The findings: drug use as self-medication
The article found that the link between substance use and mental health existed even at low levels of drug and alcohol use. Dr. Tervo-Clemmens said that teens with low levels of substance use may be self-medicating and that their relatively modest substance use is not likely to be causing underlying mental health problems.
But the research also found that the most frequent and heavy users of these substances experienced the most severe mental health symptoms. In these cases, Dr. Tervo-Clemmens said, teens may be making their symptoms worse even when they use substances to self-medicate.
Specifically, the study found that daily or near-daily substance use, but not weekly or monthly use, was associated with a moderate increase in symptoms. The researchers described the connection as “dose-dependent,” because the level of use was related to the intensity of symptoms.
Background: Two solid data sets
The strength of the study came from the use of two data sets that yielded similar findings.
One sample used data from a survey of 15,600 Massachusetts high school students with an average age of about 16. The second sample was based on similarly self-reported data from 17,000 respondents to the National Youth Risk Behavior Survey.
In both groups, the study authors noted, “alcohol, cannabis, and nicotine use had significant, moderate dose-dependent associations with worse psychiatric symptoms, including suicidal thoughts.”
Another key finding was that the link was present across multiple symptoms and across multiple substances. “It's not just cannabis, it's not just alcohol, it's not just nicotine,” Dr. Tervo-Clemmens said. “It seems that the background doesn't matter.”
What's new: a generational change
Compared to previous generations, today's teens are experiencing more mental health symptoms but decreasing drug and alcohol use. Excessive alcohol consumption and smoking, in particular, have decreased dramatically and affect a smaller portion of the adolescent population.
These general trends may support the idea that asking teens about substance use could be a way to screen for mental health problems, Dr. Tervo-Clemmens said. This is because the group of regular substance users is smaller than it was before and may be more closely linked to people who self-medicate or struggle with mental health problems.