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Addictions Advisor: Teens and Cannabis Use
By Sue Coyle, MSW
Social Work Today
Vol. 17 No. 6 P. 5

The messages surrounding marijuana use are, to say the least, a mixed bag. There are those who support legalization and those who vehemently oppose the idea. There are those who tout cannabis' medical benefits and those who declare it a gateway drug, leading to the use of "harder" substances.

The truth about cannabis is likely neither all pro nor all con, but to know the exact degree of each requires ongoing research into the effects of varying use levels on multiple populations.

One of the most critical groups to study in relation to cannabis use is the adolescent population.

Why? For one, they are using it.

"Alcohol, marijuana, and tobacco are generally the substances young people use first, not so much as a gateway but because those are the 'acceptable' substances in our society," says Joseph Lee, MD, ABAM, medical director of the national nonprofit addiction treatment provider Hazelden Betty Ford Foundation's Youth Continuum. "Some kids who experiment with various substances don't develop problems, though they may still suffer adverse events. Others do develop problems, and sometimes, it's harder to reach them because they take the current cultural rhetoric and twist it around to rationalize their use."

Added to that, young adulthood is a time of critical development and maturation. "Adolescence is a period of intense brain development, involving a pruning of neurons in certain areas and myelination of other neurons—which improves the speed and efficiency of neural communication," explains Susan Weiss, PhD, director of the division of extramural research. The sentiment is shared by Gaya Dowling, PhD, director of the Adolescent Brain Cognitive Development (ABCD) Study at the National Institute on Drug Abuse, part of the National Institutes of Health. (Weiss and Dowling spoke with Social Work Today together.)

"It is also a time of significant social and emotional development, and demanding intellectual/academic performance. Exposure to substances during this period could therefore have long-lasting (perhaps permanent) effects on how the brain develops and how the individual develops within his/her environment," Weiss continues.

At such a critical time, negative effects can compound, leading to additional adverse outcomes. Weiss notes that the effects of marijuana on motivation, learning, and memory, for example, may contribute negatively to one's academic outcomes, as well as their mental health.

Fortunately, there are numerous studies being conducted today that aim to help everyone—professionals and adolescents and their support systems—better understand the impact cannabis can have on a young brain.

ABCD Study
On perhaps the largest level is the ABCD Study, a long-term study just now in the recruitment stages. "We will be assessing children beginning when they are 9 and 10 years old repeatedly through adolescence and into young adulthood to see how the many experiences during this period interact with a child's changing biology to affect brain, social, emotional, cognitive, and academic development," Dowling says. "The study includes comprehensive assessments of physical and mental health, substance use, culture and environment, neurocognition, as well as structural and functional brain imaging, and biospecimen collection for environmental, hormonal, and genetic analyses."

Other studies have looked at similar factors but on smaller, shorter-term bases. The ABCD Study will be the most comprehensive study of its kind to date. Furthermore, by starting research when youths are 9 or 10, the ABCD researchers are more likely to have the ability to document the difference in a youth's development prior to and after the start of cannabis use.

"Importantly, this study will begin collecting this vast amount of information among children before most of them have begun to use substances, allowing us to characterize risk and resilience factors, as well as the impact of cannabis and other drug use on development," Dowling notes. "Ultimately, we hope that understanding the relationships between and among these experiences and their effects on the growing brain will provide actionable information to help educators, parents, policymakers, and health professionals improve the lives of children."

Additional Research
As the ABCD Study gets underway, there are many more smaller-scale studies looking at the effects of cannabis use on teens already in further stages or completed. For example, Josiane Bourque, a PhD candidate in psychiatric sciences at the University of Montreal, recently took part in a study that examined the effects of increased marijuana use on an adolescent's risk of psychoticlike experiences.

"Psychoticlike experiences are defined as perceptual abnormalities (mild auditory or visual hallucinatory experiences), delusional thoughts (another part of your personality takes control of your reactions), feelings of being observed [or] spied on, [and] feelings of being disconnected from everybody," Bourque says.

"Such experiences may be infrequent and thus not problematic for the adolescent," she continues. "Therefore, they fall well below diagnostic criteria of psychosis according to the DSM. However, we know from various longitudinal studies that followed these individuals that when these psychoticlike experiences are reported continuously, year after year during adolescence, then there's an increased risk of a first psychotic episode or another psychiatric condition."

Though not the initial aim of the study, Bourque and her colleagues found that marijuana use was connected to an impaired development of inhibitory control. Inhibitory control is the ability to focus on relevant stimuli while not focusing on irrelevant stimuli. It prevents an individual from acting without thought.

Additionally, the research showed that the amount of marijuana used impacted the adolescents. "In our study, we evaluated the increase or growth in marijuana use for each individual, and we found that the steeper the growth in cannabis use, the more likely participants would report increasing psychoticlike experiences," Bourque describes.

Discovering these effects is just a first step, Bourque notes. "With this study, we have a better picture of how at-risk youths are doing. We now know that approximately 8% of the general youth population report persistent and even increasing psychoticlike experiences, increasing anxiety and depression symptoms, as well as steep growth in marijuana use during high school, such that by the age of 16 the rates of using cannabis are double the rates in the rest of the sample," she says. "All this information can help us target the main component of a future preventive program: delaying substance use, giving coping skills for depressive thoughts and anxiety, normalizing psychoticlike experiences, etc."

Moving Forward
It's not just Bourque's study that serves as a first step; there is much research being done and much more to be done before the effects of cannabis on adolescents and other populations can be fully understood.

