It is never too late to be evaluated for ADHD.
If you look at lists of symptoms/checklists intended for adults and have that moment of “oh shit, that’s me,” get evaluated.
Just because one doctor/psychologist/therapist/school counselor told you once that you don’t have ADHD because ______ doesn’t mean they were right. (Especially if you’re smart, good at school, or do well when tested–people who don’t know ADHD very well might try to tell you that you don’t have it. They could be wrong.)
Trying medication is worth it. And it’s never too late to try!
The right medication is like having glasses, but for your brain. It doesn’t cure anything, but makes it so you can function more like someone who doesn’t have ADHD/bad vision.
Stimulant medications in particular have been in use for nearly a hundred years now. Taken as prescribed they have an excellent safety record. If they caused problems long-term we would know by now.
Finding the right medication/dosage is not always easy. Don’t give up because you try one medication and don’t like it. Tell your provider what you did and didn’t like about it and ask to try something else.
(That said, many side effects are temporary. Again, talk to your provider.)
If you have ADHD, the right medication can significantly ease your depression and/or anxiety. It will also make all of your current coping methods for your ADHD much, much easier.