This study followed children who were diagnosed with ADHD combined type between the ages of 7 and 9.9, along with a group of their classmates for comparison. Both groups were assessed again in adulthood, at an average age of about 25. The researchers wanted to see how estimates of who still had ADHD changed depending on how symptoms were measured.
The method made a large difference. Across 36 ways of defining persistence, the share of the childhood ADHD group who still had symptoms ranged from very low to more than half (1.9% to 61.4%). Parents reported more lasting symptoms than the young adults reported about themselves. On one rating scale, self-reports put persistence at 24.5%, while parent reports put it at 44.6%. Structured interviews and a threshold based on typical ranges also gave higher numbers than standard DSM rules.
One definition best separated who did and did not still have ADHD. It combined parent and self-reports and counted a symptom if either source noted it. This approach identified 86.1% of true cases and 73.3% of those without the condition.
The authors suggest that assessing ADHD in adulthood should include reports from others, such as parents, especially when a person's own report does not show clear symptoms.
Source: Sibley M, Swanson J, Arnold L, et al.. Defining ADHD symptom persistence in adulthood: optimizing sensitivity and specificity. Journal of Child Psychology and Psychiatry (2016). doi:10.1111/jcpp.12620