Cannabis & Mental Health: Good Or Bad?

When it comes to readily-available non-prescription legal “downer” drugs (that is to say, drugs that promote relaxation rather than “uppers” that promote stimulation), the most popular are of course alcohol and cannabis.

We’ve written a lot more about alcohol than we have about cannabis—partly because there’s simply much more research available. While alcohol has been legal (and thus easy to research) throughout many wealthy nations for a long time, the “War on Drugs”—which did not at all reduce the use of drugs—really curtailed research for a long time, and now there’s a lot of catching-up to do.

As a result, we know that alcohol is very bad for pretty much everything, including mental health—in which category it promotes/worsens mood disorders, including depression, and while often used to self-medicate against stress/anxiety, its numbing effects are short-lived and soon give the user extra reasons to be stressed and/or anxious. And, of course, it’s addictive, which is not fabulous.

So, is cannabis better?

Let’s address the topic of addictiveness first. Contrary to popular belief, it is indeed possible to become addicted to cannabis, though the likelihood of developing a substance abuse disorder is lower than for alcohol, and much lower than for nicotine.

See: Prevalence of Marijuana Use Disorders in the United States Between 2001–2002 and 2012–2013

If you prefer just the stats without the science, here’s the CDC’s rendering of that:

Addiction (Marijuana or Cannabis Use Disorder)

However, there is an interesting complicating factor, which is age. One is 4–7 times more likely to develop a substance abuse disorder (any substance abuse disorder), if one starts use as an adolescent, rather than later as an adult:

See: Likelihood of developing an alcohol and cannabis use disorder during youth: Association with recent use and age

So, if you’re in the older age group, that’s a point in favor of reduced risk.

Does cannabis increase psychiatric disease risk?

It depends. Is it occasional use, or regular? There is a difference between using it relax and unwind once in a while, and relying on it all the time.

In the US, A 2021 report from the National Survey on Drug Use and Health showed (if we extrapolate the data to a population level):

• 52,000,000 people reported cannabis use in the previous year, of whom,
• 16,300,000 met the criteria for cannabis use disorder in the previous year

So, we may assume that around 1 in 3 cannabis users meet the criteria for cannabis use disorder.

Curious about who qualifies? The DSM-5 defines cannabis use disorder as the presence of at least 2 of the following:

• Withdrawal symptoms when not using cannabis
• Cannabis is taken in larger amounts or used over a longer period than intended
• Persistent desire to cut down with unsuccessful attempts
• Excessive time spent acquiring cannabis, using cannabis, or recovering from its effects
• Cravings for cannabis use
• Recurrent use resulting in neglect of social obligations
• Continued use despite social or interpersonal problems
• Important social, occupational, or recreational activities foregone to be able to use cannabis
• Continued use despite physical harm
• Continued use despite physical or psychological problems associated with cannabis use
• Tolerance

Source: DSM-5 Criteria for Substance Use Disorders: Recommendations and Rationale

Now, with that in mind…

Researchers examined the genetic links between cannabis use, cannabis use disorder, and psychiatric conditions, and found:

• Cannabis use disorder showed strong associations with nearly all psychiatric disorders, while
• Cannabis use (not disorder) had much weaker associations, and/but showed significant links with openness and conscientiousness.

So, that’s quite a difference. But since this is a matter of genetic links (i.e. people with these genetic marks tend to have these matching traits), it’s not always immediately clear which way the causality goes, if any:

• Does the genetic marker promote cannabis use / cannabis use disorder / linked psychiatric condition(s)?
• Does the the cannabis use / cannabis use disorder cause the psychiatric condition?
• Does the psychiatric condition promote the cannabis use / cannabis use disorder?

Using a statistical technique called Mendelian randomization, some of the causality can be determined (depending on the data available, of course). Using this method, it can be known that:

• Cannabis use disorder has bidirectional causal links with psychiatric disorders, especially schizophrenia and related disorders, as well as ADHD, BPD, and PTSD.
• Major depressive disorder has the strongest reverse causal effect on cannabis use disorder. This means that people with major depressive disorder were more likely to go on to also develop cannabis use disorder.
• Cannabis use without disorder showed far fewer causal links—mostly just the non-causal links with the traits of openness and conscientiousness*.

*we might hypothesize that a person scoring highly (so to speak) on openness is more likely to try cannabis than those with lower scores on openness, and a person scoring highly (as it were) on conscientiousness is less likely to go on to develop a substance use disorder than someone with lower scores on same. However, the statistical modelling was not able to conclusively demonstrate this.

You can read the paper in full, here: The genetic relationship between cannabis use disorder, cannabis use and psychiatric disorders

Are there benefits?

The biggest benefit is “it’s a lot safer than alcohol” when one wants a way to relax and wind down, which means that it can indeed alleviate stress and anxiety—occasionally. If you’re using it all the time, however, then you may start running into the problems of feeling more stressed and anxious in its absence, of course.

Many use it for pain relief, and if that’s you, only you can judge whether the benefits outweigh the risks (and presumably you’ve concluded they do).

Many use it for sleep (indeed, it’s even sometimes prescribed for some sleep disorders), and we’ve written about that here: Sweet Dreams Are Made of THC (Or Are They?)

In the latter case, it’s worth bearing in mind that CBD alone (without THC) does seem to improve sleep (as discussed in the above-linked article), and has additional benefits too:

CBD Oil: What Does The Science Say?

Prefer a drug-free way to relax?

We recommend:

• No-Frills, Evidence-Based Mindfulness
• Meditation Games That You’ll Actually Enjoy
• Which Style Of Yoga Is Best For You?
• 7 Kinds Of Rest When Sleep Is Not Enough
• Better Sex = Longer Life (Here’s How)

Enjoy!