a co-occurring psychiatric disorder. To provide an overview of representative data, the literature review focused on national-level, population-based work from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and National Survey on Drug Use and Health (NSDUH) surveys. Considering rapidly changing cannabis laws, recent (past five-year) studies were addressed.

RESULTS

A strong body of literature shows associations between cannabis use and CUD with other drug use, psychosis, mood disorders, anxiety disorders, and personality disorders. The strongest evidence of a potential causal relationship exists between cannabis use and psychotic disorders. While some evidence shows potential directionality between cannabis use and mood and anxiety disorders, results are inconsistent. Studies have established higher rates of CUD among those with personality disorders, but little about the specifics of this relationship is understood.

CONCLUSIONS

Although the general population in the United States increasingly perceives cannabis to be a harmless substance, empirical evidence shows that cannabis use is associated both with CUD and comorbid psychiatric illness. However, there is mixed evidence regarding the role of cannabis in the etiology, course, and prognosis of a co-occurring disorder across all categories of psychiatric disorders. Future research should expand on the existing body of literature with representative, longitudinal data, in order to better understand the acute and long-term effects of cannabis on comorbid psychiatric illness.