As medical cannabis gains acceptance in our society, I am seeing more people in my practice who are new or quite inexperienced with its properties. Many of these patients are concerned that they might become addicted to cannabis.
According to a 2011 study of recreational users of drugs, the probability of becoming dependent on cannabis is 8.9%. Other substances are reported to have much higher risks of dependency: 67.5% for nicotine users, 22.7% for alcohol users, 20.9% for cocaine users. (1) Recent media reports have stated that the numbers of those seeking drug treatment for cannabis dependence are rising. But according to a recent study, 70% of Americans in drug treatment for cannabis were court-ordered to do so as part of a plea agreement, not because they are dependent on the drug. (2) Due to continued prosecution of cannabis users, the numbers of those considered “cannabis dependent” are falsely elevated — most will choose rehab over jail time. However, it’s clear that the majority of cannabis users, both medical and recreational, do not develop addiction issues.
Tolerance — defined as the need to use more of the drug to get the desired effect or less of an effect is achieved with a previously effective amount — has been demonstrated with THC use following repeated exposure. Studies in animals have suggested that tolerance appears to develop due to a reduction of the available cannabinoid receptors in the brain when they are exposed to THC on a chronic basis. (3,4) A subsequent 2012 study showed that humans have the same mechanism of tolerance. Chronic heavy users of THC-rich cannabis had a decreased number of cannabinoid receptors when compared to non-users. The same researchers also showed that this decrease in receptors was reversible; a 4-week abstinence from THC resulted in an increase of receptors to a normal level. (5) Cannabidiol, the non-psychoactive cannabinoid in the cannabis plant, does not cause tolerance as it does not work directly at the cannabinoid receptors. (6)
Withdrawal — defined as the physiological and mental effects due to the cessation of use or reduction in intake of a psychoactive substance that has been regularly used to induce a state of intoxication — was previously thought not to occur with cannabis but recent research has demonstrated a withdrawal syndrome that can occur when chronic heavy use of THC-rich cannabis is stopped abruptly. The most common symptoms associated with THC withdrawal are anxiety, depressed mood, irritability, sleep difficulty, strange or very vivid dreams, anger, and decreased appetite. Less commonly, headaches, sweating, chills, stomach pain and general physical discomfort have also been observed. These symptoms last approximately one to two weeks. (7) Cannabidiol can reduce withdrawal symptoms from THC. (8)
In my clinical practice, I find that most adults who have not used cannabis regularly in their lives, who begin to use it due to a medical condition and who find good results with improvement in their quality of life, are extremely unlikely to have dependence issues. I advise all medical patients to use the smallest dose of THC that gives the desired result, and if they are doing well, they can skip doses to keep tolerance to a minimum. Including CBD to a medical cannabis regimen will likely improve effectiveness and help keep tolerance at bay. Using the cannabinoids found in the raw, unheated flower (THCA, CBDA) will also help reduce the chance of developing tolerance and add medical benefits. If tolerance develops, abstinence from the medication for a few days or even a few weeks (as long as the patient is not suffering during that time) allows for tolerance to drop.
Although cannabis is extremely safe, dependence on any substance is possible. Chronic heavy users of cannabis often express the desire to cut back on or eliminate their use but find the withdrawal symptoms uncomfortable. I recommend using CBD-rich cannabis to help reduce withdrawal symptoms and allow the cannabinoid receptors to return to normal numbers. Once homeostasis has been achieved, THC-rich cannabis may be reintroduced with more effective results at lower doses.
Learn more about cannabis medicine in “Cannabis Revealed: How the world’s most misunderstood plant is treating everything from chronic pain to epilepsy” by Bonni Goldstein, M.D.
- Lopez-Quintero C, de los Cobos JP, Hasin DS, et al. Probability and predictors of transition from first use to dependence on nicotine, alcohol, cannabis, and cocaine: Results of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Drug and alcohol dependence. 2011;115(1-2):120-130. doi:10.1016/j.drugalcdep.2010.11.004.
- Copeland, J., et al. Cannabis Treatment Outcomes among Legally Coerced and Non-coerced Adults. BMC Public Health (2007) 7
- Oviedo, A., et al. Chronic Cannabinoid Administration Alters Cannabinoid Receptor Binding in Rat Brain: A Quantitative Autoradiographic Study. Brain Research (1993) 616: 293-302
- Fan, F., et al. Cannabinoid regulation without Alteration of the Inhibitory Effect of CP 55,940 on Adenyl Cyclase IN the Cerebellum of CP 55,940-tolerant Mice. Brain Research (1996) 706: 13-20 1996
- Hirvonen, Jussi, et al. “Reversible and regionally selective downregulation of brain cannabinoid CB1 receptors in chronic daily cannabis smokers.” Molecular psychiatry 17.6 (2012): 642-649.
- Vermersch, Patrick. “Sativex®(tetrahydrocannabinol+ cannabidiol), an endocannabinoid system modulator: basic features and main clinical data.” Expert review of neurotherapeutics 11.sup4 (2011): 15-19.
- Copersino, M., et al. Cannabis Withdrawal among Non-treatment-seeking Adult Cannabis Users. American Journal of Addictions (2006) 15: 8-14
- Crippa, J. A. S., et al. “Cannabidiol for the treatment of cannabis withdrawal syndrome: a case report.” Journal of clinical pharmacy and therapeutics 38.2 (2013): 162-164.