Exploring the stress sensitization theory with temperamentally inhibited children: a population-based study.

backgroundThis study explored whether temperamentally inhibited children who experience early trauma are vulnerable to developing internalizing problems in the face of later life-stressors.

methodsA validated screen for temperamental inhibition was distributed to parents of young children attending preschools in six government regions of Melbourne, Australia. Screening identified 11% of children as inhibited (703 of 6347 screened) and eligible for a prevention study. Participants were 545 parents of inhibited preschoolers (78% uptake), of whom 84% were followed into mid childhood (age 7-10 years: wave 1, n = 446; wave 2, n = 427; wave 3, n = 426). Parents and children then completed questionnaires for child internalizing (anxious and depressive) symptoms, and parents received a diagnostic interview for child anxiety disorder. In mid-childhood parents also completed questionnaires annually to describe recent life-stressors experienced by their child, and any potentially traumatic events in the first four years of life.

resultsOnly one in 14 temperamentally inhibited children had experienced a potentially traumatic event in early childhood. In mid childhood 56% experienced recent life-stressors. Inhibited children who had early life trauma experienced slightly more anxiety disorder and symptoms in mid childhood. Those children with more recent life-stressors in mid childhood also had slightly more symptoms of anxiety and depression. In contrast to stress sensitization, inhibited children with early trauma plus recent stressors did not show especially high mid-childhood internalizing difficulties.

conclusionsEarly life trauma and recent life-stressors each convey a small risk for children with an inhibited temperament to develop internalizing problems. Nevertheless, early life stress may not always result in negative sensitization for children in the general population.