̽��ֱ�� of Cambridge - psychiatry

Simple blood test can help diagnose bipolar disorder

sc604 — Wed, 25 Oct 2023 15:00:00 +0000

̽��ֱ��researchers, from the ̽��ֱ�� of Cambridge, used a combination of an online psychiatric assessment and a blood test to diagnose patients with bipolar disorder, many of whom had been misdiagnosed with major depressive disorder.

̽��ֱ��researchers say the blood test on its own could diagnose up to 30% of patients with bipolar disorder, but that it is even more effective when combined with a digital mental health assessment.

Incorporating biomarker testing could help physicians differentiate between major depressive disorder and bipolar disorder, which have overlapping symptoms but require different pharmacological treatments.

Although the blood test is still a proof of concept, the researchers say it could be an effective complement to existing psychiatric diagnosis and could help researchers understand the biological origins of mental health conditions. ̽��ֱ��results are reported in the journal JAMA Psychiatry.

Bipolar disorder affects approximately one percent of the population – as many as 80 million people worldwide – but for nearly 40% of patients, it is misdiagnosed as major depressive disorder.

“People with bipolar disorder will experience periods of low mood and periods of very high mood or mania,” said first author Dr Jakub Tomasik, from Cambridge’s Department of Chemical Engineering and Biotechnology. “But patients will often only see a doctor when they’re experiencing low mood, which is why bipolar disorder frequently gets misdiagnosed as major depressive disorder.”

“When someone with bipolar disorder is experiencing a period of low mood, to a physician, it can look very similar to someone with major depressive disorder,” said Professor Sabine Bahn, who led the research. “However, the two conditions need to be treated differently: if someone with bipolar disorder is prescribed antidepressants without the addition of a mood stabiliser, it can trigger a manic episode.”

̽��ֱ��most effective way to get an accurate diagnosis of bipolar disorder is a full psychiatric assessment. However, patients often face long waits to get these assessments, and they take time to carry out.

“Psychiatric assessments are highly effective, but the ability to diagnose bipolar disorder with a simple blood test could ensure that patients get the right treatment the first time and alleviate some of the pressures on medical professionals,” said Tomasik.

̽��ֱ��researchers used samples and data from the Delta study, conducted in the UK between 2018 and 2020, to identify bipolar disorder in patients who had received a diagnosis of major depressive disorder within the previous five years and had current depressive symptoms. Participants were recruited online through voluntary response sampling.

More than 3000 participants were recruited, and they each completed an online mental health assessment of more than 600 questions. ̽��ֱ��assessment covered a range of topics that may be relevant to mental health disorders, including past or current depressive episodes, generalised anxiety, symptoms of mania, family history or substance abuse.

Of the participants who completed the online assessment, around 1000 were selected to send in a dried blood sample from a simple finger prick, which the researchers analysed for more than 600 different metabolites using mass spectrometry. After completing the Composite International Diagnostic Interview, a fully structured and validated diagnostic tool to establish mood disorder diagnoses, 241 participants were included in the study.

Analysis of the data showed a significant biomarker signal for bipolar disorder, even after accounting for confounding factors such as medication. ̽��ֱ��identified biomarkers were correlated primarily with lifetime manic symptoms and were validated in a separate group of patients who received a new clinical diagnosis of major depressive disorder or bipolar disorder during the study’s one-year follow-up period.

̽��ֱ��researchers found that the combination of patient-reported information and the biomarker test significantly improved diagnostic outcomes for people with bipolar disorder, especially in those where the diagnosis was not obvious.

“ ̽��ֱ��online assessment was more effective overall, but the biomarker test performs well and is much faster,” said Bahn. “A combination of both approaches would be ideal, as they’re complementary.”

“We found that some patients preferred the biomarker test, because it was an objective result that they could see,” said Tomasik. “Mental illness has a biological basis, and it’s important for patients to know it’s not in their mind. It’s an illness that affects the body like any other.”

“In addition to the diagnostic capabilities of biomarkers, they could also be used to identify potential drug targets for mood disorders, which could lead to better treatments,” said Bahn. “It’s an exciting time to be in this area of research.”

A patent has been filed on the research by Cambridge Enterprise, the ̽��ֱ��’s commercialisation arm. ̽��ֱ��research was supported by the Stanley Medical Research Institute and Psyomics, a ̽��ֱ�� spin-out company co-founded by Sabine Bahn.

