The phenomenology of the pre-sleep state: The development of the pre-sleep arousal scale

The goal of the research reported in this paper was to develop an instrument which individuals can use to describe their state of arousal as they fall asleep. The instrument devised, the Pre-sleep Arousal Scale (PSAS). is a 16-item self-report questionnaire comprising both cognitive and somatic manifestations of arousal. In order to assess its psychometric properties, the PSAS was administered to 147 college students, 30 adult normal sleepers and 30 insomniacs along with measures of anxiety, depression and self-report indices of sleep disturbance. In addition, 31 college students monitored their sleep behavior and pre-sleep arousal over 10 consecutive nights in their own bedrooms. As evidence of the scale's validity, Cognitive and Somatic subscales were significantly correlated with anxiety, depression and general indices of sleeping difficulty. Moreover, both scales successfully discriminated insomniacs from normal sleepers and correlated significantly with nightly reports of sleep-onset latency. The Cognitive subscale, however, was more strongly associated with general as well as nightly sleep-onset latency measures than the Somatic subscale. The results suggest that the PSAS may be a useful tool for future studies of the pre-sleep state and a helpful screening measure for individuals with sleep disturbance.