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Prior to my decision to attend medical school, I was planning to become a basic science researcher. I studied biochemistry in college at a time when it was a relatively young field. My bachelor of science curriculum included 7 semesters of chemistry; 5 semesters of biochemistry, physics, microbiology, and zoology; and a senior honors thesis that entailed designing, completing, and defending a novel research project. I successfully defended my thesis, “An Analysis of the Fate of the Escherichia coli 4.5S RNA Gene in Yeast Using a Recombinant Plasmid,”

 and was planning to attend graduate school in genetics at the University of Washington in Seattle.

Between completing my senior thesis and my planned move to Seattle, I suddenly panicked and wondered: Is this truly the career path for me? Ultimately, I realized I did not have what it took to be a basic science researcher, so I worked for a year as a biochemical technician and applied to medical school—a decision I have never regretted.

Yet, I do not regret my background in biochemistry either. It is the foundation upon which all I have learned of medicine and psychiatry is built. The field of neuropsychopharmacology has evolved over the past 30 years, and I am filled with pride, awe, and excitement to have witnessed the clinical advancements that basic science researchers have made possible. However, in my opinion, there is 1 significant exception to all my accolades for how good science has advanced medicine: the research on cannabis.

The scientific method is used in medicine and has been the established paradigm for scientific inquiry since the 1600s. Thus, all clinical trials submitted to the US Food and Drug Administration (FDA) are meticulously designed to answer a primary outcome question about the drug under investigation. A necessary requirement of the study design is to ensure that the variables in the various arms of the study are identical except for one: drug A at dose X compared with placebo. If multiple doses of drug A or multiple drugs are being compared, each arm is precisely characterized so the conclusions drawn from the primary outcome will be highly accurate and reliable.

Over the past 10 years, I have read numerous articles in the psychiatric literature that draw conflicting conclusions about the effect of cannabis on cognition, its attendant risk of psychosis, its addictive potential, and its effect on suicidality, and about its impacts on depression, anxiety, pain relief, and apathy. (There appears to be only 1 consistent finding: Heavy cannabis use during brain development increases the risk of psychosis and cognitive impairment, especially when other risk factors are present.) A likely explanation for the wide-ranging discrepancies is that cannabis is the product of a plant that is not a single molecule or pure substance. Many articles with the word cannabis in the title can be discarded as meaningless unless the authors took the additional step of testing all of the cannabis used by their study subjects for the quantitative and qualitative molecules present.

It is well established that cannabis contains 

 These constituents include more than 100 cannabinoids, more than 200 terpenoids (terpenes), and numerous flavonoids. Two cannabinoids are most prevalent in cannabis: Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), both of which exist in an extremely wide range of ratios depending on the specific strain of cannabis assayed. Significantly, these 2 cannabinoids are oppositional in their clinical effects and have dramatically different pharmacodynamic effects. In reviewing the literature on cannabis, a consistent finding is that potency of cannabis is a proxy for the amount of THC. Although this is likely a result of the psychoactive effects of cannabis that have been noted for more than 6000 years,

 CBD has surfaced as an important cannabinoid with many positive medicinal properties. Notably, cannabis remains a Schedule 1 drug by the Drug Enforcement Administration (DEA), while CBD is unscheduled.

documents some of the significant differences between THC and CBD. Despite these differences, the vast majority of publications on cannabis draw conclusions based on participants’ self-reports of quantity and frequency of cannabis use. In these studies, the molecular components of the cannabis used are not known, nor is the important ratio of THC to CBD.

A fair analogy would be to evaluate a new drug; let us call it Sedalant. Sedalant contains a wide-ranging ratio of 2 molecules with different mechanisms of action: one a sedative, and one a stimulant. Without knowing the exact ratios and concentrations of each of these molecules in clinical studies of Sedalant, no evidence-based conclusions could be drawn from the drug studies.

