title: Which cognitions and behaviours mediate the positive effect of cognitive behavioural therapy on fatigue in patients with multiple sclerosis?
abstract: BACKGROUND
  Chronic fatigue is a common symptom of multiple sclerosis (MS). A randomized controlled trial (RCT) showed that cognitive behavioural therapy (CBT) was more effective in reducing MS fatigue than relaxation training (RT). The aim of the current study was to analyse additional data from this trial to determine whether (1) CBT compared to RT leads to significantly greater changes in cognitions and behaviours hypothesized to perpetuate MS fatigue; (2) changes in these variables mediate the effect of CBT on MS fatigue; and (3) these mediation effects are independent of changes in mood.
  
  
  METHODS
  Seventy patients (CBT, n=35; RT, n=35) completed the Cognitive and Behavioural Responses to Symptoms Questionnaire (CBSQ), the Brief Illness Perception Questionnaire (B-IPQ) modified to measure negative representations of fatigue, the Hospital Anxiety and Depression Scale (HADS), and the Chalder Fatigue Questionnaire (CFQ), pre- and post-therapy. Multiple mediation analysis was used to determine which variables mediated the change in fatigue.
  
  
  RESULTS
  Avoidance behaviour and three cognitive variables (symptom focusing, believing symptoms are a sign of damage and a negative representation of fatigue) improved significantly more in the CBT than the RT group. Mediation analysis showed that changing negative representations of fatigue mediated the decrease in severity of fatigue. Change in anxiety covaried with reduction in fatigue but the mediation effect for negative representations of fatigue remained when controlling for improvements in mood.
  
  
  CONCLUSIONS
  Change in beliefs about fatigue play a crucial role in CBT for MS fatigue. These beliefs and the role of anxiety deserve more attention in the further development of this intervention.
authors.affiliation: Expert Centre for Chronic Fatigue, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Knoop
authors.forename: K
authors.initials: K
authors.lastname: van Kessel
authors.forename: R
authors.initials: R
authors.lastname: Moss-Morris
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001007:Anxiety / Q000628:therapy; D002908:Chronic Disease; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D003863:Depression / Q000628:therapy; D005221:Fatigue / Q000517:prevention & control / Q000523:psychology*; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology / Q000523:psychology* / Q000628:therapy; D012044:Regression Analysis; D012064:Relaxation Therapy; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016896:Treatment Outcome