Pain, cannabis use, and physical and mental health indicators among veterans and nonveterans: results from the National Epidemiologic Survey on Alcohol and Related Conditions-III

Protocol for a pragmatic trial of Cannabidiol (CBD) to improve chronic pain symptoms among United States Veterans

BACKGROUND

Chronic pain affects over 100 million Americans, with a disproportionately high number being Veterans. Chronic pain is often difficult to treat and responds variably to medications, with many providing minimal relief or having adverse side effects that preclude use. Cannabidiol (CBD) has emerged as a potential treatment for chronic pain, yet research in this area remains limited, with few studies examining CBD's analgesic potential. Because Veterans have a high need for improved pain care, we designed a clinical trial to investigate CBD's effectiveness in managing chronic pain symptoms among Veterans. We aim to determine whether CBD oral solution compared to placebo study medication is associated with greater improvement in the Patient Global Impression of Change (PGIC).

METHODS

We designed a randomized, double-blind, placebo-controlled, pragmatic clinical trial with 468 participants. Participants will be randomly assigned in a 1:1 ratio to receive either placebo or a CBD oral solution over a 4-week period. The trial is remote via a smartphone app and by shipping study materials, including study medication, to participants. We will compare the difference in PGIC between the CBD and placebo group after four weeks and impacts on secondary outcomes (e.g., pain severity, pain interference, anxiety, suicide ideation, and sleep disturbance).

DISCUSSION

Once complete, this trial will be among the largest to date investigating the efficacy of CBD for chronic pain. Findings from this clinical trial will contribute to a greater knowledge of CBD's analgesic potential and guide further research. Given the relative availability of CBD, our findings will help elucidate the potential of an accessible option for helping to manage chronic pain among Veterans.

TRIAL REGISTRATION

This protocol is registered at clinicaltrials.gov under study number NCT06213233.

Child Maltreatment History, Deployment-Related Traumatic Events, and Past 12-Month Cannabis Use Among Veterans in Canada

OBJECTIVE

Cannabis use among veterans in Canada is an understudied public health priority. The current study examined cannabis use prevalence and the relationships between child maltreatment histories and deployment-related traumatic events (DRTEs) with past 12-month cannabis use including sex differences among Canadian veterans.

METHOD

Data were drawn from the 2018 Canadian Armed Forces Members and Veterans Mental Health Follow-up Survey (response rate 68.7%; veterans only n = 1,992). Five child maltreatment types and 9 types of DRTEs were assessed in relation to the past 12-month cannabis use.

RESULTS

The prevalence of lifetime and past 12-month cannabis use was 49.4% and 16.7%, respectively. Females were less likely than males to report lifetime cannabis use (41.9% vs. 50.4%; odds ratio [OR] 0.71; 95% CI, - 0.59 to 0.86). No sex differences were noted for past 12-month cannabis use (14.1% vs. 17.0%; OR 0.80; 95% CI, 0.60 to 1.07). Physical abuse, sexual abuse, neglect, any child maltreatment, most individual DRTEs, and any DRTE were associated with increased odds of past 12-month cannabis use after adjusting for sociodemographic and military variables. Some models were attenuated and/or nonsignificant after further adjustments for mental disorders and chronic pain conditions. Sex did not statistically significantly moderate these relationships. Cumulative effects of having experienced both child maltreatment and DRTEs compared to DRTEs alone increased the odds of past 12-month cannabis use. Statistically significant interaction effects between child maltreatment history and DRTE on cannabis use were not found.

CONCLUSIONS

Child maltreatment histories and DRTEs increased the likelihood of past 12-month cannabis use among Canadian veterans. A history of child maltreatment, compared to DRTEs, indicated a more robust relationship. Understanding the links between child maltreatment, DRTEs, and cannabis use along with mental disorders and chronic pain conditions is important for developing interventions and improving health outcomes among veterans.

