Instead, they may report constant mental activity and inner restlessness as their hyperactivity internalizes.Symptoms of ADHD (see table below) can vary widely between individuals and throughout the lifetime of an individual. As the neurobiology of ADHD is becoming increasingly understood, it is becoming evident that difficulties exhibited by individuals with ADHD are due to problems with the parts of the brain responsible for executive functions (see below: Pathophysiology). These result in problems with sustaining attention, planning, organization, prioritization, time management, impulse control, and decision making.The difficulties generated by these deficiencies can range from moderate to extreme, resulting in the inability to effectively structure their lives, plan daily tasks, or think of and act accordingly even when aware of potential consequences. These can lead to poor performance in school and work and can be followed by underachievement in these areas. In young adults, poor driving records with traffic violations may surface.As problems accumulate, a negativistic self-view becomes established and a vicious circle of failure is set up. Up to 80% of adults may have some form of psychiatric comorbidity, such as depression or anxiety. Many with ADHD also have associated learning disabilities, such as dyslexia, which contributes to their difficulties.Studies on adults with ADHD have shown that, more often than not, they experience self-stigma and depression in childhood, commonly resulting from feeling neglected and different from their peers. These problems may play a role in the high levels of depression, substance abuse, and relationship problems that affect adults with ADHD later in life.
Children under treatment will migrate to adult health services if necessary as they transit into adulthood, however diagnosis of adults involves full examination of their history. Treatment of ADHD is usually based on a combination of behavioral interventions and medication. Stimulant medication is the first line treatment for ADHD in adults, particularly amphetamines. Non-stimulant medications, such as atomoxetine, or Viloxazine, are also recommended for some ADHD adults. Psychotherapy such as cognitive behavioural therapy is helpful, particularly in combination with medication. Similarly, exercise, sufficient sleep and nutritious food are also known to have a positive effect. Within school and work, reasonable accommodations may be put in place, such as by structuring work tasks, and setting up clear rules and limits for tasks. Classification
The DSM-5, or Diagnostic and Statistical Manual of Mental Disorders, 2013 edition, defines three types of ADHD:

a Predominantly Inattentive presentation
a Predominantly Hyperactive-Impulsive presentation
a Combined Type, that displays symptoms from both presentationTo meet the diagnostic criteria of ADHD, an individual must display:

at least six inattentive-type symptoms for the inattentive type
at least six hyperactive-type symptoms for the hyperactive-impulsive type
all of the above to have the combined typeThe symptoms (see below) were required to have been present since before the individual was seven years old, and must have interfered with at least two spheres of his or her functioning (at home and at school or work, for example) over the last six months.