WASHINGTON – One-fourth of older adults with schizophrenia shifted between remission and nonremission status in the first-ever large-scale longitudinal outcome study of older adults with schizophrenia spectrum disorder living in the community.
The 4-year longitudinal data revealed a lower persistent remission rate than had been suggested by earlier cross-sectional studies. "Our findings suggest that in addition to the increasingly recognized difficulties that older adults with schizophrenia face with respect to physical health, there is substantially more psychiatric instability than previously believed," said Dr. Carl I. Cohen, professor of psychiatry and director of the division of geriatric psychiatry at the State University of New York Downstate, Brooklyn.
Schizophrenia typically develops in the second or third decade of life, and increasing numbers of patients are surviving into old age with the disorder. Between 80% and 85% of people aged 55 years and over with schizophrenia developed it prior to age 45, with prevalence estimates for schizophrenia in adults aged between 45 and 60 of about 0.6% to 1%.
However, over the next two decades, there will be a doubling of the number of people aged 55 years and over with schizophrenia, from about 550,000 in 2005 to 1.1 million in 2025. By that time, about one-fourth of people with schizophrenia will be in this older age bracket. And in contrast to previous decades, most of these individuals are living in the community rather than in institutional settings, Dr. Cohen noted at the annual meeting of the American Association for Geriatric Psychiatry.
Recent cross-sectional studies of older adults have found remission rates of 49% (Am. J. Geriatr. Psychiatry 2008;16:966-73), 47% (J. Int. Neuropsychol. Soc. 2008;14:479-88), and 29% (Schizophr. Res. 2011;126:237-44). In longitudinal studies of remission and associated predictors in younger persons with schizophrenia, rates of clinical remission after an initial clinical episode ranged from 17% to 88% (Curr. Opin. Psychiatry 2011;24:114-21). On follow-up, the percentage of patients maintaining remission ranged from 50% to 89% (Rev. Epidemiol. Sante Publique 2009;57:25-32 and Schizophr. Res. 2009;115:58-66), with remission occurring in some of the originally nonremitted patients over time.
There have been no previous longitudinal studies in older adults, he said.
Dr. Cohen and his associates previously conducted a cross-sectional study of 198 community-dwelling adults with schizophrenia aged 55 years and over, and found that that 49% met the clinical criteria for remission, 66% met the Positive and Negative Syndrome Scale (PANSS) criteria of 3 or fewer of 8 domains, and 83% had had no hospitalizations in the past year (Am. J. Geriatr. Psychiatry 2008;16:966-73). Thus, "the study showed that symptom remission is a realistic goal for many patients," Dr. Cohen said.
In that study, four variables were associated with remission: fewer total network contacts, a greater proportion of intimates, fewer lifetime traumatic events, and higher Dementia Rating Scale scores. Type of residence, use of mental health services, and use of psychotropic medication had no significant association with remission, he said.
In the current longitudinal study, a total of 104 patients aged 55 years and older with schizophrenia spectrum disorders participated in follow-up interviews. They were followed for a mean of 52 months (range, 12-116 months). They had a mean age of 61 years, 55% were men, and 55% were white. Two-thirds (65%) lived in supported residences, while the other 35% lived independently or with family members.
To meet the criteria of remission, subjects had to score 3 or below on 8 symptom domains derived from the PANSS, and were required to have no hospitalizations during the previous year. The PANSS domains used were P1 (delusions), P2 (conceptual disorganization), P3 (hallucinatory behavior), N1 (blunted affect), N4 (passive/apathetic social withdrawal), N6 (lack of spontaneity and flow of conversation), G5 (mannerisms and posturing), and G9 (unusual thought content).
On follow-up, there were nonsignificant changes in the percentages meeting the outcomes of remission, including no hospitalizations in the past year (49% at baseline, 40% at follow-up), overall symptom remission (56% at baseline, 47% at follow-up), positive-type symptom remission (66% at baseline, 72% at follow-up), and negative-type symptom remission (64% at baseline, 68% at follow-up).
"If you look cross sectionally, you don’t see much change," Dr. Cohen noted.
However, a great deal of movement occurred between groups. Just 25% met remission criteria at both assessments, and an additional 35% did not meet remission criteria at either assessment. Another 25% went from meeting remission criteria at time 1 to not meeting remission criteria at time 2, and 16% went from not meeting remission criteria at T1 to meeting remission criteria at T2.