Is The Prevalence Of Psychosis In The Very Old Decreasing? A Comparison Of 85-Year-Olds Born 22 Years Apart

Objective To elucidate whether there is a decrease of psychotic symptoms in 85-years-olds without dementia and if factors associated with psychotic symptoms have changed, we studied two birth cohorts of 85-year-olds born 22 years apart. Methods Every second, 85-year-olds in Gothenburg, Sweden was invited to neuropsychiatric examinations in 1986 to 1987 (participation 63.1%, N = 494) and in 2008 to 2010 (60.5%, N = 571). A close informant was interviewed by a psychiatrist or a research psychologist. Results The prevalence of psychotic symptoms in 85-years-olds without dementia decreased from 10.1% in 1986 to 1987 to 3.2% in 2008 to 2010 (P < .001). Disability in daily life (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.1-4.5), depressed mood (OR, 3.9; 95% CI, 2.1-7.1), irritability (OR, 3.6; 95% CI, 1.2-10.5), and suicidal ideation (OR, 4.1; 95% CI, 2.1-8.0) were associated with psychotic symptoms in both cohorts. Mean mini-mental state examination (MMSE) score was lower in those with psychotic symptom compared with those with no psychotic symptoms (Cohort 1986-1987, 26.4 vs 27.8, Cohort 2008-2009, 26.1 vs 27.7, t value -4.24, Pr > t < 0.001). Conclusion The prevalence of psychotic symptoms decreased between 1986 to 1987 and 2008 to 2010 among 85-years-olds without dementia. These symptoms were associated with broad psychopathology, worse performance in cognitive testing, and with disability of daily life in both cohorts.