Children were administered the 23-item Pictorial Depression Scale (PDS), a forced-choice, self-rating scale [37,38], to assess presence or absence of depressive symptoms (e.g. feelings of loneliness, lack of enjoyment of games, problems with sleeping or attention). The PDS was adapted from the Children's Depression Inventory developed by Kovacs [39] and has been validated for use with children as young as 4 years of age. It consists of pictures of two side-by-side, identical children corresponding to the sex and race of the child, with neutral facial expressions. Pairs of statements, one of which reflects depressive symptomatology, are recited to the child; for example: ‘This child feels sad’ and ‘This child does not feel sad’. The child is then asked to point to the figure that is most like him/her. The order of presentation of negative versus positive statements is counterbalanced to eliminate response bias. Using a cut-off of >10, the PDS distinguished between depression and non-depression in a sample of child in-patients [38]. We grouped children with a PDS score ≥10 as exhibiting positive DEP (PDEP) and <10 as non-depressed (NDEP) [37]. To corroborate children's self-reports of depression, each mother completed a 25-item scale that measured child temperament [40].
