Medical Cannabis and Addictions
October 2015
Charlie Reznikoff
Medical Cannabis Topics
• Is marijuana addictive?
• Is medical cannabis addictive?
• Will medical cannabis lead to increased
adolescent use of recreational marijuana?
• How has the addictive stigma affected
doctors’ attitudes about medical cannabis?
• Other important toxic effects of cannabis.
Is marijuana and/or medical
cannabis addictive?
Diagnosing Marijuana use disorder
A pattern of marijuana use over 12 months
• Mild: 2-3 symptoms
• Moderate: 4-5 symptoms
• Severe: >/=6 symptoms
Diagnosing marijuana use disorder
1. Larger amounts over longer periods of time than intended
2. Desire or unsuccessful efforts to cut down or control use
3. Time is spent to obtain, use or recover from the effects
4. Craving
5. Failure to fulfill role obligations at work, home or school
6. Persistent or recurrent social or interpersonal problems
7. Social, occupational, or recreational activities are given up
8. Recurrent use in situations that are physically dangerous
9. Use despite medical or psychiatric harm
10*.Tolerance
11*.Withdrawal
*If the substance in question is a prescribed substance, these
criteria are eliminated
Cannabis ranked
against other
drugs of abuse
Lancet 2007, 369, p10471053
What makes a drug addictive?
• Stimulates the nucleus accumbans
– And how powerfully it does so
• Rapid entry into the brain
– Inhaled > IV > snort > eat or drink
• Rapidly wearing off
• Tendency to cause physical dependency
– Causing withdrawal, tolerance
• Ability to improve mood
Crack cocaine smoked
• Stimulates the nucleus accumbans
–And how powerfully it does so
• Rapid entry into the brain
–Inhaled
• Rapidly wearing off
• Tendency to cause physical dependency
– Causing withdrawal, tolerence
• Ability to improve mood
Heroin IV
• Stimulates the nucleus accumbans
– And how powerfully it does so
• Rapid entry into the brain
– Inhaled > IV
– Rapidly wearing off
• Tendency to cause physical
dependency
–Causing withdrawal, tolerance
• Ability to improve mood
Marijuana smoked
• Stimulates the nucleus accumbency
– And how powerfully it does so
• Rapid entry into the brain
– Inhaled
• Rapidly wearing off
• Tendency to cause physical dependency
– Causing withdrawal, tolerence
• Ability to improve mood
Likelihood of Addiction after experimentation
Center for substance abuse, university of maryland, 2008
Is Marijuana Addictive?
If <18 years, risk of addiction increased to 17%
www.drugabuse.gov/publications/researchreports/marijuana/marijuana-addictive
Self reported
symptoms
newly sober
users compared
to former
users.
Budney et al, J of Abnl
Psyche 2003 vol 112 #3
p393
Cannabis withdrawal:
Mild, not life threatening, irritability,
poor sleep, poor appetite,
restlessness
Requires no treatment, only
education and reassurance
Psychopharmacology, Nov2006, Vol. 188 Issue 4, p425-444, 20p, 1 chart, 3
Distribution of THC in the Body (lipid soluble)
Kreutz & Axelrod (1973)
Inhaled cannabinoids are more
addictive than eaten, but also more
easily dosed to avoid side effects
(see below)
Comment on addiction and
diversion of dronabinol….
Comment on addiction and
diversion of dronabinol….
I’ve never heard of it happening!
THC vs CBD
CBD may offset addictive properties
of THC
Conclusion:
Medical cannabis might cause or
feed addiction in some who use it.
I would consider it a mild to
moderate side effect.
So it is addictive in some….
Why care?
• Docs are worried about the use of an
addictive drug:
– Interfering with other medical care compliance
– Replacing more standard medical cares
– Causing harm to patient, family, community
– Dominating or distracting the medical visit
Are medical cannabis laws bad
public policy that will increase
adolescent marijuana use?
Why would a young person try
something new?
• Acceptability
• Availability
• Perceived safety
Strict laws do not align with low use
What about the “gateway effect”?
What about the “gateway effect”?
• Liberalizing marijuana law will uncouple
marijuana use from other, harder drugs, and
will close the gateway to other drugs
• Liberalizing marijuana law will lead to an
increase in youth using marijuana, altering
their brains in a way to make them vulnerable
to other harder drugs, opening the gateway
Physician’s concerns about
medical cannabis for pain
87 primary care providers responded
to a three question survey
Years lived with disability 1990-2010
Patients chronically medicating pain
symptoms with intoxicants
Pain
Anxiety
Withdrawal
Survey conclusions
• Mixed opinions on intractable pain
• Lack of medical knowledge about cannabis is
common
• High concern about how medical cannabis
would affect the providers’ workday
Physician concerns
• Practicing medicine outside the evidence base
norms, conventional pharmacies
• Recreating the opioid-for-pain epidemic
• Challenging conversation, demanding patients
• Paperwork and red tap
• Time and energy to learn something new
• Personal opinions about marijuana
Other important toxic effects of
(medical) cannabis
“Active Placebo”
Set & Setting
Cannabis dilates blood vessels
lightheadedness & increase in resting
heart rate with THC use
Marijuana stimulates appetite
Alcohol
Carbos
American Journal of Cardiology 2006 98: p478
Kaiser study: 62,000 patients
no association with marijuana and
heart attacks or strokes
Work place accidents associated with
cannabis use
• Macdonald S, Hall W, Roman P, Stockwell T,
Coghlan M, Nesvaag S. Testing for cannabis in the
work-place: a review of the evidence. Addiction.
2010;105:408-416.
New Zealand Dunedin Study
>1000 cohort studied over 38 years
• Updated summer 2012
• Neuropsych declines across the board in MJ
users
• Age and dose dependent
–Mental health
–Verbal IQ
–Academic achievement and job
satisfaction
• Adolescents who used marijuana regularly
were significantly less likely than their nonusing peers to finish high school or obtain a
degree. They also had a much higher chance
of later developing dependence, using other
drugs, and attempting suicide
Marijuana and Psychosis
• Worsening of preexisting schizophrenia
– Increased psychiatric hospitalizations
• Acute reversible psychotic reaction
– Increased likelihood of eventual schizophrenia
• Acute irreversible psychotic reaction
– Psychotic break, Schizophrenia
Zammit brit journal of psyche nov 2008 193 (5) p357
D’souza, int. review of neurobiology 2007 (78) p289
Moore et al. LANCET July 28, 2007 P.319
Cannabis and psychosis
• 24% new psychosis cases linked to thc
consumption
• BBC news 16, feb 2015
Mental Illness and Marijuana use
Conclusions about Medical Cannabis
• THC containing drugs affect the brain’s
pleasure center and can cause addiction
• Medical THC has low-medium risk of addiction
• Unknown public health effect on adolescents
• Physicians are not ready for medical cannabis
• There are many important side effects of
cannabinoids aside from addiction
Other conclusions
• Some will get addicted to medical cannabis
• Driving work and parenting may be affected
by medical cannabis
• Mood, psychotic disorders and brain
development is affected cannabis
• Medical cannabis is NOT more toxic than
many commonly used medications
• Docs have a lot to learn about medical
cannabis!
Thank you!
Questions?