What is the main disability and it's affects?

Garth was diagnosed with an intellectual disability pretty early in life. When he was very little it was thought that he just had a developmental delay. Because he was thought to have a developmental delay he was given services to help him to catch up with his peers socially and mentally. When
Garth was little he had problems relating to his classmates and friends and had trouble communicating with them and along with that he had trouble beginning relationships with his peers. His disability also caused him problems in school because he was and still is unable to read and struggles with basic math that is used though everything.
Later in his life when Garth didn't grow out of his developmental delay or continue to progress he was reevaluated and it was decided that he actually had an intellectual disability, which affected his development and they began to think that he would remain at the developmental age of about a 6 year old. Today Garth is 25 and is still has the mental abilities of a six year old. This also affected him socially and in school. Socially he still has some problems making friends and figuring out how to relate others. His also still continues to have problems in school with learning and problem solving techniques.
While Garth has these problems his amazing special education teachers have helped him to be able to work through these problems and still find success.