Welcome to the Oxford Psychiatry Podcast series. I'm Charlotte Allen, and today I'm here with Professor Catherine Hamah,
who's a professor of cognitive neuroscience and research fellow at Corpus Christi College.
She's also director of the Psychopharmacology and Emotional Research Lab here at the Department of Psychiatry.
And her research focuses on the psychological mechanisms of antidepressant
drug action by exploring drug effects on human models of emotional processing.
And I'm sure she'll tell us today a little bit more about what that means, a bit more about her current research.
Welcome, Governor. Thank you for coming today to talk to us. Before we talk about your research.
Could you tell me a bit about your career so far and how you ended up working in psychology and the boundary between psychology and psychiatry?
Sure. Yes. Well, thank you very much for having me on your podcast. And I started off studying experimental psychology at the University of York,
and I became particularly interested in how the brain works and how it could go
wrong and how we might be able to treat things that go wrong with the brain.
And then I decided to do a study looking at the role of dopamine and the effects of drugs that would be on dopamine and how
we process reward and pleasure and how we learn about these kinds of things to do with drugs like amphetamine or cocaine.
But then I was really interested in applying this same kind of background to human psychopharmacology and psychiatry and disorders like depression,
anxiety disorders and bipolar disorder.
And I was able to come here to Oxford as my first postdoctoral research position was working with Professor Clive Goodwin and Professor Philip.
I'm looking at the effects of an amino acid depletion in acutely unwell manic patients.
So that was a really interesting experience because I got the opportunity to be in psychiatry department for the first time in a psychiatric ward.
I got to learn about how to assess patients who were undergoing those kinds of experiences and looking for changes with this amino acid milkshake.
So that was a steep learning curve. And then I became particularly interested in how antidepressant drug treatments may work,
particularly this interface between psychology and psychiatry and pharmacology,
and really trying to understand how the drug treatments which are using these kinds of conditions,
affect how we deal with emotional information, how our brain responds to different types of emotional and social situations
in a way that can help us understand how these drug treatments are working.
And so since that time, I've seen that kind of line of research through a series of different types of roles.
I got a training fellowship from the Medical Research Council to set me off on that path and then a subsequent fellowship.
And I'm now here as a professor of cognitive neuroscience department parliament.
That's really interesting. Thank you. This what inspired you to embark on this research career?
I think it started from a very basic interest in the brain being this complete mystery and
knowing very little about the brain and what happens when different things go wrong in the brain.
And it seems to me really uncharted territory and also in a way that might be particularly useful to
human health when things go wrong in the brain or when people suffer from mental health disorders,
there are treatments available, but they're not perfect and treatments.
And so I think it's it's a much needed area to try and develop and understand how treatments are working so
we can develop new ones and improve the overall treatment of all of these different kinds of disorders.
And so I think for me,
it's a combination of being a very exciting and research trajectory with lots of unanswered questions and lots of things to find out about.
Every day is different, but also it's research within a very applied setting with the real aim is to try and improve and treatment for people,
particularly with depression and mood disorders and anxiety disorders.
And so I think that that is a it's a really exciting and much needed area that kind of keeps me going and getting out of bed in the morning.
Yes, it is a valuable thing to do. Yes. And could you say a bit more about what you've done so far with your research about what your findings were,
how the antidepressants do work, actually? Yes.
So when we started taking antidepressant drug action, the most often viewed with antidepressants work by reversing chemical imbalances in the brain.
So things like serotonin were thought to be important in depression and how drug treatments work.
And so if you went along to the doctor or your friends, how how my treatment has my treatment working, most people would answer that kind of level.
It works by increasing level of serotonin in your brain, but it became clear that that's only really part of the answer.
It doesn't really tell you why increasing serotonin in your brain can help to treat them any different, often psychological symptoms of depression.
So feeling low, not having the same kind of pleasure in things that you normally enjoy, problems and concentration, anxiety.
It's not really clear how changing serotonin is leading to changes in those kinds of symptoms at the same time.
Psychologists often focus on negative biases in how we process information so that when we're depressed,
we know that we're more likely to focus on negative things that have happened or negative cues in the environment,
much more than we focus on positive keys. And we do this even when we're not noticing that we're picking up any information at all.
So very implicit ways of dealing with emotional information become much more negative when you're depressed.
So effectively, you're just receiving a lot more negative information without being aware of where it's coming from.
And we were able to put these two things together because we found that when we gave people an antidepressant,
the processing became a lot more positive. They were more likely to pick up on positive facial expressions of emotion.
They were more likely to remember positive words in a memory test.
And the interesting thing was that that happened without them noticing not they didn't feel any happier or any more positive at that stage.
And it also occurred very, very quickly. And we know that with antidepressants traditionally need to take the drugs for
a good few weeks before he noticed any change in your symptoms of depression.
But actually, this research showed that as soon as you take in the very first advanced depressant and it's been absorbed,
you can start to see the psychological changes. You feel any better.
