In a four-arm randomized trial in Australia, brief cognitive behavioral therapy for insomnia (CBT-I) significantly reduced insomnia symptoms in women receiving chemotherapy for breast cancer, with a reduction described as clinically significant.
Bright light therapy used alone did not outperform sleep hygiene education for either insomnia or fatigue.
Neither intervention showed a significant main effect on fatigue, although fatigue fell in all four groups.
Combining CBT-I with bright light therapy produced no additive or synergistic benefit and had the lowest adherence and highest dropout.
Among women with metastatic breast cancer, bright light therapy was associated with improvement in insomnia and fatigue, but this is a subgroup signal requiring confirmation.
Insomnia improvement in the CBT-I group appeared to rebound during follow-up, suggesting a need for continued support.
Study snapshot
Design: four-arm randomized clinical trial (SleepCARE)
Setting: five hospitals in Australia
Participants: 219 women undergoing chemotherapy for breast cancer; mean age 50.7 years; 26.9% with metastatic disease
Arms: CBT-I alone; bright light therapy alone; CBT-I plus bright light therapy; sleep hygiene education control. All arms received sleep hygiene education.
Interventions: brief CBT-I (one one-to-one consultation plus email support) and bright light therapy using light-therapy glasses for 20 minutes each morning; six-week intervention period
Reported outcome: insomnia symptoms during the intervention, with fatigue also assessed; follow-up extended to six months
Main result: CBT-I was superior to non-CBT-I for insomnia; bright light therapy alone was not superior to control; no significant main effect on fatigue for either intervention
Citation: Do TT, Maccora J, Wallace R, et al. JAMA Netw Open. 2026;9(8):e2630320. doi:10.1001/jamanetworkopen.2026.30320
