Short answers, pulled from the story.
The core symptom of attention deficit hyperactivity disorder is inattention, which requires at least six symptoms for children under 17 to establish a diagnosis. These symptoms must persist for six months or more and appear in multiple settings like home and school.
Genetics account for 70 to 80 percent of attention deficit hyperactivity disorder variance according to twin studies. Siblings of children with attention deficit hyperactivity disorder are three to four times more likely to develop the disorder than siblings of those without it.
Brain imaging studies show reduced volume in the left prefrontal cortex among individuals with attention deficit hyperactivity disorder. Structural MRI scans reveal thinner posterior parietal cortex compared to control groups along with smaller subcortical volumes including the accumbens amygdala caudate hippocampus and putamen.
Medications including methylphenidate and amphetamine derivatives serve as first-line treatments for most patients with attention deficit hyperactivity disorder. Approximately 70 percent respond positively to their initial stimulant choice while only about 10 percent fail to respond to either amphetamines or methylphenidate entirely.
About 15 percent of children diagnosed with attention deficit hyperactivity disorder continue meeting full criteria at age 25 years old. Worldwide estimates suggest 2.58 percent of adults have persistent forms and over 366 million people show symptomatic versions globally.