Naturally occurring cannabis plants produce roughly an equal ratio of THC to CBD, containing approximately 2% of each. However, over the decades, with selective breeding in some strains, THC has been increased significantly while CBD has been virtually bred out. 

 analyzed the concentrations of THC and CBD from 38,681 samples of illegal cannabis seized by the DEA between 1995 and 2014. The authors found a clear trend of increased THC in cannabis over time, with an average concentration of 4% in 1995 that increased to 12% in 2014. Simultaneously, CBD concentration steadily declined, from 0.5% in 2004 to less than 0.2% in 2014. The investigators concluded that the ratio of THC to CBD increased from 14-fold in 1995 to 80-fold in 2014.5 Some strains of cannabis today may contain up to 30% THC with virtually no CBD, while other strains have high concentrations of CBD with minimal THC.

To further complicate the cannabis story, very few of the other cannabinoids in cannabis plants have been characterized pharmacodynamically or pharmacokinetically. The characterization of 3 of these more than 100 cannabinoids—Δ-9-tetrahydrocannabivarin, cannabichromene, and cannabigerol—tells us that they are 

Interestingly, the odors (skunk is a common description) often associated with cannabis are largely due to the complex combination of terpenes, another compound that complicates the study of cannabis. (Cannabinoids are odorless.) An extensive literature documents the essential role terpenes play in the biology of the cannabis plant, the plant’s production of cannabinoids, and the properties of a specific strain of cannabis that help determine its market value. Terpenes likely also contribute pharmacodynamic and pharmacokinetic effects that impact the neuropsychopharmacology resulting from ingestion of each different strain of 

Several publications since 2018 have appropriately concluded that we know very little about the range of pharmacological effects from cannabis due to the large variability of cannabinoids, terpenes, and flavonoids that are present in 

For this very reason, it would be contrary to the scientific method of research to attempt to gain FDA approval of cannabis.

Only 1 of the more than 100 cannabinoid components in cannabis has been sufficiently studied to receive FDA approval: CBD. Following a comprehensive analysis as well as clinical trials of pure CBD, it received 

 for the treatment of seizures in Dravet syndrome and in Lennox-Gastaut syndrome in children and adults.

 We may see additional approvals in the future for this well-studied compound, as a growing and consistent body of evidence shows that pure CBD in defined dosages has antipsychotic effects in patients with schizophrenia.

The practice of medicine is built upon evidence-based treatments that have been appropriately vetted by well-established protocols. CBD traveled this path to become an FDA approved drug, and so should any other component of the 500-plus molecules in cannabis. Accordingly, clinical publications should be held to a higher standard of identifying and defining what components of cannabis are relevant in any article being submitted for publication.

With each passing year, more US states legalize cannabis for medical use, recreational use, or both. It is likely that federal laws will eventually make cannabis use legal on a national level. That will create an opportunity to require a comprehensive analysis and disclosure of all the components of the numerous strains of cannabis currently being sold in state dispensaries or on the streets. Concurrently, the individual molecular components of the cannabis plant should be identified and pharmacologically characterized. This would create a treasure trove of possible drug candidates for specific clinical indications, and it would allow for a more informed choice when choosing a cannabis product.

In this scenario, cannabis should be regulated federally similar to tobacco products and alcohol. Both of these have significant risks, and both are tightly controlled. Ideally, the taxes imposed on federally regulated cannabis could help fund the extensive research needed to allow a more competent understanding of the complex combination of molecules that different strains of cannabis contain.

1. The word cannabis should not be used casually in medical literature, as it is nonspecific and includes varying molecular combinations of diverse cannabinoids, terpenes, and flavonoids.

2. Future research involving cannabis should use a single strain in each study; each strain used should be analyzed quantitatively and qualitatively for biologically active components.

3. If multiple strains are used in a clinical trial, they should be analyzed (as noted in #2), and each strain should be studied as a separate arm compared with placebo.

4. Increased funding is needed to accurately characterize the 500-plus molecular components of the cannabis plant, including the pharmacokinetics and pharmacodynamics of each component.

5. A public education campaign should aggressively disseminate the molecular facts about cannabis, especially the oppositional effects of THC and CBD. Similarly, the risks of increased psychosis and cognitive impairment with heavy regular use of THC in the developing brain should be explained, much like disclaimers on alcohol about drinking during pregnancy.

6. Cannabis should be federally legalized and regulated similarly to alcohol and tobacco products.

7. Cannabis should not be regulated by the FDA due to its extreme heterogeneity of components and the associated unpredictable pharmacological properties.

