This population-based study of primary care patients investigated the prevalence of common behavioral health conditions across cannabis use frequency in a large health system in Washington State, Kaiser Permanente Washington. (Cannabis is legal for both medical and non-medical use in Washington.)
Using electronic health record data collected as part of CTN-0065, cannabis frequency was categorized into three levels of past-year use: none, less than daily, and daily.
Other behavioral health conditions identified through screening included: depression symptoms, unhealthy alcohol use, and any illicit drug and/or medication misuse. EHR-documented tobacco use and composite indicators for both mental health and substance use disorder diagnoses were also assessed for the past year.
Analysis revealed a strong association between the frequency of cannabis use and tobacco use, depression symptoms, and other drug use, as well as diagnosed mental health and substance use disorders.
Tobacco and unhealthy alcohol use were most common among young adult patients who reported daily and any past-year cannabis use, respectively.
Among patients who used cannabis daily, nearly 50% reported depression symptoms and more than 35% had a past-year mental health disorder diagnosis.
Conclusions: Asking about the frequency of cannabis use as part of routine behavioral health screening primary care in a state with legalized use identifies patients at increased risk for substance use and mental health conditions. Patients with mental health conditions who use cannabis frequently can then be engaged in discussions of how their use relates to their mental health conditions.