I was diagnosed with add as a child, but was taken off meds at 12. i'm always tired and have trouble finishing tasks. is it possible i still have add?

Yes: Adults can have add. Symptoms include difficulty concentrating, difficulty finishing tasks, losing things, problems at work, and relationship problems. Chadd.Org is a good website. Or talk to your doctor.

Rule of thirds: About 1 out of 3 kids with add/adhd will grow out of any benefit from medications. About a third will go off medications for personal reasons, side effects or not wanting to be medicated. The final third represent a core of adults whose lives are better with medication use. Any decision to use these should be undertaken only after a frank discussion with your pcp.

Yes: 67% of untreated or under treated adhd children will go on to have adult adhd. Since you were not throroughly treated, your satistical risk for persistence is 67%. Now 18'years later, that you're an adult, you need a complete and proper reevaluation by a competent doctor to assess your status and need for treatment.