8. Cannabis should not be prescribed by medical practitioners. However, as molecular components of cannabis are developed and garnish FDA approval, those components should be prescribed appropriately.

9. Pharmacological exploration and development of cannabis components that demonstrate medical benefits should be continued. CBD is a successful model of such.

10. Medical practitioners should discuss cannabis with their patients only after they have attained competence in understanding the science and factual risks/benefits/adverse effects of cannabis, similar to how a practitioner would discuss alcohol or tobacco use.

With this structure in place, we have the ability to inform and support our patients appropriately. And, with more information, we can help end the cannabis confusion.

 is medical director, Brain Health, Exeter, New Hampshire; Editor in Chief,

; staff psychiatrist, Seacoast Mental Health Center, Exeter; Consulting Psychiatrist, Exeter Hospital, Exeter; Consulting Psychiatrist, Insight Meditation Society, Barre, Massachusetts.

1. Miller J. An Analysis of the Fate of the Escherichia coli 4.5S RNA Gene in Yeast Using a Recombinant Plasmid. Senior undergraduate honors thesis. University of Washington, Amherst; 1981.

2. Lafaye G, Karila L, Blecha L, Benyamina A. Cannabis, cannabinoids, and health. 

4. Atakan Z. Cannabis, a complex plant: different compounds and different effects on individuals. 

5. ElSohly MA, Mehmedic Z, Foster S, et al. Changes in cannabis potency over the last 2 decades (1995-2014): analysis of current data in the United States. 

6. ElSohly MA, Radwan MM, Gul W, et al. Phytochemistry of Cannabis sativa L. 

7. Nachnani R, Raup-Konsavage WM, Vrana KE. The pharmacological case for cannabigerol. 

8. Sommano SR, Chittasupho C, Ruksiriwanich W, Jantrawut P. The cannabis terpenes. 

9. Booth JK, Bohlmann J. Terpenes in cannabis sativa – from plant genome to humans. 

10. Baron EP. Medicinal properties of cannabinoids, terpenes, and glavonoids in cannabis, and benefits in migraine, headache, and pain: an update on current evidence and cannabis science. 

11. Jett J, Stone E, Warren G, Cummings KM. Cannabis use, lung cancer, and related issues. 

12. Epidiolex. Greenwich Biosciences; 2020. Updated April 2020. Accessed July 7, 2021. 

13. McGuire P, Robson P, Cubala WJ, et al. Cannabidiol (CBD) as an adjunctive therapy in schizophrenia: a multicenter randomized controlled trial. 

14. Elsaid S, Le Foll B. The complexity of pharmacology of cannabidiol (CBD) and its implications in the treatment of brain disorders. 

15. National Academies on Sciences, Engineering, and Medicine. 

The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research

16. Rong C, Carmona NE, Lee YL, et al. Drug-drug interactions as a result of co-administering Δ9-THC and CBD with other psychotropic agents. 

10 keys to understanding the science of cannabinoids. 

Cannabis Confusion

Patients increasingly ask about cannabis and whether it can be useful for sleep, PTSD, pain, and even dementia. In this video, Timothy W. Fong, MD gives a brief overview on emerging issues in cannabis. On Monday, May 3, Dr Fong and colleagues will speak at this year’s APA meeting in a presentation titled “

Facing the Challenge of Cannabis Legalization: Psychiatry’s Role

Dr Fong is Professor of Psychiatry & Director, UCLA, and Co-Director of UCLA’s Gambling Studies. The presentation is in collaboration with Laurence Westreich, MD; Kevin Allen Sevarino, MD; and Frances Rudnick Levin, MD.

Timothy W. Fong, MD, touches on our current understanding about cannabis use for psychiatric disorders.

Addressing Myths and Facts About Cannabis Use

For the full report of survey results, see 

You Spoke, We Listened. Psychiatry's Cannabis Survey

Clinical Management of Cannabis Complications


Thomas R. Kosten, MD, and Christopher D. Verrico, PhD

The Age of Cannabis Has Arrived: Issues for Older Adults

Cannabis 2021: What Clinicians Need to Know

Cannabis and Psychosis: A Synthesis of Quantitative Reviews

How to Discuss Cannabis With Your Patients

Infographic: A Snapshot of Psychiatrists' Attitudes Toward Cannabis

Research on psychiatrists' attitudes on the potential of cannabis in psychiatry.

