도파민: 고통이 없으면 쾌락도 없다
왜 천국은 심심하고, 지옥은 재밌는 것일까? 그 근본적인 원인은 바로 스트레스를 받는 만큼 도파민 분비량이 상대적으로 많아지기 때문이다.
도파민의 발견
도파민은 1958년 스웨덴의 아비드 칼슨(Arvid Carlsson) 박사와 그의 연구팀이 최초로 발견한 필수적인 신경전달물질이다. 도파민은 뉴런에서 분비되는데, 이 뉴런의 위치에 따라서 그 기능이 다양하다. 그중에서도 도파민이 가장 주목받는, 그리고 중요하게 기여하는 기능이 바로 보상(reward) 및 동기부여(motivation) 능력이다. 이 기능 덕분에 우리는 도파민이 분비될 때 좋은 감정을 느끼게 된다. 그리고 이 좋은 감정은 정도에 따라서 행복과 쾌락으로 나눌 수 있다.
행복과 쾌락의 경계
도파민네이션(Dopamine Nation)의 저자이자 스탠퍼드대학교 의과대학교수인 애나 렘키(Anna Lembke)는 책에서 행복과 쾌락을 달리 정의한다. 행복은 도파민이 조금씩 분비되는 현상으로, 우리가 흔히 일상에서 느낄 수 있는 ‘소확행'이 이런 행복을 느끼는 상태에 부합한다. 이와는 달리 쾌락은 도파민이 일상적인 수치를 넘어선 정도로 분비되는 현상으로, 생일선물과 같은 작은 쾌락부터 마약처럼 극단적인 쾌락까지 정도는 다양하지만 행복 그 이상을 쾌락이라고 표현할 수 있다.
도파민: 쾌락은 고통을 수반한다
쾌락은 행복과는 달리 필연적으로 고통을 수반한다. 우리 몸은 언제나 저울의 균형을 유지하려고 노력하기 때문에 도파민의 분비가 쾌락을 느끼게 만들었다면, 이를 상쇄하기 위해 도파민과 반대되는 물질 또한 분비된다. 다만 이 과정에서 ‘반대 물질의 분비’라는 힘이 한쪽 저울에 가해지게 되면 본래의 균형을 이루는 것에 그치지 않고 쾌락을 느낀 만큼 고통 쪽으로 저울이 기울어진다는 것이다. 그렇기 때문에 고통 없는 쾌락이 없는 것이다. 예를 들어 친구들과 즐거운 시간을 보내고 난 뒤의 외로움, 꿈같은 여행이 끝나고 난 뒤의 공허함처럼 행복을 넘어선 쾌락을 느꼈다면, 그에 대한 반작용으로 고통을 느끼게 된다.
심심한 천국, 재밌는 지옥
이 원리를 앞서 언급했던 예시에 적용해 보자. 지옥과 같은 환경에 놓인다면 우리는 도파민 분비량을 넘어서는 스트레스를 받을 것이다. 그렇다면 그에 대한 반작용으로 우리 몸은 도파민을 더욱 분비할 것이고, 같은 상황이 주어지더라도 평상시에 스트레스를 받던 사람이 그렇지 않던 사람보다 도파민 분비량이 더 많을 것이다. 그리고 도파민 분비량 증가는 곧 더 강한 행복으로 이어진다.
반대로 어느 쪽으로도 추가 기울어지지 않은, 향상성이 유지된 삶을 살아온 사람이라면 그만큼 일상 속에서 느끼는 행복 또는 도파민의 양이 그렇지 않았던 사람에 비해 적어지게 되는 것이다. 또한, 작은 행복이 반복되면 우리 몸은 점차 도파민 감도를 줄인다. 이 현상을 도파민에 내성이 생긴다고 표현한다. 도파민 내성인 사람은 행복을 잘 느끼지 못하게 되고, 이 내성 상태가 도파민 중독의 시작점이다.
