Ten year follow-up of depression after diagnosis in general practice.

BACKGROUND: Depression is a serious illness with a high recurrence rate, mortality, and suicide rate, and a substantial loss of quality of life. Long-term course of depression, in particular of patients not referred to specialist care, is not completely clear. We performed a study in which the course of depression in general practice was studied for 10 years after the first diagnosis. AIM: To learn more about long-term course and outcome of patients with depressive illness for a full 10 years after diagnosis.
METHOD: A historic cohort study with 386 patients classified as depressive before January 1984, recruited from four general practices belonging to the Continuous Morbidity Registry of the University of Nijmegen in The Netherlands. This cohort was followed up for 10 years. Mortality was compared with a control group matched for age, sex, social class, and practice. Of 222 patients out of this cohort who could be followed up for a full 10 years after diagnosis, the case records were studied in detail.
RESULTS: No statistically significant difference was found in mortality between the 386 patients and the control group. Recurrence of depressive episodes did not occur in about 60% of the 222 patients (confidence interval 54% to 67%). Of the depressive patients, 15% were referred to secondary care and 9% were admitted to hospital.
CONCLUSION: Mortality, suicide, and recurrence rate were lower than expected, taking into account what is known from depression studies in psychiatry. These results stress the importance of long-term prospective follow-up studies of all patients with depression because of the emphasis on case-finding and treatment without exact knowledge of long-term course and outcome of patients who were not referred.