Aim: Psychological factors such as personality traits may affect the adjustment capacity and Quality of Life (QOL) in Ulcerative Colitis (UC) patients. Type D personality has some similarities with general personality traits of UC patients. The aims of this study were to compare NEO personality profile and type D personality between healthy normal group and UC patients; and to determine the possible relationship between type D personality and QOL in UC patients. Materials and Methods: The sample of study comprised of 58 UC patients and 59 healthy control subjects (from their family members). All participants were requested to fill out NEO‑FFI, Type D personality (Ds14) Scale and WHO‑Quality of Life Questionnaire. Results: The findings indicated that UC patients scored higher in neuroticism (P<0/01); lower in extraversion (P<0/01) and openness (P<0/05) than healthy controls but their differentiation were not significant in agreeableness and conscientiousness. The findings showed that 59% of UC patients and 33% of the control subjects had type D personality; and the differences in frequency of type D between the two groups were significant (P<0/05). The mean QOL scores of type D personality in UC patients was significantly lower than patients without type D personality (F= 7/55, P<0/01). Type D personality could better predict QOL of UC patients than NEO dimensions. Conclusions: Differences were observed between UC patients and their healthy family members, in terms of personality factors. Type D personality may be regarded as an important factor that may bring about some adverse effects in QOL among UC patients.