도파민 중독
도파민이 문제 되는 이유는 도파민 중독 현상 때문이다. 마약과같이 인위적으로 도파민의 분비를 촉진하는 촉매제를 섭취하여 도파민 분비량이 급증하게 되면, 우리 몸은 향상성에 위험을 느껴 초장부터 도파민의 분비를 억제한다. 도파민이 생성되지 않는 상태가 디폴트 값이 될 때, 마약 투약자는 일상에서 전혀 행복을 느끼지 못하는 상태에 이른다. 그래서 한 번 마약을 접한 사람은 행복을 느낄 수 있는 유일한 방법이 마약이고, 그마저도 내성이 생기면 점차 양을 늘릴 수밖에 없기 때문에 약에 중독되고 결국엔 사망에 이르게 되는 것이다.
부족한 게 없는 사람
최근 남양유업 창업주 손자가 상습적인 마약 투약 혐의로 구속 기소 바 있다. 그뿐만 아니라 공범으로 재벌 3세들 또한 수사 선상에 올라 화제가 되었다. 재벌 3세, 유명 연예인 등 모든 것을 다 가진 듯한 사람들이 꾸준히 마약 혐의로 체포되는 이유가 뭘까? 부족한 게 없는 사람들이기 때문이다. 대부분의 사람들이 명품을 결제할 때 쾌락을 느낀다면, 이들은 명품을 구매하는 것에 내성이 있는 상태이다. 마약처럼 인위적인 자극만이 이들이 쾌락을 느낄 수 있게 해주기 때문에 부족한 것이 없을수록 마약에 의존하게 된다.
저자는 도파민 내성이 생기는 것을 방지하기 위해 도파민 공백기를 가져보자고 주장한다. 자극적인 음식을 참고, 비싼 명품 백의 결제를 미루고, 찬물 샤워를 통해 스트레스를 주는 등 ‘쾌락 과잉 시대에서 몸의 균형을 찾기 위해 노력하자'라고 말한다. 이러한 습관이 결국 도파민 분비량을 높여주게 되고, 일상에서 느낄 수 있는 행복을 극대화하면서도 도파민에 중독되지 않는 건강하고 행복한 삶을 살 수 있게 해준다.
now we're walking around with a balance
that's chronically tilted to the side of
pain we've actually changed our hedonic
or Joy set point now we need to use not
to get high or feel pleasure but just to
level the balance and feel normal
foreign
foreign foreign
[Music]
[Music]
thank you foreign
[Music]
when we talk about alcoholism or
substance abuse we know that it is bad
because there are obvious Health
consequences and also we see a lot of
bad examples probably around so we know
that it's somewhat bad but some
behavioral addiction being addicted to
Netflix being addicted to YouTube or
social media shopping eating mukbang
video gaming other things right let's
say that I'm doing my job well and I'm
not harming anyone but is that still bad
is that still that we should recover
from and why is that yeah that's a great
question so thank you for asking that
when we think about how we're harming
our bodies with addictive behaviors for
example digital addictions Tech the
internet our devices we really need to
conceptualize the brain as the end organ
that is being damaged it's true that
alcohol damages the liver and the
pancreas and the brain and other organs
the heart too and that's not so true of
Behavioral addictions but behavioral
addictions do cause a kind of brain
damage and specifically the brain damage
that they cause is by flooding our
brains with these highly reinforcing
behaviors and essentially releasing a
lot of dopamine are reward
neurotransmitter in a specific part of
the brain called the reward circuit what
ends up happening is that our brains
have to try to compensate for all of
that reward by down regulating or
decreasing our own dopamine production
and transmission so that ultimately we
change our hedonic or Joy set point and
we end up in a chronic dopamine deficit
State and that is the damage that we're
causing because that state is very
similar to depression the universal
symptoms of withdrawal or the dopamine
deficit state are anxiety irritability
depression insomnia inattention as well
as craving or intrusive thoughts of
wanting to use our drug of choice and
Manufacturing lots of narratives to that
end I also want to add that as with
addictions to drugs and alcohol there
are a lot of interpersonal consequences
as a result of addiction to the internet
and to our devices for example were much
less present in real time for other
people I see a lot of parents for
example who are not able to be fully
present for their children people who
are not able to be present for their
spouses or other family members or
friends because of the amount of time
energy and creativity they're putting
into consuming uh you know digital media
yeah so I was going to ask this question
later on in the interview but I want to
jump into this section in the book
called The Pleasure and Pain balance so
basically there is a chapter you talk
about this balance between Pleasure and
Pain and they are co-located which was
fascinating to me can you explain a
little bit more about that because I do
have a follow-up question about that
sure so by almost any brain measure what
we find is that the same parts of the
brain that process pleasure also process
pain and it looks like they work like
opposite sides of a balance so if you
imagine a beam on a central fulcrum and
that beam represents how we process
Pleasure and Pain when we do something
pleasurable like watch a Netflix movie
we experience pleasure that releases
dopamine in the brain's reward pathway
in the balance tilt to the side of
pleasure when we burn our hand on a hot
stove that tilts the balance to the side
of pain and and there are certain rules
governing this balance and the first and
most important rule is that the balance
wants to remain in the level position
that is to say parallel with the ground
so that with any deviation from
neutrality our brains are going to work
