BACKGROUND: Clinical observations and epidemiological studies suggest that experiences of negative life events, especially those manifested as depression, may contribute to an increased susceptibility to periodontal disease. OBJECTIVE: In the present study, the prevalence of some negative life events and psychological factors and their relation to periodontal disease were investigated. The sample consisted of individuals 50-80 years of age from an extensive cross-sectional epidemiological study performed in 1993 in the city of Jönköping, Sweden. METHOD: 298 dentate individuals from the Jönköping study were randomly selected. Clinical and radiographic examinations included registration of the number of existing teeth, plaque index, gingival index, pocket depth, and alveolar bone loss. In addition, a questionnaire about socioeconomic status, life events, and psychological and stress-related factors was used. RESULTS: The results revealed that, in addition to the well-documented periodontal disease risk factors such as increased age, oral hygiene status, and smoking, the loss of a spouse (being a widow or widower) and the personality trait of exercising extreme external control were also associated with severe periodontal disease. CONCLUSION: The findings support recent studies suggesting that traumatic life events such as the loss of a spouse may increase the risk for periodontal disease. Above all, the present results indicate that an individual's ability to cope with stressful stimuli (coping behavior), as measured by the beliefs of locus of control of reinforcements may play a role in the progression of periodontal disease.