Infographic: A Snapshot of  Psychiatrists' Attitudes Toward Cannabis

Enlightening survey results reveal what psychiatrists think about medical marijuana/cannabis use, how or whether to discuss with their patients, and what biases might get in the way of such conversations.

A new question must be added to the list that mental health clinicians ask their older patients while taking a history, regardless of age: “Have you used any cannabis products recently?”

I learned this lesson during a follow-up appointment with an 82-year-old man with Alzheimer disease. He reported some rather abrupt cognitive decline, and I asked him and his wife about recent medical changes without finding any clear precipitant. Finally, his wife sheepishly confessed that their son had sent them a grab bag of cannabis-derived products that the patient was taking. The family was desperate for anything to help his cognitive decline and they had heard that cannabis was a miracle cure for Alzheimer disease and many other conditions. Unfortunately, the patient received no benefit but did experience some mild, noticeable adverse effects. Without my probing, I never would have known. The next patient I asked explicitly about using cannabis products responded in an equally explicit manner: “No I haven’t,” he said, “but can you get me some?” It was clear that the age of cannabis had arrived.

Older individuals with psychiatric disorders are increasingly using cannabis, largely in the form of prescribed medical marijuana and cannabidiol (CBD). This trend has been driven by several factors: reduced stigma, lifted restrictions on possession and sale by most states, and the enormous proliferation of articles and ads that tout supposed benefits of 

 for many conditions that afflict the elderly, including chronic pain, peripheral neuropathy, stress, anxiety, depression, insomnia, headaches, and the adverse effects of chemotherapy.

 As a result, medical marijuana use by individuals 65 or older has increased more than 8-fold in recent years, from less than 0.5% in 2006 to 4.2% in 2018

). In a survey of 345 adults in Colorado, 16% had used medical marijuana since legalization, with half the users being 75 or older.

 CBD has seen a particularly enormous surge in interest and availability after it was exempted from federal regulations in the 2018 US Farm Bill. Since then, it is estimated that 6.4% of adults aged 45 to 55 and 3.7% of those 55 or older have used CBD at least once.

Although the cannabis sativa plant contains hundreds of chemicals known as cannabinoids, the 2 main active chemicals are Δ-٩-tetrahydrocannabinol (THC) and CBD. THC has both psychotropic and euphoric properties and confers the high associated with marijuana, while CBD is noneuphoric because it does not activate the cannabinoid 1 receptor like THC does. The same plants that produce THC also produce CBD. Both THC and CBD come in a variety of forms; they can be smoked, vaped, eaten, ingested as liquids, used as oils, and applied via creams and cosmetics.

The psychotropic effects of both THC and CBD are mainly because of their interaction with endogenous cannabinoid receptors in the brain, as well as activation of a variety of other cannabinoid and noncannabinoid receptors (ie, serotonergic, glutaminergic, µ-opioid, and α1-adrenergic) in the central nervous system and on immunologic cells. Based on their known and theorized properties, marijuana and CBD have been proposed as remedies to modulate symptoms of stress, insomnia, pain, inflammation, and cognitive impairment, particularly in older individuals. As a result, there are many unsubstantiated claims that THC and/or CBD can treat Alzheimer disease, Parkinson disease, schizophrenia, and anxiety and mood disorders.

Several small case series have suggested a tentative basis for some of these claims. For example, a study looked at the use of an oral spray containing THC and CBD for peripheral nerve pain and found that it was well tolerated and showed a trend toward improvement in pain and sleep.

 Medical marijuana use has been associated with some improvement in both movements and neuropsychiatric symptoms in individuals with Parkinson disease.

 One small case series found improvement in behavioral and psychological symptoms of dementia from cannabis oil containing THC.

 A related randomized control trial of 50 individuals with dementia and associated neuropsychiatric symptoms did not see any benefit from THC, but did find it was well tolerated and with no appreciable effect on memory.

 Despite these limited data, agitation associated with dementia is a qualifying condition for medical marijuana in several states.