very hard to restore a level balance and
the way that our brains do that is first
by tilting an equal and opposite amount
to whatever the initial stimulus was so
let's say I eat a piece of chocolate or
drink a glass of wine that releases
dopamine I then get a tilt to the side
of pleasure but as soon as that happens
my brain adapts by down regulating
dopamine transmission and production I
like to imagine that as these
neuroadaptation Gremlins hopping on the
pain side of my balance to bring it
level again but the Gremlins really like
it on the balance so they don't get off
as soon as it's level they stay on until
the balance is tilted and equal and
opposite amount to the side of pain
that's the come down The Hangover the
Blue Monday or that moment of wanting
one more piece of chocolate or to watch
one more Tick Tock video now if I wait
long enough those Gremlins hop off and a
level balance is restored but the key
piece here is that for every pleasure we
pay a price and that price is the
feeling however fleeting of pain in its
aftermath usually manifested as cravings
for wanting to do it again now you might
ask yourself why would Mother Nature
make a pleasure pain balance that you
know requires us to feel pain after
every pleasure well it's not that mother
nature is cruel for no reason it's that
this kind of configuration is highly
adaptive for a world of scarcity and
ever-present danger which is the world
that human beings have existed in for
most of humanity which is to say what
better way to motivate the organism to
continually seek the next pleasure than
by ensuring that that pleasure is
fleeting very short in duration and by
making it have making the organism
experience pain in its aftermath which
then motivates the individual to get out
of Pain by seeking yet more pleasure so
that that's the first rule of the
balance now to understand what happens
in the brain as we get addicted it's
important to appreciate that this
balance was created over many years of
evolution for a very modest rewards that
were very difficult to acquire
the idea being we would have to do a lot
of work to find you know a drink of
water or a berry bush with five berries
on it but now we live in this world that
we have created a overwhelming over
abundance almost every Behavior has
become drugified so now what we're doing
is we're slamming down on the pleasure
side really hard and really fast right
now we need a whole lot more Gremlins
hopping on the pain side side to restore
homeostasis and with repeated exposure
to the same or similar rewarding
stimulus we start to accumulate more and
more Gremlins on the pain side of the
balance in an effort to try to restore
homeostasis but eventually what happens
is that they're just there are enough
Gremlins on that pain side to fill this
whole room and now they're camped out
there they've got their tents their
barbecues they're not going anywhere and
now we're walking around with a balance
that's chronically tilted to the side of
pain we've actually changed our hedonic
or Joy set point now we need to use not
to get high or feel pleasure but just to
level the balance and feel normal and
when we're not using we're walking
around feeling the universal symptoms of
withdrawal which again are anxiety
irritability insomnia depression and
craving so when I read that part it was
a super interesting but also I was a
little bit scared because I want to have
fun in my life and I will also want to
like what have what people call Big Time
in my career in my life right so I want
to experience that excitement and
adrenaline surge sometimes but according
to your book that will be definitely
followed by some kind of pain and some
kind of depressive um feelings and
emotions so I was a little bit worried
but we still want to thrive in our
Korean in life and we still want to have
a lot of fun then what can we do like
obviously we don't want to experience
pain but is that just a way to go should
we just soak it up and what's there yeah
I mean I think one way to think about
this is there's sort of good dopamine
and bad dopamine in fact it's all the
same dopamine but the way that we get
our dopamine and of course we want to
experience you know pleasure and joy in
our lives and we are reflexively
designed to approach pleasure and avoid
pain and dopamine is our key reward and
pleasure neurotransmitter but you know
it's it's a matter of how much dopamine
how often and what we did to get there
when we're talking about intoxicants
whether it's cannabis cocaine alcohol
nicotine pornography video games certain
types of social media those are drugs
and they release a lot of dopamine very
quickly in our brains and if we're going
to engage in those types of you know
