The first step is to see a psychiatrist and take the medication they recommend. For me it was an immediate night-and-day difference. I don't know why the hell I wasted so much of my life before I finally went and got treatment. Don't repeat my mistake.

Problems with attention can come from many places, and from your post I can see you know that.

As for ADHD, the attention thing is not even close to the main thing, but it is unfortunately a main external observable (like hyperactivity), and so that why its so grossly misnamed.

Having ADHD means lots of things, like:

 - You either get nothing done all day, manage 3 times 5 minutes of productivity,  or do 40 hours of work in 5 wall clock hours.

 - Doing on thing, you notice another "problem", start working on that and then repeat, do that for 8 hours and all of a sudden you have started 20 things, and no progress on the thing you actually wanted to do (see this for a fictional but oh so accurate depiction)

 - Constant thoughts, usually multiple streams at once, the only time this stops is in deep sleep (not while dreaming). Feels like sitting with a browser, 100+ tabs open, active tab changes randomly with short intervals, no add blocker, all videos auto-play and volume is on.

 - Get unreasonably angry / annoyed for no reason. Quickly revert back to a good mood, for no reason.

 - Absolutely no fucking patience with "normal" people.

 - Can't function around other peoples piles of stuff, but no problem with own piles or clutter.

 - Task paralysis, for days and sometimes weeks or months. You know exactly what to do, you know exactly how to do it, and yet you cannot do it (feels a bit like anxiety). This is infuriating.

 - Hyperfocus, if you can channel and direct it its almost a superpower, if not its just infuriating for everyone around (and a massive time sink, if you end up doing something irrelevant).

 - See and hear EVERYTHING or oblivion, no middle ground (infuriating to others).

And so much more.

And in case anyone is wondering, yes I have ADHD or as my Psychiatrist said 5 minutes into our first meeting "I have no doubt you have raging ADHD, but lets do this properly and jump through all the diagnostic hoops"

As for tricks, I really don't have any to offer, mainly because you really need to know for sure if you have ADHD or not.

If you do, medication is the way to go, and that has to be dialed in carefully. This can take a long time, I know of people who spend years trying different medications and combinations.

Once you get to that point, you now have a baseline for how ADHD impact you, and at this point you can start developing strategies for how to manage the ADHD controlled things.

Lastly living with ADHD is hard, it always hard, its always bone breaking hard, everything has to be fought for.

We know what we should do, we know how we should do it, but we can't, constant regret, guilt and shame.

We act inappropriately (a lot), and we always know what we did, constant regret, guilt and shame.

To sum it up, ADHD is hard, its guilt, its regret, its shame, and NTs have no idea what lies behind those 4(3) letters (ADHD/ADD)

I have been diagnosed with ADHD, which in my case leans heavy into the “inattentive” presentation, and less into the hyperactive. Go see a psychologist. They have a diagnostic test, which for me was administered over two days.

ADHD often comes with comorbidities. In my case that’s stress-induced depression. When I’m under a persistent stress, within a week it two I’ll be kicked into a depression, where I suffer from anhedonia.

I take medication for both, and it’s changed my life. I still experience my symptoms, but they have a reduced impact on my life. Getting the diagnosis was very validating. I used to do a lot of negative self-talk, and looked at my symptoms as personal failings. It was only after my son was diagnosed early in his school career that I got myself tested, since we share many symptoms.

Now I understand my brain better, and I try to be kind and patient with myself as I also do with my son. I don’t apologize for my symptoms now (unless I inadvertently hurt someone), but instead thank those affected for their patience.

ADHD is hard sometimes, but my coping mechanisms can actually be an advantage at times. For instance, I’m a software engineer by trade, and because of my poor working-memory, I have built up discipline to code in such a way as to minimize a mental context (Kolomogrov complexity is generally a good proxy) for any bit of code. This isn’t just good for me, but is actually good for everyone I work with. Nested code in my bane, so I aggressively avoid it.

