The Role of Affective States in CBT-I Effectiveness: Validation of the Italian Version of POMS in Insomnia Population

Mood states may impact the response to Cognitive-Behavioral Therapy for Insomnia (CBT-I), the first-line treatment for chronic insomnia. Indeed, literature reported a bi-directional relationship between depressive and insomnia disorder (ID) symptoms. The aim of this study was to evaluate the psychometric properties of the Italian version of the Profile of Mood States (POMS) scale and to investigate the role of affective states in a large sample of patients with ID following CBT-I. 448 insomnia patients (59% female, age = 42.25 ± 12.96) were evaluated pre- and post-group-CBT-I by means of insomnia severity and affective states indices. We tested the psychometric properties of the Italian version of POMS in ID population. A mediation analysis was performed to investigate the relationship between transient affective states, depression symptoms, and insomnia treatment outcomes. The Italian version of POMS is a reliable and valid tool for evaluating affective states. CBT-I improves both insomnia and mood states indices. Furthermore, CBT-I’s effectiveness on insomnia severity is significantly influenced by changes in affective states during therapy, with depressive mood playing a relevant role. Affective states play a significant role in improving the severity of insomnia. The improvement in ID following CBT-I is not solely due to changes in depressive symptoms but also to transient affective states. The introduction of a reliable tool for the evaluation of mood states in chronic insomnia patients appears to be of relevance in research and clinical settings.