Many respond to the research in the article as if it establishes that biological deficiencies cause children to meet the criteria of the ADHD diagnosis and that medications are "correcting" those deficiencies. However, the findings could also mean that children doing ADHD behaviors frequently will also respond in particular ways (including brain responses) when required to do particular kinds of tasks. These same children may respond (including brain responses) differently when doing other kinds of tasks (particularly those they initiate and enjoy).
1. The research does not tell us whether medication is the only way to get a child diagnosed with ADHD to respond in a more typical way. New learning might also help them respond (including brain response) in a "normative" fashion.
2. The research does not tell us whether the observed biological pattern is the cause or consequence of doing ADHD responding. We might also deduce that responding with ADHD behavior over time changes biological development (including brain responses) just like what happens when people eat poorly or have stress.
Always remember, when people took "diet pills" their house cleaning improved (and very likely their brain responses changed as well). However, no one thought they were correcting a biological deficiency when that happened.