Being diagnosed also helped me be a better father. I don’t chastise my son when it takes him an hour and a half to do the dishes, with several reminders to stay on task. Instead, I focus on developing coping mechanisms and coaching, while practicing active patience. (It’s really annoying having to keep telling him to stay on task sometimes, but I know it’s not intentional.)

Other mitigation strategies involve not relying on my brain for things that it’s not good at. I use timers and my calendar to mitigate my poor temporal depth perception. I used reminders a lot because, I am terrible at recalling important information at some predetermined time or under some condition.

Another big helper is a mnemonic I developed: “‘Later’ is a lie.” I have learned from experience, if I want something done, it’s best if I do it immediately, rather than lying to myself (or others) that I’ll do it later. Too often I simply fail to recall that I need to do it at the appropriate time. This also helps my son.

I’m not sure if I answered your questions very well. This is a complex issue, requiring complex mitigation strategies along-side medical interventions. Everyone’s presentations are a bit different, requiring different interventions. A doctor can help you develop them. Be kind and patient with yourself.

Oh! Check out How to ADHD on YouTube. The woman that makes them is adorable and informative. I’ve gotten a lot of good out of her videos.

Tip #1: don't do this alone, don't do it casually.  Talk to an actual psychiatrist (or multiple - it often takes a few tries to find one you trust).  

Tip #2: try lots of things, including (prescribed) drugs, meditation, various CBT interventions, and anything else that seems promising.  Don't neglect nutrition and sleep hygeine, either.

I strongly suspect I have something in the same general cluster you speak of, but I don't have a diagnosis. There's a sustained and entirely artificial shortage of ADHD meds. I take 450mg bupropion XL, which seems to work pretty well for me.

It might be that drugs will help here, but even if you're on drugs, I think brain training over long periods of time is worth investing in.  Some examples which I have put effort into:

1. Mindful meditation.  Every time your brain drifts, notice it, and correct it. Practice until you're good at it.  It will take years.
2. Brute force reading.  Sit down to read something you know you need to read, but that you know you'll have a hard time with.  Every time your brain drifts, notice it, and correct it.  If you can't remember what you just read, go back to the top and read it again until you do.  Practice until you're good at it. It will take years.
3. [If you're in a cover band] Play boring yet incredibly popular songs with your band.  Every time your brain drifts, you'll notice it, because you'll forget where you are in the song and you'll make a mistake and your band mates and the audience will notice.  It's brain training for focus, with an actual social consequence.

I think self-care and radical self-acceptance are no. 1, and then therapy to deal with the side effects of being undiagnosed for so long, thereafter psychiatry to deal with lingering symptoms that can't be corrected with coping strategies. A skills group is very helpful too! Best is to find a group of friends who is accepting and can help you stay patient with yourself to find the best way for YOU to live with adhd -- even if it might be different than what "regular society" may expect. 

Here are a few great resources I have started to find since my (somewhat) recent diagnosis: 

• https://www.additudemag.com/
• https://chadd.org/
• https://www.adxs.org/en 

It has also felt hopeful to keep in the loop with research articles on adhd and new treatments / insights / coping options. :) You can do this, for example, by having various journals (like Nature) email you when new articles on the topic (keywords) come out. 

Like others have said already, the first step is diagnosis. I found it really helpful to get my diagnosis through a hospital with a neuropsychiatric/psychology department, since they may provide more help post-diagnosis than other places, such as getting you started with therapy or psychiatry, as well as other resources. They will also be the best people to talk to about if you think you might have other diagnoses that interact with one another. 

Good luck! And keep hope :)

Not sure how much sense it makes to comment on my own post, but thinking about ADHD sparked another question that’s probably not worth a sep post: if, as seems more and more likely, I indeed have ADHD, and it’s what makes me unproductive and therefore indirectly what made me depressed, … then I really should think about how people who discovered they had ADHD only relatively late, after it had made them make a few poor choices, managed to spring back, and ‘recover’ not from ADHD, but from the consequences of having had undiagnosed untreated ADHD. Any advice on that?