Attention-deficit/hyperactivity disorder symptom expression: A comparison of individual age at onset using item response theory

Background:The D5M-IVage at onset criterion for attention-deficit/ hyperactivity disorder (ADHD) has been a subject of debate. In D5M-5, the required age at onset (ie, the age by which impairing symptoms must have been present) has increased from 7 years to 12 years. The present study examined measurement properties of ADHD symptoms according to age at onset. Method: Data were derived from the 2004 2005 National Epidemiologic Survey on Alcohol and Related Conditions, which included 34,653 US participants. Among participants with a lifetime D5M-/V diagnosis of ADHD (assessed using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-IV), we compared the psychometric properties of the 18 ADHD symptoms according to 3 categories of age at onset (7 and 12 and 7 and 12 and <18 years. In both dimensions of ADHD (ie, inattention and hyperactivity- impulsivity), there was no significant DIF between age at onset groups. Conclusions: Expression of D5M-I V ADH D sym ptoms was not affected by age at onset in the 3 groups considered.This study provides psychometric support to the change in the age criterion introduced by D5M-5 and further suggests that the age at onset criterion could be extended to 18 years without changing the psychometric properties of the ADHD symptoms.