Older marijuana users in substance abuse treatment: Treatment settings for marijuana-only versus polysubstance use...

Growing numbers of older adult marijuana users make understanding the marijuana-related treatment needs and treatment-related characteristics of this age group increasingly important. In this study, we examined four types of marijuana-involved admissions (marijuana as the only substance; marijuana as the primary substance with other secondary/tertiary substances; marijuana as the secondary substance; and marijuana as the tertiary substance) by treatment setting.

Data came from the 2012-2017 Treatment Episode Data Set-Admissions (TEDS-A), which includes 851,652 admissions by those aged 55+. Using multinomial logistic regression analysis, we focused on the 120,286 marijuana-involved admissions to test the hypothesis that polysubstance use would be associated with a higher likelihood of using detoxification and rehabilitation settings than ambulatory/outpatient settings.

Of all marijuana-involved admissions, 7.5% were marijuana-only, 12.7% were marijuana-primary, 58.4% were marijuana-secondary, and 21.4% were marijuana-tertiary admissions. Compared to marijuana-only admissions, admissions involving other substances were associated with a higher likelihood of detoxification and rehabilitation than ambulatory/outpatient treatment (e.g., RRR = 5.79, 95% CI = 5.08-6.61 for detoxification and RRR = 3.19, 95% CI = 2.89-3.52 for rehabilitation among marijuana-tertiary admissions). Referral source, first age of marijuana use, race/ethnicity, and homelessness were significant covariates.

Given increasing numbers of older-adult marijuana users, healthcare providers should screen older adults for marijuana and other substance use, and substance abuse treatment programs should become more responsive to older adults' needs.