Why Dopamine Makes People More Impulsive
knowingneurons.com
knowingneurons.com
As someone with adhd, my psychiatrist has explained it to me in terms of Dopamine. In his words, stimulant medications help to treat symptoms of adhd, in part, by creating dopamine when we either lack it or have a weakened response to it. This flood of dopamine keeps us from being impulsive, in his explanation.
In other words, I am more impulsive without stimulants and the explanation I was given is that my brain is too busy seeking out dopamine and thus always looking for excitement. By providing dopamine through medication, that seeking behavior diminishes and I am more focused and less impulsive.
So, something doesn't add up. Either my psychiatrist has been misinformed or there is a lot more going on here / my understanding is very off base.
First: Stimulant drugs typically release or inhibit reuptake of both dopamine and norepinephrine. Dopamine actually converts into norepinephrine in the brain, complicating things further. L-DOPA, which is described in this article, is not a stimulant drug: it only raises dopamine concentration, and nothing else. It's the direct precursor molecule for dopamine.
Raising norepinephrine along with dopamine can create a focused and patient effect in some people (and sometimes a somewhat euphoric effect); raising just dopamine will generally create a euphoric, relaxing, reward-seeking effect. I don't know the entire pharmacology behind why that is. I seem to recall that DA and NE may be able to directly modulate each other.
Dexedrine (dextroamphetamine), another ADHD medication, has a higher dopamine:norepinephrine ratio than Adderall does (i.e. it releases proportionally more dopamine). It doesn't work for some ADHD sufferers, because they become too euphoric.
Second: Stimulant medication is also more about trying to maintain steady levels of dopamine in the brain at all times, rather than constantly or intermittently fluctuating levels. If you were to take Adderall just once per week, for example, you would probably not get a lot of chronic relief. Taking small doses of L-DOPA every day could maybe help some ADHD sufferers after a week or two (though this is mostly just a theory on my part), for example, but this can lead to psychosis and many other dangerous problems, so is highly discouraged.
Someone please feel free to correct me if I got anything wrong here. I don't have formal education in medicine or neurobiology.
When I said "not get a lot of symptom relief", I meant regarding general life functioning, not short-term response. Obviously Adderall will provide quick relief for an ADHD sufferer; it just won't help them in the long-term unless they take it regularly.
Which is why many ADHD sufferers take stimulant medication regularly. However, that doesn't mean the medication doesn't provide relief that improve general life functioning.
Similarly, chronic pain may be treated with morphine, which provides short-term pain relief and improves general life functioning when taken regularly.
> Stimulant medication is also more about trying to maintain steady levels of dopamine in the brain at all times
I don't think this is accurate. Rather, it depends on the attention and performance requirements of the sufferer. Children may only need symptom relief while in school, whereas adults may need relief through most of their waking hours.
It seems unlikely that someone would really need relief from ADHD symptoms while sleeping.
See my comment here: https://news.ycombinator.com/item?id=10368605
Based on the literature, it seems like a probable explanation.
Perhaps there's something else in ADHD people wiring that cause a different response, but even normal college students took ADHD medication to help focus.
> Attention-deficit drugs increase concentration in the short term, which is why they work so well for college students cramming for exams.
> Versions of these drugs had been given to World War II radar operators to help them stay awake and focus on boring, repetitive tasks.
> And when we reviewed the literature on attention-deficit drugs again in 1990 we found that all children, whether they had attention problems or not, responded to stimulant drugs the same way.
I've always been baffled how I didn't see this for myself years ago - after all, that's exactly what caffeine does for millions of people.
Worse, though, people with ADHD are prescribed stimulants for long-term use, and even after the medicine ceases to be effective - because your body adapts to it over time - you can't just stop taking it, because withdrawal sucks.
[1] http://www.nytimes.com/2012/01/29/opinion/sunday/childrens-a...
I should probably talk to my doctor to see if I have ADHD, instead of occasionally self-medicating.
