Objectives. To investigate the direction of a possible relationship be
tween peptic ulcer disease and personality disorders. Design. A cohort
study of 50-year old patients, observed for 2 decades. Setting. Glost
rup County, Denmark (population 100000). Subjects. A representative sa
mple of 50-year old people born in 1914 (n = 673) were followed for 20
years, All 673 filled in the Minnesota Multiphasic Personality Invent
ory (MMPI) in 1964 and 513 were retested with MMPI in 1974. Main outco
me measures. Prevalence of peptic ulcer disease 1964, incidence of pep
tic ulcer disease 1964-84, MMPI scores. Results. The prevalence of pep
tic ulcer disease in 1964 was 7% and the average annual incidence in t
he period 1964-84 was 2.1 per 1000 persons. Those with incidental pept
ic ulcer in 1964-84 had normal MMPI scores in 1964, whilst those with
peptic ulcer in 1964 had a slight but statistically significant increa
se in one neuroticism scale (HS) only. The group with prevalent ulcer
disease in 1974 exhibited statistically significant increases in the t
hree neuroticism scales (HS, D, HY) and in scale Pd and scale Pt at MM
PI retesting. In addition they had statistically significantly higher
scores in the three neuroticism scales compared with the other persons
who still had normal scores in all scales. Conclusions. Personality d
isorders in patients with peptic ulcer are consequences of the disease
and not causal factors.