Objective: To explore the underlying structure of symptom presentation in older adults with major depression by identifying homogeneous clusters of individuals based on symptom profiles.
Design: Secondary data analysis using latent class cluster analysis.
Setting: Clinical Research Center for the Study of Depression in Later Life conducted at Duke University.
Participants: Three hundred sixty-six patients age 60+ who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for major depression and were enrolled in a longitudinal naturalistic treatment study.
Measurements: Responses to the 10 items of the Montgomery-Asberg Depression Rating Scale at the time of study enrollment.
Results: The authors identified four latent clusters of older adults with major depression. Patients in Cluster 1 (47.2%) had mean scores of average severity for reported and apparent sadness and lassitude and low mean scores for reduced appetite. Patients in Cluster 2 (27.1%) had higher mean scores compared with Cluster 1 for all items, and particularly for apparent sadness. Patients in Cluster 3 (18.9%) had the lowest mean scores for both apparent and reported sadness, but a similar profile compared with Cluster 1 for inner tension, reduced sleep, reduced appetite, and concentration difficulties. Cluster 4 (6.8%) had the highest mean scores for each item. Both apparent and reported sadness accounted for a large amount of variance among the four clusters. Patients in Cluster 4 were more likely to have 12 or less years of education and/or one or more functional limitations.
Conclusion: The heterogeneity in symptom presentation among older adults diagnosed with major depression can potentially inform the development of DSM-V.