Study: Adolescents Who Use Substances at Higher Risk for Mental Illness, Suicide

A study conducted by a faculty member at the University of Minnesota Medical School and Masonic Institute for the Developing Brain has found that high school students who report using drugs, alcohol or nicotine are at higher risk for suicidal thoughts and other mental health disorders. 

With a team of colleagues from the U of M and Massachusetts General Hospital, Brenden Tervo-Clemmens. Ph.D., an assistant professor, developmental neuroscientist and clinical psychologist with a research focus on adolescent brain development, analyzed survey results from more than 15,000 high school students across Massachusetts and an additional independent sample of 17,000 high school students from across the United States. His research was funded by the Massachusetts Department of Public Health, the National Institute on Drug Abuse and the American Psychological Foundation.

Tervo-Clemmens and his colleagues discovered that high school students who reported using cannabis, alcohol or nicotine were more likely to have thoughts about suicide, feel depressed or anxious and exhibit inattention or hyperactivity. The resulting study, “Substance Use, Suicidal Thoughts and Psychiatric Comorbidities Among High School Students,” was published in the Jan. 29, 2024, issue of JAMA Pediatrics. 

The team’s study results, Tervo-Clemmens said, “highlight the prevalence of psychiatric co-morbidities among young people who use substances, and they lend strong support for the notion that screening, prevention, intervention and policy efforts need to comprehensively address targets beyond substance use alone.” While earlier studies focused on links between the use of particular substances and rates of mental illness, this study found a link between mental illness and use of a range of substances.

“Other studies looked at connections between the use of specific substances like nicotine and suicidal ideation,” Tervo-Clemmens  said. He explained that his team’s research found that “it doesn’t really matter the substance use type or the mental health symptoms.” To put it plainly, he continued, “with more substance use there are more mental health symptoms.” 

Some risks the study highlighted were particularly alarming; thoughts of suicide, for instance, were approximately five times more prevalent among study participants who used substances daily or near daily compared with those who did not. And higher rates of psychiatric symptoms were detected even among adolescents with relatively low levels of substance use. 

The study’s large data set of more than 30,000 adolescents made its results particularly robust, Tervo-Clemmens said: “What we wanted to show was no matter the substance use time or mental health symptom, all substance use was related to more mental health symptoms. We wanted to demonstrate how widespread this connection was.” The research, he explained, helped make connections that hadn’t been made before. “We want to comprehensively look at the relationship between the types of substance use and the types of mental health symptoms,” he said. 

Having a deeper understanding of these connections could help direct advocacy and policy change around adolescent mental health and substance use, Tervo-Clemmens said. It may also underline the reality that mental health and addiction are nearly always closely related.  

“I think that just knowing, just describing what are the mental health needs of teenagers that do use substances, even if we can’t figure out what is tied to what, is important in the treatment and policy direction,” he said. This research, Tervo-Clemmens explained, informs his daily practice as a psychologist: “As a clinician, what I should look out for if I see a teenager that uses substances? How can I best help to treat them and support their mental health?”

Which Came First?

For years, people in the mental health or addiction-treatment field have struggled with the question of, “Which came first — the addiction or the mental illness?” One interpretation of Tervo-Clemmens’ research may be that there is no way or need to understand which came first. 

Heather Jones, Ph.D., is a licensed psychologist and vice president of mental health, family and children’s services for the Hazelden Betty Ford Foundation. She said that in her work with adolescents struggling with substance use disorder (SUD), she is often not able to tease out whether her clients’ mental illness inspired their addiction or if their addiction caused their mental illness. 

“I think that it is a chicken or egg situation,” Jones said. “It is very much a two-way road. There are likely common risk factors — both genetic and environmental — that lead to mental health challenges and substance use.” She thinks it is best to set that question aside and instead focus on treatment and recovery.

“It is interesting in our field that we ask this question,” Jones said, “because in medicine, if we hear that diabetes and heart disease exist at the same time in one patient we aren’t surprised. We’d just treat both illnesses. And we wouldn’t focus on getting to the bottom of which came first.”   

