Risks and Benefits of Marijuana Use
Drew Shoemaker, MD, FASAM
Cannabis History
Marijuana was first use for medicinal purposes around 200 B.C.
The plant was first utilized as a source of hemp for making textiles
It was later selectively cultivated for its psychoactive properties
In 1940, cannabidiol was isolated from the marijuana plant
In 1964, THC’s chemical structure was characterized
Marijuana Images
Marijuana Images
Hashish
THC Resin
Cannabidiol vs THC
Cannabidiol vs THC cont…
THC is the compound most responsible for the psychoactive effects of marijuana.
THC acts on both CBD 1 and CBD2 receptors.
CBD1 receptors are located primarily in the central and peripheral nervous system.
The are in particularly high concentration in the amygdala and hippocampus which are involved in learning and memory.
Cannabidiol vs THC cont….
CBD is does not act directly at the CBD1 or CBD2 receptors, but does affect the tone of these receptors by mechanism that have not been well characterized.
CBD has been described as having “promiscuous” pharmacological activity across a range of receptor targets.
Prevalence of Marijuana Use
About 18% of Americans ages 12 or older (about 52.5 million persons) used cannabis in the past 12 months.
About 8.3% of 8th graders, 19.5% of 10th graders and 30.7% of 12th graders have used cannabis/hashish in the past 12 months.
Among Americans 12 and older, about 5.8% have cannabis use disorder (about 16.3 million persons).
This means that about 3 in 10 of persons who use cannabis, have cannabis use disorder.
What is Cannabis Use Disorder? (DSM 5)
Cannabis is often taken in larger amounts or over a longer period than was intended.
There is a persistent desire or unsuccessful efforts to cut down or control cannabis use.
A great deal of time is spent in activities necessary to obtain cannabis, use cannabis, or recover from its effects.
Craving, or a strong desire or urge to use cannabis.
Recurrent cannabis use resulting in a failure to fulfil major role obligations at work, school, or home.
Continued cannabis use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of cannabis.
What is Cannabis Use Disorder?
Important social, occupational, or recreational activities are given up or reduced because of cannabis use.
Recurrent cannabis use in situations in which it is physically hazardous.
Cannabis use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by cannabis.
Tolerance, as defined by either of the following:
a. A need for markedly increased amounts of cannabis to achieve intoxication or desired effect.
b. A markedly diminished effect with continued use of the same amount of cannabis.
What is Cannabis Use Disorder
11. Withdrawal, as manifested by either of the following:
a. The characteristic withdrawal syndrome for cannabis (refer to DSM-5 for further details).
b. Cannabis (or a closely related substance) is taken to relieve or avoid withdrawal symptoms.
Cannabis Use Disorder Severity
Mild cannabis use disorder is defined as the presence of 2-3 of these criteria
Moderate cannabis use disorder is defined as the presence of 4-5 criteria
Severe cannabis use disorder is defined as the presence of 6 or more criteria
Marijuana Potency
The amount of tetrahydrocannabinol (THC) in marijuana has increased steadily over the years.
30 years ago, most available marijuana had about 5% THC
It is now over three times that at just above 15%
Other sources of THC such as hashish and resin can run even higher (up to 95%)
Marijuana Potency Cont..
This is largely due to increases in selective cultivation of strains of cannabis with higher THC content
Increases in the understanding cultivation techniques to maximize THC content of existing strains
Means of concentrating THC in resins and oils have allowed these products to contain higher amounts of THC.
What are the sequelae of increased THC Concentration in Marijuana?
Studies have shown negative cognitive effects of heavy consistent marijuana use especially during the ages of 15-25
Studies show a significant increase in cannabis induced psychosis
Increases in the risk of developing cannabis use disorder, especially when marijuana use begins at an early age.
Increase in non medical use of opiates later in early adulthood.
Increase in other substance use disorders in early adulthood
Marijuana Use Sequelae
Prenatal use of marijuana is associated with various adverse outcomes in offspring including tests of neurocognitive function in a study of 11, 489 youth.
Prenatal use of marijuana is associated with preterm birth, hypertensive disorders of pregnancy, stillbirth and small for gestational age.
Marijuana use is associated with decreased REM sleep, especially in youth.
Marijuana use in pregnancy is associated with an increased risk of miscarriage.
Recent Paper on the Risks and Benefits of Marijuana Use.
Meta Analysis Findings
Marijuana use was associated with:
1. Negative effects on cognition
2. Negative effects on mental health
3. Increased risks of motor vehicle accidents
4. Detrimental effects on offspring of mothers who use marijuana in pregnancy.
5. Can markedly impact brain development when use starts in teenage years.
Meta Analysis Findings Cont.
5. Is associated with attention, social and behavioral problems in offspring of mothers who use marijuana in pregnancy.
6. Is associated with low birth weight, still birth, small for gestational age and hypertensive disease in pregnancy in mothers who use marijuana in pregnancy.
7. Heavy marijuana use is associated with increased incidence of schizophrenia, especially in those with a family history of schizophrenia.
Thoughts…
Your patients are using marijuana
They often buy it from “unlicensed vendors”. Who may have other substances available.
Marijuana is often laced with other substances.
“Legal” does not mean any harmful effects of use are negated.
References
1. Meier MH, et al. Persistent cannabis users show neuropsychological decline from childhood to midlife. PNAS. 2012:E2657–E2664.
doi: 10.1073/pnas.1206820109.
2. Bonnet U, Preuss UW. The cannabis withdrawal syndrome: current insights. Sub Abuse Rehab. 2017;8:9–37
3. Freeman TP, Winstock AR. Examining the profile of high-potency cannabis and its association with severity of cannabis dependence. Psychol Med. 2015;45:3181–3189
Reference Cont..
4. Regional brain abnormalities associated with long-term heavy cannabis use. Arch Gen Psychiatry. 2008;65:694–701.
5. Patterns of cannabis use during adolescence and their association with harmful substance use behavior: findings from a UK birth cohort. J Epidemiol Community Health. 2017;0:1–7. doi: 10.1136/jech-2016-208503..
6. Olfson M, et al. Cannabis use and risk of prescription opioid use disorder in the United States. AJP in Advance. doi: 10.1176/appi.ajp.2017.17040413.
References Cont…
7. Paul SE, Hatoum AS, Fine JD, Johnson EC, Hansen I, Karcher NR, Moreau AL, Bondy E, Qu Y, Carter EB, et al. Associations between prenatal cannabis exposure and childhood outcomes: results from the ABCD study.JAMA Psychiatry. 2021; 78:64–76.
8. Tassinari CA, Ambrosetto G, Peraita-Adrado MR, Gastaut H. The neuropsychiatric syndrome of Delta--sup-9-tetrahydrocannabinol and cannabis intoxication in naive subjects: A clinical and polygraphic study during wakefulness and sleep. In: Nahas GG, editor. Marijuana and medicine. Towana: Humana Press Inc; 1999.
9. Coleman-Cowger VH, Oga EA, Peters EN, et al. Prevalence and associated birth outcomes of co-use of cannabis and tobacco cigarettes during pregnancy. Neurotoxicol Teratol. 2018;68:84–90
10. Marco Solmi et al. Balancing risks and benefits of cannabis use: umbrella review of meta-analyses of randomised controlled trials and observational studies. BMJ2023;382:e072348
Balancing risks and benefits of cannabis use: umbrella review of metaanalyses of randomised controlled trials and observational studies BMJ 2023; 382 doi: https://doi.org/10.1136/bmj-2022-072348 (Published 30 August 2023)