[1] Peking Univ, Sch Nursing, Beijing, Peoples R China
[2] Peking Univ, Hosp 6, Psychiat Dept, Beijing, Peoples R China
[3] Peking Univ, Natl Inst Drug Dependence, Beijing Key Lab Drug Dependence Res, Beijing, Peoples R China
[4] Peking Univ, Sch Nursing, 38 Xueyuan Rd, Beijing 100191, Peoples R China
[5] Peking Univ, Natl Inst Drug Dependence, Beijing Key Lab Drug Dependence Res, 38 Xueyuan Rd, Beijing 100191, Peoples R China