Scientist Franz Max Albert Kramer worked as a psychiatrist in Poland and the Netherlands in the early twentieth century and is known for his contributions to research on psychological conditions that experts call hyperkinetic syndromes. Children with hyperkinetic syndromes display inattention, overactivity, and impulsivity. Along with scientist Hans Pollnow, Kramer defined a specific kind of hyperkinetic syndrome based on an initial case study of seventeen children, initially known as Kramer-Pollnow Syndrome. In 1980, the third edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-III, renamed Kramer-Pollnow syndrome to be attention deficit disorder, or ADD. A later revision, in 1987, renamed it attention deficit hyperactivity disorder, or ADHD. Kramer advanced child psychiatry research by laying the groundwork for further research on and understanding of what experts call, as of 2021, ADHD.