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Managing Cannabis Use and Its Potential Risks

October 21, 2016

SAN ANTONIO—As regulations around cannabis continue to loosen, it is important for clinicians to work with patients who use it and help them reduce the potential risks, Psych Congress attendees were told.

“As much as we might not like our patients to use cannabis, the reality is many of them are,” said Andrew Penn, RN, MS, NP, CNS, APRN-BC, a member of the Psych Congress Steering Committee. “The genie is out of the bottle at this point and we are effectively working and living in a post-Prohibitionist world whether we like that or not.”

“Just telling people to not use it isn’t good enough. We need to do better than that,” he said. “We need to be good guides and shepherds for our patients to help them understand what the risks are and how to minimize those risks.”

Strategies for Engaging With Patients Who Use Cannabis

Although 24 states had some degree of legalization of cannabis prior to November’s election, and 5 states voted in November on changes to their laws, it is unclear whether usage rates have been rising among adults, and, if so, by how much. Penn cited 2 national surveys that both found an upward trend in adult usage, but with widely different amounts; one found a 131% increase from 2001 to 2013, and the other reported a 19% increase from 2002-2013.

But among young people, the number of users remains relatively flat. They are not starting any younger, but those who are using cannabis are doing so more frequently, said Penn, Psychiatric Nurse Practitioner at Kaiser Permanente in Redwood City, California. 

“What this tells me is we really have an opportunity to get better with our education,” he told the crowd of mental health professionals. “That upward trend correlates with a perception that cannabis does not pose any great risk, and that is an issue that I would take issue with.”

Andrew Penn, RN, MS, NP, CNS, APRN-BC, presents a talk on cannabis at Psych Congress
Credit: Terri Airov

Penn explored several “harm reduction” strategies clinicians can use to help limit the possible side effects of cannabis use, by using it less frequently, later in life, and through safer routes.

Penn emphasized the importance of getting young people who are interested in cannabis to wait until they are older to use it. He cited a study published in 2016 that found regular cannabis use in boys could raise their risk for subclinical psychotic symptoms. The risk increased by 21% for each year they used it, and, in some cases, persisted even after a year of abstinence. Another study, published in 2014, found that the onset of schizophrenia was 3 years earlier in patients with cannabis exposure.

Further, younger users are more likely than adults to become dependent on cannabis, and are more likely to see a larger drop in their IQ score than people who begin using it at an older age. Long-term dependence on cannabis is associated with downward socioeconomic mobility, a study published in 2016 found.

“This is really my take-home message for my patients. Cannabis isn’t going anywhere. If you can wait to start using it, the longer you wait, the better,” he said.

To help reduce the amount of cannabis being used by patients, Penn recommended having them track their intake using a simple log or a mobile app, or using a scale to set aside a designated daily amount.

Patients can also pay attention to the product labels on cannabis they purchase. Penn encouraged looking for a lower level of (–)-trans-Δ9-tetrahydrocannabinol, known as THC, and a higher level of cannabidiol, known as CBD, but warned labels aren’t always accurate. He advises patients to be very careful with use of concentrates, which can be made in unsafe environments, and synthetic cannabinoids, which are far more potent and can carry different dangers.

Cannabis edibles and vaporized cannabis can be safer routes, Penn said, and do not irritate the respiratory system. Patients starting to use edibles should begin with one serving or a low dose until they know how the product affects them, he warned. 

Penn also warned against threatening a relationship with a patient because of substance use, and encouraged clinicians to use respectful, neutral language when talking with patients. “The way we ask our questions is really important,” he said.

­–Terri Airov


“Cannabis: What do Mental Health Professionals Need to Know?” Presented at the 29th Annual U.S. Psychiatric & Mental Health Congress; October 21, 2016; San Antonio, TX.

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