Recently, a young family came to me to have their 3 year old son evaluated. He was a delightfully active and normally developing toddler, but they were concerned that he had been having difficulty with his transition to a new nursery program. Teachers were complaining that he wouldn't listen, would throw toys and disrupt circle time. His parents were concerned that he might have ADHD.
Parents of very active three year olds--myself included--may find themselves checking off all the boxes if they read through the diagnostic criteria for ADHD: Trouble sitting still, often interrupts others or talks out of turn, difficulty with tasks of sustained mental effort, acts as if driven by a motor. But in a three year old, these behaviors may be developmentally appropriate. It is important to consider that the ability to focus and control impulses falls on a spectrum--some three year olds may be able to listen quietly to a story book for 10 minutes and others will begin to fidget. At this age, children test limits by not listening. Tantrums are still frequent and totally normal--although your toddler may have a bigger vocabulary, he lacks the emotional regulation skills to use that vocabulary when he becomes upset.
There can be red flags: If a child has severe outbursts--if they are flipping furniture, hurting others or hurting themselves when they tantrum, or if they are so distressed that they spend a good portion of the day out of control and seem unhappy or irritable all the time, there may be a deeper underlying problem. Common reasons that a toddler may exhibit these sorts of behaviors include speech delays--children without the vocabulary to express their needs are more likely to use behaviors to communicate; Trauma or extreme stress can also lead children to act out--divorce, illness in a parent or other conflict at home, witnessing violence at home or being the victim of abuse, and sometimes even happy stressors like the birth of a sibling can cause children to regress. It is also important to consider whether the nursery program has adequate supports--if a child does not exhibit these behaviors at home, it is important to investigate what is different about school--and to make sure that there is enough staff to give a child adequate attention and that they are attuned to the child's needs.
Take-home: Age three is usually too early to diagnose ADHD. At this age, it is developmentally appropriate for children to be very active and to tantrum when upset. It is always important to compare children's level of hyperactivity and impulsivity to behavioral norms for other children the same age. When we expect more from our children than they are developmentally capable of doing, we run the risk of pathologizing normal (but still very challenging) behaviors. However, red flags such as extreme aggression or irritability may indicate an underlying problem. Seeking help is a great idea as studies show that toddlers who show extreme aggression are more likely to struggle with mental health later in life.