Timmen L. Cermak, MDPrivate practice in psychiatry and addiction psychiatry in San Francisco and Marin County, CA; former president of the California Society of Addiction MedicineDr. Cermak has disclosed that they have no relevant financial or other interests in any commercial companies pertaining to these educational activities.
CCPR: Clinicians working with adolescents have seen that kids are frequently using marijuana now—and stronger strains of it. What does this exposure mean for them? Is there any suggestion that marijuana use is affecting development?
Dr. Cermak: There is conclusive evidence that marijuana use, particularly in early adolescence, can affect brain development. The best research on this is probably the Dunedin Study done in New Zealand (Meier MH, Proc Natl Acad Sci 2012;109(40):E2657–E2664). Researchers did full neurocognitive testing on 13-year-olds and then followed them at various intervals up to age 38. They demonstrated that certain subpopulations had as much as an 8 point decrease in IQ from age 13 to age 38 with marijuana use. Now, it’s important not to over-interpret these results: Importantly, the only ones who demonstrated that much of an IQ change were those who began using at the very earliest ages of adolescence. Those who didn’t smoke until they were age 18, say, but then smoked continuously and heavily from then until age 38, did not show a decline in IQ. So, that’s the best evidence that youth who begin smoking quite early on are at the highest risk of adverse effects.
CCPR: Any other possible effects on cognitive functioning with early marijuana use?
Dr. Cermak: Most of the effect is on memory, attention, and executive function. With respect to this last domain, adolescents who have been abstinent for 28 days still can show some executive function impairment.
CCPR: What points would you make for clinicians working with children and adolescents?
Dr. Cermak: Delay, delay, delay. The more success we have getting kids to delay onset of use, the more protection we provide.
CCPR: How are adolescents who start smoking a bit later, say at age 16, likely to be affected?
Dr. Cermak: The primary effect for those who begin a little bit later in adolescence is on their education, which can be life-changing. Youth who smoke regularly during adolescence, even if they don’t start at age 13, are likely to be earning about two-thirds as much as the average person at age 30. That economic impact predominantly comes from interfering with education right at the point where the adolescent’s educational trajectory is being determined. If you spend a couple of years stoned and not paying attention to your education, then stop smoking and clear your mind, you’re still apt to go to a less rigorous college—or maybe not get into college at all—because of how poorly you did in the 10th and 11th grade.
CCPR: How do you think marijuana affects the ability of adolescents to mature normally?
Dr. Cermak: Everyone moving through adolescence must master numerous psychological developmental tasks in order to navigate their way from dependence on others to a place of independence early in adult life. Unfortunately, marijuana use often substitutes for the psychological work needed to achieve those goals.
CCPR: Can you give us an example?
Dr. Cermak: We all know that development of autonomy is essential. With marijuana, adolescents need only to light up to become a marijuana smoker, which, in many people’s minds, is a step toward autonomy. They may think, “I’m told not to do this; however, I do it, so I’m an adult. I’m making my own decisions.” And they join a subculture that is attractive in many ways, creating a sense of affiliation outside of the family. But it’s an affiliation based on a narrow characteristic: drug users who share the same habit. It doesn’t come from developing the capacity to have intimate relationships outside the family. So, kids think they’re achieving movement toward adulthood when, in fact, using marijuana is a substitute for the real psychological task.
CCPR: What are your thoughts about “amotivational syndrome”?
Dr. Cermak: I actually doubted the existence of this concept until recently. While it’s clear that a lot of daily users prefer their couch over anything else, I wasn’t sure one could measure motivation scientifically. However, recent work using brain imaging looked at the brain’s response to anticipatory reward (Martz ME et al, JAMA Psychiatry 2016;73(8):838–844). For regular marijuana smokers who are not stoned at the time they are being tested, the brain reward mechanisms respond less to the anticipation of monetary reward when compared to the response seen in non-marijuana smokers. This suggests that the reward mechanisms develop a narrow salience for marijuana-related experiences that can dominate other kinds of rewards necessary for a broader range of development.
CCPR: What else should clinicians know?
Dr. Cermak: There are two other pieces of research I think everyone treating adolescents should know about. One is work by Staci Gruber that offers good evidence that marijuana users are processing affective cues differently than nonusers (Gruber SA et al, Drug Alcohol Depend 2009;105(1–2):139–153). That fits with what I hear from many family members of regular smokers, which is that they lack a certain emotional presence. The other result is from research using the Iowa gambling task, which assesses real-life decision-making and risk-taking. Regular marijuana smokers are less deterred by the large losses and attracted to the large gains. This research shows that users are apt to stick with a strategy that trades lower overall payoff for higher short-term gain. It’s a perfect example of people not learning from their mistakes (Wesley MJ et al, Psychiatry Res 2011;191(1):51–59).
CCPR: Are there other potential adverse effects for adolescents?
Dr. Cermak: THC decreases the ability to respond to negative reinforcement. Our endocannabinoid system is a natural balm that helps prevent aversive experiences from overwhelming us; however, constant overstimulation of that system deprives us of an important source of learning.