But your your brain and your psychology is becoming shifted towards the more positive perspective.
And our hypothesis is that these changes in processing of what allows patients to feel better at the time,
as he starts taking more positive information, it starts to reinforce more positive views of yourself and your place in the world.
And this allows you to recover in interactions with things that are going on in your environment.
And so this really puts a very psychological view on how antidepressant drug treatments are working.
And it gives you all kinds of ideas about how you might facilitate the effects of antidepressants or how you might be able to test new ones,
or how you might be able to think about combining psychological treatments with drug treatments.
And so I think it's it's an interface of lots of different areas that hopefully by having this broader perspective,
we can give a better answer for how these drug treatments are working in a way that might help treatments in the future.
Certainly seems very helpful for patients to know about that and also for clinicians
who are prescribing drugs to know how their treatments might be being affected.
Yes, as you say, he can boost that with the psychological treatment than the latter.
Absolutely. And a lot of patients and clinicians have got to move up in presenting this work at conferences,
meetings and said it seems to ring true that actually you can start to see differences in patients, perhaps how they're interacting,
perhaps how they're smiling in response to things that the other people are doing that seem to suggest that the anti depressants,
it's not like a switch that's directly targeting your mood, per say, but it's affecting how you're taking in information.
And if you're taking in more positive information, you can respond to it even before you necessarily conscious of it.
So it certainly seems to me to be something that is that lines up with with what patients themselves have experienced,
as well as the clinicians treating them. Well, that's great.
What's your current research focussing on?
Well, we're we're continuing with this research, looking at the effects of antidepressants on emotional processing.
But we're particularly interested in if we can use this approach to predict who's likely to respond to antidepressant drug treatment.
So we know that there's a lot of variability in the response to different types of treatment.
Around 40 to 60 percent of patients will respond to any first given antidepressant treatment.
But the moment there's no real way.
Knowing who is likely to benefit from a particular treatment and because of the delay in seeing antidepressant effects,
this can often be a very long and frustrating experience for patients because they may try one antidepressant.
It doesn't work and they might have to try a different dose or a different type of antidepressant effectively through a process of trial and error.
So what we are interested in is that if these early changes in emotional processing are a mechanism by which the treatments are working,
then those patients that show really good changes,
early changes in emotional processing should be the ones who then go on and respond to the treatment in question.
And if you can tell that after just one dose, after a few days,
is that really dramatically reduces the waiting time for quite a dramatic effect on patients and their ability to get effective treatment.
So the aim is that it would result in speedier and more timely management of patients with depression.
And so if if you're a patient and you're experiencing these kinds of symptoms instead
of waiting effectively months before you find the right combination of treatments,
you could cycle through these different options much more quickly and effectively come up with the right balance of treatments and much more quickly.
And we know that the experience of depression is a very individual experience.
Not all treatments will work for everybody, and often it is about trying different things and different combinations,
different doses and and getting the best possible combination for each and every patient.
So one of the aims that we're currently working on is looking at these these early shifts in emotional processing as predictors of clinical response.
That sounds really useful and nice that the research is applicable in clinical practise and we'll have quite a major impact.
Yes. And I think the second potential application of that is that we're working together with pharmaceutical drug
companies to use these kinds of measures as screening tools for completely new types of treatment for depression.
So at the moment, most treatments target the same kinds of chemicals in the brain, particularly ones like serotonin and noradrenaline.
But there's lots of interest and lots of research on completely different types of target in the brain for depression.
And the key problem that pharmaceutical companies have is how to prioritise testing different treatments over one another.
There have been huge advances in the chemistry and biology of making new drug treatments,
but to actually effectively test it in a sample of depressed patients takes many years and many billions of pounds.
And what we hope to do is use these kinds of early markers as a way of screening new treatments that look
particularly promising and may therefore be fast tracked through to the full randomised clinical trial.
And I think this potentially this kind of approach may have a huge impact on how drug treatments are developed and particularly,
again, making these drug treatments available in a more timely manner.
And I think this could be a particularly exciting way forward because there is such a lot of new knowledge about new targets for depression.
And yet there's this real bottleneck in getting them tested out into the in the clinic and so we can prioritise which ones are the most important.
I think that this is another potential application of this kind of work.
Oh, I agree. It's a really exciting as a way forward thinking.
If people want to learn more about your research, particularly psychiatrist or psychologist interested in doing research,
how should they contact you or where can they find more information?
You can find more information on our in the Department of Psychiatry university page.
There's also a short video about some of this work with some pictures of the kinds of emotional stimulus stimuli that we use
in these kinds of studies on YouTube that you can have access to by typing something like Catherine Harmer and Depression.
And of course, everyone's very welcome to email me directly for more information.
And I can be very happy to send papers to meet people who are interested in doing this kind of research.
Great. Well, thank you very much for talking to me today. Thank you very much.
Thanks.