MedicalResearch.com Interview with: Guohua Li, MD, DrPH Finster Professor of Epidemiology and Anesthesiology Columbia University Irving Medical Center MedicalResearch.com: What is the background for this study? How was the ADHD diagnosis determined? Response: The reported prevalence of ADHD in children and young adults in the United States has more than doubled since the 1990s because of improved diagnosis.  Currently, ADHD affects about 13 percent of children under 18 years of age and eight percent of adults under 45 years of age.  Little is known about the prevalence of ADHD in older adults although it is estimated that ADHD symptoms may persist throughout the lifespan in about one-third of children diagnosed with the disorder.  Diagnostic criteria for adulthood ADHD include having five or more relevant symptoms, adverse impact on social, academic, and occupational activities,  and onset of symptoms before age 12. In this study, ADHD status is determined based on an affirmative response to the question of whether the participant had ever had ADHD or had ever been told by a doctor or other health professional that he or she had ADHD. (more…)