An observational study in Sleep Quality and Cognitive Functions, sponsored by Uskudar University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-29.
Sponsored by Uskudar University · Observational
This observational cross-sectional study aims to examine the association between sleep quality and cognitive functions in healthy young adults. Subjective sleep quality will be assessed using the Pittsburgh Sleep Quality Index, and objective sleep parameters will be collected using a wearable device over five consecutive days. Cognitive functions will be evaluated at a single assessment session using standardized neuropsychological tests, including measures of attention, executive functions, and verbal memory. The study seeks to explore relationships between subjective and objective sleep measures and cognitive performance. Findings from this study may contribute to a better understanding of how sleep quality is associated with cognitive functioning in healthy young adults.
This study is designed as an observational, cross-sectional investigation conducted in healthy young adults to examine the association between sleep quality and cognitive functions. Participants will be recruited from a non-clinical population and will undergo a single assessment period. Subjective sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI), a self-report questionnaire evaluating sleep quality and sleep-related disturbances over the previous month. In addition to subjective measures, objective sleep parameters will be collected using a wearable device worn continuously for five consecutive days. Wearable-derived sleep metrics will include total sleep time, sleep efficiency, sleep onset latency, and wake after sleep onset, as provided by the device's standard algorithms. Cognitive functions will be evaluated during a single in-person assessment session following completion of the sleep data collection period. Cognitive assessment will include standardized neuropsychological tests measuring attention, executive functions, and verbal memory. Attention and executive functions will be assessed using the Victoria Stroop Test, and verbal memory processes will be evaluated using the Öktem Verbal Memory Processes Test, administered according to standardized procedures. Demographic information and relevant background variables will be collected to characterize the study sample. Statistical analyses will primarily focus on examining associations between subjective and objective sleep parameters and cognitive test outcomes. Correlation analyses and multivariable statistical models may be used to explore relationships between sleep quality and cognitive performance while accounting for potential confounding variables. This study aims to contribute to the understanding of how variations in sleep quality are associated with cognitive functioning in healthy young adults, using both subjective and objective sleep measures.
2,722 studies on the registry are indexed under Sleep Initiation and Maintenance Disorders; 726 are open to participants now.
This study's planned enrollment of 75 is below the median of 138 across 318 observational studies indexed under Sleep Initiation and Maintenance Disorders.
Browse Sleep Initiation and Maintenance Disorders studies →Uskudar University is the lead sponsor of 170 studies on the registry; 36 are open to participants now.
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The study population consists of healthy young adults aged between 18 and 35 years. Participants are recruited from a non-clinical population and are required to be fluent in Turkish to ensure valid administration of cognitive assessments. Individuals with self-reported good general health and without active medical, neurological, or psychiatric conditions that may affect sleep or cognitive functioning are eligible. All participants are able and willing to comply with the study procedures, including wearing a wearable sleep monitoring device for five consecutive days and completing a single-session cognitive assessment.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Healthy young adult participants without diagnosed neurological, psychiatric, or sleep disorders who undergo assessment of sleep quality and cognitive functions during a single observational assessment period.
Composite Objective Sleep Quality Index Derived From Wearable Device
A composite objective sleep quality index will be derived from wearable device data collected continuously over five consecutive days. The composite score will be calculated by combining standardized values of total sleep time, sleep efficiency, sleep onset latency, and wake after sleep onset into a single summary measure representing overall objective sleep quality.
Time frame: During 5 consecutive days around baseline assessment
Sleep Quality (Pittsburgh Sleep Quality Index Scores)
Subjective sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI). The total PSQI score ranges from 0 to 21, with higher scores indicating poorer sleep quality.
Time frame: Baseline (single assessment)
Cognitive Performance (Victoria Stroop Test Scores)
Attention and executive functions will be assessed using the Victoria Stroop Test. Outcome measures include completion time and error scores obtained during the test.
Time frame: Baseline (single assessment)
Verbal Memory Performance (Öktem Verbal Memory Processes Test Scores)
Verbal memory will be evaluated using the Öktem Verbal Memory Processes Test. Outcome measures include standardized scores reflecting learning and recall performance.
Time frame: Baseline (single assessment)
Plan to share: No — Individual participant data will not be shared because the study involves sensitive personal data related to sleep patterns and cognitive performance, and participant consent for data sharing was not obtained. Data will be used solely for the purposes defined in the approved study protocol.
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