Long-term outcome of depressive pseudodementia in the elderly

BackgroundThe term depressive pseudodementia has proved to be a popular clinical concept. Little is known about the long-term outcome of this syndrome.AimsTo compare depressed elderly patients with reversible cognitive impairment and cognitively intact depressed elderly patients.MethodsAll patients suffering from moderate or severe depression admitted to St Margaret's Hospital, UK as inpatients or day hospital outpatients between January 1 1997 and December 31 1999 (n = 182) were screened for entry into the study. Eligible patients were divided into those presenting with pseudodementia and those who were cognitively intact and followed up for 5 to 7 years.ResultsSeventy-one point four percent of those suffering from pseudodementia had converted into dementia at follow-up compared to only 18.2% in the cognitively intact group. The relative risk was 3.929 (95% CI: 1.985 to 7.775) and the ‘number needed to harm’ 1.88.ConclusionsReversible cognitive impairment in late-life moderate to severe depression appears to be a strong predictor of dementia. Inpatients and day hospital outpatients with depressive pseudodementia should probably have a full dementia screening, comprehensive cognitive testing and ongoing monitoring of their cognitive function.