The last talk was about

electronic technology and enhancing the brain.

My talk's about an old technology enhancing the brain;

an old technology that of course, you all know and love,

and that's called drugs.

But I'll come to that in a minute.

I'm going to start with the brain

because it's the most complex and evolved element

in the whole universe.

It's what got you here today, and hopefully, will get you home tonight.

A single mouse brain has more computing power

than all the computers on Earth today.

Your brains are at least a million times more powerful.

But unfortunately, it can go wrong.

Over the last few years,

we've discovered the scale of problems that brain disorders produce.

The sum total of illness and cost to society from brain disorders

is greater than that from cancer,

cardio-vascular disease, and diabetes put together.

You see on the graph there

it's the equivalent each year to nearly 800 billion euros.

It is if we're paying off the Greek debt every year

in the burden of illness produced by brain disorders.

We know that investment in these disorders is not matching the enormous burden.

Here, you can see on the left hand graph, the red circle;

'brain disorders' are way outside the predicted line of investment.

They're the largest disability,

and the investment is disproportionately low.

On the right-hand side, you can see one of the reasons for this.

You can see the attrition rate for drugs

that go through discovery into development.

Look at the second cylinder there.

You can see that from 200 Alzheimer's drugs in development,

only one reaches the clinic.

The brain is a very difficult organ to treat.

Why does the brain go wrong?

It goes wrong because of external influences:

malnutrition, still a big problem;

parental and other abuse - psychological and physical -;

toxins - particularly alcohol.

These are images of my own research showing a normal brain at the top

and a brain severely damaged by alcohol misuse lower down.

Infections such as meningitis, encephalitis are still common,

and trauma is a massive problem

in terms of leading to long-term brain damage

particularly in young men.

And then, there are internal aspects of the brain development

that can go wrong: related conditions like autism.

You can have acquired abnormalities like epilepsy

and there are age-related changes such as dementia.

But the real focus of my talk today is how the brain limits itself

and how we can perhaps expand its capacity or take away the limit it puts on itself.

Your brain is most flexible when you're a baby.

Some people would argue

that the whole process of education is about taking away flexibility

and forcing every one of you to think and behave in the same way.

It's about getting conformity of process

which of course is useful

if you're trying to speak a language the same way as other people,

but may not be useful

if it limits how you can deal with other things such as problems.

And also, the constraining of the brain in itself can lead to problems;

if there is not enough of it in the right place,

you get disorders such as ADHD and schizophrenia.

If you get excessive constraints,

you can end up with disorders like OCD and addiction.

And also the resilience in the brain can be impaired,

and that will lead to disorders such as anxiety and depression.

The core of my talk really is showing you how we can now understand

the limitations that the brain constrains the mind with

through using drugs.

This research really goes back to the 1950s

and the personal experience of this man, Aldous Huxley,

who used peyote and used LSD, psychedelic drugs,

to understand his mind.

He wrote about it in the book "The Doors of Perception,"

and he used this quote from William Blake

to explain how these drugs changed his mind.

He said, "If the doors of perception were cleansed,

everything would appear to man as it is, Infinite.

For man has closed himself up

till he sees all things through narrow chinks of his cavern."

And Huxley realized that what psychedelics do

is take away this phenomenon that he inferred

which is that "the brain is an instrument for focusing the mind."

Modern neuroscience has shown they were right.

Because, what we now know

is that the brain creates what the mind thinks it's doing.

Here is an example of vision.

You might be looking out at a glorious sunset,

but in reality, the light rays go into your retina

and are transformed into a series of electrical impulses

which pass into parts in your brain.

And those parts of the brain reconstruct an image

that they think you're seeing.

And that image, in the words of Blake,

is seeing through the constraints, the chinks of the cavern

that your brain puts on it.

And if you have mental illness - for instance, depression or addiction -

then what you see is also constrained by your brain.

So depressed people don't see even the brightness of the sky.

They see a dull grey.

And of course, people with addiction

when they see through the chinks of their cavern,

they simply see the drugs that they're addicted to.

Psychedelic drugs take away that limitation.

They allow the mind to work in a much more flexible way.

This is our research using psilocybin in magic mushroom juice.

Those two images contain the same number of connections.

But on the left-hand image, under placebo,

you see that most of the connections are around the edge.

The brain talks to itself in regional ways.

But under psilocybin,

there's a massive cross-talk, much more integration;

parts of the brain which haven't talk to each other since you were children

are able to engage.

And that's how people can get new insights

and also, potentially overcome damage of dysfunction of the brain.

Here is another study using LSD showing essentially the same thing.

On the left-hand side,

you see the visual cortex is normally very local in how it works.

But under LSD, when people have their eyes closed,

they can see enormously vivid, interesting sets of images.

And that's because the brain is much more interconnected under LSD

than normal.

Here you see that the visual cortex

connects to most of the rest of the brain in that state.

We've been able to utilize this liberation of processing of the brain,

produced by psychedelics,

to treat people with depression.

Here is a study published last year

where we took people with depression

who failed two previous anti-depressive treatments,

and also had failed psychotherapy.

They were given a single dose of psilocybin,

and you can see there, that a week later,

all of them had recovered to some extend,

and half of them were now in a state of remission.

They were in the yellow bar there,

which shows that their depression has actually gone away.

And that's not the first evidence

that psychedelics have therapy or have therapeutic uses.

We also have evidence from around the world

that psilocybin can be useful in helping people deal with alcohol dependence,

with smoking dependence, with obsessive compulsive disorder.

And most recently,

two major studies showing it can help people come to terms

with the anxiety and the depression

which almost always accompany a diagnosis of a terminal illness.

So, these drugs can have potentially enormous opportunities

for helping people deal with mental distress.

It's not just psychedelics that can have that potential.

Many illegal drugs have medical uses.

So for non-psychedelics such as MDMA, ecstasy,

where there is good evidence in post-traumatic stress disorder

and also some studies going on in addiction.

And of course, there is cannabis

where we have a range of different disorders

from pain, spasticity, cancer, epilepsy,

inflammatory diseases, and also sleep disorders.

All of these, potentially, are amenable to treatment with cannabis.

So, why don't we use these drugs?

That's because the WHL and the UN have said they are too dangerous,

which is certainly untrue.

I can tell you categorically

none of our patients died in the experiments we did on them.

Most of our governments perpetuate this lie.

And many of us - hopefully, not you - have closed minds.

We do not want to believe that these might have therapeutic utility.

So I want to say to you now,

surely now: you, if not everyone,

should accept the fact

that these drugs potentially could be very important medicines.

For the sake of the millions of people in the world who could be helped,

it's time to say there should be no limits

to the therapeutic research we do with these drugs.

Thank you.

(Applause)