Occasional pot smokers may be lighting up for a quick high or to have a good time with friends. But some teens and young adults could be turning to marijuana to self-medicate their negative moods away. And they are doing so at a time when they are already at an increased risk of mental health problems like depression and bipolar disorder.

Understanding what causes young people to use marijuana is not just about keeping them away from this drug, which is still illegal in most states. It is also a matter of encouraging them to seek help for mental health problems and to learn positive coping skills for the stresses of these often turbulent years.

Tracking moods in teenagers, who are already at the right age for mood swings, is not always easy. Researchers from Boston turned to handheld computers to quietly track the moods of a group of regular marijuana users. What they found is that negative moods like irritability and anger often preceded pot use.

"Young people who use marijuana frequently experience an increase in negative affect in the 24 hours leading up to a use event, which lends strong support to an affect-regulation model in this population," said the study's lead author Dr. Lydia Shrier, of the division of adolescent and young adult medicine at Boston Children's Hospital, in a press release.

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Marijuana Used to Cope with Strong Emotions

According to the researchers, teens and young adults may be using marijuana to smoke away their worries. For health professionals who work with teens, this kind of self-medicating is not surprising, but can lead to more problems down the road.

“You feel a certain way and you really don’t have a coping mechanism to express your emotions properly, and then you turn to drugs,” said Stephanie Moir, a licensed mental health counselor at Serene Mind Psychology in Tampa, Florida. “And it just becomes a cycle, and they don’t even realize why they’re doing it. A couple of months into it, it’s just a habit.”

Moir sees teens using marijuana to cope with many problems, primarily family conflicts, academic stress, and dealing with other relationship issues, often between boyfriends and girlfriends.

While occasional users of marijuana may experience mostly pleasant effects, more frequent users could experience a mood drop after they stop using, which in turn can lead them right back to lighting up.

“When you look at what happens to people with chronic use of marijuana, particularly in late adolescent and young adult populations, what you see is chronic anxiety, emotional blunting and indifference, and loss of motivation that becomes a chronic syndrome,” said Dr. David Sack, an addiction psychiatrist and CEO of Promises Treatment Centers in California and Texas.

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Negative Moods Are Common Before Lighting Up

In the new study, published September 15 in the Journal of Studies on Alcohol and Drugs, researchers followed 40 men and women between the ages of 15 and 24 for two weeks. The young people tracked their mood and recent marijuana use several times a day, in a special program on a handheld computer. In addition to these random reports, they also recorded their mood just before and after each time they actually lit up.

During the 24 hours prior to marijuana use, the young adults in the study were more likely to report experiencing a negative mood — such as feeling distressed, upset, guilty, or scared. 

In addition, almost two-thirds of the young people met the criteria for marijuana addiction. The authors hope that substance abuse treatment could be improved by teaching people to use more positive coping techniques when their mood drops, before they reach for marijuana.

However, the study only included a small number of teens and young adults, so the results may not apply to all young people who use pot. Still, the researchers have found a convenient way to track moods at several moments throughout the day, something that could be used during larger studies on a more diverse group of people.

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Young Users' Brains Are Still Developing

Although the study focused specifically on moods like irritability and anger, mental health problems are an even bigger concern among younger users of marijuana, since this is a time when their brains are still developing.

“Part of the problem is that [young people] are starting to use the drug that exacerbates mood problems at a time when they’re at the greatest risk,” said Sack. “When you look at adolescents who are admitted to treatment facilities for problems with drugs or alcohol, 70 percent of them had a pre-existing emotional problem — either attention deficit disorder, conduct disorder, antisocial personality disorder, depression, or bipolar disorder.”

This does not mean that marijuana is causing the mental health problems, but pot use may make those conditions worse. 

Given the large number of young marijuana users who also have emotional issues, and the possible rise in marijuana use as the drug is legalized, Sack sees mental health therapy as an integral part of any substance abuse program.

“At our programs,” he says, “we have addiction psychiatrists and mental health therapists, because we see this as such a common co-occurring disorder.”

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