This paper reviews the literature on the ongoing effects of attention deficit disorder (ADD) and attention deficit hyperactivity disorder (ADHD) in adults. It notes that 66 percent of individuals diagnosed with ADD or ADHD as children continue to experience one or more symptoms as adults, most commonly restlessness, distractibility, and impulsiveness. The paper begins with a review of the history of ADD and methodological considerations including changing terminology, research designs, sample attributes, and assessment methods. Next, the impact of ADD in adulthood is directly addressed for the areas of academic and vocational adjustment, social adjustment, emotional adjustment, and long-term effects of stimulant treatment. Implications of the Americans with Disabilities Act are also discussed. The final section addresses further research needs. (Contains 52 references.) (DB)