SleepCARE Trial: CBT-I, Not Bright Light Therapy, Improves Insomnia During Breast Cancer Chemotherapy

• 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