Effects of mindfulness-based cognitive therapy on breast cancer survivors with insomnia: A randomised controlled trial.

OBJECTIVE: We investigated the effects of mindfulness-based cognitive therapy on insomnia (MBCT-I) in breast cancer survivors. METHODS: In total, 136 participants were allocated randomly to a MBCT-I group or a waitlist control (WLC) group. Indicators of insomnia and mindfulness were evaluated using the Insomnia Severity Index, actigraphy and the Five Facet Mindfulness Questionnaire. Data were collected at baseline (T1), post-intervention (T2), 3-month follow-up (T3) and 6-month follow-up (T4) time points. RESULTS: Insomnia severity decreased significantly in the MBCT-I group, compared with the WLC group, at T2, T3 and T4 (all p < .001). We found that 59.6% of the MBCT-I group with moderate and severe insomnia improved to no insomnia and subclinical insomnia at T4 relative to T1, accounting for 7.9% and 55.3%, respectively. Compared with the WLC group, the MBCT-I group improved on actigraphy measures of sleep; they exhibited a pattern of decreased sleep onset latency and waking after sleep onset, as well as increased total sleep time and sleep efficiency. Mindfulness also increased more in the MBCT-I group than in the WLC group at T2, T3 and T4 (all p < .001). CONCLUSIONS: MBCT-I may be an efficacious non-pharmacologic intervention to improve sleep quality in breast cancer survivors.