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Interview: University of Montreal Professor Natalie Castellanos-Ryan, Ph.D., discusses personality traits that may make teens more prone to drug use

Interview: University of Montreal Professor Natalie Castellanos-Ryan, Ph.D., discusses personality traits that may make teens more prone to drug use

Substance abuse is prevalent worldwide and responsible for the loss of many lives. Addiction affects young and older adults alike. Teenagers are prone to addiction for a number of reasons. Because their frontal lobes are still developing, they are more prone to participating in high-risk behavior. They are more vulnerable to peer pressure. In addition, they are more curious than the average adult.

Natalie Castellanos-Ryan, Ph.D., and other experts weighed in as to whether certain personality traits could lead to addiction. Listen to the full program, “4 Personality Traits = Addiction,” on demand at the “In Your Right Mind” radio program website. This exclusive question-and-answer session with Dr. Castellanos-Ryan dives deeper into the realm of addiction in young adults and how their brains are wired in relation to substance addiction.

Question: Why is age of first use of alcohol so critically important?

Answer: Over the last 20 years, several studies have shown that the earlier the onset of alcohol use, the higher the likelihood of developing a substance use disorder later in adulthood. More recent studies are finding that this is also the case for cannabis use. Because the brain continues to develop across adolescence and early adulthood, it is hypothesised that alcohol and other substances may have stronger neurotoxic effects on the adolescent brain than a more developed adult brain. There is evidence that supports this hypothesis, particularly coming from animal studies, but also for hypotheses that posit that social factors are also at play. For example, some studies have shown that the earlier the onset of alcohol or other substance use the more likely you are to skip and/or drop out of school, hang out with more deviant friends or engage in delinquent behaviours, all of which can affect, in turn, a range of social and health outcomes.

Q: What personality traits make teenagers more inclined to drug use?

A: Our research has shown that high scores on personality traits such as impulsivity, hopelessness and sensation seeking are associated with an increased risk of initiating substance use early and developing alcohol and substance use problems. Impulsivity refers to a general failure to plan ahead and an inability to control or regulate emotions and behaviors. Sensation seeking refers to the tendency to seek out excitement, crave fun and not have much tolerance for boredom. Finally, hopelessness is a tendency to have a negative outlook about life and one’s future.

The personality trait of anxiety sensitivity, which is the tendency to be highly sensitive to the bodily sensations when experiencing anxiety, is also associated with risk of developing substance use problems, but later in development, i.e., in adults rather than adolescents. During adolescence, anxiety sensitivity is either not associated with risk of substance use or with reduced risk of developing substance use problems.

One thing I do want to make clear is that, although findings show that personality traits like impulsivity, hopelessness and sensation seeking are significantly associated with higher risk of developing substance use problems, this does not mean that all impulsive, hopeless or sensation-seeking adolescents will develop problems. In our studies, we find that about 50 to 60 percent of adolescents who score high on these traits will develop substance use problems a couple of years later. That would be comparable to having a 1 in 2 chance of developing problems, while the risk is much lower in those who do not score high on these traits (e.g., 1 in 10).

Q: How does the addiction pathway in the teenager’s brain differ from an adult’s brain? Can teenagers become hooked on substances faster than adults? If so, why?

A: Although different drugs affect the brain in different ways, many drugs raise the level of dopamine in brain circuits that are related to reward and pleasure. The brain is designed and wired to release dopamine to encourage and reinforce self-sustaining behaviors that contribute to health, well-being, learning and the strengthening of social bonds, such as hanging out with friends, listening to music, doing exercise (all of which we could consider natural rewards). Drugs can hijack this process by flooding the brain’s reward circuits with much more dopamine than natural rewards produce. This creates an especially strong drive to repeat the drug-taking experience.

This can happen in adults and adolescents alike. However, as the adolescent brain continues to develop and does not reach full maturity until our mid-20s, adolescents may be more vulnerable to the effects of drugs. Different areas of the brain develop at different rates. For example, parts of the brain that process rewards and certain basic emotions – implicated in driving drug use – are the first to mature while the prefrontal cortex and its connections to other brain regions develop last. The prefrontal cortex could be likened to the control center of the brain; it is in charge of evaluating situations, planning, decision-making, and emotional and behavioral control. Because of this development gap between the brain areas driving our impulses and those responsible for controlling those drives and impulses, it is believed that adolescents may be more likely to take drugs again and for their brain to more easily reinforce the neural links between pleasure and drug taking. Moreover, this also makes it more likely that drugs alter key, but still developing, brain areas necessary for good decision-making and self-control, which further reduce someone’s ability to control one’s drug use.

Q: What are common signs and symptoms of drug use in teenagers?

A: Although each teenager is different and symptoms will vary a lot from teenager to teenager, some common first signs to look out for are changes in appetite or sleep patterns, as well as changes in behaviors, particularly those related to decreasing performance in school and work (e.g., decreasing grades, skipping school or work). Other symptoms include a lack of motivation, sudden changes in personality and mood such as increases in irritability, agitation, an inability to focus, fearfulness, anxiety and paranoia.

Q: Can people become addicted even though they only use substances once in a while?

A: Yes. While some people can use substances once in a while and not become addicted, others will become addicted.

Q: Does marijuana use lead to the use of other drugs?

A: It can, yes, but as much as other substances do (e.g., tobacco). There was a time when marijuana was referred to as a “gateway drug,” but there is little evidence supporting that this is the case. While many young people using marijuana also drink alcohol and/or smoke tobacco, only some will use other drugs.

Q: Why do some people become addicted, while others do not?

A: For many researchers in the field of addiction, including myself, this is the most important question to focus on. There is still a lot we don’t know and need to continue to work on, but what we do know is that certain individual and biological characteristics (e.g., certain genes, family history of alcohol and drugs, personality and temperament), environmental factors (e.g., experiencing trauma, neglect or being exposed to violence) and the interaction between these factors, place individuals at higher risk of developing addiction. Adolescents and adults with these individual characteristics and/or who lived through traumatic experiences will be more likely to drink or use drugs to cope with their emotions, thoughts and different aspects of their life they find difficult, which in turn will make them more likely to become dependent on alcohol and drugs. For others, it may be that something in their brains makes alcohol and drugs much more reinforcing or rewarding than for the rest of us.

Q: Should we be as concerned with prescription drugs as we are with illegal substances such as cocaine, heroin and methamphetamine?

A: Yes, prescription drugs can be just as addictive as illegal substances and can lead to a range of negative health and social outcomes.

Q: Can a person be too young to become addicted to alcohol and drugs?

A: No, one can become addicted regardless of the age.

About Natalie Castellanos-Ryan, Ph.D.

Natalie Castellanos-Ryan, Ph.D., is a professor at the University of Montreal who studied cognitive, personality and biological risk factors for alcohol and drug misuse. She co-wrote “Sensitivity and Specificity of a Brief Personality Screening Instrument in Predicting Future Substance Use, Emotional, and Behavioral Problems: 18-Month Predictive Validity of the Substance Use Risk Profile Scale,” in which concurrent and predictive validity tests showed that all four brief scales – hopelessness (H), anxiety sensitivity (AS), impulsivity (IMP) and sensation seeking (SS) – were related in theoretically expected ways to measures of substance use and other behavioral and emotional problems. Her current research focuses on how pubertal development, childhood executive function development and personality can predict risky behavior, particularly substance use problems in adolescence and early adulthood.