Perceived harmfulness of various alcohol- and cannabis use modes: Secular trends, differences, and associations with actual substance use behaviors among Norwegian adolescents, 2007-2015 (2019)

Background: How youth perceive harmfulness of risk behaviors such as substance use relates to their engagement in those behaviors. Yet, little is known about how different substance use modes (i.e., variations in amounts and use frequencies) are perceived. We investigated how adolescent perceptions of harmfulness of various alcohol- and cannabis use modes changed over time, compared to one another, and related to actual substance use behaviors.
Methods: We examined nationally-representative repeated cross-sectional samples of 16-year olds in Norway, assessed in 2007, 2011, and 2015 (NTotal = 9296) as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Adolescents reported their: 1) lifetime alcohol- and cannabis use, and 2) perceived harmfulness of various alcohol- and cannabis use modes.
Results: Prevalence estimates for perceived harmfulness: 1) remained high and stable, or increased for alcohol use modes, and 2) declined for all cannabis use modes (i.e., using 1-2 times, occasionally, and regularly) since 2007-cohort. High quantity daily drinking was more commonly perceived as harmful than minimal or occasional cannabis use. Even though culturally-relevant use modes (i.e., weekend heavy drinking and experimental cannabis use) were not most commonly endorsed as harmful, only perceptions of those use modes as harmful were inversely associated with actual substance use.
Conclusions: How adolescents from Norway perceived harmfulness of alcohol- and cannabis use depended on the specific substance, its use modes, and secular cohort. Perceived harmfulness was associated with measures of actual substance use predominantly along the culturally- and adolescent-relevant modes of use.
Highlights:
Perceived harmfulness of alcohol and cannabis use among adolescents in Norway depended on the specific usage modes.
Perceived harmfulness of alcohol and cannabis use among adolescents in Norway followed diverging secular trends.
Prevalence of perceived harmfulness of alcohol use significantly increased for weekend heavy drinking mode since 2007.
Prevalence of perceived harmfulness of cannabis use declined for all examined usage modes - since 2007.
Only perceptions of harmfulness from adolescent-relevant usage modes were associated with actual substance use.