Photoperiod during maternal pregnancy and lifetime depression in offspring

Abstract

Experimental studies indicate that perinatal light exposure has enduring effects on affective behaviors in rodents; however, insufficient research has explored this hypothesis in humans. We examined photoperiod (i.e., day length) metrics during maternal pregnancy in relation to lifetime depression in the longitudinal Nurses' Health Study (NHS) and NHS II. 160,723 participants reported birth date and birth state (used to derive daily photoperiod based on published mathematical equations), and clinician-diagnosed depression and antidepressant use throughout adulthood. Logistic regression was used to estimate odds ratios (OR) (and 95% confidence intervals [CI]) for depression (defined as clinician diagnosis and antidepressant use) across quintiles of two exposures during maternal pregnancy: 1) total photoperiod (total number of daylight hours) and 2) differences between minimum/maximum photoperiod; each trimester of pregnancy was examined separately. Total photoperiod during maternal pregnancy was not associated with depression overall or by trimester of pregnancy. However, larger differences between minimum/maximum photoperiod during maternal pregnancy were related to lower odds of depression (multivariable [MV]-adjusted OR: 0.86, 95% CI: 0.83, 0.90 comparing extreme quintiles of exposure; p-trend<0.0001); this association appeared specific to the second trimester of pregnancy (MV-adjusted p-trends = 0.03, <0.0001, and 0.3 across the three trimesters, respectively). In addition, birth at higher latitude (where larger differences in minimum/maximum photoperiod exist) was associated with a significant reduction in the lifetime risk of depression. These findings are consistent with an emerging hypothesis in which perinatal light exposure may influence risk of depression, and they might be understood through the conceptual framework of adaptive developmental plasticity.

Sequential Photoperiodic Programing of Serotonin Neurons, Signaling and Behaviors During Prenatal and Postnatal Development

“…Recent epidemiological data indicates that the life-time risk of depression may be reduced by high amplitude changes in photoperiod during human gestation (Devore et al, 2018). Thus our current study focused on the developmental intervals during which high amplitude swings in photoperiod may program the serotonin system in mice as a potential model for the human findings.…”

“…Monoamine turnover of serotonin and dopamine is lower during winter and fall seasons (Chotai and Adolfsson, 2002; Lambert et al, 2002) and an interaction between candidate genes for mood disorders and births in winter/fall seasons has been identified, demonstrating a gene × environment risk for these disorders (Chotai et al, 2003). Most recently, human epidemiological work suggests that high amplitude photoperiodic changes during the second trimester of gestation can result in decreased risk for depression in the offspring later in life (Devore et al, 2018). Thus, the day length or photoperiod influences the development of affective disorders.…”

Circadian photoperiod alters TREK-1 channel function and expression in dorsal raphe serotonergic neurons

“…Early-life experiences have enduring effects on neural development, which in turn impact behavioral phenotypes in adulthood 1-4 . Day length (photoperiod) is a pervasive environmental signal that has been shown to program function of serotonergic function and behaviors in rodents 1, 5,6 , and recently has been shown to associate with the life-time risk of major depression in humans 7 . Nevertheless, the neural and molecular correlates underlying this complex relationship remain to be found.…”

Studying birth month and mortality: what about the perinatal photoperiod?

“…With perinatal time of year (season) as one determinant of the perinatal photoperiod, researchers could simply include perinatal location (latitude) to develop dose metrics. Some of Zhang’s coauthors have previously assessed perinatal photoperiod associations with disease in the Nurses’ Health Study cohorts 3. They could now test how perinatal photoperiod associates with cardiovascular disease and overall mortality.…”