365 male patients with MA addiction were surveyed using SCID-I (Structured Clinical Interview for DSM-IV Axis I Disorders, SCID-I, Chinese version) from DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition, American Psychiatry Association, 1994) at the Xinkaipu detoxification center in Changsha, Hunan Province and the Baini Lake compulsory detoxification center in Xiangyin, Hunan Province from March 2013 to January 2014 (see Figure 1). Patients aged 16-60 were recruited into the case group if they matched the diagnostic criteria for MA addiction of DSM-IV. We excluded those with severe physical diseases, organic brain diseases, primary mental disorder or other substance addiction. According to the recruitment criteria, 224 MA addicts were recruited into the case group. Healthy patients (109 male) matched by age were recruited into the control group from the health management center of the Second Xiangya Hospital of Central South University. We excluded those with severe physical illness, organic diseases of the brain, primary mental disorder or other substance addiction. This study was approved by the ethics committee of Second Xiangya Hospital of Central South University. Participants (patients and healthy controls) were informed of the research process and provided written informed consent.
