I've got ADHD and it has been both a blessing and a terrible curse at times! My problem tends to be attentional though I do have some hyperactivity traits especially when stressed.
The good points were that when I worked in a fast paced, high energy environment I thrived. I had to make snap decisions quickly without waiting around and mulling things over endlessly. The problem is that I hadn't really got a slower gear until the past few years.
The difficulties I find are:
Procrastination about work related boring tasks - I am not interested in a lot of the administrative stuff and I can put things off for years! It piles up and then I end up overwhelmed. It is worse when its stuff around the house like bills, repairs etc.
Losing keys, wallets, ipods, phones, cards every day. I have had to invest in key finders for everyday items as I spend so much time trying to locate things I put somewhere and forgot. I can walk into a room, forget what I was going in for and walk out with one less thing!
I seem rude and inattentive at times; I have to consciously focus on what a person is saying and resist the urge to turn away and do something else. I didn't notice it til my colleague said I was rude and dismissive. In context, she was crying about her son's potential prison term and I walked off mid-conversation without saying goodbye.
My memory is shocking. I can have a conversation and ten minutes later I can't recall any of it.
I had a somewhat fiery temper in my younger years though as I have aged I have been able to manage a little more.
Anxiety, anxiety and more anxiety.
What I have found that helps:
Mindfulness - it is SO hard when you start and demoralising. Though apparently evidence suggests it can be very good for ADHD and impulse control and I've really found it helpful. Notice when you are drifting onto another topic/activity etc and bring yourself back.
Lists. List after list after list. I love a list. Colour code it. Make it interesting. Plan things to a high degree of specificity. Even at your most picky and anal you will still seem a bit more chaotic than people who don't plan like it.
Post-its and other notes - I have to stick them everywhere. My memory is shocking - my job relies on detail so I have to note everything. Normally in short/bullet points so I can recall what was said.
Tell people what you need! - all of my colleagues know that if they want me to read an email they need to stick "URGENT" in the title and it needs to be a line or less. If it has to go on and on then bold/red the bit you want me to action/see. I won't ever read more than a line or two, it is all boring so get to the point (ironically given the length of my posts!) Also get them to cut all the "hope you are well" nonsense (at least for me) I don't care if you hope I'm well, what do you want me to do!?
Remind people to give you a gentle nudge - if you seem rude, ask people to gently let you know. I've found relationships are much better this way.
Set expectations - I tell people that I can come off as a bit abrupt, short and inattentive and the reason (I don't bang on about it, jus so people who need to know are aware. For example boss, close colleagues, people who rely on you). I will often send the following response to a 2 page email:
"Yes"
And people get uppity about it if they don't know what you are like. I don't ask for concessions, just know that if you ask me a question I will likely answer with a word. No point dragging it out (irony noted!)
Be a bit kind to yourself - I used to kick myself constantly. My partner is very understanding which helps!