Pain: Cannabis Withdrawal Syndrome

Research shows that 40% of individuals using cannabis recreationally report withdrawal symptoms. In an effort to shed some light on these symptoms in individuals using cannabis for pain management, researchers at the University of Michigan Addiction Center conducted a prospective study on a cohort of 527 adults who used cannabis to manage chronic pain. All participants were Michigan residents; 82% were white, and 49% identified as male, with an average age of 45.6 years. Participants were certified by the state of Michigan to use medical cannabis for non– cancer-related pain management.

A 15-item assessment tool was used to measure withdrawal symptoms, such as sleep difficulties, headache, nausea, anxiety, irritability, and anger. The study examined baseline cannabis withdrawal symptoms and empirically grouped patients into groups based on whether they had zero to mild symptoms, moderate symptoms, or severe symptoms (meaning they had most or all of the symptoms on the assessment tool). After the initial baseline assessment was completed, participants filled out the questionnaire at 12 months and again at 24 months, retroactively assessing withdrawal symptoms experienced when they discontinued cannabis use for any significant length of time (the amount of time that needed to elapse to constitute a significant amount of time wasn’t specified, as it varied by individual).

Analysis of baseline reports showed that about 41% of participants experienced zero to mild withdrawal symptoms, typically reporting sleep difficulties and cannabis cravings. Thirty-four percent of study participants experienced moderate symptoms, including sleep difficulties, cannabis cravings, decreased appetite, irritability, restlessness, and anxiety when reducing or ceasing cannabis consumption. Finally, 25% of participants experienced severe symptoms, including all symptoms on the 15-item assessment tool except sweating. Sleep difficulties were found across all three groups.

During the two years tracked by the study, approximately 10% of study participants reported an increase in their withdrawal symptoms with continued cannabis use (meaning they continued to use cannabis to cope with their withdrawal symptoms, which made their withdrawal symptoms worse, causing a cycle of cannabis use and withdrawal). The majority of individuals with mild withdrawal symptoms didn’t experience worsening symptoms over the two years studied, and individuals with moderate withdrawal symptoms were more likely to experience improvement in their symptoms than were those in the other two groups.

The study demonstrated that the duration of cannabis use was related to withdrawal symptom severity—the higher the frequency of use, the more severe the withdrawal symptoms. Similarly, individuals consuming higher doses of cannabis for longer periods of time also reported more severe withdrawal symptoms.

Researchers also found that participants with the most severe withdrawal symptoms were more likely to be younger in age and have poorer mental health.

Cannabis Withdrawal Syndrome
The results of the analysis demonstrate that cannabis consumption isn’t without consequence, despite being hailed as a safe drug; cannabinoids act on the endocannabinoid system and affect the brain. If cannabis is used consistently and then stopped, the brain will react to its absence, as seen by the withdrawal symptoms reported by participants in this study.

Lara Coughlin, PhD, is the addiction psychologist who led the research study. In light of her experience working with patients as part of University of Michigan Addiction Treatment Services as well as the findings of the study, she recommends that patients who utilize cannabis for medical reasons be informed of the risk of cannabis withdrawal syndrome.

Though preventing withdrawal symptoms was “beyond the scope of the study,” according to Coughlin, she explains that clinicians should practice harm reduction techniques such as monitoring the frequency and quantity of cannabis used by their patients for pain management. Patients should also be educated on withdrawal symptoms and encouraged to report signs of withdrawal as soon as they experience them. Such harm reduction techniques also include educating patients on the potency of THC products and the warning signs of potential cannabis dependency, including the need to increase the dose and potency of cannabis to achieve the same effects experienced at the onset of use.

Furthermore, though cannabis withdrawal symptoms can be severe and affect daily life, they’re different from opioid and alcohol withdrawal symptoms. According to Coughlin, “opioid withdrawal is very intense, and alcohol is the most life-threatening. Cannabis withdrawal isn’t a medical concern in the same way, but it is a negative experience. There’s the concern that people will use more cannabis to avoid the withdrawal symptoms, and they enter a cycle, perpetuating more withdrawal symptoms. This can influence psychological health and functioning and interfere with daily activities, including operating vehicles and performance at work.”

Additionally, it appears that the type of cannabis consumed can affect withdrawal symptoms. The study found that a higher percentage of people who smoked cannabis were in the “severe” withdrawal category at baseline compared with the moderate and zero to mild withdrawal categories. “We didn’t see this same association in people who vaped, who reported eating cannabis, or who used it topically. We did note that some people smoked, vaped, and ate cannabis—so that’s the caveat to our finding.”

Moreover, Coughlin and her research team found that people who vaped were significantly less likely to transition into a less severe withdrawal category, and that younger people were more likely to transition to a more severe category than older individuals.

For the most part, Coughlin explains, individuals who discontinued cannabis use and didn’t resume it during the two-year study period saw their withdrawal symptoms disappear after a few weeks. Aside from frequency and dosage, it’s unclear why some people have worse withdrawal symptoms than others. “We don’t know why people have more symptoms or not,” Coughlin says. “It could be their predisposition, but it also has to do with use dosage. The bad news is that if you had severe withdrawal symptoms at start of study, then it’s pretty likely you’ll experience pretty severe withdrawal symptoms throughout.”

Implications of Research Findings
Though this study evaluated patients using medical cannabis under the supervision of a medical professional, the findings hold immense value for individuals in states where cannabis is legalized and who use it to manage pain on their own.

“My biggest goal from this study is to educate those who are using cannabis and then go without cannabis and experience withdrawal symptoms—that they should consider that their symptoms are related to their cannabis use and not related to underlying conditions,” Coughlin says.

“I want people to get curious about what might be actually causing their symptoms. In some cases, withdrawal symptoms might be from reducing cannabis use and might not be in any way related to their chronic pain conditions. In those cases, using more cannabis won’t make those symptoms go away.”

Coughlin also notes that there isn’t sufficient medical evidence to determine whether cannabis is an effective long-term tool for chronic pain management. “The science hasn’t caught up with the daily practice of cannabis use yet. That information may be forthcoming,” she says. “Behavioral pain management has the best empirical support as an option for chronic pain management.”

According to Coughlin, psychosocial treatment, such as cognitive behavior therapy, should be offered as an alternative for those struggling with chronic pain. Cognitive behavior therapy is a form of empirically supported treatment that’s been tested in randomized control trials. “It’s a way to help people manage their pain and thoughts that can lead to catastrophizing,” Coughlin says. “Cognitive behavior therapy can also help people to make sure they continue to engage in behaviors in their day-to-day life, where they’re getting physical activity at a paced rate so their pain doesn’t increase over time. Physical activity and cognitive restructuring are crucial, because they help people not let their pain be the primary focus of all their decisions.”

— Sandeep Kaur Dhillon, MS, RDN, received her master’s degree in nutrition and exercise physiology from Columbia University. She completed her dietetic training in New York City and practices as a dietitian in Los Angeles.