Why Solitary Cannabis Use May Signal Greater Risk

When people talk about cannabis use among teenagers, the conversation usually focuses on familiar questions, such as how often they are using it, how much they are consuming, and how old they were when they started. However, there may be another, even more important question worth asking: Are they using cannabis with other people or by themselves?

Emerging research suggests that the setting in which young people use cannabis may provide important clues about their overall risk profile. While social cannabis use was common among the high school students studied, those who also reported using cannabis alone appeared to experience substantially more negative consequences across several areas of life. Let’s dive into the research and what this means moving forward for cannabis harm reduction for teens.

What Is Solitary Cannabis Use?

Solitary cannabis use simply means consuming cannabis without other people present. For example, two teenagers might report using cannabis once a week, but their experiences could look very different. One might primarily use with friends in social settings, while the other might regularly use cannabis alone at home. While frequency of cannabis use among teens is often studied, the setting may tell us something about why, when, and how that use is occurring. For parents, clinicians, educators and researchers, that difference could matter.

The 2026 study¹, published in Addictive Behaviors, took a deeper look at cannabis-use settings among high school students in Norway and specifically looked at whether solitary use was associated with different characteristics and consequences. And the researchers found a pattern that deserves a closer look.

A Closer Look at the Study

Researchers analyzed data from two nationally representative surveys of Norwegian high school students conducted in 2021 and 2025. The analysis included 973 students who reported cannabis use during the previous year, with approximately 62% of participants being male. Students provided information about how they used cannabis, along with demographic and psychosocial characteristics and negative consequences they had experienced.

Nearly all of the students reported some form of social cannabis use, but approximately 24.3% also reported using cannabis alone. That means roughly one in four past year cannabis using students in the study fell into what researchers described as the “Solitary+” group. This was particularly interesting because solitary users were not simply a random subset of cannabis users. Their patterns reflected distinct demographic and psychosocial characteristics.

Solitary Use Was Linked to More Consequences

Students who reported solitary cannabis use experienced a greater overall number of negative consequences than those who reported social use without solitary use. The difference was notable. On average, the Solitary+ group reported 5.41 negative consequences, compared with 2.89 among the comparison group.

Researchers also found that solitary use was associated with greater odds of experiencing consequences across seven of the ten harm domains examined. Among those areas were mental health, apathy, relationships, school, and law enforcement. After accounting for multiple potential risk factors, including how frequently students used cannabis, the associations with several types of problems remained.

For example, solitary use was associated with higher odds of mental health consequences, with an adjusted odds ratio of 1.7. The association was stronger for apathy, at 2.1, and relationship-related problems were also associated with an adjusted odds ratio of 2.1. School-related consequences had an adjusted odds ratio of 1.8, while law-enforcement problems had an adjusted odds ratio of 2.2.

In other words, the relationship between solitary use and negative outcomes could not simply be explained by cannabis-use frequency in the researchers’ analysis. That is what makes the finding especially intriguing.

Why Cannabis Use Setting Matters

Frequency remains an important part of understanding cannabis use, but it may not tell the whole story. A young person who uses cannabis socially may be motivated primarily by social experiences, peer relationships, or shared recreational activities. Someone who frequently chooses to use alone may have a different set of motivations or circumstances.

Solitary use could, for example, occur alongside social withdrawal, emotional difficulties, boredom, coping behaviors or other psychosocial factors. It could also simply reflect personal preference or circumstances. The study does not establish which explanation applies to individual teenagers. Instead, it suggests that use setting may provide an additional piece of information when assessing cannabis use among young people. That could be particularly valuable for harm reduction strategies, because a teenager who uses relatively infrequently might otherwise appear to have a lower-risk pattern based solely on frequency.

Solitary Cannabis Use Is Not a Diagnosis

It is important not to turn this finding into a simple rule that solitary cannabis use equals a cannabis problem. The study does not support that conclusion. Some young people may use cannabis alone without experiencing significant difficulties. Likewise, social cannabis use does not automatically mean that someone’s use is low risk. The researchers were studying associations within a population, not diagnosing individual students.

There is also an important limitation, as the study was cross-sectional, meaning the researchers examined reported cannabis use and consequences at a particular point in time rather than following individuals over many years. Therefore, the findings cannot determine whether solitary cannabis use contributed to the negative outcomes, whether existing problems contributed to solitary cannabis use, or whether both were influenced by other underlying factors, and that distinction matters.

Could Solitary Use Become a Screening Signal?

Perhaps the most practical implication of the research is not that solitary cannabis use should be treated as a problem by itself, but that it could become a screening signal worth asking about.

For clinicians, a simple question about whether a young person typically uses cannabis alone or with others could potentially provide additional context during an assessment. For parents, noticing that a teenager has shifted from primarily social use to regularly using cannabis alone might be a reason to start a conversation, but not necessarily a reason to immediately assume the worst. And for schools and public-health researchers, understanding use settings could help identify patterns that are missed when cannabis consumption is measured only by frequency.

The Bigger Picture on Teen Cannabis Use

Teen cannabis use is not one uniform behavior. Two young people can report the same number of cannabis-use days while having dramatically different experiences, motivations, and outcomes. Research increasingly benefits from looking beyond simple measures of how frequently a substance is used.

The Norwegian study adds another dimension to that conversation. Its most important message may be that context matters. Among the high school students studied, approximately one in four cannabis users also used cannabis alone. Those students reported a greater number and wider variety of negative consequences, including problems involving mental health, apathy, relationships, school, and law enforcement. These associations persisted even after researchers accounted for cannabis-use frequency and other risk factors.

That does not make solitary use a definitive warning sign, but it does make it a potentially useful question. Rather than asking only, “How often are you using cannabis?” researchers, clinicians, and families may increasingly need to ask, “How are you using it, and what is happening around that use?”  Sometimes, that additional context can reveal a much more complicated picture than a number on a frequency scale can provide.

References:

^{1. A.L. Bretteville-Jensen, J.B. Andreas, Cannabis use settings matter: National-level prevalence rates, correlates, and consequences of solitary cannabis use among high school students in Norway, Addictive Behaviors Addictive Behaviors (2026), doi: https://doi.org/10.1016/j.addbeh.2026.108820}