Risk factors for recurrence in depression in the Lundby population, 1947-1997

Background: Depression is a common disorder in both men and women, and the recurrence rate is high. The aim of this study was to identify risk factors for recurrence in depression in the Lundby Study. Methods: The Lundby Study is a community-based longitudinal study with focus on mental health. The study started in 1947 and three follow-ups have been carried out since, the last one in 1997. The population consists of 3563 subjects. Data from 508 subjects afflicted by depression was gathered. Premorbid factors (gender, socioeconomic status, marital status, personality and heredity) and factors related to the first depressive episode (age, degree of impairment and melancholic depression) were investigated regarding their influence on the risk for recurrence in depression. Multiple logistic regression was used in the calculations. Results: Risk factors associated with recurrent depression were melancholic depression at first onset (OR 3.52 [95% CI 1.62-7.66, p< 0.001]), young age as compared to old age at first onset (OR 0.51 [95% CI 0.28-0.92, p = 0.03]) and a premorbid nervous/tense personality (OR 1.77 [95% CI 1.22-2.56, p< 0.01]). Demographic factors, including gender, had no effect on the odds of recurrence. Limitations: The Lundby Study spans over 50 years, making the results vulnerable to changes in diagnostic regimes and recall bias. Conclusion: Melancholia at onset, regardless of severity of symptoms, had the greatest impact on the risk of recurrence in depression in the Lundby Study. Information about risk factors for recurrence in depression are useful in offering effective preventive measures in the form of psychotropic drugs and psychotherapy, and deciding the length of follow-up.