It is first important to note that our study did not employ systematic population-based sampling – our study population consisted of patients being treated at a specific treatment center. As such, we cannot draw conclusions regarding populations other than the one under study. Results based on this kind of sampling must reflect various well-known ascertainment biases. With that major caveat in mind, the four main findings of our study with respect to this sample are: 1) onset of MA use and dependence was earlier in males as compared to females 2) females were more likely to experience MA withdrawal, (especially hypersomnia), 3) females were more likely to be MA dependent and to use MA more heavily than males, and 4) nicotine dependence is an associated factor shared by MA dependent men and women, whereas ASPD is more characteristic of males.
