Attention deficit hyperactivity disorder: Comorbidity and medication use

Children presenting with symptoms suggestive of Attention Deficit Hyperactivity Disorder (ADHD) may have other disorders resembling ADHD leading to inappropriate stimulant medication use. Objective: This study was designed to establish diagnoses in children presenting for evaluation of ADHD, behavior problems or learning problems. Pre-evaluation stimulant use was assessed. Methods: Subjects were 189 children ages 2-15 years referred for a comprehensive evaluation of ADHD, behavior problems or learning problems. Each was evaluated by a developmental pediatrician with additional assessments as needed by a psychologist and/or speech pathologist. DSM-IV criteria were used to formulate diagnoses for ADHD, specific learning disability (SLD), mental retardation (MR), language disorder (Lang), and other DSM-IV disorders (DIS). Medication use was reviewed. Data was analyzed by age groups ≤5 years or >5 years. Results: See Table. Referral Complaint Diagnosis N(%) Total N=189 N ADHD SLD MR Lang DIS ADHD 109 65(60) 32(29) 16(15) 20(18) 54(50) Behavior Problems 54 12(22) 6(11) 23(43) 31(57) 38(70) Learning Problems 26 5(20) 13(50) 8(31) 5(19) 13(50) Of children evaluated for ADHD, 40% did not have it. Significantly fewer (p<0.01) children ≤ 5 years were diagnosed ADHD (24%) than those >5 years (63%). In subjects ≤5 years, 35% had MR, 50% Lang, and 49% DIS. SLD was present in 41% of children >5 years. In subjects whose pre-evaluation complaint of ADHD was confirmed, 48% used stimulants. In those not diagnosed ADHD, 10% used stimulants pre-evaluation. Conclusions: Children presenting with behavior problems or those ≤5 years are at higher risk for MR, Lang, and DIS and less likely to have ADHD. Children presenting with learning problems or those >5 years are more likely to have SLD and/or ADHD. Stimulant use pre-evaluation appeared appropriate. Multiple diagnoses were common for all ages and presentations, emphasizing the importance of comprehensive evaluations.