High potency intoxicants we just have to
make sure that we leave enough time in
between use
to let those Gremlins hop off so that we
can restore homeostasis what happens
when we get into repeated especially
daily use is that you know we accumulate
those Gremlins on the pain side of the
balance and push ourselves into the
dopamine deficit State we also have to
pay attention to quantity when we use
intoxicants because if we're using a
whole lot of that we're slamming that
balance down hard and fast to the side
of pleasure and potentially over time
maybe doing some damage to that balance
so we want to keep a subtle easily
responsive balance that most of the time
hangs out here in homeostasis but is
also responsive to rewards and painful
stimuli and what we're essentially doing
in stimulating our brains all the time
with all of these reinforcers is we're
making it impossible to appreciate those
more modest rewards which would be
highly rewarding if we weren't
bombarding our our brains with these
other high potency drugs the other thing
too is that it's possible to get
dopamine indirectly by paying for it up
front so I talk about this in the book
as pressing on the pain side first so
that is intentionally doing things that
are difficult to get those Gremlins to
switch over to the pleasure side in an
effort to bring that balance level again
because they will do that it works both
ways for example we know that when
people engage in exercise dopamine
levels will increase over the latter or
last part of the exercise and then
remain elevated for hours afterwards
before coming back down to the Baseline
level of tonic dopamine firing without
going below Baseline into that dopamine
deficit state so that's great that means
we got a hit of dopamine that lasted for
hours that never required us to get into
the state of craving anxiety despair
because we did the work up front in
order to get that dopamine other meth
methods are things like intermittent
fasting ice cold water plunges but even
effortful engagement creative Pursuits
your academic Pursuits your focused flow
concentration is a great source of
dopamine they're effortful right you
have to pay for your dopamine up front
so let's say that I'm a Netflix addict
actually Netflix
for hours let's say I had a hard day at
work I came home and I know that Netflix
is the way to go and I know I feel safe
there by watching it but I know that
somewhat I'm addicted to Netflix I
wanted to work on that to recover most
recommend exercise or writing a journal
or meditation so that's good but I still
think that there is a very very tiny
moment between when you feel like oh I
want to watch Netflix Netflix is the
only thing that I want to do and later
on when you feel like oh no let's not do
it I'll write about it instead or I'll
go out exercise or take a walk so
there's still very like there's very
moment in between those two different
moments I think and I kind of keep
failing
um handling that moment right is there
anything that we could do to win the
fight yeah so I mean I think that's very
insightful of you and you describe that
really well we can all relate to that we
wake up in the morning with that new
resolve not to do a certain Behavior at
the end of the day and the end of the
day comes and we do the behavior we're
tired our willpower is exhausted we feel
like we've worked hard all day we want
to reward ourselves the reward is right
there what I recommend is something
called a dopamine fast where we actually
commit in advance to abstaining from our
drug of choice whatever it is in this
case Netflix for four weeks why four
weeks because four weeks is the average
amount of time it takes to reset reward
Pathways for those neuro adaptation
Gremlins to hop off the pain side of the
balance and for homeostasis to be
restored now you could say well okay
you're asking me to quit for four weeks
I can't even quit for one night how have
you helped me it does make a difference
when you mentally and potentially
verbally commit to this period of 30
days or four weeks of abstinence and you
prepare for it in advance and one of the
key points of preparation is what I call
self-binding self-binding is the ways
that we actually put both literal and
metacognitive barriers between ourselves
and our drug of choice so that we're not
relying exclusively on Willpower to not
use we're actually making a barrier that
allows us to press that pause button
between desire and consumption and have
just enough time to do something else so
for Netflix the example would be that
you would unsubscribe from Netflix for
example anything you can do to create
barriers maybe you want to have they
make these time safes now where you can
