Sudden gains-sudden and large decreases in depression severity in a single between-session interval-were identified by T. Z.Tang and R.J.DeRubeis(1999).This study aimed at investigating the occurrence of sudden gains in the process of therapies in China,as well as its magnitude,session of occurrence,reversal rate and the relationship between sudden gains and outcome.Then it was tested whether the initial symptom severity and working alliance would be associated with sudden gains. 82 clients were involved in this longitudinal study.The depress...