The last fifty years have been decades of unprecedented prosperity. This has had a profound effect upon the way we are bringing up children. Our children are growing up in homes where they are constantly placated and amused by having access to endless numbers of toys. Whenever they are bored they can immediately go to their video games, computer, television, phone a friend or text on their cell phones. Their every need is instantly acknowledged and fulfilled.
This state of affairs is perhaps at least partially responsible for the explosive rise in the incidence of ADHD. I see an intimate connection between instant gratification which has become the norm in bringing up children in today's culture and the proliferation of the disorder of Attention.
Such a constant state of satisfaction leads children to develop a very high rate of dopamine secretion and a mental makeup which seeks pleasure continually and instantly. When such children attend classrooms and have to learn tasks that are not always a matter of instant gratification they quickly lose interest and attention.
A child who grows up in a culture of instant gratification is used to getting immediate success. If one toy ceases to give pleasure his modus operandi has been to move on to the next one. If one show on television does not keep him amused he changes the channel. His video games have allowed endless shooting of the bad guys and therefore quick successions of dopamine secretion.
Tasks required at school are neither highly rewarding, at least not immediately, nor do the reward occurs frequently. One must go through a number of stages of hard work before reaching one's goal/success. Consequently, the secretion of dopamine, the reward neurotransmitter, does not happen that readily. The task has to be painfully mastered before pleasure is allowed. The child who has grown up in a culture of instant gratification loses interest quickly at hard tasks that school demands and starts daydreaming of scenarios which promise instant pleasure because his brain is conditioned to have very high levels of dopamine secretion. He is also fidgety because in his unconscious he is conjuring up scenes where he would rather be instead of where he is at the moment. His body, without his conscious knowledge, squirms and moves to get out of his seat. This is the "hyper" part of the ADHD.
If a child comes from a background where taking on the challenge of hard tasks is considered worthwhile because there is a big reward at the end, in other words where there is great desire in the child, constitutionally or because of upbringing, to please parents and teachers, he may overcome this need for instant gratification. Otherwise, he starts developing defiant attitude towards authority if they keep on pressuring him to pay attention to the task at hand rather than daydream. This is the oppositional defiant aspect of ADHD.
Of course, there is also another very important factor to the cause of oppositional defiance of ADHD children. When a child goes to school and finds that other children perform better because they can pay attention to what is taught while he cannot, the same humiliating situation is most likely also occurring at home where his siblings who do not suffer from attention problems are doing better than him. In these cases, murderous (obsessional) rage is generated. This rage finds expression in defiance, failure to perform tasks, stubbornness, arguing, and doing just the opposite of what is demanded. Later, obsessional defenses will emerge to control this rage.
Dopaminergic drugs work by keeping a constantly high level of dopaminergic activity. This removes from the child the motivation to be some other place doing tasks that will boost up his dopamine secretion. Since it is already artificially high from the dopamine pills the child does not have to daydream nor fidget to be "elsewhere" where there is better promise for immediate gratification. This enables him to pay attention to what is being taught.
Also, the function of dopamine is not so much to give pleasure as to enable one to focus/pay attention. What gives us pleasure is what we focus upon. Dopamine narrows the range of our perceptual and motor world allowing focus which in turns allows pleasure. The high rate of dopamine activity brought on by the dopaminergic neurotransmission enhancing drug gives the illusion to the ADHD afflicted child that what is being taught is what is giving pleasure/satisfaction, so he focuses upon whatever is happening right then and there.