PLAY Study Findings (Project to Learn About ADHD in Youth)
The study was designed to follow children from elementary school through adolescence and investigate the short and long-term outcomes of children with ADHD. The study questions were to examine:
- The prevalence and treatment of ADHD in children
- The existence of co-occuring and secondary conditions in children with ADHD
- The types and rates of health risk behaviors in children with ADHD
- Current and previous treatment patterns of children with ADHD
The study included children from six school districts with diverse populations from varied geographical settings. Because the study population was drawn from a school based sample, it provides information on ADHD symptoms and diagnosis and children’s development over time.
This method of sampling children from the schools made it possible to find children who are likely to have ADHD, but have not yet been diagnosed with the condition, to learn more about their development over time.
Findings from selected studies that were conducted using these data are shown below.
Prevalence and treatment of ADHD in children
Personal stories from people who are living with ADHD.
Parent and teacher information was used to identify children with symptoms and levels of impairment that fit the diagnostic criteria for ADHD. To determine the prevalence of ADHD in school-based samples of children, teachers screened 10,427 children in South Carolina and Oklahoma. Parent reports were collected on 855 children.
- The number of children in the community sample who had enough symptoms to fit the ADHD diagnosis at the time of each child's first assessment was 8.7% in South Carolina and 10.6% in Oklahoma.
- The number of parents in the community sample who reported that their children were taking ADHD medication was 10.1% South Carolina and 7.4% in Oklahoma.
- Of those children taking ADHD medication, only 39.5% (South Carolina) and 28.3% (Oklahoma) had enough symptoms to fit the ADHD diagnosis.
These findings show that ADHD estimates in this sample were at the upper end of the range of prevalence found in previous studies. There was a large portion of children taking ADHD medication who did not meet the ADHD diagnostic criteria. However, these children had more ADHD symptoms, on average, than other children in the comparison group who were not taking medication. Many children meeting diagnostic criteria had not been previously identified and were not receiving medication treatment, suggesting that the condition remains underdiagnosed.
Read more about prevalence of ADHD here.
Wolraich, M.L., McKeown, R.E., Visser, S.N., Bard, D.E., Cuffe, S.P. Neas, B., Geryk, L.L., Doffing, M., Bottai, M., Abramowitz, A.J., Beck, L., Holbrook, J.R., and Danielson, M.L. (2014). The prevalence of ADHD: Its diagnosis and treatment in four school districts across two states. Journal of Attention Disorders, 18(7), 563-575.
Persistence of ADHD symptoms over time
To find out whether ADHD symptoms persist from early childhood through late adolescence, parents were asked at the first visit and all follow up visits whether their children had symptoms of ADHD (hyperactivity or impulsivity).
- Parents were likely to report inattentive (30%) and hyperactive or impulsive (hyperactive-impulsive; 27%) symptoms in their children during early childhood, but were less likely to report hyperactivity-impulsivity symptoms as children reached late adolescence. Parents’ report of inattention remained consistent as the child aged.
- The proportion of children with a high number of inattentive symptoms was similar across age groups, from young childhood to late adolescence.
- The proportion of children with a high number of hyperactive-impulsive symptoms decreased with age, regardless of the child’s sex, ADHD medication use, or whether they had a psychiatric disorder in addition to ADHD.
- Children who had many hyperactive-impulsive symptoms were more likely to continue having these symptoms as teenagers if they also had many inattentive symptoms.
You can read more about this study here.
Holbrook, J.R., Cuffe, S.P., Cai, B., Visser, S.N., Forthofer, M.S., Bottai, M., Ortaglia, A., and McKeown, R.E. (2014). Persistence of parent-reported ADHD symptoms from childhood through adolescence in a community sample. Journal of Attention Disorder; Jul 3, 2014 (published online).
Changes in ADHD prevalence when diagnostic criteria are applied more strictly
This study examined how the estimates of ADHD prevalence vary by how ADHD diagnostic criteria are determined and used to make a diagnosis. The American Psychiatric Association's Diagnostic and Statistical Manual (DSM-5) diagnostic guidelines require 6 or more symptoms that appear before age 12, cause impairment in more than one setting (e.g., home and school), and are based on more than one type of person that observes and reports on the symptoms in the child (e.g., parent and teacher). Often all of the criteria are not used, but researchers showed that if they aren’t, there is clearly an effect on the estimated prevalence.