Correlates of cannabis use in a sample of mental health treatment-seeking Canadian armed forces members and veterans

OBJECTIVE

Canadian Armed Forces (CAF) members and Veterans are more likely to experience mental health (MH) conditions, such as posttraumatic stress disorder (PTSD), than the general Canadian population. Previous research suggests that an increasing number of individuals are employing cannabis for MH symptom relief, despite a lack of robust evidence for its effectiveness in treating PTSD. This research aimed to: (1) describe the prevalence of current cannabis use among MH treatment-seeking CAF members and Veterans; and (2) estimate the association between current cannabis use and a number of sociodemographic, military, and MH-related characteristics.

METHOD

Using cross-sectional intake data from 415 CAF members and Veterans attending a specialized outpatient MH clinic in Ontario, Canada, between January 2018 and December 2020, we estimated the proportion of CAF members and Veterans who reported current cannabis use for either medical or recreational purposes. We used multivariable logistic regression to estimate adjusted odds ratios for a number of sociodemographic, military, and MH-related variables and current cannabis use.

RESULTS

Almost half of the study participants (n = 187; 45.1%) reported current cannabis use. Respondents who reported current cannabis use for medical purposes had a higher median daily dose than those who reported current cannabis use for recreational purposes. The multivariable logistic regression identified younger age, lower income, potentially hazardous alcohol use, and increased bodily pain as statistically significant correlates of current cannabis use among our MH treatment-seeking sample. PTSD severity, depressive severity, sleep quality, and suicide ideation were not statistically associated with current cannabis use.

CONCLUSIONS

Almost half of our treatment-seeking sample reported current cannabis use for medical or recreational purposes, emphasizing the importance of screening MH treatment-seeking military members and Veterans for cannabis use prior to commencing treatment. Future research building upon this study could explore the potential impact of cannabis use on MH outcomes.

Association of cannabis use with patient-reported pain measures among adults with chronic pain in US states with medical cannabis programs

INTRODUCTION

Most Americans live in a state that has legalized cannabis as a medical treatment for pain, but it is unclear how chronic pain intensity relates to cannabis use. Our objective was to examine the association between patient-reported pain measures and cannabis among adults with chronic pain.

METHODS

This cross-sectional study of a representative sample of adults reporting chronic non-cancer pain in 36 states and DC with active medical cannabis programs from March to April 2022 assessed cannabis use for chronic pain, categorized as active (within 30 days), past (>31 days), or never use (referent). Measures were pain intensity (primary) and interference, Widespread Pain Index, and number of chronic pain diagnoses.

RESULTS

Among 1628 participants (57% female, 69% white), 352 (22%) actively used cannabis to treat chronic pain, 137 (8%) reported past cannabis use, and 1139 (70%) never used cannabis. In adjusted models, active cannabis use was associated with higher scores for pain intensity (score difference 1.03, 95% CI 0.05 to 2.02) and pain interference (score difference 1.82, 95% CI 0.99 to 2.65) compared with never use. Persons who actively used cannabis had higher Widespread Pain Index scores (score difference 0.56, 95% CI 0.26 to 0.86) and more chronic pain diagnoses (difference 0.45, 95% CI 0.06 to 0.83).

CONCLUSION

People with chronic non-cancer pain who used cannabis for pain reported non-clinically meaningful worse pain measures and greater burden of chronic pain conditions than their counterparts who never used cannabis. Alternatively, those with worse pain and greater burden of pain appear more likely to use cannabis.

Mental and Physical Health Conditions Among U.S. Veterans with Cannabis Use and Cannabis Use Disorders

Purpose of Review

Veterans are a large population that is disproportionately affected by various physical and mental health conditions. The primary aim of this review is to provide a concise overview of recent literature on the prevalence of cannabis use and cannabis use disorder (CUD) among US Veterans, and associations with mental and physical health conditions. We also addressed gaps in the literature by investigating associations between CUD and mental and physical health conditions in 2019 data from the Veterans Health Administration (VHA; N=5,657,277).

