Why antidepressants are not sufficient to fight depression? | Aleksandr Zharkovsky | TEDxLasnamäe

It is long-known that depression is an illness, and it must be treated. But even now there exist many myths about antidepressants and about what a patient has to do to get better.

Aleksandr Zharkovsky is a professor of pharmacology and drug toxicology at The University of Tartu and a participant of many pharmacologist societies.

This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at http://ted.com/tedx

Hello everyone.

You know, this was beautiful music.

I think of inviting
those guys to my lectures,

100 percent attendance will be guaranteed.

(Laughter)

The organizers have put wires all over me

and said that now I am
a part of a collective mind,

that we are one brain.

One part of this brain,
which is me, wanted to ask you:

"Do you know whose self-portrait it is?"

Van Gogh, Vincent Van Gogh.

Very well.

And this one?

Pablo Picasso.

You sure know this guy.

Harrison Ford, a Hollywood actor.

Do you know what these people
have in common?

They all suffered from depression.

A very approximate estimation suggests

that about 350 million people in the world

are currently diagnosed with depression.

And the costs of treatment,
of taking care of those people,

is about 210 billion dollars per year.

According to the World
Health Organization,

by 2020,

depression will become the second
most common cause for disability.

In other words, this disease
is the disease of the century.

The disease of our society.

Interestingly enough,
the World Health Organization

has conducted research is some countries

to see how widespread the depression
is among the population.

Which country do you think ended up first

in terms of depressed people?

Surprisingly, it was sunny France.

In France, every fifth adult

is diagnosed with depression.

You know, there is one country

that had no depressed patients till 2020.

Who can name that country?

China.

And it is not because it is
a communist country and everyone is happy.

(Laughter)

In the framework of the Chinese culture

depression is not a disease

but a personality trait.

And since 2000, when Chinese adopted

the criteria of depression
for the patients,

the depression appeared immediately.

But even by now,
it is around nine percent.

These are interesting facts.

The number of depressed people
grows constantly,

and we are facing
some very serious problems.

Look at this slide and these numbers.

Fifty percent of depressed people
do not get diagnosed.

Why?

A depressed person
will never come with a complaint

about feeling unhappy

or having a bad mood

or having lost the meaning of life.

To a depressed person, this doesn't look
like disease symptoms,

and so doctors cannot
establish such diagnosis.

Moreover, there are
no lab tests available.

We can take blood and analyse it,

but it will not help us
recognizing depression.

The depression diagnosis gets established

as a result of a dialogue
between a doctor and a patient.

What is a necessary condition for that?

At least one of them has to be healthy.

(Laughter)

Which is not always the case.

Moving on.

For treating patients with depression
we use a certain type of medicine

called antidepressants.

Sadly, the effects of antidepressants
develop very slowly.

Only during second month
of constant use of the medicine,

a patient starts feeling some improvement.

But during that period,

patients experience nothing
but the side effects of this medicine,

before the healing effects
stat taking place.

And 50% of people drop using the medicine

within first weeks of taking it.

Furthermore,

let's have a look at the last sentence.

In the case of 30–40 percent
of the patients

the medicine has no effect whatsoever.

And it is a huge, huge problem.

For many years, the scientists
were looking for a molecule of happiness,

thinking that the lack
of a particular molecule in the brain

was the cause of depression.

The search was unsuccessful

because the way our brain works

is based on neural networks

where millions of nerve cells
form a network,

and hundreds, thousands of molecules
make the network function.

And a failure in one or many molecules

can lead to such effect.

So I can say that

even today we know neither the cause

nor the mechanics of this disease.

But there are many interesting theories.

And one of the theories -

that's the theory
I am going to tell you about.

There was this guy in 1965,

a scientist Martin Seligman.

He was performing tests on dogs.

He would put a dog into a cage -

such tests are prohibited now

as ethical norms do not allow

using dogs in such experiments -

and passed a current
through half of the cage,

a weak current which was
nonetheless rather unpleasant for a dog.

He would be doing so for five to six days.

On day seven he would put
an animal into this cage,

immediately subjecting it to pain,

but leaving the door of the cage open.

It gave the dog an opportunity
to escape the unpleasant sensation.

What happened?

80% of dogs were indeed
running out of the cage,

but 20% stayed inside,

sort of consenting to the pain.

He called it "learned helplessness",

which in Estonian sounds as

'õppitud abitus',

or "выученная беспомощность" in Russian.

In his article, he wrote:
"I taught the animals to be unhappy".

