According to this study, older persons with insomnia are more likely to acquire memory deterioration and long-term cognitive impairment, such as dementia.
The journal SLEEP published a study based on data from over 26,000 adults aged 45 to 85 who participated in the Canadian Longitudinal Study on Aging. The researchers compared completed self-reported assessments of sleep and memory and neuropsychological testing in multiple cognitive areas from 2019 and 2022. Participants who reported deteriorating sleep quality over the three-year period were also more likely to experience subjective memory impairment.
Big data and keen concentration
Cross explains that, unlike prior studies on sleep quality, this one benefits from its massive data collection and focus on sleep disorders. Insomnia has been categorised as a mental disorder in the Diagnostic and Statistical Manual of Mental Disorders, the most widely used reference manual among clinicians worldwide.
Insomnia is more than tossing and turning before bedtime “Symptoms of difficulty falling asleep, remaining asleep, or waking too early must be present three nights per week for three months. Insomniacs must also indicate that daytime functioning is impaired by their sleep disorder “Cross explains.
For this study, the researchers classified their respondents into one of three groups: those who reported no sleep issues at the beginning of 2019, those who had some insomnia symptoms, and those who acquired probable insomnia. In the 2022 follow-up data, those who reported a reduction in sleep quality – from no symptoms to probable or some insomnia, or from some symptoms to probable insomnia – were more likely to report memory decline or have it diagnosed by a doctor.
In addition, they were more likely to exhibit a higher prevalence of anxiety, sadness, daytime drowsiness, breathing disruptions during sleep, other sleep-related problems, smoking, and a higher body mass index (BMI) score. All of these are considered cognitive decline and dementia risk factors. In addition, men with insomnia performed worse on memory tests than women, indicating that older men may be at a larger risk.
Zhao, J-L., et al. (2022) Insomnia disorder increases the risk of subjective memory decline in middle-aged and older adults: a longitudinal analysis of the Canadian Longitudinal Study on Aging. Sleep. doi.org/10.1093/sleep/zsac176.