Is Functional Improvement Always Correlated with Symptomatic Improvement in Children With Attention-Deficit/Hyperactivity Disorder Managed with Oros Methylphenidate? A Prospective Open-Label Naturalistic Follow-Up Study

OBJECTIVE: To investigate the relationship between symptomatic improvement and functional improvement in children with attention deficit hyperactivity disorder (ADHD) who were being treated with OROS methylphenidate. METHODS: Parents evaluated the severity of ADHD symptoms on the Turgay-DSM-IV ADHD/Disruptive Behavior Disorders Scale (T-DSM-IV). They assessed functioning on the Weiss Functional Impairment Rating Scale- Parent Form (WFIRS-P), and the Pediatric Quality of Life Inventory (PedsQL) was used to assess quality of life. Clinicians rated global outcome on the Clinical Global Impressions Scale (CGI). Response was measured in terms of the following criteria: a 20% change in symptoms, a CGI-I score that was much improved (2) or very much improved (1), or an improvement of 0.25 (the minimally important difference) on the WFIRS. Improvement in quality of life was defined as ≥ 20% change in PedsQL score. RESULTS: Sixty-three children completed the study. After 12 weeks, 77.7% of patients met the a priori criteria for treatment response rate. Among patients who exhibited improvement in symptoms, 42.9% also showed improved functioning. Among those who showed improved functioning, 95.5% showed improvement in symptoms. Of patients who showed improvement in symptoms, 34.6% percent also showed improvement in quality of life. Of those who showed improvement in quality of life, 94.4% also showed improvement in symptoms. CONCLUSIONS: Evaluation of changes in functional improvement, quality of life improvement, and symptom improvement during ADHD treatment enables clinicians to identify individuals whose functional impairment/quality of life persists despite symptom improvement. On that basis, additional treatment interventions can be organized for those individuals.