Decreased sustained attention, processing speed and verbal learning memory in patients with insomnia in Chinese young and middle-aged adults: a cross-sectional study

Abstract

To examine whether insomnia disorder is associated with cognitive impairment in young and middle-aged Chinese adults. A case–control sample of 98 adults aged from 18 to 65 years old from Guangdong province underwent clinical history, physical examination, and cognitive assessments. We examined the trail-making test (TMT), basic symbol coding test (BASC), continuous performance task (CPT), category fluency test (CF), visuospatial memory test (BVMT), and verbal learning test (HVLT). Moreover, we assessed sleep and mood conditions with Pittsburg Sleep Questionnaire Index (PSQI), Epworth Sleepiness score (ESS), Self-rating Anxiety Scale (SAS), Self-rating Depression Scale (SDS) and Fatigue Assessment Scale (FAS). We used descriptive statistics, an independent t test, bivariate correlation analysis and analysis of covariance (ANCOVA) to assess the statistics produced. Compared to healthy controls (N = 49), individuals with insomnia disorder (N = 49) showed a decreased level of TMT, BASC, CPT and HVLT, which indicates that the insomniac has processing speed, sustained attention and verbal learning memory deficits. Also, the score of SAS, SDS, FAS, ESS and PSQI had a significant difference between the control group and insomnia group. All the cognitive scores were correlated with the severity of insomnia. Young and middle-aged adult insomnia are associated with deficits in speed of processing, sustained attention and verbal learning memory, which may suggest that before old age, these domains of cognitive function of people with insomnia disorder have begun to change. It may provide a clinical reference for recognizing cognitive function impairment in young and middle-aged patients with insomnia.