Gruber and colleagues studied a sample of middle-aged individuals using medical marijuana over 3 months and found improvements in 

 and reductions in depression, insomnia, and impulsivity.

 They also saw a reduction in the use of benzodiazepines and opioids as well as a normalization of brain activation waves to states seen in normal controls. It is not clear, however, if these neurocognitive results were the direct result of the medical marijuana or an indirect benefit of decreases in pain, anxiety, and 

Although there are many other in vivo, in vitro, and animal studies of THC and CBD, it is clear that evidence is limited, and there are few randomized controlled trials to support most of their theorized clinical benefits. In addition, these studies are based on a variety of cannabis products from multiple sources and with variable contents.

 The 2 exceptions include a Food and Drug Administration (FDA)-approved form of synthetic THC known as dronabinol, which is used for treating appetite and weight loss resulting from AIDS as well as nausea and vomiting from chemotherapy, and a medication containing CBD for the treatment of 2 rare childhood seizure disorders. Dronabinol has also been studied in Alzheimer disease to treat anorexia and agitation and was found to be well tolerated with variable efficacy for both conditions.

, a CBD-THC combination, has been approved for the treatment of muscle spasms associated with multiple sclerosis.

The use of medical marijuana and CBD in older adults must be approached with caution because there are several potential adverse effects. It has been well established that heavy marijuana use in both young and middle-aged adults can cause mild functional and structural brain impairments affecting attention, 

, motor coordination, verbal memory, and executive function.

 Although these effects may be more variable with lighter use in older adults, they may be amplified by preexisting brain impairment as well as by underlying pulmonary and cardiovascular conditions, especially when medical marijuana is smoked or vaped.

 One review of 184 older patients (median age, 82) who were on medical marijuana for 6 months found that approximately 80% reported some benefit for the treated symptoms, but one-third reported adverse effects, including dizziness (12%) and sleepiness and fatigue (11.2%).

 Other reported adverse effects from a national epidemiologic survey included changes in mood and cognition, psychosis, increased heart rate and blood pressure, urinary retention, and blurred vision.

 In addition, THC has been associated with impaired driving in young adults, which could also be a problem in older drivers who may be impaired at baseline.

 of CBD use found that it is generally well tolerated with few adverse effects, the most common one being diarrhea.

 Other adverse effects associated with CBD include nausea, drowsiness, fatigue, dry mouth, and mood changes. Keep in mind that CBD is an inhibitor of several cytochrome P450 enzymes, including CYP1A2, CYP2B6, CYP2C9, CYP2D6, and CYP3A4. CBD can lead to drug-drug interactions with several commonly used medication groups in older patients, including blood thinners, antibiotics, anticonvulsants, antidepressants, and antipsychotics.

What To Ask Patients, and What To Tell Them

In this new era of medical marijuana and CBD, there are several important takeaways for clinicians working with older patients. Do not assume that because a patient is elderly and has physical or cognitive limitations that they do not fit the profile of a cannabis user. To the contrary: Every older patient along with their caregivers should be queried as to their use of cannabis, whether recreationally, from mail order or friends and family, or through a prescription. To this end, every clinical history should include questions about the use of cannabis products, including the stated reasons for use, the type of marijuana or CBD being used, and observed benefits and adverse effects. Concomitant medical conditions must be reviewed for potential vulnerabilities, such as an individual with hypertension using a product that increases blood pressure or heart rate, or an individual with chronic obstructive pulmonary disease using vaping oils. Potential 

 also need to be considered, with a focus on the categories of medications discussed in the article.

Patients and their caregivers need to understand that nearly all benefit claims are largely unsubstantiated, as they lack a rigorous scientific basis. Slick articles and ads generally exaggerate potential benefits, or they refer to in vitro or animal studies and anecdotal reports, making them sound as if they constitute direct evidence of clinical effects. They also need to understand the differences between THC and CBD, along with the fact that production is largely unregulated, so products can have many different ingredients and properties. Several studies have found wide discrepancies between labels for cannabis products and their actual contents, especially when it comes to the amount of THC or CBD.

 Thus, many products that claim only to have CBD actually have varying degrees of THC present. This lack of consistency often accounts for both inconsistent clinical effects as well as adverse effect issues, and these factors lead many older adults to discontinue use of cannabis products.

