Oh yeah, this old debate. Well, here are the key questions:

  • If cannabis is addictive, why are some people able to use it without apparent problems?
  • if cannabis isn’t addictive, then why do other people wind up in addiction treatment, seeking help for drug problems that prominently feature cannabis?

Riddle me that, Batman. The best answer is the one we came up with explain the selectivity of alcoholism: Differences in individual susceptibility.

Cannabis is addictive, yes. But not everybody who uses it will become addicted. Genes play a role, and regular use over time, and possibly even the THC content of cannabis, which appears to be ever-increasing.

There’s also persistent confusion over the use of the terms addiction and dependence. When the average Joe thinks of addiction, it’s mainly in terms of an inability to stop without withdrawal discomfort. But that’s closer to a definition of dependence, which can, we’re told, occur as an independent syndrome, with or without other symptoms of addiction.

As for cannabis withdrawal, it’s real. Usually found among chronic users, it includes a host of familiar symptoms, ranging from anxiety and insomnia to nausea and stomach pains. Discomfort may persist for a month — perhaps not as severe as with opioids or alcohol, but still subjectively significant. Here’s a reference from the National Center for Biotechnology Information.

The other trademark features of addiction– powerful cravings, loss of control, continued use despite adverse consequences — can occur in the absence of withdrawal. So a counselor might encounter a patient who was experiencing significant life problems associated with marijuana use, yet did not appear to experience withdrawal upon cessation of drug use.

Anyway, the theory goes like this: some human beings, through a combination of genetics and environment and probably bad luck, are vulnerable to cannabis use disorders, just as some drinkers are vulnerable to problems with alcohol. The bad news is we have no foolproof way to predict which of us have that vulnerability. As a result, we learn through experience — often the most painful sort.

Oh, there are clues– if you have a family history of addictions, for instance, you might want to watch out. But that’s easy to ignore if you’re young and interested in experimentation. Maybe someday medical science will come up with blood test or the equivalent that allows us to assess risk for future difficulties with substances.

Some day…