Heroin addiction has emerged as a serious problem with tremendous impacts on the addicts and the society. Since the introduction of opioids substitutive treatment in 2006, more than 30,000 heroin addicts had received treatment, and nearly 12,000 continued on treatment currently. However, an unknown proportion of patients hidden in community remained un-treatment. To motivate the community heroin addicts is thus a challenging task.

It is suggested that decision making deficit is core feature which determine outcomes and treatment motivations in patients with addiction disorders. Recently, the state-of-the-art development of epigenetics uncover that environmental modification, via altering level of DNA methylation and gene expression will influence on neurocognitive functioning.

Via respondent-driven sampling, this study aims to recruit a representative sample targeting at the hard-to-reach community heroin addicts. The goal of this study is to identify the clinical feature as well as decision making-related neurocognitive deficit in these patients. Moreover, the investigators will explore the interplay of clinical features, DNA methylation and gene expressions on opioids receptor genes. The findings will help to clarify the clinical characteristics of community heroin addicts, to uncover the links between DNA methylation and clinical features of heroin addiction and to develop modifiable treatment targets in the future.

Inclusion Criteria:

• 1) 20 to 65 of age; 2) meeting DSM-IV criteria of opioids dependence

Exclusion Criteria:

-

community heroin addicts