The potential for cannabis withdrawal to mirror depressive symptoms may further contribute to under-detected drug use problems and unmet treatment needs. Regardless of cause, patients in depression treatment samples often have AUDs or use marijuana , and there is a need to initiate efforts in psychiatry treatment contexts that focus on marijuana use. This will be important as psychiatry providers often do not advise patients to reduce drug use in the context of depression treatment , and patients who use drugs and have depression often receive services in psychiatry contexts rather than specialty addiction treatment . Future work should address marijuana use, in addition to alcohol and depression symptoms, among patients with depression and AUD in psychiatry treatment settings. Limitations should be noted. Patients were recruited from an outpatient psychiatry setting, which may limit generalizability. Our enrollment criteria required participants to have mild depression based on having a PHQ-9 score ≥ 5. Yet, a PHQ-9 score of 10 only indicates the presence of major depression based on the DSM-IV criteria, after which thorough diagnostic assessments are required before patients can be assigned a formal diagnosis of major depressive disorder based on the DSM-IV or DSM-5 criteria. As only the PHQ-9 was available to measure depression in this study, and a relatively low cutoff score was used for enrollment, many of our participants would not have met criteria for major depressive disorder. Our findings should be considered within the context of these caveats. We know from the parent study that 12.0% had cannabis dependence , and it is possible that some participants were reporting symptoms consistent with cannabis withdrawal syndrome rather than depression. Our measure for AUD is limited because of its focus on the DSM-IV criteria and its reliance on self-report information. Due to changes in the DSM-5 criteria for AUD, our estimates based on the DSM-IV criteria may underestimate AUD compared to studies using the DSM-5. Our finding of worse functioning for AUD patients using marijuana was limited to PHQ-9 functional impairment,hydroponic racks which was assessed by one item and limited to depression related functioning.
Our use of the MCS-12 to measure mental health functioning is limited because of its global focus and its incorporation of depression symptomatology into the measurement . Future work would benefit from examining indicators of functional impairment potentially less confounded with symptoms. Marijuana use was dichotomized, which reduces statistical power and our understanding of patterns over time. We could not examine drug use other than marijuana over time due to low base rates. Because data on patterns of use and the primary compounds of marijuana were not available , we are precluded from commenting on the contribution of these factors to the outcomes studied. All measures were based on self-report, and future work may benefit from confirmatory structured assessments as well as laboratory tests to provide a more accurate assessment of psychiatric symptoms and drug use, respectively. While more research is required to replicate these results, findings indicate that whether patients with depression and AUD experience clinically problematic outcomes may be influenced by marijuana use. It would be valuable for future treatment and prevention efforts to assess and address marijuana in the context of outpatient psychiatry treatment, and such efforts should focus on patients with depression and AUD, in order to improve patient outcomes.Chronic pain affects approximately one-third of the U.S. population, and opioid prescriptions have substantially increased over the last 20 years . In parallel, there has been an increase in opioid-related complications, with opioid overdose deaths quadrupling between 1999 and 2015. Growing concerns about the risks of opioids, including overdose-related deaths and opioid use disorder, have prompted greater focus on the more judicious use of these agents for managing pain and the need to identify other agents to treat pain. The data on the efficacy of cannabinoids in the management of pain is evolving. In a systematic review, there was low-strength evidence that cannabis is effective for treating neuropathic pain and insufficient evidence of its effectiveness for other types of pain. The American Academy of Neurology has endorsed use of cannabinoids for the pain and spasticity associated with multiple sclerosis but cautions that the safety profile of cannabinoids has not been compared to other approved drugs.
Despite the lack of robust evidence for efficacy of cannabinoids in pain management, marijuana has been approved by legislatures or ballot initiative for the management of pain in over 30 states. Recent data suggest that medical marijuana laws have been associated with lower state-level opioid overdose mortality, hospitalizations related to opioid complications, detection of opioids among fatally injured drivers, and prescription of analgesics. These ecologic studies, while hypothesis generating, do not inform our understanding of the individual effects of marijuana use or combined marijuana and opioid use. Prospective cohort studies and clinical trials are needed to improve our understanding of the effects of cannabis on pain management. Nonetheless, these studies have spurred discussion about the potential for marijuana to serve as a substitute for opioids, particularly in contexts where marijuana is increasingly available through legalization. Small surveys of convenience samples of American and Canadian marijuana users have reported that substitution of marijuana for opioids is common, ranging from approximately 30% to 97% . To our knowledge, there are no nationally representative surveys examining substitution and reasons for substitution among the general US adult population. We examined the prevalence and reasons for substitution of marijuana for opioids among US adults taking opioids for pain, as well as the factors associated with substitution.Details of survey development have been previously published. The survey questions were designed based on a review of the literature and existing national surveys and interviews with substance abuse experts and marijuana distributors and dispensary staff . The survey asks about a wide range of topics, including perception of risks and benefits associated with marijuana use, comparisons of marijuana to other substances , and pertinent public health questions relevant to implementing marijuana legalization. The current study is based on the questions that were designed to assess the extent and reasons for substitution of marijuana for opioids. All questions used Likert scales for response options and were edited to meet an 8th-grade reading level. Prior to administration, our survey was tested on a convenience sample of 40 adults to ensure question reliability and validity. Volunteers were comprised of a panel of patients from the investigator’s clinics and were offered no incentives to volunteer . We ascertained opioid use with the following question: “In the past 12 months, have you regularly taken opiate medications such as Vicodin, Percocet, or OxyContin to treat pain? Do not include pain medications that can be bought without a prescription such as aspirin, Tylenol, or Advil.” We ascertained marijuana use with the following questions: “Have you ever used marijuana?” and “How long has it been since you last used marijuana?”