I get much less impulsive also, car rental managd my own mood much better. My blood pressure add resting heartrate has also improved since I started with the stimulants. A bit unusual according to my doctors.
YMMV - the medication is crude, but being without is not really an option - it's really nice to start being able to plan, and actually decide what actions to take instead of simply doing whatever feelt good at the time.
Students low on the attention spectrum (but either just above ADHD diagnosis or without the resources to get diagnosed) are probably more likely to self-medicate.
So, the fact that some students who self-select for self-medication show improvements isn't necessarily evidence that someone in the middle or upper end of the attention spectrum will see improvements. However, it does suggest a need for research into the effects on randomly selected non-ADHD-diagnosed people.
Definitely not generally true.
Why do people continue saying this?
A lot of people just get better lives. YMMW.
* animals that lose their dopamine learning mechanisms can still learn new things
* even when dopamine is there, sometimes the system will continue to respond to unconditioned responses that are learned and expected
* microinjections of amphetamine do not increase reward expectation - they increase peak of desire for reward - like when food is more tempting after not eating the whole day; sometimes a nasty salty taste is desirable in sodium deficiency, say
* system is computing value, rather than learning
* incentive-salience is a cue-trigged type of wanting; say someone else across the room lighting up a cig cueing your desire
* the cue becomes an attention magnet - the cue is very hard to not want to pay attention to
* the mesolimbic state of brain at a certain instant in time plays a huge role in amplifying responses to cues - hunger increases desire for food, repeated experience of drugs amplify the cue for drugs
* an addict is a person who will have a super strong dopamine response when provided opportunity, due to sensitization of cue-triggered want - even months after enduring withdrawals, acquired hypersensitivity may still exist
Like the joke about the drunk looking for his keys only right next to the door - "because that's where the light is".
"Approximately 90% of the human body's total serotonin is located in the enterochromaffin cells in the GI tract, where it is used to regulate intestinal movements."
Dopamine is more specific, playing an important role in the limbic system, but is not limited to it. Its functions are not completely understood, and again depend on the receptor.
Better to think of the function of neurotransmitters as dependent on both system AND receptor. The function of neurotransmitters, like dopamine, can be simplified, but others, like glutamate, are extremely complicated.
The neural structure of the brain is very complex and involves dozens of neuronal molecules acting on a wide variety of neurons.
It's incredible that we have psychiatrists prescribing all sorts of inhibitors/activators to alleviate various disorders. A lot of these drugs have unknown mechanisms. Even when the mechanism is understood no one understands how these drugs are working on the whole brain.
Of course there are varying degrees of ADHD. But if some of these descriptions fit you. You might have ADHD.
"Everyone encounters some task he doesn't particularly enjoy, but most people are able to find a way to complete the boring aspects of their job, says de Marneffe. People with ADHD, however, have a hard time doing that."
"If you (sometimes) fly off the handle in a fit of anger or frustration one moment but are completely over it in the next, it might be a sign of ADHD."
-you have a hard time sitting for multiple hours
http://www.health.com/health/gallery/0,,20490145,00.html --15 Signs You May Have Adult ADHD--
As for me, for some tasks, such as writing documentation for something I knew nobody would ever read, my brain would refuse to focus. I would look for more important things to do and never get a page of documentation done.
Do people without ADHD agree to do useless things because they're told to?
There are some people, however, that will, in sheer determination to do what is expected of them, stare anxiously at their screen, hoping to focus their attention to the task at hand. No distractions, just a text editor waiting for some text. The problem is, the thoughts just don't surface. They try to psych themselves up, remember that their lively hood depends on it, that they don't want to let their coworkers down, etc. Sure, their gut tells them that they're working on the wrong solution to the wrong problem, but they remind themselves to keep a good attitude, remembering that this is what their employer deems both valuable and necessary. The hours tick by. It's 6pm, but they're convinced that they'll be able to turn it around. A couple more hours pass by. "If I just get this done, I get to spend time with my family, or go see my friends, or have some semblance of balance." It's 10pm. They cry for a bit, manage to get a bit of work done, and shortly after 1am, they hop in bed and call it a day. As they doze off, they lament their inability to power through uninspiring work (particularly work that they know could be obviated by better practices/tools/business-sense/etc.)