Recent Findings

In total, 25 studies were reviewed. In 2019, the prevalence of Veteran cannabis use ranged from 11.9%-18.7%. Cannabis use and CUD were associated with bipolar disorders, psychotic disorders, suicidality, pain conditions, and other substance use, but less consistently associated with depressive disorders, anxiety disorders, and posttraumatic stress disorder. Analyses of 2019 VHA data indicated that CUD was strongly associated with a broad array of physical and mental health conditions and mortality.

Summary

Cannabis use and CUD are prevalent and highly comorbid with other conditions among US Veterans. Harm reduction methods tailored to these populations are needed.

Chronic Pain, Cannabis Legalization and Cannabis Use Disorder in Veterans Health Administration Patients, 2005 to 2019

Background

The risk for cannabis use disorder (CUD) is elevated among U.S. adults with chronic pain, and CUD rates are disproportionately increasing in this group. Little is known about the role of medical cannabis laws (MCL) and recreational cannabis laws (RCL) in these increases. Among U.S. Veterans Health Administration (VHA) patients, we examined whether MCL and RCL effects on CUD prevalence differed between patients with and without chronic pain.

Methods

Patients with ≥1 primary care, emergency, or mental health visit to the VHA and no hospice/palliative care within a given calendar year, 2005-2019 (yearly n=3,234,382 to 4,579,994) were analyzed using VHA electronic health record (EHR) data. To estimate the role of MCL and RCL enactment in the increases in prevalence of diagnosed CUD and whether this differed between patients with and without chronic pain, staggered-adoption difference-in-difference analyses were used, fitting a linear binomial regression model with fixed effects for state, categorical year, time-varying cannabis law status, state-level sociodemographic covariates, a chronic pain indicator, and patient covariates (age group [18-34, 35-64; 65-75], sex, and race and ethnicity). Pain was categorized using an American Pain Society taxonomy of painful medical conditions.

Outcomes

In patients with chronic pain, enacting MCL led to a 0·14% (95% CI=0·12%-0·15%) absolute increase in CUD prevalence, with 8·4% of the total increase in CUD prevalence in MCL-enacting states attributable to MCL. Enacting RCL led to a 0·19% (95%CI: 0·16%, 0·22%) absolute increase in CUD prevalence, with 11·5% of the total increase in CUD prevalence in RCL-enacting states attributable to RCL. In patients without chronic pain, enacting MCL and RCL led to smaller absolute increases in CUD prevalence (MCL: 0·037% [95%CI: 0·03, 0·05]; RCL: 0·042% [95%CI: 0·02, 0·06]), with 5·7% and 6·0% of the increases in CUD prevalence attributable to MCL and RCL. Overall, MCL and RCL effects were significantly greater in patients with than without chronic pain. By age, MCL and RCL effects were negligible in patients age 18-34 with and without pain. In patients age 35-64 with and without pain, MCL and RCL effects were significant (p<0.001) but small. In patients age 65-75 with pain, absolute increases were 0·10% in MCL-only states and 0·22% in MCL/RCL states, with 9·3% of the increase in CUD prevalence in MCL-only states attributable to MCL, and 19.4% of the increase in RCL states attributable to RCL. In patients age 35-64 and 65-75, MCL and RCL effects were significantly greater in patients with pain.

Interpretation

In patients age 35-75, the role of MCL and RCL in the increasing prevalence of CUD was greater in patients with chronic pain than in those without chronic pain, with particularly pronounced effects in patients with chronic pain age 65-75. Although the VHA offers extensive behavioral and non-opioid pharmaceutical treatments for pain, cannabis may seem a more appealing option given media enthusiasm about cannabis, cannabis commercialization activities, and widespread public beliefs about cannabis efficacy. Cannabis does not have the risk/mortality profile of opioids, but CUD is a clinical condition with considerable impairment and comorbidity. Because cannabis legalization in the U.S. is likely to further increase, increasing CUD prevalence among patients with chronic pain following state legalization is a public health concern. The risk of chronic pain increases as individuals age, and the average age of VHA patients and the U.S. general population is increasing. Therefore, clinical monitoring of cannabis use and discussion of the risk of CUD among patients with chronic pain is warranted, especially among older patients.

