Long-Term Follow-up and Phenomenologic Differences Distinguish among Late-Onset Schizophrenia, Late-Life Depression, and Progressive Dementia

Objective: The diagnosis of patients with late-life onset of hallucinations and delusions but an absence of mood or cognitive disorder remains controversial. The authors used long-term follow-up and phenomenology to assess whether outcome varied by diagnosis. Methods: Twenty-eight individuals with late-life psychosis but no mood or cognitive disorder were compared with 48 individuals with late-life major depression and 47 individuals with psychotic symptoms and late-life dementia. All subjects were followed for a minimum of 1 year. Data from the last time examined were used to determine likelihood of death at 84 months by Kaplan-Meier analysis in all groups and the likelihood of developing dementia in the depression and late-life onset psychosis groups at 120 months. Results: Patients with dementia-plus-psychosis were more likely to die at 84 months than those with major depression or late-onset hallucinations and delusions. Subjects with depression or late-onset hallucinations and delusions did not differ in likelihood of developing dementia at 120 months. Conclusions: These results support the hypothesis that a condition characterized by psychiatric symptoms and no mood symptoms can begin in later life and that this disorder is not a precursor to dementia.