Psychiatric and substance use disorders among adults over age 50 who use cannabis: A matched cohort study using...

Adults over age 50 increasingly use cannabis, but few studies have examined co-occurring psychiatric and substance use disorders (SUDs) in this population. The current study utilized electronic health record (EHR) data to compare adults age 50 + with ICD-10 cannabis codes (cases) and matched controls on common psychiatric and SUDs from 2016 to 2020.

Patients age 50 + from an integrated healthcare system in Hawai'i were identified using ICD-10 codes for cannabis (use, abuse, and dependence) from 2016 to 2018. In a matched cohort design, we selected non-cannabis-using controls (matched on sex and age) from the EHR (n = 275) and compared them to cases (patients with an ICD-10 cannabis code; n = 275) on depressive and anxiety disorders and SUDs (i.e., tobacco, opioid, and alcohol use disorders) over a two-year follow-up period.

Participants were 62.8 years (SD = 7.3) old on average; and were White (47.8 %), Asian American (24.4 %), Native Hawaiian or Pacific Islander (19.3 %), or Unknown (8.5 %) race/ethnicity. Conditional multiple logistic regression was used to estimate odds ratios comparing cases vs controls. Participants with an ICD-10 cannabis code had a significantly greater risk of major depressive disorder (OR = 10.68, p < 0.0001) and any anxiety disorder (OR = 6.45, p < 0.0001), as well as specific anxiety or trauma-related disorders (e.g., generalized anxiety disorder, PTSD) and SUDs (ORs 2.72 - 16.00, p < 0.01 for all).

Over a two-year period, diverse adults age 50 + in Hawai'i with ICD-10 cannabis codes experienced higher rates of subsequent psychiatric and SUDs compared to controls. These findings can guide efforts to inform older adults about possible cannabis-related risks.