Research in Context

Evidence before this study: Only three studies have examined the role of state medical cannabis laws (MCL) and/or recreational cannabis laws (RCL) in the increasing prevalence of cannabis use disorder (CUD) in U.S. adults, finding significant MCL and RCL effects but with modest effect sizes. Effects of MCL and RCL may vary across important subgroups of the population, including individuals with chronic pain. PubMed was searched by DH for publications on U.S. time trends in cannabis legalization, cannabis use disorders (CUD) and pain from database inception until March 15, 2023, without language restrictions. The following search terms were used: (medical cannabis laws) AND (pain) AND (cannabis use disorder); (recreational cannabis laws) AND (pain) AND (cannabis use disorder); (cannabis laws) AND (pain) AND (cannabis use disorder). Only one study was found that had CUD as an outcome, and this study used cross-sectional data from a single year, which cannot be used to determine trends over time. Therefore, evidence has been lacking on whether the role of state medical and recreational cannabis legalization in the increasing US adult prevalence of CUD differed by chronic pain status.Added value of this study: To our knowledge, this is the first study to examine whether the effects of state MCL and RCL on the nationally increasing U.S. rates of adult cannabis use disorder differ by whether individuals experience chronic pain or not. Using electronic medical record data from patients in the Veterans Health Administration (VHA) that included extensive information on medical conditions associated with chronic pain, the study showed that the effects of MCL and RCL on the prevalence of CUD were stronger among individuals with chronic pain age 35-64 and 65-75, an effect that was particularly pronounced in older patients ages 65-75.Implications of all the available evidence: MCL and RCL are likely to influence the prevalence of CUD through commercialization that increases availability and portrays cannabis use as 'normal' and safe, thereby decreasing perception of cannabis risk. In patients with pain, the overall U.S. decline in prescribed opioids may also have contributed to MCL and RCL effects, leading to substitution of cannabis use that expanded the pool of individuals vulnerable to CUD. The VHA offers extensive non-opioid pain programs. However, positive media reports on cannabis, positive online "information" that can sometimes be misleading, and increasing popular beliefs that cannabis is a useful prevention and treatment agent may make cannabis seem preferable to the evidence-based treatments that the VHA offers, and also as an easily accessible option among those not connected to a healthcare system, who may face more barriers than VHA patients in accessing non-opioid pain management. When developing cannabis legislation, unintended consequences should be considered, including increased risk of CUD in large vulnerable subgroups of the population.

Substance Use in U.S. Vietnam War Era Veterans and Nonveterans: Results from the Vietnam Era Health Retrospective Observational Study

Background: Substance use (SU) is associated with physical injury and mental health disorders in older persons, but recent research has scarcely examined SU in U.S. Vietnam-era veterans who are mostly in or near their eighth decade of life. Objectives: We compared the prevalence of self-reported lifetime and current SU and modeled current usage patterns in a nationally representative sample of veterans versus a matched nonveteran cohort. Methods: Cross-sectional, self-reported survey data were analyzed from the 2016-2017 Vietnam Era Health Retrospective Observational Study (VE-HEROeS) (n = 18,866 veterans, n = 4,530 nonveterans). We assessed lifetime and current alcohol and drug use disorders; lifetime and current use of cannabis, opioids, stimulants, sedatives, "other drugs" (psychedelics, prescription or over-the-counter drugs not prescribed/used as intended); and current SU patterns (alcohol-use-only, drug-use-only, dual-SU, no SU). Weighted descriptive, bivariable, and multivariable statistics were calculated. Covariates in multinomial modeling included sociodemographic characteristics, lifetime cigarette smoking, depression, potentially traumatic events (PTEs), and current pain (SF-8^TM). Results: Prevalence of lifetime opioid and sedative use (p ≤ .01), drug and alcohol use disorders (p < .001), and current "other drug" use (p < .001) were higher in veterans versus nonveterans. Current use of alcohol and cannabis was high in both cohorts. In veterans, very severe/severe pain, depression, and PTEs were highly associated with drug-use-only (p < .001) and dual-SU (p < .01), but these associations were fewer for nonveterans. Conclusion: This research confirmed existing concerns over substance misuse in older individuals. Vietnam-era veterans may be at particular risk due to service-related experiences and later-life tribulations. Era veterans' unique perceptions toward healthcare assistance for SU may need greater provider focus to maximize self-efficacy and treatment.

