---
title: Do women with PMDD respond differently to bright morning light?
description: Yes. Women with PMDD showed a different (blunted and reversed) response to bright morning light during their symptomatic phase.
url: https://niyora.com/research/papers/blunted-phase-shift-responses-to-morning-bright-light-in-premenstrual-dysphoric-1997/
---

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- Do women with PMDD respond differently to bright morning light?

Non-randomised trial, 1997

# Do women with PMDD respond differently to bright morning light?

Yes. Women with PMDD showed a different (blunted and reversed) response to bright morning light during their symptomatic phase.

 Early or limited evidence

8 women with PMDD and 5 healthy women

## What they did

After a 2-month assessment period, researchers tested 8 women with PMDD and 5 healthy women during both their asymptomatic and symptomatic menstrual phases. They measured whether morning bright light suppressed melatonin and whether it shifted the timing of melatonin release.

## What they found

Morning light suppressed melatonin similarly in both groups. However, during the symptomatic phase, PMDD women showed a different response to light timing. In 4 of 5 healthy women, morning light advanced melatonin timing, but in PMDD women it was delayed in 3 women and unchanged in 5 women.

## What it means for you

Women with PMDD may have a problem with their biological clock during the second half of their cycle, but not because the pineal gland that makes melatonin is broken. Light therapy might help, but this is a very small pilot study with only 8 women.

8

PMDD women studied

5

healthy control women

4 of 5

controls with advanced timing

## About the study

Original title Blunted phase-shift responses to morning bright light in premenstrual dysphoric disorder Authors Parry BL, Udell C, Elliott JA et al. Journal Journal of biological rhythms Year 1997 Study design Non-randomised trial Participants 8 What was tested Morning bright light exposure Read the paper [doi.org/10.1177/074873049701200506](https://doi.org/10.1177/074873049701200506)

## Topics

[Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Premenstrual dysphoric disorder (PMDD)](https://niyora.com/research/topics/condition-pmdd/)[Low mood and depression](https://niyora.com/research/topics/symptom-depression-mood/)[Sleep and insomnia](https://niyora.com/research/topics/symptom-sleep/)[Light therapy and sleep deprivation](https://niyora.com/research/topics/treatment-light-therapy/)

Research tells you what helps on average. Niyora helps on the day it hits.

Calm down, see it another way, and decide what to say, with a PMS and PMDD app built by a doctor.

## Related studies

Randomised trial, 2023

Does a one-week sleep and light intervention help PMDD mood symptoms?

Randomised trial, 1997

Does light therapy affect melatonin in women with PMDD?

Randomised trial, 1994

How does light therapy affect hormone levels in women with PMDD?

Review, 2024

Can sulpiride help women with both PMDD and IBS?

Study, 2011

Does bright morning light reset the body clock differently in women with PMDD?

Study, 2010

Are women with PMDD more sensitive to how light affects sleep hormones?

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