To evaluate the effectiveness of cognitive behavior therapy for insomnia (CBT-i) in chronic insomnia patients in terms of the improvements of psychological and sleep diary parameters.

Patients who met the diagnostic criteria of chronic insomnia, were divided into primary group or comorbid group. Both groups received standard CBT-i interventions. Psychological scales and sleep diaries were used to evaluate participants' severity of insomnia and psychological conditions related to insomnia at four time points: before intervention (baseline), immediate after intervention, 4 weeks and 16 weeks after intervention.

Both groups achieved significant improvements after intervention on psychological measurements and sleep diary parameters. Such improvements were maintained at 4-week and 16-week follow-ups. The sleep diary data indicated that by the end of the intervention, there were significant differences on sleep onset latency (51.72 min to 10.53 min in primary group, P<0.01; 59.26 min to 15.67min in comorbid group, P<0.01) and sleep efficiency (71% to 95% in primary group, P<0.01; 68% to 90% in comorbid group, P<0.01). There were differences on sleep onset latency (10.00 min vs. 13.93 min, P<0.05), total sleep time (355.71 min vs. 327.85 min, P<0.05) and sleep efficiency (95% vs. 91%, P<0.01) in primary group and comorbid group respectively. No differences were found on wake after sleep onset in the two groups.

Chronic insomnia patients with or without comorbidities both have improvements after CBT-i. Sleep diary parameters rather than psychological measurements are different in two groups. Thus, CBT-i is an effective non-pharmaceutical therapy inpatients with chronic insomnia.

Sleep initiation and maintenance disorders; Cognitive behavior therapy; Physical disorder; Sleep diary