Explore the relationship between cannabis use and psychosis.
TALES FROM THE CLINIC
In this installment of Tales From the Clinic: The Art of Psychiatry, we explore the relationship between cannabis use and psychosis, and look at potential legal issues. As more states make recreational cannabis use legal, also increasing is the risk of psychiatric comorbidity associated with cannabis use disorders. Worsening of anxiety, concentration, and the potential for psychosis development have been well documented, subject to individual risk factors. The link to resulting social and legal disparities is rooted in systemic, societal structures. This installment highlights associated issues and the complex interaction between sociocultural stressors and resulting neurobehavioral symptoms.
“Gary” is a 25-year-old Black veteran who was recently discharged from the US Army after serving for 4 years. During his service, he experienced a traumatic brain injury (TBI) and returned home to live with his parents in rural Texas. Since returning home, Gary has been struggling with his mental health and uses cannabis daily to self-medicate. He enrolled in a local college but dropped out his second semester when he developed a psychotic disorder.
Gary has been unable to keep a job for more than a few weeks, and his parents are growing increasingly frustrated with him. He also declined disability benefits. Gary’s parents have been doing their best to provide him with the support he needs, but they recognize that his continued cannabis use poses a problem. They check in on him daily and offer him a listening ear when he needs one. They encourage him to engage in activities he used to enjoy.
His parents have actively explored mental health services in the area and are hopeful that they can find a way to help Gary, even though the closest psychiatrist is 3 hours away. His parents tell you during the first appointment that you are the first psychiatrist to see Gary.
Frustrated with his situation, Gary tells you he smokes cannabis because it helps “quiet his mind and sometimes the voices.” Gary shares that this week he was found by police at a busy intersection running toward cars and pedestrians. Gary was taken to jail for cannabis intoxication and possession. His parents hired a lawyer to fight these charges, but Gary’s psychotic symptoms prevent him from working with his legal counsel. With adherence to antipsychotic medications and cooperation with his lawyer, it is possible Gary could fight these charges. However, Gary tells you he does not want to stop smoking cannabis. He also does not want to try the medications you offer because the voices tell him it is not necessary. He points out that his incarceration and your recommendations are unfair since cannabis is being legalized in many states.
Stories like Gary’s are all too common. Cannabis is the most commonly used illicit drug in the US, with 15.3% of the population using the drug.1 Reasons for cannabis use can be found in the Figure. The main active ingredient in the cannabis plant is Δ-9-tetrahydrocannabinol (THC), just 1 of more than 100 cannabinoids identified. The potency and THC content in cannabis directly correlate with the prevalence of psychotic features among users.2 Results of a study from 2002 to 2013, the National Epidemiologic Survey on Alcohol and Related Conditions, showed that as compared with nonusers, those with any use of nonmedical cannabis and those with cannabis use disorder were at increased risk of self-reported psychosis regardless of degree of use.3 Moreover, the literature suggests that cannabis increases the risk of developing schizophrenia 3-fold in a dose-response relationship.4
Earlier epidemiological studies merely linked heavy, sustained use of cannabis to development of first break psychosis, with extensive research in the decades following trying to elucidate whether cannabis is psychotogenic and whether it is causal for schizophrenia and schizophrenia spectrum disorders. Factors to consider when assessing a cannabis user for psychosis can be found in the Table.5-9 Gary’s presentation conjures up an age-old question, “Which came first, the chicken or the egg?” Was Gary’s psychosis a result of his cannabis use or did the cannabis use exacerbate a preexisting psychopathology?
