Cannabis Use During Early Pregnancy and Child Diagnoses of Depressive and Anxiety Disorders

Objective: Prenatal cannabis use is associated with adverse pregnancy and neonatal outcomes, but research on its association with child anxiety and depressive disorders is limited. This study aimed to test the hypothesis that prenatal cannabis use is associated with child anxiety or depressive disorder diagnoses. Method: Population-based retrospective birth cohort study of children (N = 115,553) born between 1/1/2011 –⁠12/31-2017 to pregnant individuals (N = 97,376) universally screened for prenatal cannabis use. Cox proportional hazards regression models examined associations between cannabis use during early pregnancy (at ~8-10 weeks gestation based on self-reported use or a positive urine toxicology test for delta-9-tetrahydrocannabinol [THC]) and child anxiety and depressive disorders from ages 6 to 13 years based on diagnosis codes, adjusting for maternal sociodemographic and clinical characteristics. Results: The median age at pregnancy onset was 31 (inter quartile range [IQR] = 6) years. Most pregnancies (61.4%) were to non-White individuals; 4.4% screened positive for any cannabis use; 3.7% had a positive toxicology test and 1.9% self-reported use. Overall, 9,230 children were diagnosed with an anxiety disorder at median age of 8 (IQR = 3) years and 1,224 with depressive disorder at median age of 9 (IQR = 3) years. Prenatal cannabis use was associated with a lower risk of child anxiety disorders (aHR:0.84, 95%CI: 0.75-0.95), which remained significant when defined by a toxicology test but not by self-report. Maternal prenatal cannabis use was not associated with child depressive disorders (aHR:1.15, 95%CI: 0.85-1.54). Conclusions: Prenatal cannabis use during early pregnancy was not associated with an increased risk of offspring early onset anxiety or depressive disorders.