Yunnan Institute for Drug Abuse, Kunming, China (JS, XW, GZ, JG, XL, JL); National Addiction Centre, Division of Psychological Medicine and Psychiatry, Institute of Psychiatry, King's College, London, UK (MW).
Send correspondence and reprint requests to Jiucheng Shen, MD, MPH, Yunnan Institute for Drug Abuse, 300 Xi-Hua-Yuan, Wu-Jia-Dui, Kunming 650028, Yunnan Province, China. E-mail: [email protected].
Received 21 February, 2014
Accepted 15 November, 2014
Ethic approval: This study received ethic approval for secondary analysis from IRB of Yunnan Institute of Drug Abuse (IRB00002096, FWA00020775).
Conflicts of interest: None declared.
