Treating Postpartum Insomnia: A Three Arm Randomised Controlled Trial of Cognitive Behavioural Therapy and Light Dark Therapy

Abstract

Background: Insomnia symptoms are common during the postpartum period, yet interventions remain scarce. This trial aimed to simultaneously examine the efficacy of cognitive behavioural therapy (CBT) and light dark therapy (LDT), targeting different mechanisms, against treatment-as-usual (TAU), in reducing maternal postpartum insomnia symptoms. Methods: This three-arm randomised controlled trial recruited from the general community in Melbourne, Australia. Nulliparous females 4-12 months postpartum with self-reported insomnia symptoms (Insomnia Severity Index [ISI] scores >7) were included; severe medical/psychiatric conditions were excluded. Participants were randomised 1:1:1 to CBT, LDT, or TAU stratified by ISI (< or ≥14) and infant age (< or ≥8 months). Participants and principal investigators were unblinded. Six-week interventions were delivered via digital materials and telephone. The primary outcome was insomnia symptoms (ISI), assessed pre-, midpoint-, post- (primary endpoint), and one-month post-intervention. Analyses were intention-to-treat using latent growth models. Outcomes: Participants were recruited from 2018-09-07 to 2020-03-23. 114 participants (CBT=39, LDT=36, TAU=39; M age =32·20±4·62 years) were randomised (all included in analyses), 108 completed the intervention, one withdrew, and five did not respond to contact. There were significantly greater reductions in ISI scores in CBT and LDT (effect sizes -2·01 and -1·52 respectively, p 0·08). Four participants (11%) in the LDT group reported headaches, dizziness, or nausea; no others reported adverse events. Interpretation: Therapist-assisted CBT and LDT were safe, feasible, and efficacious in reducing postpartum insomnia symptoms. Clinical Trial Registration Details: The trial was registered prospectively with Australia and New Zealand Clinical Trials Registry (ACTRN12618000842268). Funding Information: Australian National Health and Medical Research Council, Department of Education RTP Scholarship. Lucimed SA supplied light therapy glasses. Declaration of Interests: Verma and Quin are recipients of Australian Government Research Training Program Scholarship; Bei (APP1140299) and Wiley (APP1178487) are supported by National Health and Medical Research Council Fellowships. Rajaratnam is the Chair of the Sleep Health Foundation (Australia) and separately received a payment from the Restorative Sleep Expert Panel (USD1000 paid to the University). Lucimed SA provided light therapy glasses free-of-cost for the duration of the trial; Lucimed SA had no input to the design and execution of the trial. Ethics Approval Statement: Ethics approval was obtained from the Monash University Human Research Ethics Committee (9780) and the Department of Education and Training Victoria (2018_003774). Informed consent was obtained from all participants.