... Psychology, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.2Graduate School,Chinese Academy of Sciences, Beijing, China.3Department of ... National Bureau of Statistics of China: China Statistical Yearbook. Beijing2003.18. Pan A, Franco OH, Wang YF, Yu Z, Ye X, Lin X: Prevalence and geographicdisparity of depressive symptoms among middle-aged ... researchers. All disparitiesbetween them were resolved by consensus.Quality assessmentAlthough many scales are availabl e to assess the validity and quality of trials, none can provide an adequatelyreliable...