A Pilot Nurse-Administered CBT Intervention for Insomnia in Patients with Schizophrenic Disorder: A Randomized Clinical Effectiveness Trial

Insomnia is a highly prevalent disorder among the population with schizophrenia and has a significant impact on their quality of life. Cognitive behavioural therapies (CBT) have shown effectiveness in the treatment of insomnia in the general population. The aim of this this pilot study was to evaluate the effectiveness of a group intervention led by nurses in an outpatient mental health centre. The group work combined cognitive behavioural and psychoeducational therapeutic interventions to improve insomnia in patients with schizophrenic disorder and their health-related quality of life. This randomized clinical trial included intervention and control groups with follow-up assessments at 6 and 9 months, using the Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and EuroQol-5D (EQ-5D) scales. The inclusion criteria were as follows: over 18 years of age, diagnosis of schizophrenia, and a score of >7 on the ISI scale. The total sample was 40 participants. The ISI scale showed a mean difference of 3.63 (CI 95%: 2.02-5.23) (p = 0.000) and 4.10 (CI 95%: 2.45-5.75) (p = 0.000) and a large effect size (F: 28.36; p = 0.000; eta p2: 0.427). Regarding the PSQI scale, the mean difference was 3.00 (CI 95%: 1.53-4.49) (p = 0.000) and 2.30 (CI 95%: 0.85-3.75) (p = 0.000), with a medium effect size (F: 18.31; p = 0.000 eta p2: 0.325). The EQ-VAS scale showed a difference in mean scores between the groups of 10.48 (CI 95%: -19.66--1.29) (p = 0.027). CBT adapted for populations with mental disorders, carried out by nurses, is effective in improving insomnia and health-related quality of life.