What to look for regarding the age of onset before diagnosing ADHD

Clinicians are understandably concerned about making a valid diagnosis of attention-deficit/hyperactivity disorder (ADHD). One feature of ADHD that helps to differentiate it from other conditions is its early age of onset.

But, regarding the early age of onset of ADHD, what exactly should we look for? Let’s understand this clearly by looking at a few patient scenarios and asking ourselves whether or not a diagnosis of ADHD should be made in each of those patients based on the DSM-5-TR™ diagnostic criteria for ADHD.