I didnt get diagnosed until I was 29. My son was diagnosed with ADHD and upon educating myself for him, i discovered that I should be diagnosed as well. Let me tell you, it changed my life. All of the years I spent questioning why things were do difficult for me and easy for others, wondering what was wrong with me finally had some answers. Medication is not a cure, but it gives the area of my brain that lacks concentration, motivation and endurance to complete simple tasks the "jump start" it cannot do on its own. I believe education, awareness and support are just as vital as medication in coping with the different wiring my brain has.
The difficult part with diagnosis and treatment with mental and mood "disorders" is that there isnt a blood test one can take and have the answers as to what a person needs to take, how much and how long. Its trial and error which can be just as hard to deal with as the disorder itself. However once a person finds support, diet, exercise, has educated themselves, and for some found the right meds or med combination, there is happiness and contentment....a light at the end of the tunnel, so to speak.
Sorry to rant, but this is a subject I feel so strongly about.