Non-ulcer dyspepsia, also termed "nervous dyspepsia," is a heterogeneous syndrome: ulcerlike symptoms can occur with the irritable bowel syndrome, gastroesophageal reflux, and other disorders. In addition, there is a significant subgroup of non-ulcer dyspepsia sufferers who have no disorder associated with, and no known cause for, their dyspepsia, and the dyspepsia in this subgroup is given the provisional name of "essential dyspepsia." The aim of this study was to assess if psychological factors are associated with patients who present with essential dyspepsia. Psychometric testing was carried out on 76 essential dyspepsia patients (including 18 patients with gastroduodenitis), 76 randomly selected dyspepsia-free community controls (matched for age, sex, and social class), and 66 duodenal ulcer controls. Essential dyspepsia patients were retested a mean of 3.6 mo later. Using stepwise regression analysis, the initial scores of essential dyspepsia and duodenal ulcer subjects showed them to be more neurotic, anxious, and depressed than community controls; these abnormalities persisted in essential dyspepsia patients on retesting and were not affected by the symptom status. It is concluded that essential dyspepsia patients who present for investigation with symptoms are more likely to be persistently neurotic, anxious, and depressed than dyspepsia-free controls, and this is unrelated to the presence of symptoms, but the association may not be of major clinical significance, as the numerical differences observed between groups were small and the correlation coefficients were low.