A new study from the University of Pennsylvania following teenagers’ pot use gets at a chicken-or-egg question that’s been the subject of some debate: Whether pot use precedes psychological problems, or it’s the other way round. In the new research, published in the journal Addiction, the researchers focused on conduct problems, like cutting school and stealing, which can turn into the more significant conduct disorder.
They found that, for the most part, pot use did not precipitate conduct problems, but rather, conduct problems often preceded pot use. Not surprisingly, the authors suggest that self-medication may be at play.
The team studied 400 kids between 10 and 12 years old, beginning in 2004. They were asked a number of questions—about their behavior and mental health, substance use, and their friends’ substance use—once a year till 2010 and then once more in 2012. Urine tests were used to verify the self-reports about pot use.
And though it was just correlation, the results were telling. Among the 365 kids who continued the study till the end, there was no sense that pot use increased the risk of conduct problems.
“The present findings showed that… CP [conduct problems] predicted cannabis use but not vice versa, particularly during mid–late adolescence,” the authors conclude in their paper. “Thus…we were able to demonstrate for the first time that increases in CP precede increases in cannabis use within individuals.”
There was also a connection between having conduct problems and being drawn to peers who smoked pot. “Interestingly, the results show that not only do conduct problems such as school truancy and theft predict cannabis use, but adolescents who display conduct problems are also drawn to cannabis-using peers,” said author Ivy Defoe in a statement. “These affiliations predict increases in cannabis use and, eventually, cannabis use disorder, as our results show.”
Again, the authors suggest that teens who have conduct problems may be using pot to self-medicate or to cope with their problems, particularly “disapproval of their behavior problems,” perhaps from parents or teachers.
All this said, it’s probably more complicated than just “troubled kids self-medicate with pot.” Other research has found that marijuana does seem to increase the risk for other psychiatric and cognitive issues. One recent study found a connection between marijuana use and poorer cognitive performance, including reasoning, inhibitory control, and, as others have, memory. Another study found that quitting pot can help restore some of the memory loss that comes from marijuana use.
Another body of work has found that although it’s complicated, pot smoking is linked to increased schizophrenia risk, at least in those who are already at higher risk of the disorder. The connection between pot and other mental health disorders like depression and anxiety is less clear, but it probably goes in both directions. Interestingly, one study looked at depression and pot use later on, and found that young teens who have more depression symptoms are more likely to smoke pot when they’re 18, which may reflect the idea that kids with (untreated) mental health issues may be more likely to self-medicate with pot.
If nothing else, the new study on conduct problems shows that pot doesn’t necessarily “cause” mental health problems by itself, and it may well be the opposite, at least for some kids—it’s probably often a salve for those dealing with serious issues. Kids and teens who go through any kind of stressors—abuse at home, violence, bullying—or who have untreated mental health disorders might well use pot to numb themselves out as a coping mechanism.
This is probably not a great thing in-and-of itself, since marijuana is linked to its own set of negative effects, and there are far more effective ways of treating mental health problems. Unfortunately, access to pot is probably easier for some than access to good mental health care. But the study does deepen the conversation, and suggest that when kids are using pot—or other drugs—it’s important to think about the drug not as the problem, but as a symptom of something else.