Targeted school based intervention to improve depressive symptoms among at risk Chilean adolescents

1. Beck Depression Inventory II (BDI-II) was was to assess depressive symptoms and to determine recovery rate: percentage of students included in the study who had lower than 11 points for boys and lower than 16 points for girls 3 months after completing the intervention
2. This is a brief and well-established depression questionnaire translated to different languages and used widely throughout the world
3. It has previously been used among adolescents in Chile and in other Latin-American countries showing good psychometric properties
4. It is self-completed which has the advantage of reducing potential observer bias since it is unlikely that observers will be completely blind to allocation
5. The BDI- II also provides a good measure of the cognitive changes expected to occur with the intervention

1. Revised Child Anxiety and Depression Scale (RCADS): this is an adaptation of the Spence Child Anxiety Scale (SCAS) and intends to assess symptoms of DSM-defined anxiety disorders and major depression
2. The scale consists of 47 items that on the basis of exploratory factor analysis are allocated to six subscales:
2.1. Social phobia (9 items)
2.2. Panic disorder (9 items)
2.3. Major depressive disorder (10 items)
2.4. Separation anxiety disorder (7 items)
2.5. Generalized anxiety disorder (6 items)
2.6. Obsessive-compulsive disorder (6 items)
3. Items have to be scored on a 4 point scale
4. RCADS subscale scores can be obtained by summing across relevant items
5. We excluded the depression and separation anxiety sub-scales because these were either covered by other scales or irrelevant to students of this age
6. School records of academic performance: we will only use grades obtained through formal testing because these are standardised across schools
7. Other assessments:
7.1. Measures of psychological functioning: Children’s Automatic Thoughts Scale (CATS)This self completed scale assesses a range of negative self statements in children and young people aged 7-16. For each item the child is asked to rate whether they have had a similar thought over the past week. Each item is rated as “not at all” (scores 0), “sometimes” (scores 1), “fairly often” (scores 2), “often” (scores 3) or “all the time” (scores 4)
7.2. Confirmatory factor analysis identified 4 distinct but correlated factors relating to thoughts about physical threat, social threat, personal failure and hostility. Internal consistency for the total score was high (Cronbach Alpha=0.95) with acceptable test –retest reliability (0.79). The scale has been found to effectively discriminate between a community and clinical sample with the personal failure sub-scale being the strongest predictor of depressive symptoms. The 10 item personal failure sub-scale will be used.
7.3. The Short Form of the Social Problem-Solving Inventory Revised (SPSI-R Short Form)will be used to assess problem-solving dimensions. The SPSI-R Short Form is a 25-item self-report instrument that measures two adaptive problem-solving dimensions (positive problem orientation and rational problem solving) and three dysfunctional dimensions (negative problem orientation, impulsivity/carelessness style, and avoidance style). Each item is rated on a 5-point scale ranging from not at all true of me (0) to extremely true of me 7.4. Alpha coefficients for the subscales range from .72 to .85
7.5. Studies with the Spanish version of the SPSI-R Short Form confirmed its factor structure and obtained adequate alpha coefficients for the five subscales. In the more recent study, alpha coefficients were .55, .73, .66, .70, and .69 for positive orientation, negative orientation, rational solving, impulsivity, and avoidance, respectively.