I've had this research question this week and been looking at some studies (of one which supposedly Leigh Brasington was the research subject), but it hasn't yet cracked this nut, so I would appreciate your thoughts.  

From what you've experienced, seen or heard: Does it appear to you that the dopamine "boosts" from concentration meditation (and ultimately the respective states and jhanas) can predictibly relieve ADD-symptoms such as forgetfulness and unstable motivation?

Let's say I mastered concentration so well that I could tap into the jhanas regularly. Could that be sort of like taking a dose of some (mild?) dopamine inducing drug? And if so, would there be a time frame for that glow/boost of dopamine (and serotonin or what not) last?

Or will the meditator just "barrow" dopamine from their normal brain connectability and maintain the same levels outside of meditation?

Maybe you would even say that insight meditation would be a way better choice of focus if you want to naturally increase dopamine and serotonin levels? 

Thank you guys in advance!

I do not have ADD or ADHD but did know a close friend that did. He had the condition from birth, he told me, and was worsened from prescription medications at an early age that lasted into his teens. He tried meditating on his own a few times for relief and on one such occasion, he managed to accidentally astral project. He fell into a coma that lasted two days and when he came to, he retold of floating around his body, meanwhile, some malicious force was shadowing him keeping him from re-engaging. This mess went down before I met the fella so I can't validate any of it and remain indifferent. He avoided practise after the fact.

I found him to only have a rudimentary grasp of meditation that was sullied by lotts of woo woo nonsense, mysticism. His lense of enlightenment was the Native American's awakening or the buddhist's 4th jhana. I instructed and guided him through a few sits and learned that instead of being grounded in his physical body, his center of awareness was his prana, or energies. I established his meditative "symptoms" over some dialectic discussions and going back and forth matching circumstances with my own practice. It just seemed to me that he was navigating life under blurred sensate awareness. Clarity was obscured by inculcated ideologies and psychedelic legends.
But the clearest factor was that his meditative ability was naturally great! He was easily propelled into deep states without even trying. This could be considered dangerous as one could easily "slip" out of the body and without the necessary comprehension over what actually is happening, is what he may or may not have experienced. 

Everyone is born different, some are fine genetic specimens... some, like me, are born with extra fluid in their eyes and require glasses others are born with exceptional skills... and some are just born more sensitive to life. It's all fine of course, in the end, this is not about becoming super-human, it's about realizing that being human is super. I gave him some advice, to form some sort of fitness regimen and get to know the mechanisms of his body more. And to remember that the breath is always there as an anchor. We all have to deal with our past Karma. Meditation did finally bring relief but only after he had made newfound insights into his own nature. He still has a long path to walk but unfortunately, he says he doesn't have the time to meditate on his own ...

I'm not shy to the subject of chemical imbalances and actually I'm quite glad to have faced such phenomena too, just for the experimental aspects of the scientific investigation. My condition is somewhat rare and is also characterized by heightened dopamine levels. The first step is not to jump onto the cushion and meditate, it's acceptance. In Buddhism, one definition of a demon is a thought principle that has branched away from the "normal conscious" or a traumatic memory that split from "the mind". Denial only strengthens the demon, makes the event harder to deal with. I tried therapy for many years to no avail and refused medication. I quit therapy and took my care into my own hands, and by extension, the universe you could say  I'm able to hold down a fine job, have romantic relationships, I have a plethora of hobbies that I enjoy, and maintain good company. It's part of the treatment to keep a positive mindset! Happiness is an emotion and those cant be faked while a positive mentality is just a world view, and those get stronger the more you refine them. Sulking into depressive episodes and becoming a hermit would probably only do more harm than good. The opposite if depression isn't happiness, it is vitality!
I'm a big advocate about getting one's psychological trip in order FIRST before meditation is turned to. 

Through meditation, I have learned that I am impotent against my bodily chemistry... I have noticed that only a dash of sadness causes me to break out in acne and predisposes me to sickness. I cannot sleep unless I feel adequate either, my vibrancy is too affected. Manic episodes when I was younger would leave me sleepless for days. after 4 or 5 days I would begin to pass out randomly. I remember one occurrence that happened while walking home from school... I was walking down a sidewalk and just like that LIGHTS OUT! 
I woke up 2 hours later, nothing seemed stolen; this was normal to me. And with those two hours, I would stay up for another number of days until my next moment of collapse. Meditation helped me to steady myself and instead of sleep, I would meditate to compensate for the lack of oxygen reaching my brain. Meditation, staying in good spirits, and having a grasp of the human condition acted as my cures. 
I'm sure it's possible to achieve a level of manipulation over these chemicals but I haven't been able to. It's all just been about finding balance. I can say now though that I do feel "cured". Of course, it's still there, but it has no hold over me. I can use meditation to shift into sleep and it makes no impediment to my life. My mother doesn't share in my condition but she too surrenders to her bodily chemistry, and there is a history of mental illness in my family, just past Karma that needs to be dealt with  The central nervous system requires psychological health to perform normal functions. 

