Pre-Sleep Arousal Scale (PSAS): psychometric study of a European Portuguese version

Pre-sleep arousal constitutes one of the major features of insomnia. As such, it is imperative to have adequate instruments to measure this construct in both clinical and research settings. The Pre-Sleep Arousal Scale (PSAS) is the most well-known measure to evaluate pre-sleep arousal. The current study aimed to examine some of the psychometric properties of a European Portuguese version of the scale.

For this purpose, data from 691 undergraduate students from a medical school were analyzed. Internal consistency indices and factor analysis were performed. In addition, the association between the PSAS and its subscales with other measures was also examined. Finally, PSAS scores of self-reported insomniacs were compared with those of self-reported non-insomniacs.

The results indicated that the PSAS comprises a cognitive scale and a somatic scale, both with adequate internal consistency indices (α = 0.82 and 0.79, respectively). However, a three-factor solution also seemed plausible, suggesting that the original somatic arousal subscale might be divided into two subscales. Significant associations between the PSAS total score and its subscales were found with other concurrent measures such as sleep reactivity to stress, arousability and neuroticism. Self-defined insomniacs presented higher levels of cognitive and somatic arousal than healthy individuals.

Further investigations of the PSAS are needed to refine its psychometric properties and explore its research and clinical utility in other populations.