Developmental fluoxetine exposure affects adolescent and adult bone depending on the dose and period of exposure in mice.

At the end of gestation, fetal skeleton rapidly accumulates calcium, and bone development continues in offspring postnatally. To accommodate, maternal skeletal physiology is modulated in a serotonin-dependent manner. Selective serotonin reuptake inhibitors (SSRIs) are generally considered safe for treatment of major depressive disorder, postpartum depression, and other psychiatric illnesses during the peripartum period, but because serotonin affects bone remodeling, SSRIs are associated with decreased bone mass across all ages and sexes, and the impact of SSRIs during fetal and postnatal development has not been fully investigated. In the present study, our aim was to examine developmental fluoxetine exposure on offspring skeleton and to assess varying degrees of impact depending on dose and window of exposure in short-term and long-term contexts. We established that a low dose of lactational fluoxetine exposure caused a greater degree of insult to offspring bone than either a low dose during fetal and postpartum development or a high dose during lactation only in mice. We further discovered lasting impacts of developmental fluoxetine exposure, especially during lactation only, on adult bone and body composition. Herein, we provide evidence fluoxetine exposure during early development may have detrimental effects on the skeleton of offspring at weaning and into adulthood.