There is a subgroup of chronic insomnia sufferers who consistently report extended periods of little or no sleep with no evidence of objective sleep disturbance and without the level of daytime impairment commensurate with the degree of sleep deficits reported. This is the defining characteristic for the diagnosis of Paradoxical Insomnia in the International Classification of Sleep Disorders, 2nd Edition.
In 2002 Allison Harvey proposed that a distorted perception of sleep is one of the core perpetuating factors for insomnia (Behaviour Research and Therapy, 21, 869-893). Her reasoning was that if a patient with insomnia consistently perceives that he or she is not getting enough sleep, sleep related anxiety and preoccupation will be fueled, which, in turn, fuel poor sleep because they are not conditions conducive to optimal sleep.
Underestimation of objective (polysomnographic) sleep duration was found to be prevalent among insomnia patients with 6 or more hours of objective sleep duration, but not in those with an objective sleep duration of less than 6 hours (Fernandez-Mendoza, et al., 2011. Psychosomatic Medicine, 73, 88-97). These misperceiving patients also were found to have depressive and anxious-ruminative personality traits and poorer coping resources. In contrast, objective short sleeping insomnia patients have been found to be characterized by physiological hyperarousal symptoms such as activation of the stress system, hypertension, diabetes, and neurocognitive deficits, which are generally not found in the misperceiving group.Tags: insomnia, sleep misperception, treatment