The study investigated the relationships between specific demographic, psychosocial, and physiological variables and the severity of duodenal ulcer disease in a population of patients with proved duodenal ulcer. Intercorrelations between psychosocial and physiological variables were also studied. The study design was cross sectional and retrospectively assessed life change units and DUD severity during the previous 6 months in 39 male ulcer clinic outpatients. Anxiety, depression, life change units, the family environment, ABO blood type, secretor status, serum pepsinogen, and serum fasting gastrin were evaluated. A DUD severity score was calculated from self-reported ulcer pain symptoms and ulcer complications. Gastrin levels correlated significantly with three Family Environment Scale (FES) subscales, including: (a) independence, (b) achievement orientation, and (c) expressiveness. Duodenal ulcer disease severity scores correlated with Zung SDS scores, but not with state or trait anxiety, life change units, or the FES.