This is a short conceptual paper, not a study. The authors did not collect any data or study any people. Instead they make an argument about how children with ADHD are seen in research and in schools.
They say these children are usually viewed through a deficit lens, meaning the focus is on their problems and symptoms. The authors argue that research and school practice should also take a strengths-based, positive-psychology view. That means giving equal attention to what these children do well, to the things that protect them, and to their resilience, alongside the usual symptom-focused treatment.
The only number the paper reports is how common ADHD is. It states that about 5 to 10% of school-age children have ADHD, both in Canada and internationally.
The authors are open that the research they build on is thin. They note that studies of protective factors in children with ADHD are scarce, that little is known about school factors that lead to positive outcomes, and that few strengths-based programs have been designed for this group. They do point to some early findings, such as work on knowledgeable and supportive schools and teachers (DuPaul et al., 2011). So they describe the evidence as emerging rather than absent. All of this concerns children, not adults.
Source: Climie E, Mastoras S. ADHD in schools: Adopting a strengths-based perspective.. Canadian Psychology / Psychologie canadienne (2015). doi:10.1037/cap0000030