CCPR: Let’s go back to the clinician. What stance do you recommend when an adolescent insists on smoking?
Dr. Cermak: Motivational interviewing is important here. If you get into an argument with an adolescent who is smoking, you simply intensify the person’s defenses. The most important thing in the beginning is to listen with as much curiosity as possible. You have to be nonjudgmental, putting your fears and opinions on the back burner. The goal is to develop a therapeutic relationship with a kid by demonstrating you genuinely want to know what makes using marijuana appealing. The more you can get someone to describe in detail the perceived benefits of using marijuana, the more you’re giving that person an opportunity to be understood and find out what the problem is. Suppose your patient starts by saying, “When I smoke, I can chill. I can relax for the first time. It’s the only thing that really gets me away from school and family stress.” Okay, now you know you’re dealing with a kid who may have excessive anxiety and stress—something you can address later on.
CCPR: How do you follow up from there?
Dr. Cermak: One thing almost everyone will endorse when we explore the benefits of marijuana is the kind of novelty it brings—an antidote to boredom, if you will. Essentially, all marijuana users like the freshness that makes walking down the hallway to the bathroom an adventure. I acknowledge that we all like that kind of novelty, then point out that THC is actually just mimicking our natural cannabinoids, which act in those same brain areas to increase the sense of novelty.
CCPR: So, you’re drawing on what we’ve learned about the endocannabinoids.
Dr. Cermak: Right. I ask, “Do you know how marijuana works to produce the effects you like?” Most kids have scant knowledge of the subject and generally are intrigued to learn how marijuana works. Once we’ve started to talk science, I explain what we’ve learned regarding the effects of THC. For example, I mention that when marijuana hits the cannabinoid receptors, their number reduces by as much as 20%–60% in different parts of the brain. Hearing that, most kids easily guess what the effect is: It’s the opposite of being stoned. If being stoned makes things novel, then if you’re not stoned and don’t have as many receptor sites, you’re even more bored than before. If marijuana tends to relax you, and you reduce the receptors and you don’t have any marijuana on board, then you’re more likely to be tense and anxious or irritable. If it helps you go to sleep, not using is apt to lead to a little bit of insomnia.
CCPR: This lets you talk about what’s not so good about a particular patient’s marijuana use.
Dr. Cermak: Yes. Fairly frequently, people latch onto, “Yeah, I don’t like …” This is where I give it a name: They don’t like “a cannabinoid deficiency state.” This is a much more palatable term than the word “withdrawal,” which no one wants to hear. Kids get that using THC helps the deficiency but begins generating a roller coaster.
CCPR: What about the literature on marijuana’s possible association with schizophrenia?
Dr. Cermak: I think it’s conclusive at this point that there’s a doubling in psychotic disorders that are either schizophrenia or schizophrenia-like; marijuana also can worsen psychosis regardless of the underlying process causing it, such as mania or depression as well as schizophrenia. The research gets complex, but over and over it shows the epidemiology is pretty clear: the earlier someone starts smoking, the more likely that person’s risk of psychosis roughly doubles (McGrath J et al, Arch Gen Psychiatry 2010;67(5):440–447). The problem is, the prevalence of schizophrenia is so low that a doubling doesn’t cause much alarm—unless you have one of these tragedies going on in your family or with your next-door neighbors. It’s not going to tip public policy.
CCPR: Some clinicians won’t prescribe any other medication to someone using marijuana. What’s your stance?
Dr. Cermak: We simply don’t know how someone bouncing between excessive and diminished endocannabinoid activity is going to affect other medications. If a kid is prescribed a psychoactive medication, I emphasize that I don’t know what using marijuana will do, but that its effects are unlikely to be positive: Science tells us marijuana alters the activity of all the other neurotransmitters. So, if I’m trying to help mood or anxiety with a medication that affects a particular neurotransmitter, and the patient is using something that can dominate and modulate that neurotransmitter, we’re working at cross purposes.
CCPR: Do you prescribe such medications if you know a kid is using marijuana?
Dr. Cermak: Sometimes I will, because I don’t think any serious medical damage is likely, but I make it clear that using marijuana is likely undoing the effect of what I’m prescribing.
CCPR: This sounds like you’re back to your earlier intervention.
Dr. Cermak: Yes. The primary rationalization we get for marijuana use is that “this is my medicine, and that’s why I’m taking it.” So, using motivational interviewing, I get very intrigued: “Okay, what is it you’re taking the medicine for? What are the symptoms? Has that really been well evaluated?” Anyone describing marijuana as medicine is saying there is some sort of problem. I’m a doctor, so that’s what I want to be able to help the person understand.
CCPR: I understand you’re working on a book to try to help the dissemination of marijuana research within the field.
Dr. Cermak: Right. The working title is Taking Marijuana Seriously. My primary goal is to turn the research into a narrative, so that people will begin understanding how each piece of research led to the next piece and then the next. I hope it will give both clinicians and the general public much greater access to what we know about marijuana. CCPR: Thank you for sharing your extensive experience, Dr. Cermak.