Data from parents and teachers of 2000 randomly selected children has revealed that only 29% of children with attention problems finished high school compared to 89% of children without such problems. When it came to hyperactivity, the difference was smaller: 40% versus 77%. After taking account of factors such as socioeconomic status and health issues that are correlated with ADHD, inattention was still a highly significant contributor, but hyperactivity was not.
Yearly assessments of the children were taken from age 6 to 12, and high school graduation status was obtained from official records. Attention problems were evaluated by teachers on the basis of behavior such as an inability to concentrate, absentmindedness, or a tendency to give up or be easily distracted. Hyperactivity was identified by behavior such as restlessness, running around, squirming and being fidgety.
The researchers make the excellent point that those with attention difficulties are often forgotten because, unlike hyperactive children, they don't disturb the class.
The findings point to the need to distinguish inattention and hyperactivity, and to provide early preventive intervention for attention problems.