actually put your smartphone or your
laptop up in a safe and put the timer
yeah and that will force you you know to
not to not and then in in place of
um you know that activity you want to do
activities that are actually more
painful than withdrawal so a lot of
things people are like okay I'm gonna
give up Netflix but I'm gonna smoke pot
instead I'm gonna give up Netflix and
I'm gonna eat chocolate cake that's not
a good idea because that will just
trigger your reward pathway and make you
want to watch Netflix even more instead
what you do is you say you know what in
the evening I'm gonna go for a walk or
I'm going to write a letter to a friend
or a relative every evening I'm going to
read a really difficult book I've been
wanting to read about you know the
history of South Korea and and what
people find is that the first two weeks
are really difficult as we're in
withdrawal with that balance weighted to
the side of pain but slowly those
Gremlins get the message they start to
hop off and by about 10 to 14 days we
find that our balance is beginning to go
back to the level position it's less
hard and also we're able to enjoy more
modest rewards right we're able to
actually start to remember what it felt
like to enjoy reading a good book or
reading the newspaper in the evening or
just sitting and watching the sunset
with a nice warm cup of tea or something
like that by the time they get to week
four or 30 days they really feel much
better they're less anxious they're less
depressed they've gotten a lot more
stuff done that they had wanted to get
done not just the stuff at work but like
they cleaned out their closet you know
stuff that they every day they go oh I
need to clean out that closet okay I
need to clean up that closet all of a
sudden that closet is clean you know
they've reached out to people they made
connections again you know the auto
stimulation that we get from Netflix and
other digital media it really is the
same as kind of getting drunk every
night and it's it's just it just
isolates us more and more I want to talk
a little bit about how to get out of
detox so for example I did 30 day no
smartphone challenge multiple times okay
and I feel great like this is amazing my
quality of the sleeve is better I was
more present and house is clean yeah
right as you described like you can't
see it the difference but in the end I
came back to square one what happened to
me it it same thing happened to me with
intermittent fasting so you haven't done
this for 30 days now you are so waiting
to go back and you end up binge eating
the food or you end up being you
watching the Netflix because you are 30
days away from that so is there any
strategy to smartly get out of the detox
so that you don't go back to your old
happy even after feeling amazing yeah
seeing all this good changes right the
key with being successful after the
dopamine fast is to make a very specific
plan you know and make it tailored to
your individual needs but but just make
a I'm gonna this is how I'm gonna use
digital media going forward and then see
what works like you you tried it and you
didn't work so you need to come up with
a different plan right something that's
that's working better for you so we've
been talking about quitting or detoxing
there is a group of people who said it
is impossible to moderately use
but there is a group of people no that's
not possible you should quit 100 is
there such a thing like moderately using
once you are addicted to something can
you go back to that yeah so this is a
great question and a really relevant
question for for beer or other alcohols
but also for food which food has become
highly drugified and also for digital
devices because those are a part of our
everyday lives so we many of us can't
quit them the old way of thinking was
that once you had become addicted to
alcohol the only pathway for Recovery
was to abstain from alcohol but recently
what we're finding is that some people
can with tremendous effort and after a
period of abstinence so that's really
important you have to have that dopamine
fast first they can return to using
alcohol in moderation and I have had
patients who have been alcoholic or
addicted to alcohol who after a long
period of absence were able to return to
drinking and keep it in in a moderate
amount but it took a lot of effort for
them to do that they had to do a lot of
self binding right a lot of
accountability a lot of tracking so they
could be honest with themselves and with
others some of them say you know it's
kind of not even worth it because with
one or two drinks I don't get the
feeling that I want I'd rather just not
drink at all but abstinence should come
first yes before yeah you have to do the
