Toward a new understanding of mental illness Thomas Insel
[Music]
[Music]
so let’s start with some good news and
the good news has to do with what do we
know based on biomedical research that
actually has changed the outcomes for
many very serious diseases start with
leukemia acute lymphoblastic leukemia a
ll most common cancer of children when I
was a student the mortality rate was
about 95 percent today some 2530 years
later we’re talking about a mortality
rate that’s reduced by 85 percent 6000
children each year who would have
previously died of this disease are
cured if you want the really big numbers
look at these numbers for heart disease
heart disease used to be the biggest
killer particularly for men in their 40s
today we’ve seen a 63 percent reduction
in mortality from heart disease
remarkably 1.1 million deaths averted
every year aids incredibly big has just
been named in the past month a chronic
disease meaning that a 20 year old it
becomes infected with HIV as expected
not to live weeks months are a couple of
years as we said only a decade ago that
is thought to live decades probably to
die in his 60s or 70s from other causes
altogether these are just remarkable
remarkable changes in the outlook for
some of the biggest killers and one in
particular that you probably wouldn’t
know about stroke which has been along
with heart disease one of the biggest
killers in this country is a disease in
which now we know that if you can get
people into the emergency room within
three hours of the onset some 30% of
them will be able to leave the hospital
without any disability whatsoever
remarkable stories good news stories all
of which boiled down to understanding
something about the diseases that has
allowed us to detect early and intervene
early early detection early intervention
that’s the story for these successes
unfortunately the news is not all good
let’s talk about one other story which
has to do with suicide now this is of
course not a disease per se it’s a
condition or it’s a situation that leads
to mortality what you may not realize is
just how prevalent it is there are
thirty eight thousand suicides each year
in the United States that means one
about every 15 minutes third most common
cause of death amongst people between
the ages of 15 and 25 it’s kind of an
extraordinary story when you realize
that this is twice as common as homicide
and actually more common as a source of
death than traffic fatalities in this
country now when we talk about suicide
there is also a medical contribution
here because ninety percent of suicides
are related to a mental illness
depression bipolar disorder
schizophrenia anorexia borderline
personality there’s a long list of
disorders that contribute and as I
mentioned before often early in life but
it’s not just the mortality from these
disorders it’s also morbidity if you
look at disability as measured by the
World Health Organization with something
they call the disability adjusted life
years it’s kind of a metric that nobody
would think of except in economists
except it’s one way of trying to capture
what is lost in terms of disability from
medical causes and as you can see
virtually 30% of all disability from all
medical causes can be attributed to
mental disorders neuropsychiatric
syndromes you’re probably thinking that
doesn’t make any sense I mean cancer
seems far more serious heart disease
seems far more serious but you can see
actually they’re further down this list
and that’s because we’re talking here
about disability what drives the
disability for these disorders like
schizophrenia and bipolar and depression
why are they number one here well there
are probably three reasons one is that
they’re highly prevalent about one in
five people will suffer from one of
these disorders in the course of their
lifetime the second of course is that
for some people these become truly
disabling and it’s about four to five
percent perhaps one in twenty
but what really drives the
numbers this high morbidity and to some
extent the high mortality is the fact
that these start very early in life
50% will have onset by age 14 75% by age
24
a picture that is very different than
what one would see if you’re talking
about cancer or heart disease diabetes
hypertension most of the major illnesses
that we think about as being sources of
morbidity and mortality these are indeed
the chronic disorders of young people
now I started by telling you that there
were some good news stories this is
obviously not one of them this is the
part of it that is perhaps most
difficult and in a sense this is a kind
of confession for me my job is to
actually make sure that we make progress
on all of these disorders I work for the
federal government actually I work for
you you pay my salary and and maybe at
this point when you know what I do or
maybe what I failed to do you’ll think
that I probably ought to be fired and I
could certainly understand that but what
I want to suggest and the reason I’m
here is to tell you that I think we’re
about to be in a very different world as
we think about these these illnesses
what I’ve been talking to you about so
far is mental disorders diseases of the
mind that’s actually becoming a rather
unpopular term these days and people
feel that for whatever reason it’s
politically better to use the term
behavioral disorders and to talk about
these as disorders of behavior fair
enough they are disorders of behavior
and they are disorders of the mind but
what I want to suggest to you is that
both of those terms which have been in
play for a century or more are actually
now impediments to progress that what we
need conceptually to make progress here
is to rethink these disorders as brain
disorders now for some of you you’re
gonna say oh my goodness here we go
again we’re gonna hear about a
biochemical imbalance so we’re going to
hear about drugs or we’re going to hear
about some very simplistic notion that
will take our subjective experience and
