Diagnosing Attention-Deficit/Hyperactivity Disorder (ADHD) in adults can be quite difficult, especially if that diagnosis was not made earlier before the age of 7 years. Signs of ADHD in adults include inability to concentrate, difficulty in organizing and completing tasks, easy distractibility, and sudden decision making without a thought of the consequences. These symptoms may also be caused by mood disorders (such as depression and bipolar disorder), alcohol/illicit drug abuse, and personality disorders (such as Borderline Personality Disorder), which may all co-exist with ADHD.
The treatment of adult ADHD with amphetamines or Ritalin may help with an increased attention span, improved mood, and decreased impulsivity. I urge you to seek evaluation by a psychiatrist, if your symptoms are causing significant social, occupational, and/or academic impairment.