Internalizing problems, externalizing problems, and prosocial behavior - three dimensions of the strengths and difficulties questionnaire (SDQ): A study among South African adolescents.

This study aimed to examine the factor structure of the Strengths and Difficulties Questionnaire Self-Report version (SDQ-S), its psychometric properties and measurement invariance by gender and language spoken at home, among secondary school students in Western Cape, South Africa. A sample of 3,542 adolescents in Grade 8 (Mean age = 13.7 years) completed the SDQ-S in a three-language questionnaire (Afrikaans, English and isiXhosa). The data were collected from 42 secondary schools in Cape Town, South Africa. Confirmatory factor analyses with the WLSMV estimator with adjustment for cluster effects (schools) were applied. The SDQ-S was originally developed to cover five domains: four "difficulty" domains (hyperactivity/inattention, emotional, conduct, and peer) and one "strengths" domain (prosocial behavior). When the five factors were tested on the data for the current study, poor fit was obtained. After excluding four items, a three-factor solution with no cross-loadings and no correlated error terms obtained acceptable fit. The results are consistent with previous studies. Strong measurement invariance across genders and language spoken at home was confirmed. In studies of community samples, the use of the SDQ-S scale as an instrument with a three-factor dimension (internalizing, externalizing and prosocial) may be more appropriate than using the original five-factor model.