Sibling studies of maternal smoking during pregnancy and subsequent risk of depression have produced mixed results. A recent study identified not considering the amount of maternal smoking and age of onset as potentially masking a true association. We examine these issues and also the amount of maternal smoking during pregnancy as a determinant of the severity of depressive symptoms.
Methods:
We analyzed data from the community-based National Longitudinal Survey of Youth (US, 1994–2016). Mothers reported smoking during pregnancy (none,