We also have to be keen on what goes into our bodies! Our desiccated brain consists largely of fats (about 60%), the remainder being proteins, amino acids, micronutrients, and glucose. The bound lipids allow the brain's cohesion & oversee functionality. Omega 3,6, and 9 have been associated with the degradation of our intellectual capacity i.e. cognitive disorders, memory impairment, attention and concentration problems, and mood-related matters such as irritability and dramatic mood swings. Proteins advance the synthesis of amino acids, increasing the levels of tryptophan, tyrosine, histidine, etc and these trigger the production of a few important neurotransmitters and neuromodulators like dopamine and serotonin. 

Hopefully there is salvageable information that stays relevant to your interests. Take it for a grain of salt if you will

This is a very important, cogent, and useful realization, IMHO. It's borne out in my experience, too, especially in regard to brain chemistry which can overpower anything that happens practice or dharma-wise.

My experience so far is that it has a very local effect. While a regular practice might make it easier to reach concentration with regard to one’s meditation object, it doesn’t really transfer to work-related demands for one’s focus. Also, limitations pertaining to insight stages seem to trump any momentum in shamatha that I thought I was building up. Insight stages seem to depend on chemical balances as well. I tend to drop down every time I have pms. So no, not really. It might help with building good habits and coping strategies for dealing with one’s difficulties, because it generally increases wellbeing, which in turn frees more energy for self-development. But jhanas won’t be accessable when you think you need them the most.

Just as a data point (without pointing to a conclusion), I recently saw a naturopath who performed a neurotransmitter test (saliva & urine samples taken throughout the day) on me.  She was surprised to see that I had very low levels of every "happy chemical" (except dopamine was just slightly low) & said that I should be much lower functioning than I am in my life, based on these readings.  This actually reignited faith in meditation for me, for 'self work' is the only explanation I have for my continually increasing well being over the years, given that this wet ware is apparently still broken.

I have ADHD and looking to master classical concentration states if anyone needs a study participant with limited experience who is currently trying to gear life around allowing the opportunity for some serious practice time over the next few years.

offtopic, but counter to this, ayya khema recounts the pain of terminal illness:  https://www.youtube.com/watch?v=pLugPA2O9ck

I don't know the jhana's (at least I think I don't) but I have perhaps some pre-jhana or "soft jhana" experiences with elements of the seven factors of awakening present, so on this basis: I feel like the jhana's are very non-dopamine-y. Consider: dopamine hits are like gambling, drugs, sports, chess, etc. I feel they are more a "hungry ghosts" sort of thing or at least, dopamine leads to highly conditioned behavior - think skinnerian operant conditioning. Counter to conditioning,  classically, jhanas are said to enable the basis for insight to occur - leading to deconditioning / unconditioned. So, counter to dopamine, jhana's and some of these factors of awakening, absorbtion, curiosity/investigation, rapture/piti (and other factors of awakening) seem very much in the direction of serotonin. 

Literally one of the translations for 'piti' is ecstasy, and having had MDMA before, I can attest that meditative experiences can get into this territory. This points squarely at serotonin to me. 

My experience so far is that meditation really improves concentration outside the meditation object, that is one of the fundamental reasons for why is used to lubricate the vipassana. Regarding the accesibility of the jhanas i think is a matter of mastery, i haven´t reach the point where i can access the jhanas very fast in a very noisy environment or with a very bad mood, however i think that is definetly possible. Only reading the visuddhimagga you realize that there are things most people can´t dream about and that are definetly possible for a monk or a full time practicioner, like swapping all the jhanas up and down very fast while changing the objects and transpassing some jhanas, an absurd level of concentration that is required to develop the powers, according to the same book.

It's great to hear that you have improved concentration outside your formal practice. May I ask if you have a diagnosis as well, like I do (as a matter of fact, I have three different neuropsychiatric diagnoses that affect my functioning in daily life)?

