Development and validation of a new measure of everyday adolescent functioning: the multidimensional adolescent functioning scale.

Everyday functioning is an important outcome for studies of the developmental psychopathology of adolescence. An unbiased, well-validated, and easy-to-use instrument to specifically assess normal adolescent functioning is not yet available. The current study aimed to introduce and validate the Multidimensional Adolescent Functioning Scale (MAFS).The MAFS was developed by clinical consensus, resulting in a 23-item self-report questionnaire with three distinct subscales: general functioning, family-related functioning, and peer-related functioning. MAFS data were collected in a general population sample (N = 842; mean age = 15.0 years [standard deviation = .4]) at baseline and again at 1- and 3-year follow-up. Psychometric analyses included confirmatory factor analysis, calculations of internal consistency, scale correlations, and correlations with the abridged General Health Questionnaire.Confirmatory factor analysis showed that the hypothesized 3-factor structure fits well to the MAFS data. All scales showed adequate internal consistency (greatest lower bound: .75-.91) and sufficient discriminative ability (scale intercorrelations: ρ = .15-.52). Of the scales, general functioning was most strongly correlated with the General Health Questionnaire, whereas family- and peer-related functioning showed weaker correlations with this general measure. The results were stable across repeated measurements and gender groups.The MAFS is an easy-to-use instrument with good psychometric characteristics, which could be suitable for a broad range of future research applications, especially when a multidimensional and unbiased indication of normal adolescent functioning is required.