If you've _never_ experienced something like that, then I suppose you either don't have ADHD, or you've only had phenomenal working experiences.
I usually ask why the task is worth doing. If they can't come up with a valid response, I try to show them why it's not worth doing. If I can think of a better thing to do, I let them know. If this doesn't work, I will delegate or trade the task with someone else. If that doesn't work, I will often just ignore it. Usually, nobody realizes the job wasn't done, mainly because it wasn't important in the first place. Rarely will I go through the pain of doing something that I realize is not important.
Although I have never been diagnosed with ADHD, I feel like I can relate to some of the symptoms.
> There are some people, that will, in sheer determination to do what needs to be done, stare anxiously at their screen, hoping to focus their attention to the task at hand. No distractions, just a text editor waiting for some text. The problem is, the thoughts just don't surface. They try to psych themselves up, remember that their lively hood depends on it, that they don't want to let their coworkers down, etc. The hours tick by. It's 6pm, but they're convinced that they'll be able to turn it around. A couple more hours pass by. " This is such a critical project I just have to get it done. If I just can just get started, I get to spend time with my family, or go see my friends, or have some semblance of balance." they tell themselves. It's 10pm. They cry for a bit, manage to get a bit of work done, and shortly after 1am, they hop in bed and call it a day. As they doze off, they lament their inability to power through their work and lament their repeated failures.
This was me. I'd have some project to work on, interesting or not and I would have the hardest time getting started. Just getting the first bits and pieces done. Or I'd have a clear picture in my head of how I wanted to do it, what needed to be done, and how I needed to attack it to accomplish it. Then I'd try to get started and fumble about not being able to get that mental picture out into real productive work. I'd spend hours breaking tasks down into smaller bits but not get any of the bits done. I'd think to myself, I'm focused too much on this and I can't think straight any more I'll just take care of another task for a bit and come back to this. Six hours later I've forgotten about it completely and then panic when I realize it. Once it was crunch time, or it was so late the only way to finish was to pull an all nighter I'd some how miraculously get things done well enough to stay out of trouble. I powered through these problems in my 20's by pouring in 15+ hour days regularly. I nearly destroyed my relationship with my wife. I had friends and colleagues that knew I'd get things done but couldn't count on it always being the best quality or on time. I couldn't do that any more when I hit my 30s, started a family, and the toll of the hours and lack of sleep really hit harder. Speaking to my Dr and getting an ADHD diagnosis, some medication and some tools to approach my issues from different angles have been life changing.
Having days where I just stare at the computer for hours with zero ability to really engage in a task is not normal. It didn't happen every day, but enough to help me realize something was not right.
btw, another symptom that I had is zero patience for certain sounds. Clicking pens, dishwasher, and more. My mind would fixate on it. Background noise made it so much harder to focus. Now it is less of a issue.
Probably educating people on how they are wired to seek things (a good drive when you are talking about going out and securing food/resources) and how to direct that towards healthy pursuits instead of unhealthy ones would go a long way.
Lots of pharmaceuticals can regulate dopamine in various ways too. The issue as it relates to impulsivity seems to be caused by a combination of dopamine driven seeking behavior and more primal parts of the brain hijacking decision making.
It is the combination of primal parts of the brain doing decision making with the brain's propensity for seeking that causes negative impulsivity, so that could be aided by increasing gray matter (meditation) and regulating dopamine (healthy seeking) but you can only do so much.
It seems like so much "crime" is really impulsivity, and so I often have thought about ways you can reduce impulsivity, but it always seems to come at the cost of considerably altering how someone's brain works, which not everyone is open to.
I imagine any pure dopamine agonist can be prone to creating an impulse disorder if you take a sufficiently high dose.