Clinical parameters predict HRQoL in inflammatory bowel disease (IBD), however some patients have impaired HRQoL despite clinical remission; furthermore, Crohn's disease (CD) is associated with smoking, while ulcerative colitis (UC) is largely a nonsmokers’ disease, indicating that psychological distress and personality variables might mediate the relationship of clinical variables with HRQoL and smoking.

To assess psychological distress and personality traits in IBD and their contribution to the formation of HRQoL and smoking habits.

In 76 IBD outpatients we compared psychological distress symptoms and defensive profile between CD and UC. In another study of 185 IBD patients, we tested the relation of psychological distress, defense mechanisms and personality traits with HRQoL, smoking, and nicotine dependence.

CD patients presented a more immature defensive profile. The more psychologically mature IBD patients had lower relapses and surgical operations’ rates. Psychological distress was associated with impaired HRQoL in a dose-response fashion. Somatization was independently associated with impaired HRQoL and mediated the relationships of anxiety and depression with HRQoL. In CD, the relationship of the smoking-linked personality characteristic “impulsive sensation seeking” with current smoking and nicotine dependence was stronger.

IBD patients exhibit several specific psychological difficulties in adaptation to stressors. Apart from addressing timely psychological distress and somatization symptoms, clinicians and consultation-liaison psychiatrists should consider the patients’ defensive profile, since such personality traits, although usually underestimated, are strongly independently associated with the disease's outcome. Our findings might be also relevant to more effective interventions targeting smoking cessation in CD patients.