Difference between Autism and ADHD

Dear Ask The Doctor: My brother was diagnosed ADHD when he was younger but now that he is older (about 12) he seems to act more and more like he has Autism is there any way I might be able to tell the difference?

Dear Remain: Autism and Attention deficit hyperactivity disorder are 2 seperate conditions. Autism is typically characterised by the following

1) Lack of /limited social interaction , failure to develop peer and friendly relationships, an absence or lack of emotion and social interatcions

2) Delayed or absent speech and/or marked limitations in speech

3) Repetitive behaviours and activities like rocking,playing with the same toy etc

For a diagnosis of Autism these features should be present before 3 years of age.

ADHD on the other hand  is associated with
1)Inattention like carelesss mistakes, inability to concentrate and complete a task, easily distractable,

2)Hyperactivity like cannot sit still in a chair, always on the go. talks excessively,

3) Impulsivity symtoms like answering out of turn, cannot wait in long ques, interupts others.

As you can see the 2 are extremely different and it is usually simple to distinguish between them for a trained proffesional. I hope this helps.