ReviewThe neurodevelopmental effects of serotonin: A behavioural perspective

- Mood-related behavioural changes are observed after both prenatal and postnatal SSRI exposure.
- Autism-related features arise in response to early postnatal increases in serotonin levels.
- Sexual behaviour is affected by SSRI exposure during the late postnatal period.

Serotonin is well known for its role in psychiatric disorders like depression and autism, but it is less clear how aberrant behaviour associated with these disorders are shaped by serotonergic alterations during prenatal and postnatal development. The use of serotonergic antidepressant agents and other drugs during pregnancy and breastfeeding can change brain development, and the behavioural consequences may depend on the stage of development; prenatal, early and late postnatal. The aim of this review is to provide an overview of the behavioural consequences of changes in serotonin levels during these three critical developmental stages. The studies together demonstrate that risk for mood disorders (including social deficits) is related to serotonergic perturbations during the prenatal and postnatal phases, whereas risk for autism-like features and sexual abnormalities increases when serotonin levels are increased during the postnatal period. This insight may inform timed strategies to reduce risk for psychiatric disorders.