Overall, 2645 males and 304 females participated in the study. The prevalence of methamphetamine dependence was 26% among males and 45% among females. All participants were on stable methadone doses. All participants were on methadone treatment for at least six months. There were no significant group differences in terms of mean age (t = 0.76, P = 0.89), mean education (t = 0.94, P = 0.84), living condition (X
2 = 0.84, P = 0.66), marital status (X
2 = 0.82, P = 0.67), employment (X
2 = 0.91, P = 0.87), and duration of methamphetamine dependence (t = 0.25, P = 0.26). Lifetime methamphetamine treatment was only 24% among males and females. This was limited to a therapeutic community program. Females were more likely to self - report depression (53% versus 22%, P < 0.05) and frequent psychiatric hospitalisations (28% versus 16%, P < 0.05) than males while males were more likely to self - report criminality (43% versus 24%, P < 0.05) and poor concentration (39% versus 13%, P < 0.05) than females (See
Table 1). All males and females reported that these social and health problems were related to methamphetamine dependence among them.