Medical Examiner

Cannabis Addiction Is Not Heroin Addiction. That Doesn’t Make It Any Less Real.

A large minority of people have trouble with cannabis, and for those people, it’s important to find help.

A joint of marijuana.
Photo illustration by Slate. Photo by Thinkstock.

When I tell people that I am a clinical psychologist who treats people with cannabis addiction, the response that I receive can often be disbelief. “Marijuana is a natural and medicinal plant,” people tend to voice. Versions of this argument can also be found in almost every comment section of any cannabis-related news story. This is correct—cannabis is natural. Cannabis can also have medicinal benefits for problems such as certain kinds of pain and chemotherapy-induced side effects. There is even upcoming research on the use of cannabis and cannabis derivatives in the treatment of particular psychiatric disorders, such as those involving post-traumatic stress, anxiety, and depressive symptoms (though this is both a complex and contentious area of research). Nevertheless, the fact that cannabis can have medical benefits does not preclude its propensity for addiction. Neither does the fact that cannabis is natural—so are opium, coca leaves, poison ivy, and dirt. Cannabis can be helpful, and it can also be addicting.

Cannabis addiction is not pervasive, but it is also not uncommon. Our best estimate, based on conditional prevalence rates, is that, approximately 1 out of 10 people who ever try cannabis at least once during their lifetime will likely become addicted. Put another way, this means that about 90 percent of people who try cannabis do not become addicted. While the chances of becoming addicted to other drugs can be higher, such as to alcohol, cocaine, heroin, and nicotine, the story is similar with cannabis: The majority of people who try these drugs do not become addicted. As you might expect, however, the more frequently that a person uses cannabis (and other drugs), the more likely they are to develop an addiction. This should make intuitive sense: Most of the people whom you know who use cannabis are likely not addicted, but you might know one or two people where you question whether they might have a cannabis problem, particularly if they use it frequently.

As a clinical psychologist who has extensively studied and treated patients with cannabis addiction for the past 10 years, I have had a front-row seat to the many polarizing views about cannabis among people throughout the world. While cannabis has been idealized by some cultures and societies, it has been demonized by others; Western society has tended to waver between both extremes. As a result of this variability, the legal status of cannabis has also been fluid. Indeed, part of the reason for this variability might stem from the fact that cannabis can be both beneficial and harmful. Consequently, debate surrounding cannabis is often emotionally charged. When I attend social gatherings, people can be keen to express their extreme views on cannabis to me in hopes that I might validate their position. When I was a graduate student, I received both praise and scorn for my role as the lead investigator of a cannabis-addiction study via emails, internet comments on news stories in which I was referenced, and even telephone voicemails. The messages that I received were often misinformed and unbalanced compared to the information that is available in the scientific literature.

So what does cannabis addiction look like? Well, it has similarities and differences to other kinds of addiction. The term addiction itself has a rich history and has been defined in a multitude of ways. Addiction can be thought of as a brain disease accompanied by physiological dependence, which can include tolerance and withdrawal features, and changes in brain-reward circuitry. At another level of analysis, addiction lives at the intersection of psychological and social phenomena, and can consist of features such as cravings, a sense of loss of control, compulsive use, negative consequences, habitual behaviors, and functional impairment. The biopsychosocial aspects of cannabis addiction are captured well in the diagnostic criteria for cannabis-use disorder in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, aka the DSM-5. Importantly, as with other addictions, the DSM-5 includes severity specifiers that range from mild to severe, which is a nod to the idea that an addiction can vary in its strength.

In all likelihood, you will not directly die from cannabis addiction. You will never look like Leonardo DiCaprio in The Basketball Diaries squirming around on the floor with intense flu-like symptoms and the debilitating pain of an opioid withdrawal. But if you meet diagnostic criteria for a cannabis-use disorder, it is possible that you could lose your close relationships, experience difficulties at work or school, and experience worsening of mental health symptoms, such as anxiety and depression. The cannabis-withdrawal syndrome is not a heroin withdrawal, but it is akin to a nicotine withdrawal, which is meaningful because it can be a barrier to liberating people from the ball and chain, so to speak.

People with cannabis addiction often use cannabis to escape from their emotions. This robs their brain of the opportunity to practice coping with emotions in healthy ways. As a consequence, the brain becomes classically conditioned or trained to respond to difficult emotions by using cannabis. It is as if your brain salivates for cannabis every time you feel anxious, or sad, or angry, just like a dog might salivate when it hears a bell that signifies food.

It is worth knowing that what causes cannabis addiction is not exactly clear. We know that it is a multicausal, complex picture that involves the interaction of both genetic and environmental influences. Further, many (but not all) people with cannabis addiction also have other concurrent addiction and mental health concerns.

Like most things in life, cannabis addiction is not a straightforward, black-and-white concept. It is nuanced, gray, and has multiple components. I happen to provide treatment in a hospital setting to the minority of people who use cannabis and also have a cannabis addiction. It must be stressed, however, that this minority of people is a large minority given the widespread use of cannabis. My research and clinical experience has revealed to me that people with cannabis addiction can experience both confusion and stigma in society and even within addiction-treatment programs. My aim in shining a light on this issue is to help validate the experience of those people who feel unable to control their cannabis use. It is important for people with cannabis addiction and the general public to understand that cannabis addiction is not trivial, and that there is solid treatment available.