CogniFit - Chronic Insomnia and Cognitive Functioning Among Older Adults

Original Name: Chronic Insomnia and Cognitive Functioning Among Older Adults.

Authors: Iris Haimov¹, Einat Hanuka¹, Yael Horowitz².

• 1. Department of Behavioral Science, Max Stern Academic College of Emek, Yezreel, Israel.
• 2. Department of Learning Disabilities, University of Haifa, Israel.

Journal: Behavioral Sleep Medicine, 6:32-54,2008.

References to this article (APA style):

• Haimov, I., Hanuka, E., & Horowitz, Y. (2008). Chronic Insomnia and Cognitive Functioning Among Older Adults. Behavioral Sleep Medicine, 6, 32-54.

Study Conclusion

CogniFit's cognitive assessment tool allows you to accurately assess cognitive differences between healthy older adults and those with insomnia. Memory Span [t(97)=2.77, p<.007], in integration of two-dimensional tasks (visual and semantic) [t(97)=2.03, p<.049], in reaction time of sustained attention [F(1, 392)=12.35, p<.0001], in time estimation [t(97)=2.42, p<.017], and in executive functioning [t(96)=2.02, p<.045].

Context

Seniors are more likely to suffer insomnia (2%-50%). In this group, although there are certain factors that predispose to this sleep disorder (such as retirement, mourning, social isolation or disability), insomnia is usually due to different causes: primary, medical, psychiatric, drug-related. In addition, there is a high co-morbidity with other disorders. Seniors tend to find greater difficulty falling asleep, greater activation during sleep, changes in sleep stages, more arousals, less sleep time and rest.

Aging itself is associated with poorer cognitive functioning. This normally affects cognitive abilities that are highly relevant to everyday life, such as attention, inhibition, and memory. In fact, the prevalence of severe cognitive impairment in the older population is 4% to 10%.

Chronic insomnia in old age has a significant negative impact on the quality of life and increases cardiovascular risk. Given the close relationship between sleep and cognitive abilities, it is important to know the relationships between chronic insomnia in old age and cognitive functioning in seniors.

Methodology

Participants

A total of 99 independent seniors (36 men and 63 women), with an average of 72.3 years of age , participated in the study. Participants with a major medical condition, taking medication affecting the nervous system, having a history of psychiatric disorders, having dementia or depression were excluded from the study.

In order to consider a participant has insomnia, the following criteria were followed: (a) taking at least 31 minutes to fall asleep , (b) happens at least 3 nights a week , (c) during at least 6 months . This was evaluated through the Mini Sleep Questionnaire and the Technion Sleep Questionnaire. Depending on their responses, users were divided into two groups: seniors with insomnia (N=35, mean age=73.7, SD=5.7) and seniors without insomnia (N=64, mean age=71.6, SD=5.7).

Each participant's cognitive status was measured individually using CogniFit's online cognitive assessment and training tool.

Analysis

In order to work with the data, analysis of variance (ANOVA) with a bidirectional mixed design was applied, using the group as a variable between-factors and the reaction time as an intra-subject variable. A t of Student was applied for independent samples, in order to compare the differences between the participants with insomnia and the healthy ones. Finally, a Chi-square test was used as a non-parametric test.

Results y conclusions

Both groups were found to be similar in age, gender, years of education, depression score, physical health status, consumption of sleeping pills and computer skills. There were also no differences in total sleep duration, although there were significant differences in sleep efficiency, awakenings and the time it took them to fall asleep. Regarding cognitive state, significant differences were detected between insomnia users and healthy users in memory span [t(97)=2.77, p<.007], in integration of two-dimensional tasks (visual and semantic) [t(97)=2.03, p<.049], in sustained attention reaction time [F(1, 392)=12.35, p<.0001], in time estimate [t(97)=2.42, p<.017], and in executive functioning [t(96)=2.02, p<.045].

The results indicate that chronic insomnia in senior adults is associated with impaired cognitive performance . In fact, healthy seniors performed better on almost all cognitive aspects measured than seniors with insomnia. This difference was especially noticeable in the memory span, in the integration of two-dimensional tasks (visual and semantic), in directing attention to a goal, in time estimation and in executive functioning (planning).