While limited, studies also suggest that cannabis use among tobacco smokers may predict poorer tobacco cessation outcomes (122-124). An epidemiological study found that cannabis use among tobacco smokers predicted persistent tobacco use 13 years later, and also was associated with a lower probability of making a tobacco quit attempt (19). In a clinical sample, cannabis use reported at baseline greatly reduced the probability of sustained tobacco abstinence at a 6-month assessment following treatment with NRT and counseling (123).
