Multimodal Treatment of ADHD Study (MTA)

Principal Investigator: Brooke Molina, PhD

Funding Source: National Institute of Mental Health, National Institute on Drug Abuse, Department of Education, Office of Juvenile Justice and Delinquency Prevention

The Multimodal Treatment of ADHD Study, also known as “the MTA,” was a large multi-site randomized clinical trial conducted across six universities in the United States, including the University of Pittsburgh, and one university in Montreal, Quebec, Canada.  In Pittsburgh, after Drs. William Pelham and Betsy Hoza led the initial stages of the study, Dr. Brooke Molina directed the longitudinal follow-up study.  As of 2017, analyses and papers, supported by ongoing funding from NIDA, continue to emerge from this important 16 year data collection that completed in 2013.

For this study, 579 children who were 7-9.9 years old were diagnosed with ADHD, Combined Type, and randomly assigned at each site to receive one of four treatments for ADHD:

  • Intensive behavior therapy
  • Intensive medication management
  • Combined behavior therapy and medication management
  • Referral to community care (treatment provided as usual in the community)

This was the largest treatment trial conducted by the National Institute of Mental Health (NIMH) at the time. Although each of the protocol treatments were already evidence-based, their comparative efficacy was unclear, and the effects of treating children for up to 14 months was unknown.  Because of the large size of the study and many unanswered questions about ADHD life course, there was considerable interest in following the children through adolescence to track their service utilization, mental health, and general overall functioning. 

After treatment assignment, the children continued to be followed as part of the long-term observational follow-up study (study treatment only lasted for the initial 14 months of the study).  Two years into the study, 289 classmates without ADHD were recruited for comparison purposes and were also followed to help evaluate the functioning levels of the participants diagnosed with ADHD.

The final follow-up assessments were completed in March 2013, eighteen years after the study’s inception, when the participants had attained an average age of 25.

The NIMH maintains a website that provides the public with information, including publications, from this study.


View a list of selected publications from the MTA Study »

View the MTA page on the US Clinical Trials website »