Some years later, a theory appeared,

stating that the cause of depression was —

I quote —

"formation of stable negative patterns

that are fixed in the brain
due to its insufficient plasticity."

It means a person learns to be unhappy

but at the same time

brain plasticity keeps them
from retraining and becoming happy.

It is an interesting theory.

You see, our brain is very stable
and it has to be stable.

It has to remember the information,

it has to remember our skills,

this is the basis of its stability.

At the same time, the brain is bombed
by a vast flow of information,

visual, verbal,

it hears, it sees,

it undergoes constant stress.

This stability can be reached
only if the brain has plasticity.

Without plasticity this information flow,

this bombardment can destroy our brain.

Brain plasticity.

It is indispensable for learning

but it is also necessary for retraining.

Brain plasticity is quite
impressive in children.

A one-year-old child can learn
a thousand times more stuff than an adult.

They have remarkable plasticity.

This plasticity, this ability to learn

resides in a small brain structure
called hippocampus.

"Hippocampus" means a sea horse.

Really, it is highlighted over here,

it is shown in yellow in a brain,

and the way this structure looks

indeed reminds a sea horse.

What is the purpose of this structure?

It turns out that

this structure is responsible
for memory formation.

And the information
that serves as a basis for memory

is kept in this structure for two weeks,

then it is sent to other
parts of the brain.

The hippocampus
is cleared of old information

and is ready to take new information in.

And it was discovered that this structure

is the only or one of the few
locations in the brain

where a constant formation
of new nerve cells is happening.

This process is called neurogenesis.

This neurogenesis was observed
not only in children,

it was discovered in an adult brain, too.

It takes approximately a day

for around 600 to 800
nerve cells to generate;

they get organized into neural networks

and are able to perceive
the new information, to retrain.

The neurogenesis is shown on this diagram

The new cells are shown in blue here ...

What was discovered?

The patients who attempted suicide

had a lower number of these new cells.

The patients who have gone
through a serious psychological trauma

have a lower number of these cells,

fewer neurons are created
in this structure.

And the scientists suggested

that this may be the cause of depression.

A question arose:

How can we influence

the plasticity of the hippocampus
and this neurogenesis?'

It is also written in here:

a decrease in neurogenesis
may be a cause of depression.

I want to show you one slide.

Please pay attention.

We can color these new cells
created in hippocampus

in black like here and next to it, in red;

those red dots represent
the newborn nerve cells.

Then the neurogenesis processes
of a control person were compared

with that of a runner.

A runner.

Who does running mean?

It is a physical activity.

What do we see?

Look how the number
of these new cells has changed.

It turned out that physical activities
stimulate the neurogenesis greatly.

The same effect was found

in antidepressant fluoxetine — Prozac.

It too reinforces, or increases,
the number of new cells.

What else does contribute
to healing these cells?

An enhanced environment.

Children's toys have this function:

they stimulate neurogenesis in a child.

What can stimulate it in an adult?

What can count as an enhanced
environment for an adult?

Travelling.

This too enhances person's environment.

An interesting research
was conducted on taxi drivers

who constantly need
to remember how to navigate.

It turned out the volume
of hippocampus was a lot bigger

in London taxi drivers
than in the population on average.

It was an interesting publication.

Next.

I want to show you this slide,

maybe the conference organizers
will put a video for me.

Here is a child.

Young mothers, who has
children of this age?

Have you observed how they walk?

They don't walk, as some tell us.

They hop.

I have three grandchildren,
and they all hop.

None of them walks normally.

And I often hear from mothers:
"Why are you hopping? Walk normally!"

Never say that to your children.

It turns out that this hopping

contributes to neurogenesis
in the hippocampus.

This is an interesting fact
that was discovered recently.

That is, children, when hopping...

the brain sends them a signal to hop

and by hopping they improve
the plasticity of the brain.

It is great.

I like children.

There she goes!

Do you see how?!

(Laughter) (Applause)

Awesome!

I can no longer hop like that.

Let's move on.

Have a look, here I show several things

that improve our brain plasticity

and its capacity for retraining.

Here is physical activity,
here is travelling,

here are antidepressants when necessary.

Immediately a question pops up:

why doesn't all this work
for all the patients?

You see,

with all these things we give the brain
an opportunity to retrain

but it's up to the person to retrain.

Because really, everything we know,
we have learned by ourselves.

Neither professors nor school teachers —

teachers generally ruin everything —

(Laughter)

(Applause)

cannot make us learn.

The learning part is up to us.

And those things,
they will just give us an opportunity.

They will open the doors
to this retraining.

These are the things
I wanted to tell you today.

Thank you for listening.

(Applause)