Major depression (MD) occurring during pregnancy or postpartum can be a devastating illness that impairs the ability of the mother to care for her infant, disrupts the family, and adversely affects the healthy physical, behavioral, psychosocial and neurocognitive development of the child. Maternal depression increases the child’s risks for mental and medical disorders later in life, contributes to cognitive and socio-emotional impairments at 5 years, and after 13 years, to higher rates of mood and anxiety disorders in adolescence. After 20 years, the risks for anxiety disorders, major depression, substance dependence, social impairment, medical problems and mortality are higher in the offspring of depressed parents compared with the offspring of non-depressed parents. Remission of maternal depression after three months of medication treatment, however, is associated with a decrease in children’s symptoms and diagnoses.
These findings emphasize the critical importance of treating peripartum depression. Safe and efficacious pharmacological treatments, however, are limited by potential adverse effects on the fetus or breast-feeding infant and psychotherapeutic interventions by time, expense and clinician availability. Light treatment improves mood, although significant antidepressant effects may not occur until after five weeks of intervention in this non-seasonal depression. In our previous work in pregnancy and postpartum depression, we observed improvements in mood with critically timed wake therapy and light treatment administered independently. Although wake therapy exerts its antidepressant effects in 1-2 days, patients may relapse after a night of recovery sleep. As reported in other mood disorder patients, the advantage of combining wake and light treatment is that one night of wake therapy can improve depressive symptoms in one day, and hasten and potentiate the antidepressant effects of light treatment to within one week. In turn, light treatment can prevent the relapse from wake therapy that often occurs after subsequent sleep. We have applied these combined chronotherapeutics to pregnancy and postpartum depression to achieve efficacious, rapid-acting, affordable home interventions with minimal side effects, and now aim to integrate these treatments into community practice for peripartum women with mood and sleep disturbances.
Based on our previous work, we hypothesize that chronobiological mechanisms underlie these treatment effects: In pregnancy MD, we observed phase-advanced (shifted earlier) melatonin circadian rhythms, and sleep and light interventions (SALI) that restricted and shifted sleep later (early-night wake therapy-EWT: sleep 3-7 am) plus evening (PM) bright white light (BWL), which phase-delayed (shifted-later) melatonin rhythms, improved mood and sleep. In contrast, in postpartum MD, we observed phase-delayed melatonin rhythms, and SALI that restricted and phase-advanced sleep (late-night wake therapy-LWT: sleep 9pm-1am) plus morning (AM) BWL, which phase-advanced melatonin rhythms, improved mood and sleep. We also found that when combined with wake therapy, 1-2 weeks of 30 min/day of light treatment was as efficacious as 6 weeks of 60 min/day.
The significance of this work is that it may provide novel, safe, efficacious, rapid-acting, affordable home treatments without significant side effects for women suffering from pregnancy or postpartum mood and sleep disturbances, prevent their adverse sequelae, and be acceptable and feasible to disseminate and implement in community vs. hospital or clinic settings.