Unless you have been diagnosed with ADD
/ADHD as a child, you can’t have it as an adult
FACT: Many adults struggle all their lives with unrecognized ADD/ADHD impairments. They haven’t received help because they assumed that their chronic difficulties, like depression or anxiety, were caused by other impairments that did not respond to usual treatment."
From - http://helpguide.org/articles/add-adhd/adult-adhd-attention-deficit-disorder.htm
This link is worth reading.