In 2017, we conducted an Internet-based survey of 16,280 adults about perceptions of marijuana using Knowledge Panel ,indoor garden table a nationally representative panel of the civilian, non-institutionalized US population. Knowledge Panel has been in use for surveying public opinion since 1999. GfK created a representative sample of US adults by random sampling of addresses. The address-based sampling covers 97% of the country and encompasses a statistical representation of the US population. Adults were invited to join through mailings, postcards, and follow up letters. Non-responding households were called. Participation included: completing and mailing back the paper invitation; calling a toll-free number provided by GfK; and completing a recruitment form online. All participants receive the survey in the same manner, households without Internet access are provided with an Internet connection and a tablet to ensure participation. All participants in the panel are sampled with a known probability of selection. No one can volunteer to participate. Participants do not receive monetary incentives to participate but receive points that can be used towards purchases. Participants are provided with no more than six surveys a month and are expected to complete an average of four surveys a month. . For the purposes of future investigation into the role of marijuana legalization on use, California residents and young adults aged 18 to 26 years old were over sampled. Sampling weights were provided by GfK.Our response rate, defined as the ratio of all respondents to all potential respondents, was determined using methodology as outlined by the American Association for Public Opinion Research. Characteristics of the survey respondents were weighted using weights provided by GfK to approximate the US population based on age, sex, race, ethnicity, education, household income, home ownership and metropolitan area. All analyses used weighting commands using the weight variable provided by GfK to generate national estimates. To determine how well our sample compared to a national federally-sponsored survey on substance abuse and marijuana use, we first compared the socio-demographic characteristics of our survey respondents to those of the National Survey on Drug Use and Health. NSDUH is an annual federal survey implemented by the Substance Abuse and Mental Health Services Administration , which is an agency of the Department of Health and Human Services . NSDUH provides data on substance abuse epidemiology in the US. We then examined opioid substitution among respondents with a history of ever using marijuana who used opioids in the past 12 months. We used logistic regression to determine associations between socio-demographic characteristics and status of marijuana legalization in the state of residence and substitution of marijuana for opioids. The cases who were categorized as “ever” marijuana users with opioid use within the past 12 months who refused to answer were excluded from this logistic model. Analyses were conducted using R statistical software . There were very few participants with missing data and these cases were dropped from the analysis. This study was considered exempt by the University of California, San Francisco Committee on Human Research.There were 9,003 respondents, corresponding to a 55.3% response rate. Baseline characteristics of respondents were similar to respondents from the National Survey on Drug Abuse and Health, though our respondents had a slightly higher average income, suggesting our sample was representative of the US population. The mean age was 48 years, 48% were male, 64% were white, and 64% lived in a state in which marijuana was legal. Among this national sample, forty-six percent reported ever using marijuana, and 8% reported regular use of opioids for pain in the past year. Among the 5% who reported ever using marijuana and using opioids in the past year, 43% used opioids daily, and 23% reported current marijuana use . Forty-one percent reported a decrease or cessation of opioid use due to marijuana use; 46% reported no change in opioid use; and 8% reported an increase in opioid use. The most commonly reported reasons for substitution were better pain management and fewer side effects and withdrawal symptoms , compared to the non-medical reasons for use: cheaper and more social acceptance from marijuana use . In multi-variable analyses, we found no association between socio-demographics or status of marijuana legalization in the state of residence and substitution .In a nationally representative survey of US adults, substitution of marijuana for opioids, which included a substantial degree of opioid discontinuation , was common. Better self-reported pain management and fewer side effects and withdrawal symptoms were the most common reasons for substitution. Our findings are consistent with prior surveys of American and Canadian marijuana users in which substitution of marijuana for opioids was prevalent due to better symptom management and fewer adverse and withdrawal effects. Our study overcomes the potentially biased reporting in favor of substitution from prior convenience samples of marijuana users. This may explain why the prevalence of substitution in our study was lower than that of other studies in which a prevalence of up to 97% has been reported . Additionally, we focused specifically on substitution of marijuana for opioids and asked about this practice directly whereas other studies asked about substitution of marijuana for prescription drugs more broadly or indirectly assessed opioid substitution. Our results were also inconsistent with a recently published Australian cohort study which followed approximately 1,500 people with chronic non-cancer pain prescribed opioids for four years.