Tags: Cannabis; psychosocial function; adolescent use; chronic cannabis use

 

Thumbnail: This report evaluates associations between cannabis use and psychosocial functioning among people who use cannabis. It reviews recent longitudinal studies to identify potential causative links between cannabis use and psychosocial functioning. Infrequent adolescent use is associated with poorer psychosocial functioning in some areas. Frequent, chronic use in adults is associated with poorer psychosocial functioning in many areas.

 

The problem: As cannabis legislation changes and the legality of cannabis becomes more widespread, cannabis use is expected to become more common. Cannabis use is thought to influence psychosocial function in two main ways: 1- through direct pharmacological/neurobiological effects on the brain, or 2- through indirect effects on the social environment/involvement associated with illicit drug culture. In light of this, there is reason to think that increased cannabis use could contribute to worsening psychosocial functioning among some users. Thus it is important to understand any causative links between cannabis use and psychosocial function.

 

The study: This review focuses on the impact that increased cannabis use may have on psychosocial functioning. It updates previous reviews and considers recent prospective, longitudinal studies (published from 2015-2020) of cannabis use and psychosocial functioning, looking at evidence for and against causation. This study also describes implications for theory, research, prevention and policy.

 

 

Main Points:

• School grades: studies tentatively suggest that infrequent cannabis use in high school and early college are not prospectively associated with lower grades

• Educational attainment: several studies found that adolescent cannabis use was associated with a lower likelihood of completing high school and/or attaining a university degree.Studies following adolescents into adulthood also found this association.

• Unemployment: infrequent adolescent cannabis use and frequent, chronic adult use were not found to be associated with unemployment

  • However, when studies took occupational prestige and income into consideration, evidence showed that chronic, frequent adult users had attained lower success (generally in a dose-response fashion- more use associated with lower attainment)

• Financial strain: chronic, frequent adult cannabis use was found to be consistently associated with higher levels of financial difficulty, while adolescent/young adult users who quit did not show the same association.

• Other substances: infrequent adolescent use and chronic, frequent adult cannabis use were consistently associated with more frequent use of other substances and substance-use problems.

• Antisocial behavior: both infrequent adolescent use and chronic, frequent adult cannabis use were consistently associated with antisocial behaviors

• Interpersonal relationships: few studies reported on this, but those that did tentatively suggest that there is no solid link between cannabis use and relationship problems

• Associations between cannabis use and poorer psychosocial functioning could also be due, in part, to confounding factors (socioeconomically factors, genetic risks, etc)

 

Conclusions: Evidence suggests that cannabis use may not be psychosocially harmless, but there is no clear evidence that it specifically causes psychosocial problems. Some evidence is consistent with causal effects, but these observational studies are not idea for determining whether or not cannabis is the root cause of a given issue.

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Why this is a good study:

• This is a valuable study because it considers a number of different aspects of psychosocial behavior and examines their association with cannabis use

• This report identifies weaknesses in the studies reviewed which provides a direction for future research

 

Why this isn’t a perfect study:

• This review relies on the data collected from previous studies, and is thus limited in the conclusions it can draw. For example, there was little data regarding alternative risk factors associated with study subjects, so this review is unable to determine what impact these other factors might have on the psychosocial outcomes being measured.

• The studies reviewed are observational, which are excellent for documenting associations, but are less useful for conclusively determining cause and effect.

 

What this study adds:

• Unlike previous studies, this one considers studies looking at adolescents/emerging adults separately from studies that followed adolescents into adulthood

 

What it doesn’t:

• None of the studies reviewed took into account the quantity or potency of cannabis used, only the frequency, so this study cannot evaluate what impact these factors may have on the associations with psychosocial function

 

Funder: None stated

 

Author conflicts: None declared