Italian adaptation of the Insomnia Catastrophising Scale (ICS): a tool to evaluate insomnia-specific catastrophic thinking

Several cognitive mechanisms have been hypothesized to be involved in insomnia disorder. Insomnia catastrophising thinking consists of overestimating the sleep disturbance and the related daytime impairment. The present study aimed to develop and assess the psychometric properties of the Italian adaptation of the Insomnia Catastrophising Scale (ICS) in a sample of 434 university students. The ICS is a self-report tool assessing catastrophic thoughts related to nighttime (ICS-N) and daytime symptoms of insomnia (ICS-D). Participants completed the ICS as well as the Insomnia Severity Index (ISI). Factorial structure, internal consistency, as well as convergent and discriminant validity of the ICS scales were estimated. Further, analysis of variance and bivariate correlations were computed to explore the relationship between ICS and ISI. We showed the one-factor structure of each ICS subscale as it demonstrates their validity and reliability in assessing insomnia-specific catastrophising thinking. Finally, we demonstrated that catastrophic thinking is associated with insomnia severity. Overall, here we showed that ICS has excellent psychometric properties and our results suggest that ICS may be a useful screening tool to assess insomnia-specific catastrophic thoughts in both research and clinical practice.