The purpose of this scale is to assess both ADHD symptoms and functional impairment, which, although related, are distinct concepts. This distinction is critical, as some individuals may display significant symptoms with little impairment, while others may experience substantial impairment despite fewer observable symptoms.
The instrument uses a Likert scale, with ratings of 2 or 3 indicating clinical impairment. Scores can be calculated by summing all items or by averaging scores within each domain, excluding “not applicable” responses. For DSM-V- TR purposes, a domain is considered impaired if it contains at least two items scored 2, one item scored 3, or a mean score above 1.5. Psychometric testing demonstrates high internal consistency (above .8) across domains and the total scale, moderate convergent validity (0.6) with other measures of functioning, and moderate discriminant validity (0.4) from ADHD symptom measures and quality-of-life assessments. Factor analysis confirms the domain structure, with school functioning further divided into learning and behavior. The scale is highly sensitive to treatment-related change, correlating strongly with improvements in ADHD symptoms and overall psychopathology. A total score change of 13 points (about half a standard deviation) is considered clinically significant, with treatment typically producing a full standard deviation change. Risky behavior scores average 0.5 in children, rising to 1 in adolescents.
By focusing on items most relevant to a patient’s treatment goals, the scale enables clinicians to monitor changes not only in symptoms but also in functional challenges before and after intervention. Translated into 18 languages and validated in numerous studies, it remains the only functional impairment measure specifically designed for and validated in the ADHD population that examines distinct domains.
** Please note that these materials provided are drawn from open-access sources and are not authored by me **
