Light therapy may improve sleep, depressive symptoms in perimenopausal women
Among perimenopausal women with depressive symptoms, light therapy combined with other sleep interventions improved mood and sleep scores in as few as 2 weeks, according to findings from a preliminary study presented at the North American Menopause Society annual meeting.
In a small study of 17 women, the researchers found that light treatment combined with total and partial wake therapy improved symptoms by phase advancing women’s circadian rhythms of melatonin in relation to the sleep/wake cycle.
“Preliminary experimental findings suggest that sleep and light therapy may improve mood and sleep in menopausal women,” Barbara Parry, MD, professor of psychiatry at the University of California in San Diego, told Endocrine Today. “With further study, mood and sleep can be improved within 2 weeks with critically timed sleep and light interventions based on an individual woman’s circadian rhythms.”
In a randomized, parallel-design trial, Parry and colleagues assigned perimenopausal women a “phase advance” or a “phase delay” probe (control). The phase advance probe consisted of one night of late-night wake therapy (sleep from 9 p.m. to 1 a.m.) followed by 8 weeks of morning bright, white light (> 1,350 lux) for 60 minutes, starting within 30 minutes of habitual wake time. The phase delay probe consisted of one night of early-night wake therapy (sleep from 3 a.m. to 7 a.m.) followed by 8 weeks of evening bright, white light for 60 minutes, ending 30 minutes before habitual sleep-onset time.
Researchers assessed the effects of the two interventions on overnight urinary melatonin (6-sulphatoxy-melatonin), objective sleep/activity (actigraphy), mood (via the Hamilton and Beck depression ratings) and subjective sleep (via the Pittsburgh Sleep Quality Index) measures. Researchers used Cosinor analyses of multiple overnight urine samples to estimate urinary melatonin onset and offset time and acrophase (time of occurrence of the maximum urinary melatonin secretion).
In both multiple and univariate analyses of covariance, researchers found that women with depressive symptoms who received the phase advance probe experienced a phase advance in urinary melatonin offset (mean: 2 hours, 15 minutes; P = .042) and a marginal advance in urinary melatonin onset (mean: 1 hour, 57 minutes; P = .081), whereas women with depressive symptoms receiving the control condition showed nonsignificant phase delays in both offset and onset.
After the phase advance probe, women without depressive symptoms reported nonsignificant sleep worsening on the Pittsburgh Sleep Quality Index component, with a mean score decrease of –0.833, whereas women with depressive symptoms reported a nonsignificant sleep improvement (mean increase in global score of 1).
After the phase advance probe, a greater phase advance in urinary melatonin acrophase was associated with greater improvement in Hamilton mood score (P = .002). In women with depressive symptoms receiving the phase advance probe, Hamilton mood score improved by a mean of 70% (P = .007) after 2 and 8 weeks; however, researchers observed no significant mood improvement after the control phase delay probe, they wrote.
“A nonpharmacological and nonhormonal treatment of sleep and light therapy, designed to correct the abnormal timing of melatonin circadian rhythms in perimenopausal, depressed women, improves mood and sleep within 2 weeks when administered at critical times targeted to the underlying chronobiological disturbance,” the researchers wrote in an abstract. “Larger [numbers of participants] are needed to verify these results and, in the future, design treatments to individual circadian pathologies — the aim of personalized, precision medicine.” – by Regina Schaffer
Parry B, et al. Abstract S-19. Presented at: North American Menopause Society Annual Meeting; Oct. 3-6, 2018; San Diego.
For more information:
Barbara L. Parry, MD, can be reached at the University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0804; email: email@example.com.
Disclosures: The authors report no relevant financial disclosures.