ObjectiveTo examine the association between maternal depression and anxiety disorders (MDAD) and child development assessed during the kindergarten year.MethodsAdministrative data from several health and social databases in Manitoba, Canada, were used to study 18,331 mother-child pairs. MDAD over the period from one year prior to the child's birth to the kindergarten year was defined using physician diagnoses and filled prescriptions. Child development was assessed during the kindergarten year using the Early Development Instrument (EDI) which measures vulnerability across five domains of development. Structural equation modeling was used to examine associations between timing, recurrence and severity of MDAD and child outcomes. Health at Birth (preterm, low birth weight, neonatal intensive care stay and long birth hospitalization), Family Context (teen mother, lone parent, socio-economic status (SES)), child age and child sex were covariates.ResultsMDAD had a modest negative association with child EDI scores across all models tested, particularly for social, emotional and physical development. Prenatal MDAD had a stronger negative association with outcomes than other time periods; however, recurrent MDAD had a stronger negative association with outcomes than any specific time period or MDAD severity. The influence of MDAD was mediated by Family Context, which had a strong, negative association with outcomes, particularly language and cognitive development.ConclusionThe number of time periods a child was exposed to MDAD in early childhood was more negatively associated with five areas of child development than timing or severity. Prenatal exposure may be more sensitive to MDAD than other time periods. The familial context (teen mother, lone parenthood and low SES) had a stronger influence on child outcomes than MDAD. Findings can be used to inform interventions which address maternal mental health from the prenatal period onward, and to support disadvantaged families to encourage healthy birth outcomes, early childhood development and school readiness.