Asperger's is a very mild form of autism, while attention deficit hyperactivity disorder (ADHD) is characterized by problems with attentiveness, compulsions, and difficulty remaining still. ADHD and Asperger's are very different in terms of the underlying conditions. People with Asperger's tend to become obsessed with one subject and then learn every possible fact about that topic, and they also have problems dealing with people socially. People with ADHD may have trouble focusing and controlling their behavior, which can lead to a wide variety of different problems.
Even though ADHD and Asperger's aren't actually related, they can often look very similar to an outside observer, particularly someone who isn't intimately familiar with the patient. This is because both disorders can cause people to have similar social problems. Kids with ADHD and Asperger's both have a tendency to say or do things that are socially inappropriate. For the child with Asperger's, this may come from an inability to relate to people, and for patients with ADHD, it may come from an inability to moderate impulses.
Both ADHD and Asperger's can lead to problems in school, and the problems may even look very similar. ADHD and Asperger's patients both may have trouble focusing during their classes. For the child with ADHD, this may be because of an overall difficulty with prolonged attentiveness, while the Asperger's child may have a lot of difficulty focusing on things that don't fit with his primary personal interest. From the perspective of a teacher in the classroom, it can be difficult to tell the two apart, and this is one of the reasons that ADHD and Asperger's are both often misdiagnosed or sometimes even mistaken for each other.
When trying to diagnose ADHD and Asperger's, both may require extensive testing, including everything from learning disability tests to psychological studies. Usually, there is a focus on ruling out other possibilities because both disorders look very similar to several other problems. Both disorders are misdiagnosed very frequently, but overall, ADHD has this problem to a greater extent, partially because it is significantly more common. Many experts believe that many of the children diagnosed with ADHD don't actually suffer from the disorder at all.
People who suffer from ADHD and Asperger's are both prone to suffering with continued problems as adults, although this can sometimes be worse for people with ADHD. Asperger's sufferers usually have continued social problems, but those suffering with ADHD might have more difficulty holding a job or even have a tendency to be incarcerated. In the case of both disorders, adult problems can sometimes be lessened if the proper treatments are pursued during childhood.