four the minimum of four weeks of
abstinence in order to again what you
need to do is you need to reset dopamine
reward thresholds if you just try to
slowly reduce you're never going to
reset those reward Pathways and you're
always going to be craving so what the
dopamine fast allows is for people to
get out of that state of constant
craving and mental preoccupation with
their drug and they're kind of feel free
right and then once they get out of that
if they want to go back to using if they
use in very modest amounts and can keep
it modest you know then they can drink
in moderation most people with severe
alcoholism who try to return to drinking
are not successful they have what you
experience with Netflix and I experience
with romance novels are kind of what we
call an abstinence violation syndrome so
I tried many times to tame
um my demon including Netflix and beer
and other things there is some
frustration you keep trying but you are
not changing there so there is a
frustration and at some point I think
you just ended up giving up on quitting
whatever like I still have the job I
can't work like there is this
um what they call High performing
addicts and I can be one of them how do
we deal with that frustration of failing
I mean it'll be the best if we just
succeed
um with the quitting at the first trial
but if that doesn't happen yeah first of
all people shouldn't give up because the
more times they try to quit the more
likely they will eventually quit for
cigarette smoking there's actually good
data on that that the more times you try
to quit the more likely you will be
successful so we should just keep
pushing
keep pushing keep trying something
different every time
um you know because the life of being
addicted at first it may seem like oh
it's worth the trade-off but as we age
and as we as our brains age the costs
get higher and higher and we isolate
more and more and I don't think anybody
wants to live like that so this is a
question for the people who are not sure
if they're addicted but they feel like
this is not right or it could be better
how do we self-assess whether we are
addicted to something yeah so a couple
things if you find you're lying about
your use to other people even if you're
just sort of
decreasing the amount of time that
you're spending or saying you know
you're working but you're really not
working
that's a red flag for that you're doing
a behavior that you've now sort of
teetered into compulsive over
consumption and maybe even a mild
addiction so lying is something to look
for if you find that you have a lot of
mental preoccupation or narrowing of
your focus to just using your drug it's
the only thing that you enjoy you don't
enjoy other things you look forward to
it all day things that you used to enjoy
are no longer pleasurable that's highly
suggestive that you've changed your
hedonic or Joy set point and lost
literally physiologically lost the
ability to take joy in more modest
rewards we do have seven minutes so I'm
using the seven minutes I want to share
some of Korean readers reviews and
feedback about the book so I think
that's a good way to kind of end this
conversation and many people have read
it so this is all Korean version
um there are a lot these are some of the
reviews that I brought among many from
the online bookstores people are saying
that for some people this book can be a
life changer one person said that this
book literally changes I'm very honored
um you know the book has been translated
into now I think 25 languages and
counting but the Korean version is my
absolute favorite in terms of how it was
you know done and how it was translated
and how they took the artwork and and
kind of made it their own so I'm very
grateful for that and then I would just
say to folks out there you know you're
not alone we're all struggling one of
the huge messages that I hoped I would
get across by sharing my story is that
you can be you know an academic faculty
member at Stanford and know a lot about
addiction and still get addicted to
something like romance novels I think
we're all looking for that kind of
escape from our high pressure lives so I
really urge you to give this a try you
know living without your drug of choice
and see it as an opportunity not just to
explore yourself in your own life but
potentially be of service to others
because so many people are suffering and
struggling in the world today we have so
much it's this plenty Paradox right we
have so much and yet we're so unhappy
and we really need everybody to
help each other figure out how can we
live more joyful and thriving lives you
know in what's paradoxically very
difficult time in human history to be
alive