One size does not fit all: Psychometric properties of the Shona Symptom Questionnaire (SSQ) among adolescents and young adults in Zimbabwe

Background: Depression is a major contributor to the global burden of disease. Onset commonly occurs during the adolescent period. Understanding how depression tools are functioning among adolescents has been relatively overlooked. Methods: Using cross-sectional survey data among a sample of 2768 adolescents (aged 15-19) and 2027 young adults (aged 20-24) living in Zimbabwe this paper calibrated the Shona Symptom Questionnaire (SSQ) against the Self Report Questionnaire (SRQ-20) and examined the performance indices of the SSQ based on various cut points for classification. Using a multivariate logistic regression model we isolated particular characteristics to test their association with the odds of being misclassified as non-depressed by the SSQ. Results: A modified cut point of five or more substantially increases the depression estimates for both age groups. The prevalence of depression increased from 3.5% to 13.2% among adolescents and from 5.1% to 16.2% among young adults based on these revisions. Adolescents who were orphaned or ever had sex had significantly a greater odd of being misclassified. When retested using the modified cut point of five or greater, associations with misclassification disappeared. Limitations: Scales were not administered separately or in their entirety but rather overlapping items were only asked once, utilizing exclusively SRQ-20 phrasing rather than the culturally-emic language in the SSQ. Conclusions: Not all depression scales are appropriate for use among adolescents given their unique developmental stage. An alternative cut point for depression classification could improve detection of depression among Zimbabwean adolescents. (C) 2014 Elsevier B.V. All rights reserved.