Depression in multiple sclerosis: a longitudinal analysis.

High rates of depression have been documented in persons with multiple sclerosis (MS), but few studies have examined depression over time. This analysis considered data from 607 persons with MS in a 7-year period as part of an ongoing longitudinal study of quality of life in chronic illness. Latent growth curve analysis was used to examine trajectories in depression and the effects of covariates such as age, time since diagnosis of MS, type of MS, and functional limitations on the extent to which depression changed in the study period. Results of the analysis indicated that depressive symptoms fluctuated over time for individuals but did not show a tendency to an overall significant increase or decrease for the group as a whole. Younger age, longer time since diagnosis of MS, progressive forms of MS, and greater extent of functional limitation were predictive of greater depressive symptoms at Time 1. With the exception of functional limitation, which showed an association with depression at all periods, these variables did not predict changes in depressive symptoms over time. Gender was not a significant predictor of changes in depressive symptoms, nor did women have higher rates of depression as expected from previous research. The results of this analysis indicate the importance of screening for depression in all persons with MS.