Moral injury and chronic pain in veterans

Posttraumatic stress disorder (PTSD) and chronic pain are highly prevalent and co-morbid among veterans. Moral injury (MI), which results from traumatic experiences that conflict with deeply held moral beliefs, is also associated with pain. However, relationships between different types of exposures to potentially morally injurious events (PMIEs) and pain have not yet been investigated. In the current study, we investigated these relationships between exposure to PMIEs (betrayal, witnessing, and perpetration) and different types of pain (joint pain, muscle pain, and overall pain intensity), while controlling for other relevant variables (including PTSD symptoms, combat exposure, adverse childhood experiences, age, gender, and race/ethnicity). We also examined gender differences in these associations. Participants were 11,871 veterans drawn from a nationwide, population-based survey who self-reported exposure to PMIEs, PTSD symptoms, frequency of adverse childhood experiences, combat exposure, sociodemographic information, past six-month joint pain, past six-month muscle pain, and past week overall pain intensity. Population weighted regression models demonstrated that PMIEs were not significantly associated with joint or muscle pain, but that betrayal was associated with past week overall pain intensity, even when controlling for all other variables. Models investigating men and women separately found that for women, betrayal was associated with joint pain and pain intensity, but for men, betrayal was not associated with any pain outcome. These findings suggest that it may be especially important to assess betrayal when treating patients with a history of trauma and chronic pain.

Trends in Prescriptions for Non-opioid Pain Medications Among U.S. Adults With Moderate or Severe Pain, 2014-2018

As opioid prescribing has declined, it is unclear how the landscape of prescription pain treatment across the U.S. has changed. We used nationally-representative data from the Medical Expenditure Health Survey, 2014 to 2018 to examine trends in prescriptions for opioid and non-opioid pain medications, including acetaminophen, non-steroidal anti-inflammatory drugs, gabapentinoids, and antidepressants among U.S. adults with self-reported pain. Overall, from 2014 to 2018, the percentage of participants receiving a prescription for opioids declined, (38.8% vs 32.8%), remained stable for non-steroidal anti-inflammatory drugs (26.8% vs 27.7%), and increased for acetaminophen (1.6% vs 2.3%), antidepressants (9.6% vs 12.0%) and gabapentinoids (13.2% vs 19.0%). In this period, the adjusted odds of receiving an opioid prescription decreased (aOR = .93, 95% CI = .90-.96), while the adjusted odds of receiving antidepressant, gabapentinoid and acetaminophen prescriptions increased (antidepressants: aOR = 1.08, 95% CI = 1.03-1.13 gabapentinoids: aOR = 1.11, 95% CI = 1.06-1.17; acetaminophen: aOR = 1.10, 95% CI: 1.02-1.20). Secondary analyses stratifiying within the 2014 to 2016 and 2016 to 2018 periods revealed particular increases in prescriptions for gabapentinoids (aOR = 1.13, 95% CI = 1.05-1.21) and antidepressants (aOR = 1.23, 95% CI = 1.12-1.35) since 2016. PERSPECTIVE: These data demonstrate that physicians are increasingly turning to CDC-recommended non-opioid medications for pain management, particularly antidepressants and gabapentinoids. However, evidence for these medications' efficacy in treating numerous common pain conditions, including low back pain, remains limited.