Cognitive behavioral therapy for insomnia in veterans with gulf war illness: Results from a randomized controlled trial

Abstract

Aims: To examine whether cognitive behavioral therapy for insomnia (CBT-I), delivered by telephone, improves sleep and non-sleep symptoms of Gulf War Illness (GWI).

Main methods: Eighty-five Gulf War veterans (21 women, mean age: 54 years, range 46-72 years) who met the Kansas GWI case definition, the Centers for Disease Control and Prevention (CDC) case definition for Chronic Multisymptom Illness (CMI), and research diagnostic criteria for insomnia disorder were randomly assigned to CBT-I or monitor-only wait list control. Eight weekly sessions of individual CBT-I were administered via telephone by Ph.D. level psychologists to study participants. Outcome measures included pre-, mid-, and post-treatment assessments of GWI and insomnia symptoms, subjective sleep quality, and continuous sleep monitoring with diary. Outcomes were re-assessed 6-months post-treatment in participants randomized to CBT-I.

Key findings: Compared to wait list, CBT-I produced significant improvements in overall GWI symptom severity, individual measures of fatigue, cognitive dysfunction, depression and anxiety, insomnia severity, subjective sleep quality, and sleep diary outcome measures. The beneficial effects of CBT-I on overall GWI symptom severity and most individual GWI symptom measures were maintained 6-months after treatment.

Significance: GWI symptoms have historically been difficult to treat. Because CBT-I, which is associated with low stigma and is increasingly readily available to veterans, improved both sleep and non-sleep symptoms of GWI, these results suggest that a comprehensive approach to the treatment of GWI should include behavioral sleep interventions.

Keywords: Chronic multisymptom illness; Cognitive behavioral therapy; Gulf war illness; Insomnia; Telehealth; Veteran.

Fig. 1.

Consort diagram. Flowchart of participant numbers through the trial; Cognitive Behavioral Therapy for Insomnia (CBT-I); Gulf War Illness (GWI); Obstructive Sleep Apnea (OSA); Restless Legs Syndrome (RLS); Diagnostic and Statistical Manual for Mental Disorders (DSM-5); Traumatic Brain Injury (TBI); Obsessive Compulsive Disorder (OCD).

Fig. 2.

Primary outcome measures in CBT-I (red triangle) and Wait List (blue circle) groups showing means and standard deviations for scores on the Gulf War Illness Severity Index (A) and Insomnia Severity Index (B). Higher scores on both measures indicate more severe symptoms.

Fig. 3.

Secondary outcome measures for CBT-I (red triangle) and Wait list (blue circle) groups. The graphs show means and standard deviations intervals for the Fatigue Severity Scale, FSS (A); Brief Pain Inventory, BPI - pain severity index (B); BPI pain interference index (C); Multiple Abilities Self-report Questionnaire, MSAQ (D); Hospital Anxiety and Depression Scale, HADS – anxiety index (E); HADS – depression index (F); Pittsburgh Sleep Quality Index, PSQI (G). Higher scores on all measures indicate more severe or worse symptoms.

Fig. 4.

Sleep diary measures for CBT-I (red triangle) and Wait list (blue circle) groups. (A) Sleep Efficiency (SE), higher values are better; (B) Sleep Latency (SL), lower values are better; (C) Wake After Sleep Onset (WASO), lower values are better; (D) Total Sleep Time (TST), higher values are better. SE and SL data were non-normally distributed and transformed for analyses. The graphs show medians and inter-quartile range, converted back to percent and minutes. WASO and TST data were normally distributed; the graphs show means and standard deviations.