The argument surrounding whether cannabis is addictive or not remains controversial because, to put it bluntly, the answer is both yes and no. Yes, in the same way gambling, stealing, or eating sugary foods can become habitually addictive; and no on the basis that marijuana does not cause the kind of physiological cravings, self-destructive behaviors, or neurological changes that alcohol, narcotics, and other substances can. To discuss whether cannabis is addictive we must first understand what true addiction is and the different ways we experience it – complex topics themselves.
The American Society of Addiction Medicine characterizes addiction as an “inability to consistently abstain” from a substance or behavior, and we could go on for hours listing the things we humans have shown incapable of leaving alone without some serious self-restraint. It is in this sense that people (some estimate about 9 percent of users) can develop a habitual addiction; an “impairment in behavioral control” that makes it harder for them to stop using cannabis than others. Also, the National Cancer Institute tells us that “although cannabinoids are considered by some to be addictive drugs, their addictive potential is considerably lower than that of other prescribed agents or substances of abuse.”
This type of mental dependency is not the same thing as the out-of-control physical addiction some people experience with opiates, alcohol, benzodiazepines (Xanax), and other substances. The National Institute on Drug Abuse labels drug addiction as “a chronic, relapsing brain disease that is characterized by compulsive drug seeking and use despite harmful consequences,” and categorizes addiction as a brain disease because “drugs change the brain...structure and how it works.” We see this in addicts who have to take increasingly large amounts of a substance to get the desired effect, will do anything necessary to obtain that substance, and then experience uncomfortable or debilitating symptoms, such as increased blood pressure, organ failure, hallucinations, and even premature death, when abstaining from it.
Another attribute the ASAM gives to addiction is that “without treatment or engagement in recovery activities, addiction is progressive and can result in disability or premature death.” At this time simply no evidence exists to show that cannabis use progressively leads to any disability, and it hasn't been the cause of a single death. However, it is also widely recognized that some marijuana consumers experience mild physiological signs of withdrawal when they stop using cannabis, such as irritability, nausea, and insomnia, but these symptoms are typically only experienced for a few days by chronic users who quit cold turkey.
To close, people experience addiction differently (with environmental and cultural factors, genetics, one's current mental state, and learned personal resilience all playing a part) and proper research into the long-term effects of marijuana use has yet to happen. We haven't even touched on the neurobiology of addiction and how our brains can convert positive, rewarding experiences into detrimental, addictive behaviors, but we can move forward knowing that cannabis is no more addictive than your favorite snack.