Edited to add: by meditation object I meant to include investigation objects in vipassana as well. I share your experience that shamatha helps with vipassana investigations, especially directly after leaving jhana or while still being in a light vipassana jhana. That is not the same as dealing with challenges in one's daily life and work life, though, is it? Or maybe it is for some people? 

I wasn't referring to terminal illness, but to situations where someone with an attention deficit needs to deal with stuff that requires one to be at one's best in spite of chaotic stuff going on and leading to emotional reactions, as they tend to do when one is not fully awakened. I could have been clearer though. 

Edited to add: I guess what I was trying to say is that it isn't ideal to rely on jhanas for dealing with one's daily life, because if one feels that one needs jhanas to get by, that tends to transform into hindrances that will prevent jhanic access. Of course, it is possible to do shamatha exercises regardless of whether one accesses jhanas or not. I am convinced that the practice per se does make a change for the better if done diligently and on a regular basis. I think it will change the infrastructure of one's brain, because the brain is plastic. It wouldn't result in those showers of neurotransmitters that Fred was asking about, though. It isn't a quick fix but something that takes time and committment. I highly recommend doing the practice, but I think it is important to have realistic expectations. It doesn't cure ADD, as far as I know. And the hindrances that the Buddha spoke of continue to limit jhanic access along the path. One can learn to be less reactive, of course, and thus less bothered by hindrances, but that takes both insight practice and morality training, possibly therapy. Maybe there are people who just naturally aren't that bothered by hindrances, I don't know. I don't think I have ever met one. Then again, my life experiences aren't necessarily very representative. Sometimes I forget that there are real people who actually have an energy buffert for dealing with a crisis. 

I only had very bad insomnia that lasted most of my chilhood and teen years, medical prescripted, it was cured with meditation.

The afterglow of the jhana can be used for everything, from vipassana to work related stuff, like studying or doing some kind of exercise (Daniel and other people speak from experience). For doing that it becomes relevant to had achieved some kind of mastery in accesing  the jhanas fast and in any environment.

Did you and the others you are referring to have that kind of sucess from shamatha only, or did it also require diligent insight practice? Did your insomnia specifically involve attention deficit? Did the others have attention deficit?

Good questions.
I don´t know if i have an attention deficit, was never diagnosed but is a possibility.
About the shamatha, i can access fourth jhana with the fire kasina regularly, 2 hours of practice a day. However i think that if you want to master the jhanas you need at least third path, it seems to contradict those pali text criticizing hindus and ascetics mastering concentration practices and achieving powers without mastering insight.. It seems from my POV that at least third path is needed to achieve those things.
Right now i don´t do insight practice at all but is definetly planned.

That makes sense. Thanks for clarifying! I didn't mean to be provocative or anything, but thought that it might be a good idea to be explicit about circumstances in a thread like this. I'm thinking that some potential readers may not have enough background knowledge to know what it takes to master jhanas. 

Personally, I have found that some hardwired difficulties can surprisingly vanish thanks to meditation. That was the case with anxiety from eye contact* for me (I'm autistic and have ADHD and Tourette's). In that case it was stream entry that did the trick. Still, I think it is very risky to make any claims about any form of practice actually being a general cure for anything. When it comes to neuropsychiatric diagnoses, I far too often see people claim all sorts of ways to cure or overcome the difficulties. I know many people who have been traumatized and/or burned out from that, because they have had their difficulties disrespected and minimized their whole life. I wouldn't rule out any positive change either, though. 

*) The anxiety resulting from eye contact is gone. The habitual avoidance of eye contact remains to a varying extent, though, perhaps partly because I unconsciously tend to assume that other people find eye contact uncomfortable like I did for several decades. 

Thank you all; Mista, Chris, Linda, Noah, Dan and Jake for your helpful contribution to my question. 
I kept an eye on the discussion although I was verbally absent from it. 

From your responses I understand that there's no reason yet to crown Jhanas as the messiah of the ADDs, the ADHDs and all the other acronyms and isms of the psychology world. 

My last thought is, I wonder whether people with more widespread attention naturally feel more mastery with the ñāṇas rather than with the Jhanas.

No meaning to bump the thread here, I first and foremost wanted to acknowledge your responses. 
Thank you again.  

It has been interesting.

A recent thought about this is that my ADHD makes my shamatha practice more dependent on the nanas, since my ability to focus varies so much. In some nanas it just isn't possible, whereas in others, and especielly at the post 8th junction point that Daniel talks about in one of his vimeos, I can suddenly superfocus.