The adoption of evidence-based practice in social work has been widely promoted in recent years and with this, a growing emphasis on the evaluation of practice using well-validated and reliable measurement processes. The Department of Health's 'Framework for the Assessment of Children in Need and their Families' in the UK includes quantitative measures that form part of a systematic assessment of the needs of children and their families that includes assessment of parenting capacity and parental emotional state. The measure selected to assess parental mood was originally known as the Irritability, Depression and Anxiety Scale, and has been renamed within the Assessment Framework as the Adult Well-Being Scale. This instrument is designed to assess depression, anxiety, and inward and outward irritability. However, there has been relatively little contemporary evaluation of the reliability and validity of the measure, and the extent to which it measures the four constructs it is designed to assess. This research therefore conducted extensive analyses of the reliability, validity and underlying factor structure of the Adult Well- Being Scale. The four subscales did not demonstrate sound psychometric properties. At best a total score may be used as an indicator of 'overall psychological distress'.