There was a steady decrease in the estimated prevalence as more diagnostic criteria were used
- Nearly 1 in 3 children (30%) had ADHD if a parent reported 6 or more symptoms of ADHD,
- 1 in 5 children (22%) had ADHD if researchers also included those who had the symptoms by age 12 years and showed functional impairment,
- 1 in 9 children (11%) had ADHD if researchers required that a teacher also reports symptoms—reducing the estimated prevalence of ADHD by half
Applying each DSM-5 criterion reduces the percentage of children aged 4-13 years
who fit diagnostic criteria for ADHD
The percentage of children age 4-13 years meeting diagnostic criteria for ADHD was higher if the DSM-5 criteria are used than if the previous DSM-IV criteria are used (11% versus 9%) because the age of onset of symptoms requirement was changed from being less than 7 years old to being less than 12. You can read more about the study here.
McKeown, R.E., Holbrook, J.R., Danielson, M.L., Cuffe, S.P., Wolraich, M.L., and Visser, S.N. (2015). The impact of case definition on attention-deficit/hyperactivity disorder prevalence estimates. Journal of the American Academy of Child Adolescent Psychiatry; 54(1): 53–61.
Current and previous treatment patterns of children with ADHD
At children's first assessment, parents reported whether their elementary school-age children took medication for ADHD. Researchers examined the medication rate for all children with ADHD as well as the rates for the three subtypes of ADHD: children with predominantly hyperactive symptoms, children with predominantly inattentive symptoms, and children with a combination of hyperactive and inattentive symptoms.
The results showed that the use of medication for ADHD did not differ significantly by ADHD subtype:
Percentage of Children with ADHD Taking ADHD Medications by ADHD Subtype
Further, the data also showed that more than 20% of medicated youth were taking more than one medication for ADHD treatment.
Visser, S.N., Cuffe, S.P., Holbrook, J.R., and McKeown, R.E. (2010). Patterns in ADHD medication use among an epidemiological cohort of youth. Poster presented at the American Academy of Child and Adolescent Psychiatry Annual Meeting, Toronto, Canada.
Co-occurring and secondary conditions in children with ADHD
At the first assessment, children were also assessed on symptoms and impairment that would be sufficient for a diagnosis of a clinical disorder other than ADHD (co-occurring or secondary condition). The findings show that the prevalence of disorders from all diagnostic groups was higher among children with ADHD than among those without ADHD:
- 53.4% had at least one other disorder
- 44.3% had oppositional defiant disorder
- 13.5% had conduct disorder
- 16.8% had an affective or anxiety disorder
Learn more about conditions that co-occur with ADHD here.
McKeown, R.E., James, L., Cuffe, S.P., Teng, Y., and Holbrook, J.R. (2008). Prevalence of comorbid disorders and risky behaviors with ADHD in elementary-aged children. Paper presented at the Children and Adults with Attention-Deficit/Hyperactivity Disorder Conference, Anaheim, California.
At the first assessment, parents were asked about risky behaviors, including behaviors that could cause injury and early signs of cigarette smoking. Parents reported the following health risk behaviors for their elementary school-age children:
Percentage of Children Engaging in Health Risk Behavior
The results suggest that youth with ADHD are more likely than youth without ADHD to engage in risky and dangerous behaviors, such as running into the street, doing dangerous things, refusing to wear seatbelts, and smoking.
Visser, S. N., Danielson, M. L., Cuffe, S. P., McKeown, R. E., Bitsko, R. H., Claussen, A. H., Bard, D. E., and Wolraich, M. L. (2011). Health risk behaviors over time among youth with ADHD. Poster presented at the American Academy of Child and Adolescent Psychiatry Annual Meeting, Toronto, Canada.
Follow up studies are underway.
- Page last reviewed: June 26, 2015
- Page last updated: June 26, 2015
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