Finally, keep in mind that older patients with preexisting 

 such as in Alzheimer disease might be particularly vulnerable to adverse effects such as drowsiness, dizziness, fatigue, and mood changes, which in turn can account for significant and unpredictable fluctuations in cognition and behavior. Such unpredictability (in the amount of drug being ingested over time and the ensuing effects on brain and body) is exactly the sort of variability that can be hazardous in the older patient. Compounding these risks is the fact that many individuals will use products such as CBD oil without the knowledge and supervision of a knowledgeable clinician.

The bottom line is that more rigorous scientific study using randomized controlled trials is needed to substantiate the proposed benefits of cannabis and more fully understand the range and impact of common adverse effects.

is the chief medical officer at MIND Institute at Miami Jewish Health.

1. Gruber SA, Sagar KA, Dahlgren MK, et al. 

Splendor in the grass? A pilot study assessing the impact of medical marijuana on executive function

2. Grinspoon P. Older adults and medical marijuana: reduced stigma and increased use. 

Updated April 6, 2020. Accessed February 1, 2020. 

https://www.health.harvard.edu/blog/older-adults-and-medical-marijuana-reduced-stigma-and-increased-use-2-2020040119321

3. Han BH, Palamar JJ. Trends in cannabis use among older adults in the United States, 2015-2018. 

4. Reynolds IR, Fixen DR, Parnes BL, et al. Characteristics and patterns of marijuana use in community-dwelling older adults.

5. Oberbarnscheidt T, Miller NS. The impact of cannabidiol on psychiatric and medical conditions. 

6. Russo EB. Cannabis therapeutics and the future of neurology. 

7. Serpell M, Ratcliffe S, Hovorka J, et al. A double-blind, randomized, placebo-controlled, parallel group study of THC/CBD spray in peripheral neuropathic pain treatment. 

8. Shelef A, Barak Y, Berger U, et al. Safety and efficacy of medical cannabis oil for behavioral and psychological symptoms of dementia: an-open label, add-on, pilot study. 

9. van den Elsen GA, Ahmed AI, Verkes RJ, et al. Tetrahydrocannabinol for neuropsychiatric symptoms in dementia: a randomized controlled trial. 

10. Maust DT, Bonar EE, Ilgen MA, et al. Agitation in Alzheimer disease as a qualifying condition for medical marijuana in the United States. 

11. Gruber SA, Sagar KA, Dahlgren MK, et al. The grass might be greener: medical marijuana patients exhibit altered brain activity and improved executive function after 3 months of treatment. 

12. Britch SC, Babalonis S, Walsh SL. Cannabidiol: pharmacology and therapeutic targets. 

13. Antonsdottir IM, Makino KM, Porsteinsson AP. Dazed and confused: medical cannabis in Alzheimer disease. 

14. Crean RD, Crane NA, Mason BJ. An evidence-based review of acute and long-term effects of cannabis use on executive cognitive functions. 

15. Nader DA, Sanchez ZM. Effects of regular cannabis use on neurocognition, brain structure, and function: a systematic review of findings in adults. 

16. DeFilippis EM, Bajaj NS, Singh A, et al. Marijuana use in patients with cardiovascular disease: JACC review topic of the week. 

17. Abuhasira R, Ron A, Sikorin I, Novack V. Medical cannabis for older patients-treatment protocol and initial results. 

18. Benitez A, Lauzon S, Nietert PJ, et al. Self-reported cognition and marijuana use in older adults: Results from the national epidemiologic survey on alcohol and related conditions-III. 

19. Arkell TR, Vinckenbosch F, Kevin RC, et al. Effect of cannabidiol and Δ9-tetrahydrocannabinol on driving performance: a randomized clinical trial. 

20. Chesney E, Oliver D, Green A, et al. 

Adverse effects of cannabidiol: a systematic review and meta-analysis of randomized clinical trials

Cannabis use has prompted symptoms such as dizziness, sleepiness, and fatigue in older patients. Are there any benevolent effects?

