Proposition 19 (the Regulate, Control and Tax Cannabis Act of 2010) falsely claims that “Cannabis is not physically addictive.” Whether California voters choose to legalize marijuana or not, the myth that marijuana does not present the potential for being addictive, especially to adolescents and children, has been completely “busted” by scientific research from around the world. Whether the supporters of Prop 19 continue to make their false claims out of ignorance of the scientific facts, or wishful thinking, it is important for you to be well informed before casting your vote this November 2.

There are four separate lines of research that prove marijuana has all the characteristics of an addictive drug.

1. Neuroscientists have demonstrated that marijuana affects the brain’s Reward Center in exactly the same way as all other known drugs of addiction.
2. Animal studies have demonstrated consistent patterns of behavior when THC, the main active ingredient in marijuana, is given twice a day for one week and then suddenly withdrawn.
3. Clinical reports of humans reveal a similar pattern of withdrawal symptoms during the first weeks of abstinence, including:

Common symptoms

• Decreased appetite or weight loss
• Irritability
• Nervousness/anxiety
• Restlessness
• Sleep difficulties, including strange dreams and EEG changes

Less common symptoms/equivocal symptoms

• Chills
• Depressed mood
• Stomach pain
• Shakiness
• Sweating
• Anger or aggression

4. Epidemiologists have found that ~9% of people who begin smoking marijuana at 18 years or older satisfy the criteria for dependence. This number triples at ages under 18. The rate of dependence among near daily users is estimated to be 35-40% for dependence at some time in their lives.

As physicians, CSAM strongly supports the use of treatment for substance abuse rather than incarceration and recognizes the public’s right to decide the issue of marijuana legalization through the legislative process. The fact that marijuana is clearly addictive for a minority of people, and especially so for adolescents and children, does not mean that the public does not have a right to legalize its use.

However, a well informed public is a prerequisite to making good policy, and perpetrating the myth that marijuana is not addictive is a disservice to the significant minority of users who do become addicted. Legalizing another addictive drug, in addition to those already legal, is a matter for public health debate and not merely political debate. Unlimited access to marijuana will have health consequences for some, and these consequences will have to be dealt with by us all. The public needs to be aware of the addictive nature of marijuana and prepared to create an effective public health, prevention and treatment response to what will undoubtedly be an increase in marijuana use, to the detriment of a significant minority of users, if California chooses to vote for legalization

Readers who are interested in more detailed information can find a full list of references and abstracts documenting the facts presented above in the section on marijuana addiction for healthcare professionals.