Depression during pregnancy, and after birth, is associated with Sudden Infant Death Syndrome (SIDS), particularly if the mother is depressed in the year before delivery, according to a new study, presented today and due to be published later this year in the Journal of Clinical Psychology.

SIDS has been linked to psychiatric disorders in 3 studies, but these have had a number of limitations. This study set out to investigate whether there is an association between SIDS and mental illness.

It compared two groups of women. The first were women registered with a general practice on the General Practice Research Database (GPRD) who had a live birth between 1987 and 2000 and who had an infant who died unexpectedly in the first year of life, with a diagnosis of SIDS.

The second (control) group was made up of women matched for age, registered with the same general practices on the GPRD with a live birth born in the same year as a SIDS baby, but whose babies survived the first year of life.

The researchers analysed the effect of maternal psychiatric disorders and other possible risk factors.

169 mother-infant cases of SIDS were matched with 662 mother-infant controls. SIDS was found to be independently associated with a history of depression in the year before birth, smoking, and male gender. There was also weaker evidence of an association of SIDS with depression in the 6 months after birth.

The researchers conclude that women with depression during and after pregnancy need their depression identified and treated. Healthcare professionals treating them need to provide clear advice on infant care practices that may prevent SIDS. Factors mediating the association between maternal depression and SIDS need further investigation.

Royal College of Psychiatrists