Lost in the various public policy arguments fueling cannabis decriminalization and legalization 

 across the United States is the fact that a percentage of individuals who use cannabis will experience negative effects, ranging from bothersome to the catastrophic. These difficulties arise from a sharply decreasing perception of risk, easy availability of the drug, and increased potency of Δ-9-tetrahydrocannabinol (THC) preparations. The arithmetic of cannabis remains immutable: Best 

 are that about 9% of individuals who use cannabis will become dependent on the substance at some point in their life,

 and if the number of those who use cannabis goes up, the total number of those experiencing problems with the substance will rise also. Clinicians must learn to manage cannabis-related problems in this growing population.

 cannabis-dependent individuals face are serious, disheartening, and deserving of treatment. National Survey on Drug Use and Health (NSDUH) data on 505,796 Americans

 show that between 2008 and 2016 individuals aged 12 to 17, who met criteria for a cannabis use disorder (CUD), were 25% more common in states that had enacted Recreational marijuana laws (RMLs) as opposed to those who did not. In addition, the THC content of the various preparations of cannabis has risen over the past 10 years. Studies show that the mean THC concentration in smokable marijuana increased from 8.9% in 2008 to 17.1% in 2017,

 and half of those who frequently use marijuana ingest concentrates of at least 80% THC.

 in Colorado had an average THC percentage of 56.6%, while by 2017 the average was 68.6%, with some retail stores cheerfully advertising a 95% THC rate in their products.

Cannabis-related problems, like lack of motivation, usually become apparent after many years of use. Given cannabis’ pharmacological designation as a sedative-hypnotic substance, it is hardly surprising that common complaints on presentation to treatment include acute intoxication with high-potency 

; psychiatric phenomena such as depression, anxiety, and 

; and cannabinoid hyperemesis syndrome (CHS).

Clinicians should at least consider their patients’ cannabis use as a precipitating or exacerbating factor in any psychiatric or medical syndrome. Also, although the DSM-5

 contains a useful list of cannabis-related signs and symptoms, many individuals with cannabis-related problems do not meet the full criteria for CUD. For instance, while the casual cannabis smoker may present with a depressive picture but meet no other criteria for CUD, cessation of cannabis use may be necessary to achieve resolution of the patient’s dysphoria, anhedonia, and fatigue. CHS, cyclic episodes of nausea and vomiting often relieved with hot baths, can be a confusing emergency department presentation. Other medical presentations of heavy cannabis smoking include cough, bronchitis, lung hyperinflation,

 as well as acute lung injury from vaping.

 concerns related to cannabis may also generate first visits with a clinician.

, the DSM-5 criteria list the myriad problems that can arise from cannabis use. To fulfill criteria for CUD, the patient must demonstrate at least a yearlong “problematic pattern of cannabis use” and meet at least 2 of the criteria. However, the clinician would do well to consider any cannabis-related problem as a possible contributor to the patient’s reason for presentation.

The patient should be offered a coherent psychotherapy aimed at first minimizing the harms of cannabis use, and then achieving abstinence from the substance. Treatment of any co-occurring psychiatric conditions should be initiated concurrently with the below strategies, focused on cannabis cessation. Manualized techniques like cognitive behavioral therapy,

 have shown measurable, if modest, improvements in outcome criteria such as frequency of cannabis use, number of dependence symptoms, quantity of cannabis use, and negative consequences of cannabis use. These effective treatments share a good understanding of the addictive process, practical and easily deployed interventions, and a focus on small gains. Most clinicians use a mix of therapeutic techniques, which often include cannabis-specific

Peer-led support groups like Alcoholics Anonymous, although commonly recommended as an adjunct to the treatment of substance use disorders, should be carefully selected if recommended for the individual who uses cannabis. Members of peer support groups can be wrongly dismissive of those who only use cannabis. If possible, clinicians should recommend groups like 

 or specific groups which are known to understand the seriousness of CUD. Similarly, inpatient treatment or intensive outpatient programs should be carefully selected for their focus on or at least understanding of CUD.

