A just-published study has found an interesting association between pregnant womens’ exposure to natural daylight and their susceptibility to postnatal depression (PND).
“Women in late pregnancy during darker months of the year may have a greater risk of developing postpartum depression once their babies are born,” Science Daily reports.
“This is consistent with what is known about the relationship between exposure to natural light and depression among adults in the general population.”
Dr Deepika Goyal of San José State University was lead author on the study, which was just published in the Journal of Behavioral Medicine.
Read more about PND:
- Chrissy Teigen says eating her placenta saved her from second bout of PND
- A dad’s PND story: “I was doing everything I could, but it wasn’t enough”
- PND made me feel like a stranger waiting for my son’s “real mother” to show up
Darkness sparks depression
Dr Goyal and her team looked at 293 Californian first-time mums, analysing the amount of daylight they were exposed to during the final trimester of their pregnancy. They also looked at each woman’s history of depression, her age, her socioeconomic status and how much she slept.
They found that the lowest risk for depression (26 percent) was seen in women whose final trimester coincided with seasons with longer daylight hours.
The depression risk was highest (35 percent) in women whose final trimester coincided with days with fewer daylight hours. These womens’ depression-related symptoms were more severe following the birth of their babies.
Daily walks during daylight hours
The findings have lead to some specific recommendations for women who are prone to depression or are due to deliver in months when the daylight hours are fewer (like Winter).
“Women should be encouraged to get frequent exposure to daylight throughout their pregnancies to enhance their vitamin D levels and to suppress the hormone melatonin,” Dr Goyal said.
“Daily walks during daylight hours may be more effective in improving mood than walking inside a shopping mall or using a treadmill in a gym. Likewise, early morning or late evening walks may be relaxing but would be less effective in increasing vitamin D exposure or suppressing melatonin.”
Obviously more work needs to be done, but this link between light exposure and PND should definitely not be ignored.