Abstract: Objective To explore the relationships between the perfectionism,automatic thoughts and depression in medical university students,to provide suggestions for improving students' negative emotions. Methods The questionnaire including the Frost Multidimensional Perfectionism Scale,Automatic Thoughts Questionnaire and Beck Depression Inventory, was administrated among 334 students. Results Depression were significantly and correlated with automatic thoughts and perfectionism(except for the organized dimension),while automatic thoughts positively related to depression(r=0.42~0.47,P<0.01).Students' automatic thoughts had mediating effect between maladapitive perfectionism and depression (r=0.69,P<0.01), the ratio of mediating effect to total effect was 64.9%. Conclusions The effect of perfectionism on depression is partially mediated by automatic thoughts.This will provide a new perspective on depression intervention for maladaptive perfectionists.

Key words: Perfectionism, Depression, Automatic thoughts, Medical college students