As of 2020, of the 15% of the US population who met criteria for substance use disorders (SUDs), 44.9% or 17 million had a psychiatric condition.10 The data are even more startling for cannabis use with lifetime prevalence for cannabis dependence among US adults (approximately 4%). The National Comorbidity Survey found that 90% of individuals in the US with cannabis dependence also had a cooccurring psychiatric disorder.11 Conversely, individuals with mental illness are also at a higher risk for comorbid cannabis use and subsequent addiction.12
As a wave of cannabis legalization continues to sweep the US, it is important to distinguish recreational from problematic use. Problematic use entails a variety of factors, including a failure to fulfill obligations, social and interpersonal problems, physiological dependence, hazardous use, and unsuccessful attempts to cut down or stop when using larger amounts over a long period of time.
Although cannabis use may not be legal in some states, another of its active ingredients—the compound cannabidiol (CBD), which does not produce euphoria or intoxication—is readily available. Early research into the therapeutic effects of CBD compounds is promising with regards to treatment of anxiety, SUDs, posttraumatic stress disorders, and other psychiatric illnesses, and some cannabinoid compounds have been found helpful in treatment of epilepsy. With that said, many CBD products may contain amounts of THC, which can vary in concentration and effect.
State laws and public perceptions surrounding cannabis have been changing rapidly. In Texas, marijuana possession is at least a misdemeanor charge with jail time, and/or fines, progressing to felony possession if an individual is found with more than 4 oz. By contrast, 23 other states, Guam, and Washington, DC, have legalized the recreational use of cannabis. At least 38 states have approved cannabinoid products for medicinal use.13
The Marijuana Opportunity Reinvestment and Expungement Act passed by the US House of Representatives in April 2022 sought to decriminalize marijuana.14 This bill meant that cannabis would be removed from the list of drugs regulated by the Controlled Substances Act, federal criminal penalties for cannabis use would be eliminated, and past federal cannabis convictions would be expunged. However, no bill to decriminalize cannabis has successfully passed the Senate. To address the issue, in October 2022, President Joseph R. Biden announced that he would grant pardons for federal marijuana possession convictions, urging state governors to do the same for state offenses.15
These events are steps in a positive direction for thousands of individuals, particularly minority groups who are disproportionately arrested and incarcerated. An American Civil Liberties Union report from 2020 states that a Black individual is 3.64 times more likely to be arrested for marijuana possession, even though rates of cannabis use by Black and white individuals are the same.16 In some states, Black individuals are up to 10 times more likely to be arrested.16 This trend applies to every state and is prevalent in both rural and urban settings. Beyond actual incarceration, felony convictions prevent individuals from employment, housing options, and the right to vote, making this an issue of racial equity.
Individual Risk Profile
Gary faced an increased risk of arrest for cannabis possession due to his race/ethnicity. Before his arrest, Gary’s TBI history increased his impulsivity risk and could have complicated his chances at educational attainment and occupational success. Additionally, his history of military trauma may have made continued use of cannabis more likely. Gary likely used cannabis to stifle trauma intrusion and hyperarousal symptoms, as cannabinoids reduce responses to conditioned fear cues, impair retrieval of aversive memories, and trigger the extinction of unwanted memories.17
In light of his psychotic symptoms and unsafe behavior while intoxicated, Gary would have benefited from a psychiatric evaluation instead of incarceration, which could hurt his future employment prospects. Gary’s refusal of psychiatric medications and limited insight about the dangers of cannabis use and his legal predicament place him in a real quandary. Yet the severity of his psychotic symptoms is not sufficient to justify involuntary inpatient psychiatric hospitalization. Clinicians need to be ready for this type of complicated presentation as cannabis becomes increasingly legalized.
Additionally, although risk of cannabis use in triggering psychosis is recognized, the risk of use on ongoing psychotic disorders and in the exacerbation of other disorders (involving mood, concentration, and other symptoms) are not fully understood. The effects on women of childbearing age of prenatal exposure risks, early use, and exposure in early adolescence are also not fully understood. Lastly, the impact of using high concentration THC compounds for prolonged periods of time will need to be studied as legalization unfolds. The Adolescent Brain Cognitive Development Study, launched by the National Institutes of Health in 2015, aims to track brain development in children and adolescents starting at age 9 years to answer such questions.18
Outpatient motivational interviewing may have the greatest impact in promoting a collaborative patient relationship. It may not be readily apparent to patients with underlying psychotic disorders just how risky substance use can be, but the legal consequences can be life altering, impacting their prognoses. Building family support through psychoeducation can help destigmatize mental health care attainment and enhance patient motivation for sobriety. In a political climate where our patients face discrimination, it is imperative for clinicians to do what we can to treat our patients holistically.
