1) Inattentive Type ADHD
Inattentive type ADHD is real, even though debate remains on its impact and what the causes are. Adults often are not diagnosed with ADHD, but for many people who may have trouble paying attention that is exactly the cause of the problem. Hyperactivity is often associated with the condition, but inattentive type ADHD is just as real; it’s just not as visible.
Adults with ADHD are more likely to be substance abusers, particularly involving nicotine and cocaine. Both of those substances increase dopamine levels, which are typically low in people with ADHD. Dopamine is a brain chemical that carries signals between nerves and has a great impact on sleep, mood, attention and learning.
As stimulants can be effective in treating ADHD scientists believe this could explain why ADHD adults have a greater risk of drug abuse.
3) Opposite of hyperactive
The predominantly inattentive type of ADHD person may also have a very low level of energy and appear lazy or disinterested. But it could also be that they have trouble focusing or getting interested in something.
4) Still on the move
Even though the inattentive type ADHD person may not have the hyperactive trait, they will still likely have trouble sitting still. They are likely to fidget to some degree or to continue some kind of movement. Instead of needing to jump up and run around, the inattentive ADHD adult may need to tap his or her fingers or fidget with a pen constantly.
5) Paying attention
People with ADHD are said to have trouble paying attention to people, and they may at times appear to not be listening. While someone else is speaking they may be looking around, or at least looking away, and appear to be disinterested or bored. The person may be paying attention, but the ADHD causes them to need to be doing something else in addition to listening.
6) Positive aspect
ADHD is not entirely a bad thing. Some people with ADHD are often able to do several things at once, or they are able to think about and work on several things at once. A primarily inattentive ADHD person would likely be good at working under deadline pressure in a situation that requires a person to pay attention to many things at once.
7) Genetic causes
Debate continues about what causes ADHD, regardless of type. The current idea is that it is genetic in nature. If both parents have ADHD, their children will be very likely to also have ADHD. Scientists estimate there is an 80 percent "rate of heritability" with ADHD, which makes it almost as genetic as eye color. It is not necessary for both parents to have ADHD, as some studies show that at least 30 percent of fathers who had ADHD, have children with the condition. Scientists believe there is no single gene that transmits ADHD, but rather a group of genes working together.