Harmful alcohol consumption in young adult populations poses many health risks on both individualized and population-based levels. Whether it be chronic heavy drinking, or once weekly binge drinking, the consequences of dangerous alcohol consumption are numerous and well-documented. The young adult demographic also leads all other age groups in total cannabis consumption, a statistic unlikely to change as cannabis use rates continue to increase across most demographics. While the literature concerning long-term cannabis use is not as developed as that of alcohol use, the existing evidence dictates it contains the potential to cause physical and psychological harm in the form of respiratory injury and mental illness exacerbation. In furthering the trends in use, this study aims to identify patterns of alcohol and cannabis consumption on a calendar-based timeline in a young adult population.
The study’s sample consisted of data from 761 participants enrolled in a longitudinal young adult lifestyle study based out of Seattle, Washington. Eligibility criteria included being aged 18-23 years old, reporting prior-year alcohol consumption, and residing within a 60-mile radius of Seattle. Education status varied in the sample, and participant data was grouped according to enrollment status for purposes of different analyses. Participants completed surveys monthly for a total of 24 months (01/2015-01/2016) documenting the following measures: demographics, education status, typical weekly alcohol use (including heavy episodic drinking occasions), and cannabis use. The data was analyzed using multilevel random effects modelling, multivariate Wald tests, and Poisson models all seeking to compare month-to-month variations in reported behavior. Comparisons were made to measures recorded in the month of January, which was found to be an acceptable baseline measure.
Results of the analysis found participants averaged 4.79 drinks per week, with heavy episodic drinking occurring at least once in 85% of the sample. At least monthly cannabis use was reported in 47% of the sample (derived from a missingness-corrected model). Alcohol use was highest from June-October, as well as in December. In fact, the highest measures of episodic drinking occurred in December. Individuals who did not identify as 4-year undergraduate enrollees reported overall lower scores on all drinking measures. Cannabis use was found to be highest in April and December, with most discrepancies between 4-year students and non-4-year students/non-students being insignificant.
Takeaway: this study suggests calendar variation in alcohol and cannabis use to be significant among young adults, with alcohol consumption pattern differences being more distinct than that of cannabis consumption across enrollment status.