Objective: This is the seventh in a series of 10-year reviews of rating scales. Here the authors present scales measuring functional impairment, a sequela of mental illness. The measurement of functional impairment has assumed importance with the recognition that symptom resolution does not necessarily correlate with functional improvement.
Method: The authors reviewed functional impairment from multiple sources over the past 20 years. Thus, this article includes a variety of scales ranging from those that have been subject to critical review with strong psychometric support to those that have not been critically reviewed but are in widespread use to those that are still finding their niche.
Results: These scales represent a continuum of constructs from symptoms to functional impairment to contextual factors that affect youths' functioning. Most older scales have focused on developmentally delayed youths. Newer scales strive to measure functional impairment separate from symptomatology. Some newer scales are also keyed to determination of level of service need.
Conclusions: Scales measuring functional impairment can elucidate the impact of illness on youths, identify targets for treatment, determine service needs, and monitor treatment effectiveness. These scales are widely used in community mental health and health service delivery. They can assist in providing evidence-based treatment.