Does Marijuana Cause Depression in Teens? | Knowledge & Environment | DW
The way cannabis is used is changing around the world. The potential medical use is being researched more and more and legalization is being discussed. Eight countries including CanadaUruguay, Mexico and Thailand, as well as 22 US states have already legalized private consumption in leisure time. About 50 states have adopted the same for medical use. Many other countries are currently introducing legislation for this. However, as with tobacco and cigarettes, one means legalization not that the drug is not harmful.
Marijuana is one of the most used substances by teenagers worldwide. According to researchers at Columbia University in New York, more than 2.5 million teenagers use cannabis occasionally in the United States, and the number is growing. For many experts, the trend towards legalization and medical use is ringing alarm bells, especially when it comes to possible health risks for minors and young adults.
brain in development
It is not possible to say with certainty when the developmental years of an adolescent are complete. The only thing that is clear is that a lot changes biologically during this time, including in the brain. These changes make it even more difficult to determine how cannabis is affecting adolescents.
According to that National Institutes of Mental Health, an agency under the US Department of Health and Human Services, the brain continues to develop until about the age of mid-twenties. Emotional processing, stress management, rewards and motivation, decision-making, considered action, impulse control, and logical thinking, for example, unfold during this time. At the same time, gray matter in the brain decreases and more white matter is produced, allowing different areas of the brain to communicate with each other faster and more efficiently.
That makes life as a teenager difficult. Not only does their body change drastically, they often struggle with questions about their own identity, with social pressure, pressure from grades, dynamics within the family and other problems. All of these changes and stresses can make teenagers more likely to suffer from mental health issues, such as anxiety or depression. They can also be a reason they use substances like marijuana to get by. This is explained by the US authority SAMHSA (Substance Abuse and Mental Health Services Administration). Its mission is to improve the care of addicted and mentally ill people. The problem, however, is that mental health problems can worsen over the long term as a result of marijuana use.
When the brain is still developing, it is particularly sensitive to substances such as alcohol, tobacco, marijuana and other addictive substances. According to the American Academy of Child and Adolescent Psychiatry, these substances have been shown to alter or delay some of the developments that normally take place during adolescence. In the case of cannabis, there is growing evidence that it alters the brains of teenagers.
No concentration and learning problems
According to the U.S. Department of Health Centers for Disease Control and Prevention (CDC) it can mean: Difficulty thinking and problem solving, memory and learning problems, decreased coordination and difficulty concentrating. Research has found a link between cannabis use and mental health issues such as anxiety and depression observed. People who use cannabis are also more likely to have psychotic episodes.
A study published by the Journal of the American Medical Association (JAMA) looked at adolescents who had used cannabis occasionally, i.e. below the threshold of addiction, in the previous 12 months. Responses from nearly 70,000 teenagers in the 2019 National Statistical Survey on Substance Use and Health were evaluated. The study found that adolescents with light cannabis use were two to four times more likely to smoke marijuana compared to adolescents who did not smoke marijuana Mental problems such as depression, suicidal thoughts, slowed thought processes and difficulty concentrating.
This could indicate that there is a link between marijuana use and mental health problems – but the question is whether one directly leads to the other.
Another recent study published in the journal JAMA Psychiatry found that using marijuana at a young age increases the risk of developing depression or suicidal thoughts later in life. However, a 2002 study published in the Journal of Psychopharmacology showed that cannabis-using adolescents were no more likely to suffer from mental health problems, such as depression and anxiety, compared to cannabis-using adults. This only applied to teenagers addicted to cannabis.
Cross-sectional studies say nothing about causes
Correlation says nothing about causality. It’s a bit like the question of which came first, the chicken or the egg. Whether cannabis use is responsible for the tendency to develop depression and other mental health problems, or whether adolescents with these problems are more likely to use cannabis, is difficult to say.
An analysis in the journal “Frontiers in Psychiatry” from 2020 evaluated the findings to date cannabis and the brain of adolescents. Conclusion: Because of the way many of these cross-sectional studies are designed, we know little about the association between cannabis use and mental health.
Cross-sectional studies examine different groups of people at a given point in time. The aim is to collect information on a specific topic by collecting data from a large number of different people at once. The scientists then analyze this data and try to establish patterns or relationships. But what causes what? They can’t tell.
The study also suggested that both cannabis use and mental health issues could be caused by something else, such as teenagers’ susceptibility to stress and the aforementioned anxiety.
More research will be needed to find out whether cannabis use actually causes mental health problems in adolescents.
Adapted from the English by Phoenix Hanzo.
