Risk factors for cannabis use disorders and cannabis psychosis in Japan: Second report of a survey on cannabis-related health problems among community cannabis users using social networking services

AimTo determine the risk factors for cannabis use disorders and cannabis psychosis in Japan based on a 2021 online survey among Japanese users of social network services.MethodsThe 3142 respondents who had used cannabis within the preceding year were categorized into two groups based on the development of cannabis use disorder and/or cannabis psychosis. Analyses were performed to determine these conditions' risk factors.ResultsMultivariate analysis revealed that factors significantly associated with cannabis use disorders were "cannabis-use initiation at a young age " (p = 0.004, OR: 0.951, 95% CI [0.920-0.984]), "family history of mental health problems " (p < 0.001, OR: 1.988, 95% CI [1.545-2.556]), "psychiatric disorders preceding cannabis use " (p = 0.039, OR: 1.672, 95% CI [1.026-2.722]), and "use of cannabis products other than dry flower " (p < 0.001, OR: 2.725, 95% CI [1.844-4.026]). Factors significantly associated with cannabis psychosis were "cannabis-use initiation at a young age " (p = 0.011, OR: 0.888, 95% CI [0.811-0.973]) and "family history of mental health problems " (p = 0.002, OR: 2.531, 95% CI [1.400-4. 576]).ConclusionRisk factors for problematic cannabis use were cannabis initiation at a young age, pre-cannabis psychiatric disorders, family history of mental health problems, and the use of cannabis products other than dry flower. However, the causal relationship among these factors remains ambivalent.