What is Attention Deficit Disorder on adults and how is it treated? Attention deficit disorder often corrupt other people's thought on the person that has ADD. The person with ADD is very forgetful, and often get agitated easily. Moreover, people with ADD can to be thought of stupid and weird, also they tend to have unstable relationship among family, colleagues, etc. 

I would like to know what makes a person have an ADD, and if it is curable of how it is treated.
It doesn't sound like your just looking for some general info about the psychological disorder of ADHD. The thing you should maybe start out with is understanding that there are two different sub-types which will have different effects. 

Rather than explain everything, I would point you to a couple links that should answer your questions: 

For a basic definition you can look at the CDC page on ADHD.

Here is some basic info that should get you started on understanding the disorder. 

wikipedia should fill in anything else that you want to know, if you have a more specific questions, feel free to ask.