It cannot be repeated too often that about half the people with a substance use disorder also have a mental illness or, more correctly, another mental illness. According to the National Institute on Drug Abuse (NIDA), “drug addiction is a mental illness.” When a patient has a mental illness and a substance use disorder at the same time, they are said to comorbid, co-occurring disorders, or a dual diagnosis.

Usually, the terms are used for a SUD coupled with depression, anxiety, mania, or schizophrenia. but it could also be applied to two SUDs, two addictions. Substance use disorder clinicians are trained to look out for dual diagnosis because too often only one condition is noted and treated, which results in the second condition not being treated. If the two conditions are related or connected somehow, leaving half the problem untreated could allow the first condition to return.

Which makes it puzzling that more than half the mental hospitals and almost two-thirds of substance use disorder treatment centers allow tobacco to be smoked, though it is more addictive than heroin, cocaine, and alcohol. (More people die of smoking-related causes than substance use disorder.) Worse, it is available everywhere.

I imagine that the thought process goes something like: It is more important that they stop drinking/shooting heroin/popping prescription painkillers. After they have their more serious addiction under control, then they can work on kicking tobacco.

That is a poor excuse from the dual diagnosis viewpoint. Comorbid disorders may be related. Both need to be treated at the same time.

Also, smoking causes cancer. That is, smoking tobacco causes cancer. Smoking marijuana doesn’t seem to be related to higher incidents of cancer than those who don’t smoke at all (though there is a roughly equal risk of some respiratory problems). There is some evidence that marijuana has anti-cancer properties, as well as anti-opioid properties –at least, where medical marijuana is legal, there seem to be fewer opioid overdose deaths, and at least one clinic now uses cannabis as a treatment for opioid addiction.

I haven’t heard of many mainstream substance use disorder clinics allowing patients to smoke pot any more than they allow patients to get drunk.

Yes, marijuana can get you high, which doesn’t seem to be true of tobacco, but is euphoria worse than cancer? The gateway drug argument against marijuana has long been discredited, though some hold onto it tightly.

Marijuana is still too unknown a quantity among professional health professionals due to the limits to research that have hobbled scientific study. I get that. But tobacco is a well-known quantity, proven deadly and habit forming. Most young p[eople start using tobacco and alcohol before they start using pot. Those may be the real gateway drugs.