association of, nicotine dependence, in both sexes, seems warranted. Certainly, there are some limitations that need to be considered in the context of the current study, including the non-systematic sampling approach alluded to above as well as the relevant secular trends inasmuch as data collection was affected by the context of a national “war on drugs,” shifts in MA use, and shifts in those receiving treatment. First, the data are cross-sectional, and thus, the causal relationships between associated factors and MA dependence cannot be determined. Second, our study investigated only inpatients, which are likely to have more severe MA use than outpatients (although this may be mitigated by policies permitting anyone to voluntarily receive treatment). Third, given the location of the treatment center in central Thailand, our results may not be representative of all MA users in the country. Although the treatment center in our study is the largest substance use disorder treatment center in Thailand and accepts patient referrals from all regions of the country, the relevance of our findings for other treatment centers in other parts of Thailand remain to be established. Further research examining sex differences associated wtih MA use and dependence in outpatient, multicenter and randomly
