What are the differences between the PATS and MTA studies for ADHD?

Donna Hill Howes, RN
Family Practitioner

PATS study for ADHD
The Preschool Attention Deficit Hyperactivity Disorder Treatment Study (PATS) looked at the efficacy of attention deficit hyperactivity disorder (ADHD) medication treatment for preschool children. Since the Food and Drug Administration had not approved stimulant medications for use in preschoolers with ADHD, researchers wanted to find out if the medications were safe and effective for doctors to prescribe to young children.

At the beginning of the study, preschoolers were started on a non-medication behavioral treatment regimen. This treatment lasted for 10 weeks. If a child still had severe ADHD symptoms after the 10-week trial period, they were prescribed a low dose of ADHD stimulant medication. Then, the children were followed over time to see whether the medication helped their ADHD symptoms. The researchers found that stimulant medications did reduce ADHD symptoms in preschoolers, although side effects caused significant problems at times. Some of the children in the medication group experienced significant side effects and had to discontinue the study.

MTA study for ADHD
The Multimodal Treatment Study of Attention Deficit Hyperactivity Disorder (MTA) analyzed the efficacy of different treatments for children with ADHD. The MTA study compared children receiving intensive medication and behavioral treatments to children receiving less intensive treatments. Almost 600 children between the ages of 7 and 9 were enrolled in the study and randomly assigned to one of four treatment groups:

  • Intensive medication therapy
  • Intensive behavioral therapy
  • Both intensive medication and intensive behavioral therapy
  • Routine standard of care (this was the control group)

The treatments were given for about 14 months, and then the children's experiences were analyzed. Those who received both medication and behavioral therapy during the study experienced the most positive benefits.

The PATS (Preschool ADHD Treatment Study) was a huge, well-designed study that looked at giving medications to more than 300 preschoolers with severe ADHD from all over the country. It found that low doses of the stimulant methylphenidate (Ritalin) helped many of these little kids, aged three to five. The doses averaged 14 milligrams (mg) a day, but were as low as 3.75 mg. (As a reference, school-aged children typically receive a dose between 15 and 50 mg a day). However, in this case, the benefits of the lower dose may not outweigh the costs of side effects. That’s because, preschoolers tended to be more sensitive to negative side effects, such as loss of appetite, nervousness, and problems sleeping. About one in ten kids stopped taking the medications because of side effects. The medication was also linked to slower-than-average growth rates in these kids. (Over the 70 weeks of the study, the kids grew about a half-inch less and gained about three pounds less than the average for kids this age.) Bottom line: Low doses of stimulant medications can help some kids with severe ADHD, but they should be used with caution and monitored closely.


The MTA (Multimodal Treatment Study of Children with ADHD) is a major study of the treatments for ADHD. It looked at treating children with medications alone, with behavioral therapy alone, and with a combo. The first results published in 1999, found that the combo was the most successful approach. The authors talked about how just treating with a pill doesn’t help the child structure his habits to be successful in school and in life. That’s what behavioral therapy offers. A 2009 follow-up to MTA found that the medications for ADHD often become less effective after two or three years. So, as your child grows into adolescence, besides bracing yourself for some tumultuous years, you’ll want to evaluate the help he’s getting for ADHD to make sure it’s still effective and right for him.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.