A new class of drug that could prevent depression and PTSD Rebecca Brachman
So the first antidepressants
were made from, of all things,
rocket fuel, left over after World War II.
Which is fitting, seeing as today,
one in five soldiers develop depression,
or post-traumatic stress disorder or both.
But it’s not just soldiers
that are at high risk for these diseases.
It’s firefighters, ER doctors,
cancer patients, aid workers, refugees –
anyone exposed to trauma
or major life stress.
And yet, despite how commonplace
these disorders are,
our current treatments,
if they work at all,
only suppress symptoms.
In 1798, when Edward Jenner
discovered the first vaccine –
it happened to be for smallpox –
he didn’t just discover
a prophylactic for a disease,
but a whole new way of thinking:
that medicine could prevent disease.
However, for over 200 years,
this prevention was not believed
to extend to psychiatric diseases.
Until 2014, when my colleague and I
accidentally discovered
the first drugs that might prevent
depression and PTSD.
We discovered the drugs in mice,
and we’re currently studying
whether they work in humans.
And these preventative
psychopharmaceuticals
are not antidepressants.
They are a whole new class of drug.
And they work by increasing
stress resilience,
so let’s call them resilience enhancers.
So think back to a stressful time
that you’ve since recovered from.
Maybe a breakup or an exam,
you missed a flight.
Stress resilience
is the active biological process
that allows us
to bounce back after stress.
Similar to if you have a cold
and your immune system fights it off.
And insufficient resilience
in the face of a significant
enough stressor,
can result in a psychiatric disorder,
such as depression.
In fact, most cases
of major depressive disorder
are initially triggered by stress.
And from what we’ve seen so far in mice,
resilience enhancers can protect
against purely biological stressors,
like stress hormones,
and social and psychological stressors,
like bullying and isolation.
So here is an example where we gave mice
three weeks of high levels
of stress hormones.
So, in other words, a biological stressor
without a psychological component.
And this causes depressive behavior.
And if we give three weeks
of antidepressant treatment beforehand,
it has no beneficial effects.
But a single dose of a resilience
enhancer given a week before
completely prevents
the depressive behavior.
Even after three weeks of stress.
This is the first time
a drug has ever been shown
to prevent the negative effects of stress.
Depression and PTSD are chronic,
often lifelong, clinical diseases.
They also increase the risk
of substance abuse, homelessness,
heart disease, Alzheimer’s, suicide.
The global cost of depression alone
is over three trillion dollars per year.
But now, imagine a scenario
where we know someone is predictively
at high risk for exposure
to extreme stress.
Say, a red cross volunteer
going into an earthquake zone.
In addition to the typhoid vaccine,
we could give her a pill or an injection
of a resilience enhancer
before she leaves.
So when she is held at gunpoint
by looters or worse,
she would at least be protected
against developing depression or PTSD
after the fact.
It won’t prevent her
from experiencing the stress,
but it will allow her to recover from it.
And that’s what’s revolutionary here.
By increasing resiliency,
we can dramatically reduce
her susceptibility to depression and PTSD,
possibly saving her from losing her job,
her home, her family or even her life.
After Jenner discovered
the smallpox vaccine,
a lot of other vaccines rapidly followed.
But it was over 150 years
before a tuberculosis vaccine
was widely available.
Why?
In part because society believed
that tuberculosis made people more
sensitive and creative and empathetic.
And that it was caused
by constitution and not biology.
And similar things are still said
today about depression.
And just as Jenner’s discovery
opened the door
for all of the vaccines
that followed after,
the drugs we’ve discovered
open the possibility of a whole new field:
preventative psychopharmacology.
But whether that’s 15 years away,
or 150 years away,
depends not just on the science,
but on what we as a society
choose to do with it.
Thank you.
(Applause)