Cognitive Behavioral Therapy for Insomnia in Patients With Schizophrenia Without Prior Psychotic Symptom Aggravation: A Prospective Single-Arm Trial

Abstract

Objective: To determine the feasibility and efficacy of cognitive behavioral therapy for insomnia (CBT-I) in patients with schizophrenia without prior psychotic symptom aggravation.Methods: This prospective single-arm trial included 31 patients diagnosed with schizophrenia and insomnia who received CBT-I. We provided four weekly 60-min sessions of group or individual CBT-I. All patients completed several sleep-related scale assessments before and 2, 3, and 4 weeks after treatment: the Korean version of Pittsburgh Sleep Quality Index (PSQI-K), Insomnia Severity Index (ISI), Korean version of the Epworth Sleepiness Scale (K-ESS), Dysfunctional Beliefs and Attitudes about Sleep Scale-16 (DBAS-16), and sleep diary. The primary outcome was insomnia symptom changes over the treatment period, as indicated by the PSQI-K, ISI, sleep onset latency, and total sleep time from the sleep diary. The secondary outcome was improvement in maladaptive cognition associated with sleep, as indicated by the DBAS-16.Results: The total PSQI-K and ISI at each timepoint showed significant improvements over the CBT-I program period. The total K-ESS and DBAS-16 scores showed significant improvement over the treatment period. Sleep onset latency was significantly shortened; however, no significant changes were noted in the total sleep time and some PSQI-K subscales (sleep duration, use of sleep medication, and daytime dysfunction).Conclusion: Our findings suggest the efficacy of CBT-I in improving insomnia symptoms, dysfunctional beliefs, and attitudes toward sleep in patients with schizophrenia with relatively stable psychotic symptoms. Therefore, further large randomized controlled trials are warranted to provide precise estimates of the effects of CBT-I in this patient population.