Cognitive functioning in adults with chronic insomnia disorder- A cross-sectional study

Background: Chronic insomnia, affecting 15.9% of the population, is characterized by sustained hyperarousal and heightened somatic, cognitive, and cortical activity. Despite its prevalence, the precise impact of chronic insomnia on cognitive domains, particularly attention, working memory, and executive function, remains inadequately understood.

Aim: This study aims to systematically investigate the cognitive functioning of adults with chronic insomnia.

Methodology: A meticulously matched cohort of 80 participants, comprising 40 with chronic insomnia and 40 controls, participated in this cross-sectional study. The diagnosis followed strict criteria outlined in the International Classification of Sleep Disorders-3. Neuropsychological assessments, including the Digit Span Test, Stroop Test, and Trail Making Test, were employed to scrutinize attention, working memory, and executive function. Robust metrics, such as the Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), Generalized Anxiety Disorder-7 (GAD-7), and Patient Health Questionnaire-9 (PHQ-9), supported the investigative approach.

Results: Analysis revealed notable deficits in backward digit span, digit symbol substitution test, and Stroop Test (cards B and C) among chronic insomnia subjects compared to non-insomniac counterparts. Trail Making Test B indicated prolonged completion times in the chronic insomnia cohort. Despite comparable levels of anxiety and depressive symptoms, the chronic insomnia group exhibited higher ISI and PSQI scores, indicating the severity of their sleep disturbances.

Conclusion: This cross-sectional analysis reveals cognitive deficits associated with chronic insomnia, specifically impacting attention, working memory, and executive function. Even with meticulous demographic controls, chronic insomnia leaves a discernible impact on cognitive functions. The study underscores the need for precise cognitive evaluations to reveal the latent impact of chronic insomnia, offering insights for targeted interventions.