Participants
We performed a nested case-control study within the IGEDEPP
(“Gene-Environment Interaction in PPD”) prospective cohort. IGEDEPP
enrolled 3310 Caucasian women in eight maternity departments in the
Paris metropolitan area in France, between November 2011 and June 2016.
Caucasian cohort participants were selected in order to remove potential
confounding factors for genetic analysis. Other main inclusion criteria
were: age over 18, and delivery after 32 weeks of amenorrhea. Exclusion
criteria included mental retardation, dementia or schizophrenia. Women
were included in the study at the maternity department between the
second and the fifth day after delivery and were evaluated at three time
points by specially trained clinicians, over the course of one year. The
first assessment took place at the maternity department between the
second and fifth day after delivery in a face-to-face interview; the
second at 8 weeks postpartum, by phone; the third at one year
postpartum, also by phone. Among the 3310 women, 91.1% (n=3015) were
assessed at 8 weeks postpartum, and 71.0 % (n=2351) were assessed at 1
year postpartum. Clinical characteristics of the sample have been
described in previous work (29).
The research protocol (ClinicalTrials.gov Identifier: NCT01648816) was
approved by the Data Protection and Freedom of Information Commissions
and the French Ethics Committee (Ile de France I). All women received
oral and written information regarding the study and signed a consent
form.