Using brain imaging to diagnose mental illness

To mark Mental Health Week, we meet Associate Professor Marta Garrido. Dr Garrido was a laboratory leader at QBI, and won a highly competitive UQ Research award for her work in schizophrenia. Her work at QBI included researching ways to use brain imaging to identify the onset of schizophrenia as soon as possible, to provide that all-important early intervention. But to understand how the brain works in people at risk of schizophrenia, Dr Garrido says we need to stop thinking of people as mentally healthy or mentally ill. Instead, we need to think of it as a spectrum.

 

Transcript

[MUSIC]

Kirsten MacGregor

Hi, I’m Kirsten MacGregor, and this is A Grey Matter, the neuroscience podcast from the Queensland Brain Institute at the University of Queensland. In this edition, to mark Mental Health Week, we meet Dr Marta Garrido. Marta is a group leader at QBI, and recently won a highly competitive UQ research award for her work in schizophrenia. She’s researching ways to use brain imaging to identify the onset of schizophrenia as soon as possible, to provide that all important early intervention. But to understand how the brain works in people at risk of schizophrenia, Dr Garrido says we need to stop thinking of people as either mentally healthy, or mentally ill. Instead, we need to think of it as a spectrum.

Dr Marta Garrido

So, we often think about schizophrenia as a dichotomy – so people are either ill, or health, but it’s not as simple as that. In fact, the general population lies on this spectrum of psychosis, and in the general population, some people will have some tendencies to have delusions or hallucinations, and in some people this will be quite pronounced, and in other not so pronounced, even though they are functioning. The ventricles in the brain are enlarged for people with schizophrenia, so that is something that you can clearly see from an MRI image. But there are other things that are a bit harder to see, for example we know that white matter integrity is disrupted in people with schizophrenia, and you can’t see that immediately from doing a brain scan, but with a lot of processing that data, then you can eventually see this information emerging.

Kirsten MacGregor

What do you mean ‘white matter integrity’? What does that mean?

Dr Marta Garrido

Our brains are connected through white matter, and people with schizophrenia seem to have a loss of this white matter, so they will have less myelin, which is this sheet covering neurons.

Kirsten MacGregor

So you’re trying to use brain scans to detect schizophrenia earlier in the process? Is that where we’re at?

Dr Marta Garrido

Yeah, so with this idea of the continuum, or the spectrum of psychosis, we are hoping to get people who are at the end of this spectrum and who are, for that reason, at a higher risk of developing schizophrenia. But the good thing is that they haven’t really developed it yet, so they’re not taking medication, so we don’t have all the confounds of, is what we’re seeing due to the pathology or is it due to the medication, which we know has a lots of side effects as well the things that we hope that they are doing by curing. 

So by looking at what is happening early on in time, we might be able to anticipate the conversion to florid psychosis.

Kirsten MacGregor

It’s quite a compelling notion that we might be able to see mental illness though, can you see the appeal of that?

Dr Marta Garrido

See mental illness in images?

Kirsten MacGregor

On the brain scan.

Dr Marta Garrido

[laughs] So I don’t know what mental illness is – I know what brain illness is, so I would actually prefer to talk about brain illness rather than mental illness.

Kirsten MacGregor

Why is that an important distinction for you?

Dr Marta Garrido

Because I can see brains, I can’t see the mind. I can see biology that is objective and concrete, mental is kind of a little bit obscure, and also because if there is a biological cause, I think the stigma goes away. Like with any other body disease, with diabetes, with anything, also with Alzheimer’s, now we know a lot more about the biological causes, and I think that is actually quite important, because it is taking away the stigma, you know, it’s about something happening in the brain.

Kirsten MacGregor

Just generally though, what sort of roles might brain scans play in the future of neuroscience?

Dr Marta Garrido

I think it is very, very promising. Brain scans have been around for about thirty years, and we know really a lot more than we knew before about the human brain, and things like coming up with objective biological diagnoses for things, like schizophrenia, or other brain diseases, is really a promising endeavour. I also think that there are other techniques we could think about which are perhaps even more accessible than MRIs, and those are things like electroencephalogry, or EEG.

Kirsten MacGregor

That’s the cap you wear on your head?

Dr Marta Garrido

Yeah, that’s right, so you wear a cap on the head, and then you put some electrodes that you glue in temporarily, then with this you can measure the brain waves so the electric activity that is generated by your brain while you receive stimuli in the environment or execute an action. So with this technique, you don’t have the same images of the brain as such as you do with MRI, but you can see with a very, very fine temporal resolution what’s going on with the brain at a very, very fast pace, and with this technique we’ve been able to make some advances as well in terms of trying to find biomarkers specifically for schizophrenia.

Kirsten MacGregor

Like every neuroscientist I’ve met, you light up when you’re talking about the brain.

Dr Marta Garrido.

Yes.

Kirsten MacGregor

I think the wonder of it is something that is absorbing to neuroscientists. Are you aware of lighting up when talking about the brain? Is that what drives you?

Dr Marta Garrido

Yes, absolutely, I just love it, every time of the day. [laughs]. Yes, I love what I do and I love brains, and I think it’s the most fascinating thing I could ever study. I actually trained in physics, so I didn’t think I was going to be a neuroscientist until later on, but when I discovered MRI and EEG and the brain, I thought, oh my God, this is it, I love it, I would marry this [both laugh] for the rest of my life.

Kirsten MacGregor

So, crystal ball time now, particularly in terms of schizophrenia, what do you think we might see in terms of medical advances in the next decade or so?

Dr Marta Garrido

Well, I would love to see an objective diagnosis. I would love to see that we can, like we do with diabetes, and so many other diseases, do a blood test, or, you know, and we can, from that biological objective concrete test, we can make a prediction, and I would love to see that happening with brain disease.

[MUSIC]

Kirsten MacGregor

That’s Dr Marta Garrido, group leader at the Queensland Brain Institute. You can find out more about Marta, or QBI, at our website, or by following us on Twitter, Facebook, or Instagram. Thanks for your company.



Presented by Kirsten MacGregor. Produced and edited by Jessica McGaw and Donna Lu. 

A Grey Matter is the Queensland Brain Institute's podcast about neuroscience. It features music from Incompetech, available under a Creative Commons Attribution-Noncommercial license.

Music used
‘There It Is’ by Kevin McLeod – bit.ly/1nW96tY