Study of 23,000 marijuana users reveals 3 types of people at risk of withdrawal

People smoke marijuana for lots of reasons, from breaking up workouts to calming anxiety. But if they quit, some get more than they bargained for.

Weed withdrawal is not only real: it happens to more people than you might think.

In a review of 47 studies on cannabis use, researchers estimate that 47 percent of people who quit experience some cannabis withdrawal symptoms. These include, but are not limited to, irritability or aggression, anxiety, and sleep disturbance.

Together, the studies involve 23,518 people who were regular or dependent cannabis users.

In specific populations, the odds of experiencing withdrawal may be far higher, the analysis suggests. Some 87 percent of regular marijuana users living in in-patient psychiatric facilities met criteria for cannabis withdrawal. Other groups have far lower odds of withdrawal. Just 17 percent of regular marijuana users in the general population tended to meet the criteria.

The analysis was published Thursday in JAMA Network Open.

Cannabis withdrawal isn't well known, or well understood by scientists, the paper's first author, Anees Bahji, says. Bahji is a psychiatry resident at Queen's University in Kingston, Ontario.

Part of the reason why is because scientists have only just started to research this kind of drug withdrawal. But it may also be due to another factor: People may not take marijuana withdrawal very seriously.

"There might be a sense that cannabis use disorder and CWS are not “real” addictions. If this is true, then there might be some trivialization of CWS," Bahji tells Inverse.

What are the symptoms of cannabis withdrawal?

This review pools data from 47 past studies to estimate how many regular marijuana users suffer from cannabis withdrawal symptoms when they quit. It also shows why some marijuana users have higher risks than others do.

Bahji and his colleagues relied on the definition of cannabis withdrawal symptom that appears in the Diagnostic and Statistical Manual of Mental Disorders, a book that catalogs all recognized psychological conditions, to take another pass at the data gleaned from those 47 studies.

To meet the criteria for a diagnosis of cannabis withdrawal as defined by the Diagnostic and Statistical Manual of Mental Disorders, someone has to have experience at least three of the following symptoms within one week of quitting cannabis:

• Irritability, anger, and aggression
• Nervousness, or anxiety
• Sleep problems
• Changes to appetite, or weight
• Restlessness
• Depressed mood
• Headaches, sweating, nausea, or abdominal pain

These features characterize a number of conditions, which means doctors might misdiagnose withdrawal as a different psychiatric condition. Some are the very reasons people turn to smoking weed in the first place (sleeping problems jump to mind, even if it's not a sustainable solution).

But the criteria enabled Bahji and his colleagues to approximate how many people in the 47 studies had weed withdrawal symptoms, and, more importantly, discover who may have greater risk of experiencing them.

The prevalence of cannabis withdrawal was highest amongst people who were admitted to psychiatric units, at 87 percent. In outpatient facilities, 54 percent of people met the criteria.

This suggests cannabis withdrawal may disproportionately affect people who are already struggling with other psychological conditions, though this study can't rule out how those conditions played a role in the symptoms, Bahji says.

There were also significant correlations between cannabis withdrawal symptoms and regular use of other drugs, like tobacco. Numerous studies report that concurrent use of marijuana and tobacco is common. A small study on 179 people suggests the use of one drug significantly increases the probability of using the other.

These data hint dual use may play a role in withdrawal symptoms, but the review isn't designed to answer why.

How often you use marijuana probably makes a difference, too, Bahji says.

"The risk appears to be higher with higher amounts of cannabis use," he says.

"Daily cannabis use might be more likely to be associated with CWS than intermittent use."

Can you treat cannabis withdrawal?

The United States' Food and Drug Administration has not approved any drugs for the treatment of cannabis use disorder. Withdrawal symptoms are, in themselves, a symptom of that disorder.

But that doesn't mean there are no options on the table.

A 2019 clinical trial published in JAMA Internal Medicine found that regular smokers who took nabiximols (a cannabidiol-based mouth spray) ended up smoking 18.6 fewer days at the end of the experiment compared to those who took a placebo.

At the time, Nicholas Lintzeris, an addiction medicine specialist at the University of Sydney School of Medicine told Inverse that CBD-based medicines may have potential for treating marijuana use disorder, along with therapy.

For now, therapy-based approaches to treatment show the most promise, Bahji says.

"Aside from medications, there is actually more evidence for psychological treatments at this time," he says.

In the future, he and his team want to widen the options available to people who might not respond to therapy. They are designing a trial to investigate more drug-based treatments for withdrawal.

Given the results of this review, there may be many more people looking for new treatments out there than we thought.

Partial Abstract:

Study Selection: Articles were included if they(1) were published in English, (2) reported on individuals with regular use of cannabinoids or cannabis use disorder as a primary study group, (3) reported on the prevalence of CWS or CWS symptoms using a validated instrument, (4) reported the prevalence of CWS, and (5) used an observational study design (eg, cohort or cross-sectional).

Data Extraction and Synthesis: All abstracts, full-text articles, and other sources were reviewed, with data extracted in duplicate. Cannabis withdrawal syndrome prevalence was estimated using a random-effects meta-analysis model, alongside stratification and meta-regression to characterize heterogeneity.

Main Outcomes and Measures: Cannabis withdrawal syndrome prevalence was reported as a percentage with 95% CIs.

Results: Of 3848 unique abstracts, 86 were selected for full-text review, and 47 studies, representing 23 518 participants, met all inclusion criteria. Of 23 518 participants included in the analysis, 16 839 were white (72%) and 14 387 were men (69%); median (SD) age was 29.9 (9.0) years. The overall pooled prevalence of CWS was 47% (6469 of 23 518) (95% CI, 41%-52%), with significant heterogeneity between estimates (I2 = 99.2%). When stratified by source, the prevalence of CWS was 17% (95% CI, 13%-21%) in population-based samples, 54% in outpatient samples (95% CI, 48%-59%), and 87% in inpatient samples (95% CI, 79%-94%), which were significantly different (P < .001). Concurrent cannabis (β = 0.005, P < .001), tobacco (β = 0.002, P = .02), and other substance use disorders (β = 0.003, P = .05) were associated with a higher CWS prevalence, as was daily cannabis use (β = 0.004, P < .001).