Neural Correlates of Working Memory in Primary Insomnia

1307 Neural Correlates of Working Memory in Insomnia—Drummond et al INTRODUCTION Approximately 5-35% of the population report sleep disturbance problems at some point in their lives1-3 and approximately 10-15% suffer from persistent insomnia.4 Insomnia is associated with diminished quality of life,5,6 reduced work productivity,7 and increased absenteeism8; it increases vulnerability for medical disorders,8,9 psychiatric disorders,10,11 and accidents and injuries12; and is associated with increased health care utilization13,14 and decreased subjective physical and mental health.2 In addition, patients with insomnia often complain of impaired concentration, memory, and ability to accomplish daily tasks. These complaints worsen as their sleep problems increase in severity.4 Given the ubiquitous nature of daytime complaints in this population, one would expect substantial literature supporting the notion that patients with insomnia experience significant objectively measured cognitive deficits. However, data to support this concept are surprisingly sparse. Studies investigating daytime performance in patients with insomnia have focused on three main areas of performance: attention, learning, and working memory. Overall, evidence to NEURAL CORRELATES OF WORKING MEMORY IN PRIMARY INSOMNIA