['This prospective study aimed to determine predictors of persistent postnatal depression between child age one and four years, in a sample of mothers already identified as having a high incidence of postnatal depression at four months after birth and a relatively high prevalence of symptoms of depression at child age one year.', 'Data (self-report questionnaires and interview) were initially collected from 127 mothers of first-born infants recruited from a parent-craft hospital at four months postpartum. Women again completed questionnaires and interviews one year after the birth. Persistence of depression between one and four years was assessed by symptom checklists and diagnostic interview.', 'Ninety-two mothers (72%) of the original sample participated at four years. Eleven women who had first onset of depression after one year were excluded from analyses. Thirty-eight percent of the remaining sample (56% of those diagnosed with depression at 4 months) reported ongoing depression between one and four years. Severity of depressive symptoms at four months and maternal state of mind regarding attachment (assessed at 1 year) were significant predictors of persistent depression. Women with an insecure state of mind regarding attachment at one year were seven times more likely to report ongoing depression.'] Does maternal state of mind regarding attachment predict persistence of postnatal depression in the preschool years?