A cross-sectional study of the relationship between frequency of cannabis use and psychiatric symptoms among people seeking mental health and addiction services in Nova Scotia (2019–21)

Abstract

BackgroundCannabis use may be a modifiable risk factor for mental health problems; however, the role of cannabis use frequency in population seeking mental health and addiction services remains unclear. This study aimed to: 1) compare the prevalence and functional impact of psychiatric symptoms among frequent, infrequent, and non-users of cannabis; and 2) evaluate the associations between cannabis use frequency and functional impact of psychiatric symptoms in help-seeking individuals. MethodsData from the Mental Health and Addictions (MHA) Central Intake system in Nova Scotia, Canada was used. Participants aged 19–64 who received MHA Intake assessments from September 2019 to December 2021 with complete information about substance use were included (N = 20,611). Cannabis use frequency over past 30 days was categorized into frequent (>4 times a month), infrequent (≤4 times a month), and non-use. Psychiatric symptomatology consists of five domains: mood, anxiety, psychosis, cognition, and externalizing behaviors. Multivariate ordinal logistic regression was used to examine the associations between cannabis use frequency and functional impact of psychiatric symptoms. ResultsFrequent and infrequent cannabis users had a higher prevalence of psychiatric symptoms in each domain than non-users, while no significant differences were found between frequent and infrequent users. Frequent cannabis use was associated with greater functional impact of psychiatric symptoms in each domain compared to non-users, while infrequent use was only associated with greater functional impact of externalizing behaviors. ConclusionFrequent cannabis use is associated with increased prevalence and functional impact of psychiatric symptoms among adults seeking mental health services.