The Effectiveness of Cognitive Behavioural Therapy for Insomnia: Impact of Comorbidities and Dysfunctional Beliefs on Insomnia Severity in a Real-World Clinical Setting

Despite the high prevalence of insomnia, the availability of cognitive behavioural therapy for insomnia (CBT-I) in Italy remains limited. This study aimed to verify the effectiveness and feasibility of CBT-I in a real-world outpatient sample of the Santagostino Psiche in the Santagostino clinical centre. The baseline psychometric assessment was conducted using the Insomnia Severity Index (ISI), the Dysfunctional Beliefs and Attitudes about Sleep questionnaire (DBAS-30), and the Morningness-Eveningness Questionnaire (MEQ). Sociodemographic and clinical characteristics were also collected during the clinical interview and analysed. Results showed a significant reduction in insomnia severity and dysfunctional beliefs and attitudes about sleep in all the patients, except for the causal attributions of insomnia subscale. No differences in CBT-I effectiveness were found between in-person and online treatments. Psychiatric comorbidities (mainly anxiety and mood disorders) reduced the amount of improvement in insomnia symptoms, although they remained clinically relevant. Reductions in dysfunctional beliefs and attitudes about sleep were greater with higher baseline concerns about the consequences of insomnia, perceived control over sleep, and false beliefs about sleep and sleep hygiene practices. Overall, the results confirmed the effectiveness of CBT-I within the Santagostino clinical context and suggest the possible impact of psychiatric comorbidities and cognitive concern in modulating the symptomatic progress in a real-world treatment.