Four-year-olds showing debilitating signs of attention-deficit hyperactivity disorder should be evaluated by doctors, revised guidelines say.

Previously, recommendations and diagnosing and managing ADHD started with children aged six to 12. Since 2001, emerging evidence pointed to expanding the age range to include preschool-aged children and adolescents, the American Academy of Pediatrics said.

The revised guidelines suggest doctors first prescribe behaviour therapy for preschoolers, and that methylphenidate or Ritalin may be prescribed if that does not significantly improve “and there is moderate-to-severe continuing disturbance in the child’s function,” the group’s 14-member committee said.

Behaviour therapy includes training parents and teachers on techniques to help children manage their anger, such as using positive reinforcement and punishing when a child fails to meet goals.

A student at the Center for Attention and Related Disorders camp in New Fairfield, Conn. that provides structure for for children who suffer from Attention Deficit Hyperactivity. New guidelines say the diagnosis should be considered in children as young as four. Brendan Smialowski/Getty

Treating children at a young age is important because identifying them earlier and offering treatment increases their chances of succeeding in school, said Dr. Mark Wolraich, the lead author of the report in the November issue of the journal Pediatrics.

ADHD is the most common neurobehavioral disorder in children, occurring in about eight percent of children and youth, according to the report.

To be diagnosed with ADHD, a child must show key symptoms in multiple environments such as at home, at school and in relationships with their peers that are tracked over time and persist.

For elementary school children and adolescents, the group recommended both approved medications and behaviour therapy.

The behavioural approaches can help some children if they are applied consistently at home, daycare and school, said Kiran Pure, a child psychologist in Dartmouth, N.S.

"But for a large proportion of children, the part of the brain, the frontal lobe that allows them to do executive functions, require medication just to activate those centres to work," Pure said.

ADHD drugs aren't approved for use in children under age six by either Health Canada or the U.S. Food and Drug Administration.

Slow growth a side-effect

Side-effects of stimulant medications include slowing of growth in children, appetite loss, sleep problems and stomach pain.

Dr. Diane Sacks, a Toronto pediatrician and past president of the Canadian Pediatric Society, says most specialists in Canada would not prescribe stimulants for children under six because of the side-effects.

"As pediatricians, we're very concerned about growth in young children," said Sacks. "If they're on a medication that decreases appetite, we are concerned that the growth may be impacted."

Leslie Urqhart's five-year-old daughter, Holly, was having severe attention and behavioural problems at school and home when she was diagnosed with ADHD a few months ago.

Despite her initial concerns, Urqhart agreed to try medication.

"I had to swallow my fear and do what I felt what was best for her knowing that we could pull the plug at any time and I'm really glad that we did," Urqhart said. "It's made a huge, huge difference in our lives."

For teens diagnosed with ADHD, the guidelines recommended that doctors watch out for any signs of drug or alcohol abuse.

The pediatric group also released an updated toolkit to help health-care professionals to diagnose and treat ADHD, and a consumer resource book for parents.

Some of the guideline authors said they have consulting relationships with companies that sell ADHD medications.

With files from CBC's Pauline Dakin