Dr Shenoi is an addiction psychiatry fellow at Baylor College of Medicine in Houston, Texas. Dr Jessa is a psychiatry resident at Baylor College of Medicine. Dr Moukaddam is an associate professor in the Menninger Department of Psychiatry and Behavioral Sciences at Baylor College of Medicine, the Ben Taub Adult Outpatient Services director, and medical director of Baylor College of Medicine’s Stabilization, Treatment & Rehabilitation Program for Psychosis in Houston. She also serves on the Psychiatric Times Advisory Board. Dr Avellaneda Ojeda is an associate professor in the Menninger Department of Psychiatry and Behavioral Sciences at Baylor College of Medicine.
1. United Nations Office on Drugs and Crime. World Drug Report 2019. Booklet 1, Executive Summary. Accessed August 15, 2023. https://wdr.unodc.org/wdr2019/prelaunch/WDR19_Booklet_1_EXECUTIVE_SUMMARY.pdf
2. Di Forti M, Quattrone D, Freeman TP, et al; EU-GEI WP2 Group. The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study. Lancet Psychiatry. 2019;6(5):427-436.
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4. Livne O, Shmulewitz D, Sarvet AL, et al. Association of cannabis use-related predictor variables and self-reported psychotic disorders: US adults, 2001–2002 and 2012–2013. Am J Psychiatry. 2022;179(1):36-45.
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10. Key substance use and mental health indicators in the United States: results from the 2020 National Survey on Drug Use and Health (NSDUH). Substance Abuse and Mental Health Services Administration. October 2021. Accessed August 15, 2023. https://www.samhsa.gov/data/sites/default/files/reports/rpt35325/NSDUHFFRPDFWHTMLFiles2020/2020NSDUHFFR1PDFW102121.pdf
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12. Regier DA, Farmer ME, Rae DS, et al. Comorbidity of mental disorders with alcohol and other drug abuse: results from the Epidemiologic Catchment Area (ECA) study. JAMA.1990;264(19):2511-2518.
13. Medical use update. National Conference of State Legislatures. Updated June 22, 2023. Accessed August 30, 2023. https://www.ncsl.org/health/state-medical-cannabis-laws
14. House of Representatives, Congress. H.R. 3617 (EH) - Marijuana Opportunity Reinvestment and Expungement Act. US Government Publishing Office. Accessed August 15, 2023. https://www.govinfo.gov/app/details/BILLS-117hr3617eh
15. Rachko TJ Jr. Biden administration takes steps on marijuana justice reform: pardons begin to address harm to US communities of color. Human Rights Watch. October 8, 2022. Accessed August 15, 2023. https://www.hrw.org/news/2022/10/28/biden-administration-takes-steps-marijuana-justice-reform
16. A tale of two countries: racially targeted arrests in the era of marijuana reform. American Civil Liberties Union. 2020. Accessed August 15, 2023. https://www.aclu.org/sites/default/files/field_document/marijuanareport_03232021.pdf
17. LaFrance EM, Glodosky NC, Bonn-Miller M, Cuttler C. Short and long-term effects of cannabis on symptoms of post-traumatic stress disorder. J Affect Disord. 2020;274:298-304.
18. Adolescent Brain Cognitive Development Study (ABCD Study). National Institutes of Health. June 23, 2023. Accessed August 15, 2023. https://nida.nih.gov/research-topics/adolescent-brain/longitudinal-study-adolescent-brain-cognitive-development-abcd-study