Dexamethasone Suppression and Childhood Depression: Association with Categorical and Dimensional Measures

Abstract

This article examines the relationship of dexamethasone nonsuppression to both categorical (i.e., diagnostic categories) and dimensional (i.e., quantitative, multivariate) measures of depression in children. Sixty inpatients, ages 5-13 years, were administered the dexamethasone suppression test (DST). Categorical measures were the diagnoses of major depression or dysthymic disorder obtained from semi-structured interviews of child and parent. Dimensional measures of depression were the Short Child Depression Inventory (which is a child's self-report instrument) and the Child Behavior Checklist (which gave parent-rated quantitative scores for depression, aggression, hyperactivity, internalizing behaviors, and externalizing behaviors). Cortisol nonsuppression was associated with both dimensional and categorical measures of depression, but not with ratings of aggression or hyperactivity or with the diagnoses of dysthymic disorder or disruptive behavior disorder. Children with major depression had a higher rate of nonsuppression (69%) than children with either dysthymic disorder (29%) or disruptive behavior disorders (36%). Abnormal DST findings and postdexamethasone cortisol levels appeared significantly associated with higher scores on both dimensional measures of depression, but not with measures of internalizing or externalizing behavior, aggression, or hyperactivity. The total variance in dexamethasone suppression accounted for by dimensional ratings of depression was relatively modest (<20%). Although the potentially confounding roles of comorbid anxiety disorders and psychosocial Stressors remain to be investigated, it appears that biological studies of mood disorders in children may be advanced by the use of both dimensional and categorical approaches to the assessment of depression.