Antenatal depressive and anxiety symptoms in women with eating disorders who continue or discontinue antidepressant treatment in pregnancy

• Population study of antenatal depression/anxiety symptoms in eating disorders. • Continued antidepressants lessen depression/anxiety in BED in early pregnancy. • Potential worsening of depression/anxiety symptoms in BN in mid-late pregnancy. • Polygenic scores suggest personalized therapy potential in perinatal eating disorders. Limited evidence on antidepressant effectiveness in pregnant women with eating disorders (ED) challenges pharmacotherapy management. We examined antenatal depressive and anxiety symptoms with continued antidepressant use in women with ED. We used data from the Norwegian Mother, Father and Child Cohort Study (MoBa) linked to the Medical Birth Registry of Norway and MoBa Genetics. MoBa questionnaires at weeks 17 (early) and 30 (mid-late pregnancy) measured antidepressant exposure and symptoms of depression and anxiety using the 5-item Hopkins Symptom Checklist. We fitted generalised linear models and adjusted for confounding. In a subsample, we stratified analyses by polygenic-score tertiles for antidepressant response. We identified 5920 pregnancies in women with ED, mainly binge-eating disorder (BED) (84.0 %) and bulimia nervosa (BN) (12.4 %). Of these, 48 (0.8 %) continued antidepressants into early pregnancy, 93 (1.6 %) discontinued during, and 85 (1.4 %) discontinued before pregnancy. At early pregnancy only, continued antidepressant was associated with lower severity of depressive and anxiety symptoms relative to discontinuation. Among women with BED, this was specific to lower anxiety symptoms (β:-0.43, 95 %CI:-0.84, -0.02). This association was not observed in women with BN. In women with higher antidepressant-response polygenic-score continued antidepressant was associated with lower symptom severity relative to discontinued (range of β:-0.86 to -1.35). Continuing antidepressants in early but not mid-late pregnancy is associated with lower severity of depressive and anxiety symptoms in women with BED. The association observed in women with higher antidepressant-response polygenic-score calls for larger studies on personalized treatment in perinatal ED.