A common—and counterproductive—fallacy about cannabis is that the substance does not cause withdrawal. In fact, the withdrawal syndrome from cannabis, though unlikely to cause serious medical problems, is uncomfortable and a leading reason that individuals who use cannabis do not stop their use of the substance. Withdrawal therefore requires treatment. Common phenomena associated with cannabis withdrawal include irritability, anxiety, depression, insomnia, disturbing dreams, anorexia, abdominal pain, tremors, sweating, fever, chills, headache,

A powerful first step in engaging the patient in treatment to beat their dependence on the drug is the clinician’s acknowledgement of the withdrawal syndrome and offer to find symptomatic relief. Patients should remain well-hydrated, eat a healthy diet, and exercise regularly during the withdrawal period. Although no medications have been approved by the US Food and Drug Administration (FDA) to treat cannabis withdrawal, symptom-relief medications like gabapentin

 to relieve anxiety and insomnia is indicated in some cases.

Treatment of cooccurring psychiatric illnesses with the appropriate medications is vital to the treatment of CUD. Although no medications have FDA-approved indications for the specific treatment of CUD, 2 have shown suggestive data in studies, and can be prescribed for patients needing additional pharmacological support. In small studies, the anticonvulsant topiramate

 demonstrated improved retention in treatment over placebo and gabapentin

 showed better treatment retention and a decrease in cannabis use and depressive symptoms. Various trials of dronabinol and nabilone, both THC analogues; nabiximols, a combination of THC and CBD; and N-acetylcysteine, a glutamatergic modulating dietary supplement, have shown little efficacy in the treatment of CUD.

Individuals who use cannabis may question any need for addressing their use by noting the ongoing success of cannabis legalization in the US, cannabis’ lack of lethality (as compared to opioids), and the natural provenance of the smokable varieties of cannabis. Clinicians should focus instead on the clinical issues that have brought the individual to treatment. Has the drug contributed to problems at work or school? Is there a psychiatric condition that would be better treated by psychotherapy or an actual medication? Have medical problems like hyperemesis developed? Although some individuals who use cannabis arrive in the clinic simply because a family member disapproves of cannabis use, the vast majority come in became they are being harmed in some way by their 

Despite the changing cultural ethos regarding cannabis, many individuals will suffer from problems related to their use of the substance. Some will meet criteria for CUD, and some will find their educational achievement, work lives, health, and relationships profoundly damaged by the drug. Along with the clinician’s attitude of encouragement and hope about recovery, effective relapse prevention therapies should be deployed. When necessary, medications for co-occurring psychiatric conditions should be used, as should the few available pharmacologic remedies for cannabis withdrawal. Clinicians engaging with patients should model a non-judgemental attitude about the substance, be realistic about the effects of cannabis, and encourage the path for reducing or stopping its use.

is an associate professor of clinical psychiatry in the Division of Alcoholism and Drug Abuse, Department of Psychiatry, New York University School of Medicine in New York, New York. He also serves as the consultant on behavioral health to the commissioner of Major League Baseball.

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14. Stephens RS, Roffman RA, Curtin L. Comparison of extended versus brief treatments for marijuana use. 

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https://madistrict4.org/docs/MAServiceManualrev4_1.pdf

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25. Budney AJ, Roffman R, Stephens RS, Walker D. Marijuana dependence and its treatment. 

The sharply decreasing perception of risk and easy accessibility of cannabis has many patients turning towards it, despite the potential negative effects. 

This Special Report contains articles about cannabis use and its potential complications, including 

 highlights the use of cannabinoids among the geriatric population. Cannabis and cannabidiol (CBD) use in older adults has become more prevalent as a result of reduced stigma; leniency in state restrictions on possession and sale; and advertisements touting benefits for chronic pain, peripheral neuropathy, stress, anxiety, depression, insomnia, headaches, and the adverse effects of chemotherapy. Medical marijuana use by individuals 65 and older has increased more than 8-fold in recent years. The article nicely summarizes how heavy marijuana use can cause mild functional and structural brain impairments, affecting attention, processing speed, motor coordination, verbal memory, and executive function. Overall, every 

, along with their caregivers, should be queried as to their use of cannabis products. They should also be cautioned that those with preexisting neurocognitive impairment, such as Alzheimer disease, might be particularly vulnerable to adverse effects such as drowsiness, dizziness, fatigue, and mood changes.

The rapidly changing field of cannabinoids and their clinical implications poses a particular challenge in psychiatry.

Cannabis