Does cognitive behaviour therapy for insomnia reduce clinical levels of fatigue, anxiety and depression in cancer patients?

Objectives: This secondary analysis of data from a randomised controlled trial explores associations between common symptom clusters and evaluates pre-treatment to post-treatment changes in clinical levels of these symptoms following cognitive behaviour therapy for insomnia (CBT-I).

Methods: Baseline data from 113 participants with insomnia were explored to establish rates of and associations between clinical levels of fatigue, anxiety and depression across the sample. Effects of CBT-I on this symptom cluster were also explored by examining changes in pre-treatment to post-treatment levels of fatigue, anxiety and depression.

Results: At baseline, the most common symptom presentation was insomnia + fatigue, and 30% of the sample reported at least three co-morbid symptoms. Post-CBT, the number of those experiencing clinical insomnia and clinical fatigue decreased. There were no changes in anxiety rates from baseline to post-treatment in the CBT group and modest reductions in rates of those with clinical depression. Seven individuals (9.6%) from the CBT group were completely symptom free at post-treatment compared with 0% from the treatment as usual condition. Chi-square analysis revealed a significant relationship between group allocation and changes in symptoms of insomnia and fatigue. No such relationship was found between group allocation and mood variables.

Conclusions: These findings confirm the high rate of symptom co-morbidities among cancer patients and highlight strong associations between sleep and fatigue. CBT-I appears to offer generalised benefit to the symptom cluster as a whole and, specifically, is effective in reducing fatigue, which exceeded clinical cut-offs prior to implementation of the intervention. This has implications for the diagnosis/management of common symptoms in cancer patients.