Tervo-Clemmens said his team’s findings support the coexistence theory of mental illness and addiction. In his research, he explained, “You can see that even really low rates of use are consistent with mental health symptoms, which is inconsistent with the belief that more use leads to mental health symptoms. It is obviously a bidirectional relationship — particularly with high rates of use.” 

His ongoing interest in the brain development of adolescents makes these findings particularly interesting, he added. “I was trained as a developmental psychologist,” he said. “I’m interested in … seeing how we can understand how development in the brain makes kids turn into adults. I want to understand more about how what happens in the teenage years puts a person at risk of substance use as an adult.” 

For years, experts have been talking about “self-medication” — the theory that people with SUD use substances to treat symptoms of their mental illness, like using alcohol to reduce social anxiety. 

Tervo-Clemmens said that in his own practice he’s often skeptical of that concept. 

“That phrase, ‘self-medication,’ has a complex position among treatment providers,” he said. Substances like alcohol or marijuana are “not very effective medications,” he added. “As a clinician, I often talk with young people. Sometimes they will say they use cannabis because it helps them sleep better. I’ll ask, ‘How long have you been using it?’ They say ‘months,’ or even ‘years.’ I will then ask, ‘Has your sleep gotten better?’ They’ll say no. Then I say, ‘It doesn’t really work.’ We are reluctant to use that phrase ‘self-medication,’ because drugs are not really medications.” 

Treating Adolescent Addiction and Mental Illness

In her work with adolescents facing SUD, Jones said that she often tries to explain the connections between mental health and addiction. Many of her young patients may have struggled with their mental health and their addiction for years, but have not thought about how the two issues are often interconnected. When she talks to patients and their families about the connection, Jones said she often gets the same reaction. 

“Usually it is an experience or realization, like, ‘That makes total sense,’ or, ‘That explains a lot,” she said. Understanding that the two issues are so often paired can feel like a weight being lifted off your shoulders. “I think that one of the challenges when substance use is involved is there is still this underlying belief that when someone is using substances there is some moral weakness,” she said. This connection takes some of that burden off.  

Jones added that her own professional experience backs up Tervo-Clemmens’ research findings.

“What we see in our population at Hazelden Betty Ford Foundation is that over 90% of the youth coming to us have both a co-occurring mental health disorder or meet the criteria for a mental health disorder, as well as are using substances,” she said. While in the general population, more like 20%-30% of young people meet the criteria for anxiety or depression, Jones said it is different among teens diagnosed with SUD. “In our population, the ones that are coming for residential or day treatment — almost all of them meet that criteria,” Jones said. 

While some young people in Hazelden Betty Ford’s addiction treatment programs are prescribed medication to help stabilize their psychiatric symptoms, Jones said that she and her colleagues often focus on, “helping to teach young people to practice identifying and managing these symptoms and feelings over and over and over again.” 

Psychiatric medications, Jones explained, “often serve as a boost, especially in early recovery for our adolescents that struggle with  mental health challenges, but the good news is that there are many non-medical interventions for anxiety and depression that are as good or better when compared to medication alone.”

Increasingly, post-pandemic, mental health and addiction issues among teens can be triggered or enhanced by feelings of isolation, Tervo-Clemmens said. In many cases, he explained, “What drives use is feelings of loneliness and disconnection and challenges with mental health. These feelings all go together.” 

In the Hazelden Betty Ford Foundation’s residential and day-treatment programs for adolescents, Jones said there is a clear focus on building connections between participants and other young people who have experienced similar challenges. She said that the best way to counter addiction and mental illness is through building community. 

“Our model is connecting young people to each other and continuing that after they leave through support groups,” she said. “It is an antidote to the feelings of isolation that so often occur around substance use and mental health challenges. We’re connecting with people, creating empathy and offering hope.” 

Tervo-Cemmens said he hopes that the results of his research will have a larger impact on the way health care professionals assess and treat the young people in their care.

“The top-line results of this study are important for parents and providers that are not steeped in this literature,” he said. “They are a demonstration of a well-known result that substance use and psychiatric disorders are closely linked and co-occur. When we see substance use in a teenager, we should be thinking about their mental health more broadly.”