Subjective-Objective Sleep Discrepancy in Older Adults With MCI and Subsyndromal Depression

Background/Objectives: We investigated the prevalence and correlates of discrepancies between self-reported sleep quality (Pittsburgh Sleep Quality Index) and objective sleep efficiency (actigraphy) in older adults with mild cognitive impairment (MCI) and subsyndromal depression. Methods: This was a secondary analysis of a clincial trial with 59 adults aged 60 years and older with MCI and subsyndromal depression. We included baseline data on participants' subjective sleep quality, objective sleep efficiency, depressive symptoms, insomnia diagnosis, and cognitive functioning. Results: Pittsburgh Sleep Quality Index subjective sleep quality and actigraphy-measured sleep efficiency were not significantly correlated (r = -.06; P = .64), with 61% of participants having subjective-objective sleep discrepancies. Correlates of subjective-objective sleep discrepancy included the presence of an insomnia diagnosis and impaired memory, particularly delayed memory. Conclusion: These findings are important because subjective underestimation of symptoms in older adults with memory impairments may result in sleep disturbances going unrecognized in clinical practice; on the other hand, an insomnia disorder may be a possible remediable contribution to subjective overestimation of sleep disturbances.