Sleep Hygiene in Young Adulthood and Later-Life Cognitive Decline: A Systematic Review of Current Evidence

Abstract

Sleep is critical for supporting cognitive functioning and overall health including cognitive acuity, mental health, and physical well-being. Despite the importance of sleep many individuals, particularly young adults, achieve inadequate quantity or quality of sleep. It is estimated that 50 to 70 million adults in the United States suffer from sleep disorders and more than one-third experience sleep deprivation. Using Google Scholar and PubMed, 40 of the 130 surveyed studies from 2019 to 2026 were analyzed. Existing literature in the field suggests that maintaining good sleep hygiene is beneficial in young adulthood and may act as a protective factor over time. Sleep hygiene, however, may only protect against cognitive decline to a moderate extent, as cognitive decline is influenced by various factors including genetics and modifiable lifestyle factors. A key limitation across current research is the lack of long- term studies and insufficient follow-up after sleep intervention programs, which restricts understanding of their longterm effects. To address these gaps, future research should include longitudinal studies extending into late adulthood, with multiple follow-up methods to ensure participant engagement to result in long-term comparative data. The current direct evidence also remains insufficient as it focuses on short-term and cross-sectional studies. Direct evidence that sleep-hygiene interventions in young adulthood can prevent late-life cognitive decline remains limited. These findings can then be used to help guide development of more effective, preventive strategies to potentially reduce risk of cognitive decline later on in life.