Elevated stress hormone levels and antidepressant treatment starting before pregnancy affect maternal care and litter characteristics in an animal model of depression.

Many women who take antidepressant medications become pregnant while taking their medication; however, the impact of depression and antidepressant medication on fetal development is not well understood. This study used a translational animal model of maternal depression to investigate the consequences of discontinuing antidepressant medication during pregnancy. First, rats received corticosterone (CORT; 40 mg/kg, s.c.) or vehicle to induce a depressive-like phenotype. After 16 days of treatment with CORT or vehicle, animals were treated with sertraline (a selective serotonin reuptake inhibitor, SSRI; 20 mg/kg) or vehicle via gavage. Following 21 days of CORT or oil treatment, rats were mated. One group receiving sertraline was discontinued from treatment on gestational day 16, and another group continued sertraline treatment throughout pregnancy to assess the effects of discontinuation. After weaning, dams were sacrificed via perfusion to investigate neurogenesis. As intended, CORT administration created a depressive-like phenotype with increased immobility in the Forced Swim Test and reduced body weight. Interestingly, sertraline treatment could not rescue these altered features. Pre-conceptional CORT exposure resulted in smaller litters and CORT dams that received sertraline until the end of gestation spent more time off of the nest compared to CORT dams that received vehicle or discontinued sertraline during gestation. There was no difference in hippocampal neurogenesis between any of the groups. Our results suggest that treatment with antidepressants may have different effects in healthy or depressed dams, however, we need more research to investigate the detailed and long-term effects of maternal depression and its treatment in translational animal models.