Cognitive behavioural, light dark therapy help fight postpartum insomnia

New mothers who are struggling to fall or stay asleep may find relief from therapist-assisted cognitive behavioural therapy (CBT) and light dark therapy (LDT), which have been shown to be safe and effective at reducing postpartum insomnia symptoms.

In a study that included nulliparous women at 4–12 months postpartum and with self-reported insomnia symptoms, a 6-week course of either CBT or LDT resulted in significant reductions in Insomnia Severity Index (ISI) scores compared with treatment as usual (control; effect sizes, −2.01 and −1.52, respectively; p<0.001). These improvements were maintained through 1-month postintervention. [Psych Med 2023;53:5459-5469]

The CBT and LDT groups also showed significant improvements in PROMIS Sleep Disturbance that persisted through 1 month after the intervention as compared with the control group (effect sizes, −1.68 and −1.44, respectively; p<0.001). These improvements were in line with the changes in total sleep time and sleep efficiency.

Meanwhile, fatigue decreased in the CBT (effect size 0.85; p<0.001) but not in the LDT group (p=0.11).

Despite all the notable improvements in sleep outcomes, the interventions exerted no significant effects on sleepiness and symptoms of depression and anxiety compared with control (p>0.08 for all).

“[The result for sleepiness] needs to be interpreted in the context of unique postpartum circumstances, such as frequent overnight awakenings for infant care, which contribute to insufficient sleep… It is possible that sleep disruption may continue to cause sleep-related daytime consequences beyond the subsiding of insomnia symptoms,” they explained. [Sleep 2022;45:zsab293]

For depression and anxiety, on the other hand, the investigators pointed out that both conditions are multifactorial. Poor sleep, they said, is only one of the many contributing factors, and several other psychosocial factors were not addressed in either intervention. [J Affect Disord 2015;176:65-77]

In terms of safety, both therapist-assisted CBT and LDT delivered over 6 weeks caused no serious problems and were considered safe. Headaches, dizziness, and nausea were the only adverse events, being documented in four women (11 percent) in the LDT group. Dropout rates were low (one participant in the LDT group withdrew, while four in the CBT group were lost to follow-up) and satisfaction rates were high in both intervention groups.

“These findings support the existing body of literature on the efficacy of both CBT and LDT for improving sleep among diverse populations and extend the evidence base to insomnia in the latter postpartum,” according to the investigators. [PLoS One 2016;11:e0149139; Sleep Med Rev 2016;29:52-62; Obstet Gynecol 2019;133:911-919]

“While investigation of potential mechanisms lay outside the scope of the current paper, given the different focus and comprising strategies of the interventions, it is possible that improvements in insomnia symptoms were caused by different mechanisms, [such as] changes in sleep-related cognitions and behaviours in the CBT group [and] changes to circadian phase and/or amplitude in the LDT group,” they said.

The study included 114 participants (mean age 32.20 years, 89.4 percent White, 99.1 percent married to male partners), of which 39 were in the CBT group, 36 in the LDT group, and 39 in the control group. These participants reported poor sleep at baseline, with the mean ISI score falling just under the ‘clinical insomnia’ threshold of 14. The mean sleep efficiency was also low at 65.5 percent, and 76.3 percent of the participants met the insomnia disorder diagnosis criteria.