Context: Although depression in Alzheimer disease (AD) has a negative emotional and functional impact on patients and caregivers, specific criteria to diagnose depression in AD are still to be validated.
Objective: To validate a set of diagnostic criteria for major depression in AD.
Design: Cross-sectional design using latent cluster analysis (LCA).
Setting: Participants were recruited from consecutive referrals to a Memory Clinic of a tertiary hospital.
Participants: A consecutive series of 971 outpatients with probable AD.
Main outcome measure: Clusters of patients with or without major depression as determined with LCA.
Results: A LCA demonstrated three clusters that were considered to represent major depression, minor depression, and no depression. All nine Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for major depression were significantly associated with the major depression cluster. Although a diagnosis of generalized anxiety disorder (GAD) and apathy were also associated with the major depression cluster, irritability was not.
Conclusions: The DSM-IV criteria for major depression should be used unmodified to diagnose depression in AD. Future studies should determine whether GAD should be included as an additional diagnostic criterion.