What it is absolutely not,

it has nothing to do with multiple personalities.

When we think about the brain, we think

about things that can cause schizophrenia

and there are likely to be many different causes,

but we know that it's likely to be a combination

of genetics and environmental causes that will be at play,

and when I say environmental, that may include things

like the experience in the womb

and also growing up, childhood experiences,

so it's really a combination of these two big factors

that leads to abnormalities in the brain,

and these abnormalities in the brain can actually

be picked up by some of the tests that we have today.

Some of our brain imaging tests can show some

abnormal changes in some individuals with schizophrenia.

We know that some of the neurotransmitters,

the brain chemicals, are also abnormal in schizophrenia.

In particular, there is a neurotransmitter called dopamine

that is often thought to be too high or elevated

in certain parts of the brain in schizophrenia,

and quite a number of the medicines I use

to treat schizophrenia, the anti-psychotic medicines,

aim to work against dopamine.

Unfortunately, brain scans, measuring neurotransmitters,

none of these tests ever diagnose schizophrenia.

Schizophrenia is actually diagnosed

based on a clinical interview,

and that means taking a history,

hearing from the patient or their family

exactly what's been happening over time,

and also observing the patient.

Well, why would we observe the patient?

Because we know that these brain changes may actually

cause changes in how a patient behaves.

Their behavior may be altered,

and we can further break this down

into changes in the way they think

and changes in the way they act, and we think about ways

that people with schizophrenia may think differently.

We start to think about having abnormal beliefs,

something that we actually call delusions,

and they may also happen to see and hear things that

aren't there, something that we refer to as hallucinations.

Now, people can have delusions and hallucinations

in other conditions, but these are

some of the symptoms of schizophrenia.

Also, the way that they act may be different.

They may isolate themselves socially.

They may be somewhat disorganized

or somewhat confused in their actions,

especially to people looking at them from a distance.

They may have something that we call a flat affect,

and that basically means they lack emotions on their face.

This is by no means an exhaustive list,

but we can start to see that the way that they think

and the way that people with schizophrenia act,

there's a lot of changes here that people would

start to feel maybe abnormal or different.

Now, let's think a little more widely about schizophrenia.

How common is this condition?

Well, we know that approximately one percent

of people have schizophrenia.

The exact number is actually a little bit less than that

in the US; it's actually 0.7%,

and we know that males are typically affected

as much as females, and we know

that this is a condition that affects people

between the age of 16 and 30.

Although it can happen in childhood

and in older individuals, this is the most common age group,

with males being affected at a younger age than females.

When we think about schizophrenia,

we should also think about the fact

that there is something called the prodrome

and the prodrome represents a period of time

before schizophrenia, the symptoms are fully present,

but it's actually a kind of deterioration

in a person's behavior and functioning.

Things are starting to go downhill

and in the prodrome, typically what may happen is

that people will start to demonstrate

some of the signs of schizophrenia,

but what you will notice is their academic or schoolwork

may suffer, and I say schoolwork because if you think about

between 16 and 30, and if the prodrome precedes that,

you're talking about individuals

that are often still in the educational system,

but if they're working, the work can suffer.

Also, their relationships may suffer.

They may exhibit some paranoia

or suspiciousness towards other people.

Some of their thoughts may be

that people are working against them,

so they may develop some of these delusional ideas

and they may start to act differently.

The prodrome then often leads to schizophrenia

and we know that if somebody has schizophrenia,

they are at risk of having lots of different consequences.

For example, they're at a higher risk of suicide,

a higher risk of being homeless,

and a higher risk of being in prison or in jail.

So these are some basics to think about

when we start to hear the word schizophrenia.

Schizophrenia is a brain disorder that's neurodevelopmental,

a combination of genetics and environment,

and we can notice that there's differences

in brain scans and neurotransmitters,

but it's really diagnosed on clinical interview

and it affects how people think and act.

It's preceded by this prodrome period

where we notice a decrease in functioning

and schizophrenia has a lot of repercussions.

It stops people engaging in society, results in higher rates

of suicide, homelessness and incarceration.