The findings showed that clients with greater perceived stigma of addiction were less likely to receive cannabis treatment, which is consistent with the studies of Kerridge et al.,[4] van der Pol et al.,[6] and Brubaker et al.[12] An explanation of such findings is that stigma is one factor influencing substance users' decision to seek and enter treatment as well as cannabis abuse treatment utilization.[2345] Some studies have found that substance users may experience health-related stigma as a sociocultural process promoted by devaluing, prejudiced, discriminatory, negative perspectives that have labeled users as bad, dangerous, weak, immoral individuals who pose a risk to society. Stigma is a person-level barrier that refers to individuals' attitudes and behaviors that affect health decisions, which lead to avoiding treatment or dropping out prematurely.[2513] Therefore, the stigma may impair treatment utilization in several ways; for example, drug users may seek to avoid the public label and stigmatization of drug abuse and discontinue treatment prematurely or may seek to avoid the negative feelings of shame and guilt about themselves by choosing not to seek treatment.[131415] Moreover, the levels of stigma associated with each substance vary by social acceptability and its potential harmfulness, and cannabis use has become less stigmatized due to the belief that it is less harmful and has the lowest rates of disapproval compared to those of other illicit drugs. Thus, cannabis users delay seeking treatment and entering into treatment services.[416] This finding does not support those of Frischknecht et al.,[17] Brown et al.,[18] and Mohammed,[19] who found no relationship between stigma and previous treatment attempts. These potential differences might be attributed to the study population, the types of stigma, and the measurement of stigma.

Gender differences in receiving treatment were found, and females were less likely to receive treatment than males, in accordance with the findings of Wu et al.,[20] Ilgen et al.,[21] Chen et al.,[22] and Choi et al.[23] One possible explanation is that females are more likely to encounter multiple barriers to drug abuse treatment than males, such as family and partner influence and responsibilities of child care and home care, which may interfere with regular treatment, as well as a lack of support from their partner in seeking treatment, which may decrease their motivation to pursue treatment.[242526] Another reason is that the fear of treatment and a lack of information about and confidence in the treatment system keeps them from receiving treatment.[25272829] Moreover, females were more likely than males to perceive negative consequences of treatment, such as losing their job, friends, or custody of their children, as well as experiencing disrupted family relationships, all of which affected their decision to seek treatment.[272930] An alternative explanation is that female substance users were more highly stigmatized than males, and this heightened stigma led to less interest in seeking treatment. In addition, labels, guilt, and shame were significant barriers to treatment for females.[2425293031] Furthermore, clients with a family history of drug problems received more treatment in this study. Consistent with the findings of Keyes et al.,[32] Kenny et al.,[33] Tucker et al.,[34] and Kerridge et al.,[4] showed that families as a pressure structure had been involved in drug users' decision to start therapy, even if they did not consider their drug use to be a problem. The explanation for this finding is that family members of individuals with drug problems hold less stigmatizing attitudes and show positive support to their family, as shown in their involvement in treatment and discussions of their experiences of the family member with a substance use disorder, which would increase the likelihood of seeking treatment.[635] In addition, individuals may be learning from a family member who struggles with substance abuse problems, which may motivate them to seek treatment to avoid future consequences of drug abuse.[12] Our results still showed that need factors as a history of mental health problems were associated with receiving treatment. This finding is consistent with those of previous studies, such as Chen et al.,[22] Choi et al.,[23] Ilgen et al.,[36] and Blanco et al.,[37] indicating that individuals with comorbid psychiatric and substance use disorders are more likely to receive treatment. A possible explanation is that psychiatric disorders may mediate the relationship between stigma and drug abuse treatment utilization and that individuals who had received treatment had significantly more mental health problems than did those who had never been in treatment.[4638] Another explanation is that there is a greater severity of substance use disorder when it is related to a comorbid psychiatric disorder, and drug users are aware of their symptom severity as a result of prolonged substance abuse, which may lead them to suffer from illness, thus motivating them to enter treatment.[223940]

The obvious limitation of the study is its cross-sectional design, so temporality and causality could not be inferred. This perceived stigma of addiction was assessed by the addiction stigma scale for Thai people, and the findings may differ from those of other people in different contexts. Despite these limitations, our study has the strength of a large sample size and uses a nationally representative sample so that the results can be generalized. This study demonstrated the influence of perceived stigma on treatment among cannabis addicts, a hard-to-reach group. Further, longitudinal studies are needed to delineate the temporal associations between stigma and treatment utilization, as stigmatization appears to change over time. In addition, future research needs to examine the association between stigmatization and substance abuse treatment among other legal or illegal drug users, or how stigma relates to the severity of drug use behavior.