Adjunctive cognitive behavioral therapy significantly reduced insomnia in patients with schizophrenia and sleep disturbance, according to the results of a study published in Psychiatry Research. Up to 80% of patients diagnosed with schizophrenia have a concurrent insomnia disorder, and symptoms of insomnia may continue even after psychotic symptoms have stabilized with treatment.
In this nonrandomized, assessor blind study, Dong-Ki Hwang from the Department of Psychiatry, Seoul Metropolitan Eunpyeong Hospital, South Korea, and colleagues evaluated the effects of cognitive behavioral therapy for insomnia (CBT-I) in 63 patients with schizophrenia recruited from residential or rehabilitative facilities in Seoul, South Korea.
Patients received either 4 sessions of CBT-I in group sessions plus usual care (n=31) or usual care alone (n=32). The investigators administered the Insomnia Severity Index, Pittsburgh Sleep Quality Index, Psychotic Symptoms Rating Scale, Anxiety Sensitivity Index, and Beck Depression Inventory at baseline, week 4, and week 8.
Compared with the control group, those who received CBT-I demonstrated significant improvement in Insomnia Severity Index scores at both weeks 4 and 8 (medium effect size, d = 0.5 at both points), with a reduction of 6.3 points at week 8 in the CBT-I group. Pittsburgh Sleep Quality Index total score also demonstrated significant improvement at both weeks 4 and 8 (small effect size at week 4, d = 0.4; medium effect size at week 8, d = 0.5). Differences in scores between the 2 groups for the other 3 tools at weeks 4 and 8 were nonsignificant.
The researchers noted that depression and insomnia are highly related. Although the relationship is bidirectional, reductions in insomnia have a greater effect on depression than vice versa. Although no effect on depression was demonstrated in this study, researchers hypothesized that larger and longer studies may show greater effect. They added that CBT-I eventually may be shown to be an effective way of reducing active psychotic symptoms.
Among the study’s limitations were the lack of randomization and the limited duration of the study, which may not have captured all the study intervention’s effects.
Hwang DK, Nam M, Lee YG. The effect of cognitive behavioral therapy for insomnia in schizophrenia patients with sleep disturbance: a non-randomized, assessor-blind trial. Psychiatry Res. 2019;274:182-188.