The aim of the current study was to establish the causal model among parental bonding, personality characteristics, mental health, quality of life, and chronic regional pain (CRP). Thirty CRP patients and 56 mental illness patients were compared using the Visual Analogue Scale (VAS), Chinese Health Questionnaire (CHQ), Eysenck Personality Questionnaire (EPQ), World Health Organization Quality of Life-Brief-Tawain Version (WHOQOL-BREF-TW), and Parental Bonding Instrument (PBI). There were significant differences in mental health, personality characteristics, and quality of life between the CRP and mental illness groups. Structural equation modeling showed that parental bonding could directly affect personality characteristics, and, hence, directly impact disease and quality of life. CRP is different from mental illness in many dimensions. In this study, CRP appeared to be caused by actual physical dysfunction rather than mental dysfunction.