Transcriber: Reviewer: Denise RQ
Right now,
standing on this stage,
by speaking these words,
I'm changing your brain.
And I know, it sounds like a superpower
(Laughter)
but you have it, too,
you're changing my brain just by being here.
Now, it all hinges on the single most important thing
that I've ever learned as a clinical neuroscientist,
and here it is: experience changes the brain.
Your brain is exquisitely designed
to respond, to adapt to every experience you'll ever have,
every thought, emotion, action, perception,
all of it leaves an impact on your brain.
This simple insight can completely reshape
our intuitions about mental illness and about chemical imbalance,
and at the same time, it yields some simple and elegant lifehacks
any of us can use to enhance brain function.
So let's see how this works.
Today we're all gathered to bask in the warm glow of TED.
Unfortunately, our bodies, your bodies, will spend most of this time just sitting,
and that's a problem because as you might have heard
sitting is the smoking of our generation.
(Laughter)
Physical inactivity doesn't just take a toll
on our hearts, our lungs, and yes, our fat cells,
it also takes a toll on the brain.
Now, when we're physically active,
key circuits use neurotransmitters like
dopamine and glutamine and serotonin;
they start to light up in pathways scattered throughout the brain,
enhancing energy, and mood, and motivation.
It's one of the major reasons why exercise is proven to be a potent antidepressant.
So, two landmark clinical trials at Duke University:
researchers had the audacity to test exercise head to head against Zoloft.
(Laughter)
They found
30 minutes of brisk walking just three times a week was
every bit as effective as the medication in fighting clinical depression.
30 minutes, brisk walking.
Three times a week.
Lifehack.
And then, when the researchers revisited those same patients, one year later,
they found the patients who had kept on exercising,
those were the ones that were most likely to stay well.
They didn't see any similar protective benefit
of just staying on medication.
It turns out, exercise also enhances our cognitive function,
it improves memory, and attention, mental clarity;
it even helps keep your brain young
by triggering the growth of new brain cells.
So let me put it simply: exercise it's medicine.
And I mean that quite literally.
It enhances brain function as powerfully as any medication.
And trust me, if big pharma could somehow capture
the neurochemical benefit of exercise
(Laughter)
- can you see it? -
put it in a pill and then sell it to you,
they would do it in a heartbeat.
And then, they would finally have
a blockbuster drug completely free of any difficult side effects
like weight loss or weight gain, sedation,
emotional blunting, loss of libido.
OK, let's take another example.
This one's maybe more risky.
Instead of sitting here, in this darkened auditorium
what if you were to get up,
walk outside and bask in sunlight?
The instant you stepped outside,
specialized receptors in your retina in the back of the eye
would kick off an avalanche of neurological activity.
These receptors have a broadband connection
to body clock circuitry buried deep inside the brain.
These are circuits that regulate your sleep, and appetite,
and arousal, and hormone levels.
And for millions of Americans and Europeans every winter,
when the days turn cold, and bleak, and short,
at least here in Kansas,
sunlight deprivation causes all hell to break loose in the brain.
And the result is an episode
of debilitating, painful, seasonal affective disorder.
It's been discovered
up to 30% of us will have some symptoms every winter,
and anyone of us can have a decrease, a drop in serotonin-based signaling
any time we're chronically sunlight deficient,
any time we're chronically deprived of sunlight.
So, if that happens to you, if that happens to me,
what should we do about it?
We could always try medication,
after all, one out of every five Americans
takes a psychiatric drug every single day.
There's been a 300% increase in antidepressive use
just in the last 20 years.
And it raises a really interesting question:
with all this medication, with this huge increase,
why is it that there's been no corresponding decrease
in the rate of depression in the last 20 years?
Have you ever wondered about that?
How do we still have an epidemic of this illness?
I believe the answer is straightforward:
you and I were never designed
for a sedentary, indoor, sleep deprived,
socially isolated, fast food laden,
frenetic pace of modern American life.
Experience changes the brain,
and our epidemic of depression it's driven
by an even greater epidemic of unhealthy experience.
For the past seven years,
my clinical research group has been working
to help depressed patients change the way they live,
to get the exercise they need, to get the sunlight they need.
And when that's not available, we do have a lifehack, and you can see it:
it's a therapeutic light box
that simulates the effects of sunlight on the brain,
its effects, its benefits, typically kick in within five to seven days;
where medication, do you know how long?
It often takes about three to four weeks before it starts to work.
Now, what we eat also matters to the brain.
Sugar;
it turns out sugar lights up the brain's reward circuitry
about as effectively as cocaine
(Laughter)
and it's just about as addictive,
and unfortunately, it also triggers the release
of powerful inflammatory hormones
that disrupt normal chemical signaling throughout the brain.
And it's a huge problem
because the average American now consumes 22 teaspoons worth of added sugar
every single day.
Most of us would do well to cut back, and to cut way back.
And then, finally, what we think about also matters to the brain.
Have you heard of rumination?
It's the habit of dwelling on our negative thoughts
repeatedly, at length.
It ramps up our brain's stress circuitry,
and that, in turn, interferes with the whole process of memory consolidation.
It's the big reason why memory tends to suffer
whenever we're stressed and we get trapped inside our own heads.
And the research shows
we're most likely to ruminate whenever we're completely alone.
On the other hand, face time with our loved ones
it doesn't just protect us against toxic rumination,
it also directly puts the breaks on the brain's stress response.
And the benefits can range from lower anxiety
to better quality of sleep, to yes, better memory.
Now, whenever we hear the term 'chemical imbalance,'
most of us, I think, reflexively assume medication must be the answer.
Yet, the relevant neuroscience leads us to a somewhat different conclusion:
there are many different ways of changing neurochemistry,
most of them have nothing to do with medication.
That's why I believe, in the long run,
the most effective way of balancing neurochemistry is to balance our lives.
Remember, experience changes the brain.
Thank you.
(Applause)