A review article published in the journal Epidemiologia describes the impact of cannabis use on mental health among Australian and American youth.
Study: Cannabis Use and Its Impact on Mental Health in Youth in Australia and the United States: A Scoping Review. Image Credit: hikrcn / Shutterstock
Background
Cannabis has a century-old history of use for medical, spiritual, and recreational purposes. Its popularity is increasing among young people worldwide, reflecting a global prevalence of 2.8%.
The estimated prevalence of cannabis use among youth in the United States is 7.1%, making it the second-most used substance after alcohol. In Australia, cannabis use prevalence is about 34% among young people aged 14 years and above.
The use of cannabis is increasing globally because of the general perception of its harmless nature and lack of dependence. However, a large pool of evidence indicates the negative health impact of long-term and frequent cannabis use.
The psychoactive compound 9 delta-tetrahydrocannabinol (THC) present in cannabis is primarily responsible for adverse mental health outcomes among users. Cannabis also contains some beneficial bioactive compounds, including cannabichromene (CBC), which is known to have pain-relieving, neuroprotective, and anti-inflammatory properties.
In this review, authors have extensively analyzed existing evidence on the impact of cannabis use on mental health among Australian and American youth.
The nature of cannabis legalization is similar in these countries. Recreational and medical use of cannabis is already legal in many states, and others are in the process of legalizing it. Because of these factors, these two countries present a unique context for studying the mental health impact of cannabis use.
Study design
The authors searched various electronic databases to select relevant human studies on the mental health impact of cannabis use among young populations in Australia and the US. They included peer-reviewed journal articles published in English, including systematic reviews, meta-analyses, and cohort, longitudinal, and cross-sectional studies.
A total of 24 studies were selected and analyzed in the review, which included three systematic reviews and meta-analyses, seven cohort studies, seven longitudinal studies, and seven cross-sectional studies. Of these studies, three were conducted in Australia and 21 in the US.
Important observations
The studies selected in the review pointed out the negative impact of cannabis use on various mental health issues, including depression, anxiety, suicidal risk, psychosis, cannabis dependence, and other mental disorders.
Depression and anxiety
The analysis revealed that cannabis use significantly increases the risk of depression among young people aged 12 to 32 years. The risk was comparatively higher among African American females and those belonging to LGBTQI groups.
A trend of increasing cannabis use from adolescence to adulthood was observed in some studies. However, no conclusive association between the age of cannabis use and the development of depression was found.
Regarding anxiety risk, studies produced mixed results, with some showing a significantly higher risk of anxiety development due to cannabis use and others showing the absence of any such association.
Suicidal risk
The analysis revealed that cannabis use can increase the risk of suicidal ideation, suicidal thoughts, and suicidal plans among adolescents. An association of past-year cannabis use disorder, daily cannabis use, and non-daily cannabis use was also observed with higher rates of suicidal ideation, plan, and attempts among young people.
The increase in cannabis use-related suicidal risks was more significant among young people with or without cannabis use disorder. However, females showed higher susceptibility than males.
Psychosis
A direct association between the frequency of cannabis use and cannabis use disorder and the risk of psychosis was observed among young people, with females showing higher prevalence than males.
Young people who used cannabis more frequently showed a higher risk of developing psychotic symptoms, such as hallucinations and paranoia.
Cannabis use disorder and dependence
The intensity of cannabis use showed a direct association with cannabis use disorder, with recent users showing a higher risk than non-users. A higher susceptibility to develop alcohol and opioid use was observed among adolescents with cannabis use disorder.
Considering different forms of cannabis, the evidence indicated that the risk of a cannabis use disorder, abuse, and dependence is higher for blunt use, followed by dual cigar and blunt use, and non-blunt marijuana use.
Study significance
This review article highlights that cannabis use among young people is associated with the risk of developing depression, psychosis, suicidal tendencies, cannabis use disorder, dependence, cognitive impairment, and externalizing behavior, particularly attention deficit hyperactivity disorder.
The risk of developing mental health issues is associated with cannabis use frequency, duration, intensity, and types of cannabis use. Factors that can significantly increase the risk of mental health issues include female gender, minority, LGBTQI, African American, Aboriginal, and Torres Strait Islander youth, and the age of onset of cannabis use.
Overall, the findings highlight the need for increasing awareness among young people about the negative mental health impact of cannabis use.
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