This paper is a narrative review of research on ADHD across the life span, from preschool through adulthood. The author argues that ADHD is a real neurodevelopmental condition that runs strongly in families. Most heritability estimates sit near 0.75, and they approach 0.90 in people who are clinically diagnosed. Even so, the author says genes act together with family, school, peer, neighborhood, and policy factors.
The review also notes that diagnoses in the United States have grown faster than the condition itself. Among children aged 4 to 17, parent-reported "ever diagnosed" ADHD rose 41% between 2003 and 2012. That brought the rate to about one in nine children. Worldwide estimates put the true rate lower, at 5 to 7% of young people. The author links part of this rise to school accountability laws, pointing to a jump of nearly 60% in diagnoses among lower-income children in states that had just adopted such laws.
In the author's long-term study of girls with ADHD, unplanned pregnancy was far more common in women diagnosed as children (nearly 44%) than in a comparison group (10%). The author concludes that only two treatment types have strong evidence, medication and behavioral or cognitive behavioral therapy, and that combining them is usually best.
Source: Hinshaw S. Attention Deficit Hyperactivity Disorder (ADHD): Controversy, Developmental Mechanisms, and Multiple Levels of Analysis. Annual Review of Clinical Psychology (2018). doi:10.1146/annurev-clinpsy-050817-084917