For example, "[The ABCD] study is focused on adolescents, who may be among the most vulnerable to cannabis' negative effects," Weiss says, "but there are clearly other populations, including pregnant women (who are using more now than in the past) and older populations, who may be taking multiple medications for chronic illnesses that also merit further investigation. And we need to be balanced in our approach to understand myriad effects that cannabis legalization for medical or recreational use has on our society."

As the research continues to progress, social workers are tasked with determining how to work with adolescents (and adults) in reference to marijuana use. This can be difficult, as research is not often the loudest and first voice heard by teenagers. With that in mind, clinicians have to balance being informed of research with being aware of a client's needs.

Weiss recommends looking at the National Institute on Drug Abuse (NIDA) website to gather information on current research. When working with adolescents, NIDA suggests being up-front about the effects of marijuana use. "Cannabis may put their future at risk—it is linked to poorer educational outcomes, increased risk of certain mental illnesses, increased risk of addiction (compared to those who start as adults).

"Of course, not everyone is equally affected, but it is not always easy to determine who is most at risk," says Weiss.

Additionally, Lee advises being aware of the individuality of each youth and meeting them where they are. "Clinicians have to be sophisticated," he says. "They can't have a one-size-fits-all message. They have to understand the concept of risk and trajectory for young people, see who the high-risk kids are, and tailor the message and therapeutic approach for the individual.

"While clarifying myths and facts helps, it's most important to understand a young person's values," he continues. "The young people we see decide to change because there's a dissonance between their values and how they're living. We help them see that, and that's what motivates change about their substance use."
It is not an easy task, but as the research continues and more is learned about the effects—both good and bad—of cannabis on adolescents, social workers will be increasingly equipped to best serve their clients.

— Sue Coyle, MSW, is an award-winning freelance writer, a social worker in the Philadelphia suburbs, and frequent contributor to Social Work Today.



About one-quarter of adults whose marijuana use is problematic in early adulthood have anxiety disorders in childhood and late adolescence, according to new data from Duke Health researchers.

The findings, published in the November issue of the Journal of the American Academy of Child and Adolescent Psychiatry, also shed light on an estimated 4% of adults who endured childhood maltreatment and peer bullying without resorting to chronic marijuana abuse, only to develop problems with the drug between the ages of 26 and 30.

"Given that more states may be moving towards legalization of cannabis for medicinal and recreational purposes, this study raises attention about what we anticipate will be the fastest-growing demographic of users—adults," says lead author Sherika Hill, PhD, an adjunct faculty associate at the Duke University School of Medicine. "A lot of current interventions and policies in the U.S. are aimed at early adolescent users. We have to start thinking about how we are going to address problematic use that may arise in a growing population of older users."

The findings are based on data from 1,229 participants in the Great Smoky Mountains Study, a long-term study of residents in 11 counties near the Appalachian Mountains in western North Carolina, where Hispanics and Latinos are underrepresented and Native Americans are overrepresented compared with the rest of the United States.

A cohort of children in the study were enrolled as young as age 9 and have now reached their 30s. From 1993 to 2015, researchers tracked data in numerous areas of interest, including mental health, education, work attainment, and use of drugs and alcohol.

The researchers defined problematic cannabis or marijuana use as daily consumption or a habit that meets diagnostic guidelines for addiction. They tracked participants' patterns of use from the college years (ages 19 to 21) into adulthood (ages 26 to 30).

They found more than three-quarters (76.3%) of participants didn't use or develop a problem with marijuana during this period.

The remaining one-quarter developed problems that researchers grouped into three profiles—those with limited problems, persistent problems, and delayed problems.

Limited Users (13%)
• Limited problematic users had trouble with marijuana either while in school before age 16 or in their late teens and early 20s, but their habits dropped off as they aged.

• Researchers were somewhat surprised that this group reported the highest levels of family conflict and instability during childhood as compared with others in the study; these factors are often associated with more drug use.

• "When this group of children left home, they seemed to do better," Hill says. "They didn't have as many children at a young age, and they went further in their education when they were 19 to 21 compared to those with persistent and delayed profiles."

Persistent Users (7%)
• This group had trouble with marijuana beginning as young as 9 years old, and their chronic use continued into their late 20s and early 30s, the data showed.

• Large portions of this group had anxiety disorders in both childhood (27%) and at ages 19 to 21 (23%).

• They had the highest rates of psychiatric disorders and involvement in the criminal justice system, and most said the majority of their friends were drug users, too.

• "This suggests that a focus on mental health and well-being could go a long way to prevent the most problematic use," Hill says.

Delayed Users (4%)
• This was a small but unique group who made it through adolescence and early adulthood without problematic marijuana use, only to become habitual users between ages 26 and 30.

• Blacks were five times as likely as whites to be delayed problematic users in the late 20s and early 30s after not having trouble between the ages 19 to 21—a peak time for most marijuana users.

• More than one-half of delayed users were both bullied by peers and mistreated by caregivers as children, yet also had lower rates of anxiety, alcohol use, and other hard drug use compared with persistent users.

• "What we don't yet understand is how childhood maltreatment didn't prompt earlier problematic use of cannabis between ages 19 and 21—how individuals could be resilient to that kind of adverse experience for so long," Hill says. "One theory is that they were somewhat protected by having fewer peers in late adolescence who were substance users, but this is one of the questions we will continue to seek answers for."

In addition to Hill, study authors include E. Jane Costello, PhD, and William Copeland, PhD, of Duke, and Lilly Shanahan PhD, of the Jacobs Center for Productive Youth Development at the University of Zurich.