Abstract: Objective To explore the affecting factors of mental disorder offender′s competency to stand trial. Methods Assess 170 pre-trial criminal suspect or defendants′ competency to stand trial in the department of Forensic Psychiatry Forensic Medicine College Sichuan University, scale their psychological symptoms with BPRS and PANSS, collect their demographic and criminal data, then explore the affecting factors of the mental disorder offender′s competency to stand trial by means of analyzing these data using statistics description, t-test, chi-square test, rank-sum test and logistic regression analysis. Results Thinking disorder factor and active factor of BPRS and P value of PANSS affect the competency to stand trial significantly; in the incompetent to stand trial (IST) group, pearson′s ratio, pathological and unclear motivation′s ratio, schizophrenia diagnose ratio are all higher than those in the competent to stand trial (CST) group; the VIQ scores of the IST group is lower than that of the CST group, and all the deference have statistics significance. Conclusion Thinking disorder factor and active factor of BPRS, P value of PANSS, VIQ, mental disorder diagnose, mental disorder and violent behavior history, criminal motivation may affect his/her competency to stand trial obviously.

Key words: mental disorder offender, competency to stand trial, affecting factor