There have been a few prior published studies about sex differences in MA use in Thailand, a country ranked among the top worldwide for lifetime prevalence of MA use in the past decade (UNODC, 2003). However, differences between the sexes have not been examined since the enactment of new drug law enforcement policies, affording an opportunity to evaluate potentially new and/or changing patterns of MA use between the sexes. While other studies have investigated sex differences in inpatient MA users in other countries, a number of variables have not been investigated, including, for instance, severity and symptoms of MA-dependence, MA withdrawal, and factors influencing the dependence trait by sex. Morever, the chosen Thai context differs in several important respects (Hser et al., 2005, He et al., 2013), including the criteria for hospitalization (since under the new policy, Thai treatment centers hospitalized all levels of MA use severity ranging from problematic use but no dependence to severe dependence). Therefore, in addition to analyses of sex differences in MA use and dependence, the current cohort also provided an opportunity for directly comparing