turn it into MA
molecules or maybe into some sort of
very flat unit dimensional understanding
of what it is to have depression or
schizophrenia when we talk about the
brain it is anything but uni-dimensional
or simplistic or reductionistic it
depends of course of what scale or what
scope you want to think about but this
is an organ of surreal complexity and we
are just beginning to understand how to
even study it whether you’re thinking
about the hundred billion neurons that
are in the cortex or the hundred
trillion synapses they make up all the
connections we have just begun to try to
figure out how do we take this very
complex machine that does extraordinary
kinds of information processing and and
use our own minds to understand this
very complex brain that supports it
supports our own minds it’s a it’s
actually a kind of cruel trick of
evolution that we simply don’t have a
brain that seems to be wired well enough
to understand itself in a sense it
actually makes you feel that when you’re
in the safe zone of studying behavior or
cognition something you can observe that
in a way feels more simplistic and
reductionistic than trying to engage
this very complex mysterious organ that
we’re beginning to try to understand now
already in the case of the brain
disorders that I’ve been talking to you
about depression obsessive compulsive
disorder post-traumatic stress disorder
well we don’t have a an in-depth
understanding of how they are abnormally
processed or what the brain is doing in
these illnesses we have been able to
already identify some of the
connectional differences or some of the
ways in which the circuitry is different
for people who have these disorders we
call this the human connectome and you
can think about the connectome sort of
as the wiring diagram of the brain
you’ll hear more about this in a few
minutes the important piece here is that
as you begin to look at people who have
these disorders the one in five of us
who struggle in some way you find that
there’s a lot of very
in the way that the brain is wired but
there are some predictable patterns and
those patterns are risk factors for
developing one of these disorders it’s a
little different than the way we think
about brain disorders like Huntington’s
or Parkinson’s or Alzheimer’s disease
where you have a bombed-out part of your
cortex if you were talking about traffic
jams or sometimes detours or sometimes
problems with just the way that things
are connected and the way that the brain
functions you could if you want compare
this to on the one hand a myocardial
infarction a heart attack where you have
dead tissue in the heart versus neighbor
is Mia where that organ simply isn’t
functioning because of the communication
problems within it either one would kill
you and only one of them will you find a
major lesion as we think about this
maybe it’s better to actually go a
little deeper into one particular
disorder and that would be schizophrenia
yes I think that’s a good case for
helping to understand why thinking of
this as a brain disorder matters these
are scans from Judy Rapoport and her
colleagues at the National Institute of
Mental Health in which they studied
children with very early onset
schizophrenia and you can see already in
the top there’s areas that are red or
orange yellow are places where there’s
less gray matter and as they followed
them over five years comparing them to
age match controls you can see that
particularly in areas like the dorsal
lateral prefrontal cortex or the
superior temporal gyrus there’s a
profound loss of gray matter it’s
important if you try to model this you
can think about normal development as a
loss of cortical mass loss of cortical
gray matter and what’s happening in
schizophrenia is that you overshoot that
mark and at some point when you
overshoot you cross a threshold and it’s
that threshold where we talk we say this
is a person who has this disease because
they have the behavioral symptoms of
hallucinations and delusions that’s
something we can observe but look at
this closely and you can see that
actually they’ve crossed a different
threshold that crossed a brain threshold
much earlier that perhaps not at age 22
or 20 but even by age 15 or 16 you can
begin to see that trajectory for
development is quite different at the
level of the brain not at the level of
behavior why does this matter well first
because for brain disorders behavior is
the last
thing to change we know that for
Alzheimer’s for Parkinson’s for
Huntington’s there are changes in the
brain a decade or more
before you see the first signs of a
behavioral change the tools that we have
now allow us to detect these brain
changes much earlier long before the
symptoms emerge but most important go
back to where we started the good news
stories in medicine are early detection
early intervention if we waited until
the heart attack we would be sacrificing
1.1 million lives every year in this
country to heart disease that is
precisely what we do today when we
decide that everybody with one of these
brain disorders brain circuit disorders
has a behavioral disorder we wait until
the behavior becomes manifest
that’s not early detection that’s not
early intervention now to be clear we’re
not quite ready to do this we don’t have
all the facts we don’t actually even
know what the tools will be nor what to
precisely look for in every case to be
able to get there before the behavior
emerges as different but this tells us
how we need to think about it and where
we need to go are we going to be there
soon I think that this is something that
will happen over the course of the next
few years but I’d like to finish with a
quote about trying to predict how this
will happen by somebody who’s thought a
lot about changes in concepts and
changes in technology we always
overestimate the change that will occur
in the next two years and underestimate
the change that will occur in the next
10 Bill Gates thanks very much
[Applause]