Adherence to and Persistence with Antidepressant Medication during Pregnancy: Does It Differ by the Class of Antidepressant Medication Prescribed?

Pregnant women are often concerned about the impact of medication use on their pregnancy, such as congenital abnormalities. This study examined the rate of adherence to and persistence with antidepressant medications during pregnancy based on the class of antidepressants prescribed. Women who gave birth between 2012 and 2015 in Alberta, Canada; had ≥1 diagnosis of depression within 1 year of preconception in outpatient physician claims, emergency department, or hospitalization administrative data; and were adherent (medication possession ratio ≥80%) to ≥2 consecutive antidepressant prescriptions during the preconception year ( n = 1865) were included in this retrospective cohort study. The rates of adherence and persistence (prescription refill gap ≤30 days) were calculated by antidepressant class and were compared using chi-square tests. During pregnancy, 834 (44.7%; 95% CI, 42.4% to 47.0%) women discontinued antidepressants. Among those continuing antidepressants, the overall rate of adherence was 62.6% (95% CI, 59.4% to 65.7%). The rate differed significantly by medication class ( P < 0.0001), with a rate of 75.1% (95% CI, 68.3% to 80.9%) for serotonin-norepinephrine inhibitors, 60.9% (95% CI, 57.2% to 64.5%) for selective serotonin reuptake inhibitors, 42.8% (95% CI, 19.9% to 69.3%) for nonselective monoamine reuptake inhibitors, and 37.5% (95% CI, 22.5% to 55.4%) for atypical antidepressants. Only, 40.7% (95% CI, 37.5 to 44.1) of women were persistent with antidepressants for the full pregnancy period-the rate differed significantly by medication class ( P < 0.0001). Adherence to and persistence with antidepressants is low during pregnancy and varies by medication class. Low adherence and persistence can interfere with a therapeutic effect of antidepressants, which may contribute to the worsening of depression symptoms.