Psychotic symptoms and paranoid ideation in the non-demented elderly. A population study on prevalence, incidence, and associated factors, and their relationship to cognitive functioning and prognosis

Abstract

Background: Psychotic symptoms and paranoid ideation are not commonly reported in non-demented elderly, and may be underrated in traditional epidemiological studies.Aims: The aims of this study are to characterize the incidence and prevalence of psychotic symptoms and paranoid ideation and associated factors; the relationship between neuropsychological performance and psychotic symptoms and paranoid ideation and the prognosis of psychotic symptoms and paranoid ideation in non-demented elderly. Methods: Psychotic symptoms, physical disorders, disability in daily life, and sensory impairments were assessed with psychiatric and physical examinations and medical record reviews in a representative sample of 70-year-olds (N=392) from Gothenburg, Sweden in 1971. Psychotic symptoms that appeared after onset of dementia and during a delirium were not included. The sample was followed for 20 years at ages 75, 79, 81, 83, 85, 88 and 90. At age 85, the sample was extended to include every second 85-year-old in Gothenburg, and 494, including 100 from the original sample, were examined. At age 85, the examinations also included a key-informant interview, CT-scan of the brain and neuropsychological examinations. Results: Between ages 70-79 the incidence of psychotic symptoms was 4.4 per 1000 person-years, 7.9 per 1000 person-years between ages 79-85 and 1.9 per 1000 person-years between ages 85-90. After inclusion of information from key-informant interviews, the incidence of psychotic symptoms increased to 7.4 cases per 1000 person-years between ages 85-90. At age 85, the prevalence of psychotic symptoms was 10.1%, including hallucinations among 6.9% and delusions among 5.5%. The prevalence of paranoid ideation was 6.9%. Hallucinations were associated with major depressive syndrome, disability in daily life, and visual deficits. Delusions were associated with disability in daily life. Paranoid ideation was associated with visual deficits and myocardial infarction. Hallucinations, delusions and paranoid ideation were each related to an increased incidence of dementia between the ages of 85 and 88. Hallucinations were associated with increased 3-year mortality in women but not in men. Basal ganglia calcification on CT was observed in 19% of mentally healthy and 64% of non-demented 85-year olds with hallucinations or delusions (Odds Ratio 7.7, 95% Confidence Interval 2.9-29.7). Non-demented 85-year-olds with psychotic symptoms or paranoid ideation performed worse on tests measuring verbal ability, logical reasoning and two tests of spatial ability after adjustment for sex, education, hearing impairment, visual deficits, somatic disorders, depression, mortality, and incident dementia. Conclusions: We found a higher prevalence of psychotic symptoms and paranoid ideation in the elderly than previously reported and these symptoms were associated with broad psychopathology and a poor prognosis.