(E) Antidepressant Continuation and Adherence in Pregnancy and Risk of Antenatal Hospital Admission for Depression and/or Anxiety

Publication Number: 295

Background: Knowledge about the effectiveness of antidepressants in pregnancy in preventing maternal relapse of the depression is limited, which challenges pregnant women and clinicians in making evidence-based treatment decisions.

Objectives: To determine the association between antidepressant treatment continuation during pregnancy and risk for antenatal hospital admission to psychiatric wards for depression/anxiety, considering the possible risk of protopathic bias.

Methods:

Design: Cohort study based on healthcare utilization databases in 2010-2020.
Setting: Population-based, region-wide study in Lombardy, Italy.
Participants: 17,210 live-birth pregnancies within 16,252 women dispensed at least an antidepressant prescription within one-year pre-pregnancy.
Exposure: Continued antidepressant dispensation during pregnancy, modelled as time-varying exposure and with lag-times of 60 days preceding the outcome onset to minimize the risk of protopathic bias. Pregnancies within women dispensed one or more antidepressants (continuers, n=5,299 (30.8%)) were compared to antidepressant discontinuers before pregnancy (n=11,911 (69.2%)).
Main outcomes and Measures: Maternal hospital admission to psychiatric ward with a registered diagnosis for depression or anxiety disorder, or suicidal thoughts or attempts during pregnancy.

Results: There were 367 (2.1%) admissions for depression/anxiety during pregnancy, 214 among antidepressant continuers (1.2%), and 153 among discontinuers before pregnancy (0.9%). There was a paradoxical increased risk (hazard ratio (HR): 3.64, 95% CI: 2.95–4.48) of admission with antidepressant continuation. After adjusting for confounding via propensity score matching, there remained an increased risk of antenatal admission for depression/anxiety (weighted HR: 1.96, 95% CI: 1.46–2.63) with antidepressant continuation that decreased with the lag-time window of 60 days (weighted HR: 1.60, 95% CI: 1.18-2.18). To account for disease severity prior to pregnancy, the analyses were stratified according to the proportional days covered (PDC) of antidepressant treatment in the year before pregnancy ( < 60%/>60%), producing similar results.

Conclusions: In population-based settings, antidepressant continuation in pregnancy is associated with an increased risk for antenatal hospital admission for depression/anxiety relative to discontinuation before pregnancy. Confounding by disease severity remains substantial in this comparison. Our upcoming results on the effect of antidepressant adherence in pregnancy on maternal risk for antenatal hospital admission for depression/anxiety will provide important new knowledge on the effect of sustained antidepressant on maternal antenatal mental health.