As with other mental-health problems, ADHD is complex and variable. Its symptoms may mimic those of other disorders, or bona fide ADHD symptoms can be overlooked or mistaken for something else.
Severity can range from mild inattentiveness to severe and disruptive hyperactivity.
ADHD also manifests differently from person to person and can be unpredictable from day to day. To further complicate matters, an attention disorder may be accompanied by a learning disability, emotional problems, or a mood disorder, such as depression. Inattentiveness People who are inattentive typically have trouble keeping their mind on any one thing. They get bored easily, are often distracted by irrelevant stimuli, and don't seem to listen when someone is talking directly to them. Capable of devoting effortless attention to things they do enjoy, they find it extremely difficult to focus deliberate, conscious attention when it comes to other activities or to learning something new.