The role of insomnia in the treatment of chronic fatigue

J Psychosom Res. 2015 May;78(5):427-432. doi: 10.1016/j.jpsychores.2014.11.022. Epub 2014 Dec 5.


Background: The definition of Chronic Fatigue Syndrome (CFS) overlaps with definitions of insomnia, but there is limited knowledge about the role of insomnia in the treatment of chronic fatigue.

Aims: To test if improvement of insomnia during treatment of chronic fatigue was associated with improved outcomes on 1) fatigue and 2) cortisol recovery span during a standardized stress exposure.

Methods: Patients (n = 122) with chronic fatigue received a 3.5-week inpatient return-to-work rehabilitation program based on Acceptance and Commitment Therapy, and had been on paid sick leave>8 weeks due their condition. A physician and a psychologist examined the patients, assessed medication use, and SCID-I diagnoses. Patients completed self-report questionnaires measuring fatigue, pain, depression, anxiety, and insomnia before and after treatment. A subgroup (n = 25) also completed the Trier Social Stress Test for Groups (TSST-G) before and after treatment. Seven cortisol samples were collected during each test and cortisol spans for the TSST-G were calculated.

Results: A hierarchical regression analysis in nine steps showed that insomnia improvement predicted improvement in fatigue, independently of age, gender, improvement in pain intensity, depression and anxiety. A second hierarchical regression analysis showed that improvement in insomnia significantly predicted the cortisol recovery span after the TSST-G independently of improvement in fatigue.

Conclusion: Improvement in insomnia severity had a significant impact on both improvement in fatigue and the ability to recover from a stressful situation. Insomnia severity may be a maintaining factor in chronic fatigue and specifically targeting this in treatment could increase treatment response.

Keywords: Cognitive therapy; Fatigue; Insomnia; Stress.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Anxiety / etiology
  • Biomarkers / blood
  • Chronic Disease
  • Depression / etiology
  • Fatigue / blood
  • Fatigue / etiology*
  • Fatigue Syndrome, Chronic / blood
  • Fatigue Syndrome, Chronic / complications
  • Fatigue Syndrome, Chronic / etiology*
  • Fatigue Syndrome, Chronic / rehabilitation*
  • Female
  • Humans
  • Hydrocortisone / blood*
  • Male
  • Middle Aged
  • Norway
  • Regression Analysis
  • Return to Work
  • Self Report
  • Severity of Illness Index
  • Sick Leave
  • Sleep Initiation and Maintenance Disorders / blood
  • Sleep Initiation and Maintenance Disorders / complications*
  • Sleep Initiation and Maintenance Disorders / diagnosis*
  • Stress, Psychological / blood
  • Stress, Psychological / etiology
  • Terminology as Topic
  • Treatment Outcome


  • Biomarkers
  • Hydrocortisone