The ADHD adult checklist is a tool used by mental health professionals to help diagnose and treat Attention Deficit Hyperactivity Disorder (ADHD) in adults. The checklist includes 18 symptoms that are typically associated with ADHD, such as difficulty paying attention, impulsivity, and restlessness. Having a checklist can help to ensure that all symptoms are taken into account when making a diagnosis, and can also be used to track the progress of treatment.