The purpose of this research is to develop an objective assessment based on the virtual reality techniques which is used for evaluate addiction severity.

In order to evaluate the addiction severity and the effect of rehabilitation objectively, this study develops a virtual environment model based on the virtual reality technique, making the subjects in a drug related or neutral scene , at the same time recording the physical signs and eye movements index. Reliability and validity of this system will also be tested in this study. And we will construct the norm of addiction assessment system in Shanghai .The evaluating system will be very beneficial to develop novel and practical assessment for synthetic durg related disorder, and provide a reference for other drug dependence diagnosis.

Criteria for synthetic drug abusers:

Inclusion Criteria:

• In accordance with the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-4) for methamphetamine (MA) use disorders;
• Education level equal or more than 9 years;
• Have normal or corrected-to-normal vision;
• Have normal or corrected-to-normal hearing;
• Less than 3 months before last drug use;

Exclusion Criteria:

• Current substance use (except nicotine or caffeine) ;
• History of disease which influence cognition，such as seizure disorder、cerebrovascular disease、 head injury or other severe medication conditions;
• Intelligence quotient less than 70.

Criteria for healthy control:

Inclusion Criteria:

• Without schizophrenia family history;
• Without history of drug abuse;
• Education level equal or more than 9 years;
• Have normal or corrected-to-normal vision;
• Have normal or corrected-to-normal hearing.

Exclusion Criteria:

• History of disease which influence cognition，such as seizure disorder、cerebrovascular disease、head injury or other severe medication conditions;
• Intelligence quotient less than 70.

The study includes the synthetic drug abusers and healthy control into the experiment.The drug abusers will be recruited from compulsory isolated detoxification centers and non compulsory isolated detoxification institutions.The healthy control will be recruited from the residential communities.