Sabine Bahn is Professor of Neurotechnology at the Department of Chemical Engineering and Biotechnology and is a Fellow of Lucy Cavendish College, Cambridge.

Reference:
Jakub Tomasik et al. ‘Metabolomic Biomarker Signatures for Bipolar and Unipolar Depression.’ JAMA Psychiatry (2023). DOI: 10.1001/jamapsychiatry.2023.4096

Researchers have developed a new way of improving diagnosis of bipolar disorder that uses a simple blood test to identify biomarkers associated with the condition.

̽��ֱ��ability to diagnose bipolar disorder with a simple blood test could ensure that patients get the right treatment the first time

Jakub Tomasik

Cambridge Centre for Neuropsychiatric Research

Providing a drop of blood for a test

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“It’s been very humbling”: returning to the clinic during the pandemic

cjb250 — Mon, 04 May 2020 08:09:23 +0000

It’s been decades since Professor Paul Fletcher last donned scrubs, but he now finds himself helping treat psychiatric patients, sometimes in full protective gear, and learning that the best strategy is to “shut up and listen” to his colleagues.

Women in STEM: Anna Chaplin

sc604 — Thu, 09 Jan 2020 07:00:00 +0000

̽��ֱ��widespread applicability of my research is very appealing to me. Most people will be directly or indirectly affected by mental ill-health at some point in their lives. My research aims to understand the association between depression and cardiovascular health in young people.

My background is quite varied. I have a BSc in Biomedical Science and a Master’s in Biological Science (Pharmacology). I also have training in epidemiology and medical statistics. ̽��ֱ��start of the PhD was still a bit of a challenge as I had to teach myself how to code!

Cambridge is a scientific hub so there are always interesting talks or conferences to attend nearby. It’s a great place to carry out research because there are so many ongoing opportunities throughout the year. My department is particularly good at organising events as well as supporting its students during their studies.

I work on the Addenbrooke’s site and I spent most of my time analysing big data. I am working with two major UK datasets that contain long-term information of people’s health. A usual day for me consists of statistical analysis using these datasets to try and understand early life risk factors for depression. ̽��ֱ��analysis can get very complicated sometimes so I often spend time trying to create diagrams to represent what I have discovered in a clear way. Some of the most interesting days are when I present my work at meetings and get to discuss what I have found with lots of different people. ̽��ֱ��conversation often leads to exciting new ideas!

My advice to others is to trust in yourself. Be confident in your decision-making, be patient when learning new skills, and always put your mental health first.

Anna Chaplin is a PhD candidate in the Department of Psychiatry who studies the association between depression and cardiovascular health in young people. Here, she tells us about teaching herself to code, her department’s support of students, and putting your mental health first.

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New approach to drug discovery could lead to personalised treatment of neuropsychiatric disorders

erh68 — Wed, 08 May 2019 18:00:00 +0000

Mental health disorders are the leading cause of disability worldwide, accounting for 31% of total years lived with disability. While our understanding of the biology behind these disorders has increased, no new neuropsychiatric drugs with improved treatment effects have been developed in the last few decades, and most existing treatments were found through luck.

This is mainly because doctors can’t take brain tissue samples from patients in the same way that they are able to do a biopsy on a cancer tumour elsewhere in the body for example, so it’s difficult for researchers to understand exactly what to target when designing new neuropsychiatric drugs.

Now, a team of scientists led by the ̽��ֱ�� of Cambridge have shown that live blood cells from patients with mental health disorders can be used to identify potential targets for drug discovery research. Their results are reported in the journal Science Advances.

Human blood cells contain many receptors and proteins involved in signalling that are also found in our central nervous system and have been shown to be linked to neuropsychiatric disorders. Previous research has shown that there is a strong link between cells in our blood and the way our central nervous system operates, for example patients suffering from bacterial infections often show depressive-like symptoms.

This makes blood cells an ideal environment in which to test potential new drugs. There is also significant evidence that using primary cells from patients in drug development leads to a higher success rate for effective drug discovery.

“Psychiatric disorders are increasingly recognised as disorders of the whole body,” said Professor Sabine Bahn from Cambridge’s Department of Chemical Engineering and Biotechnology, who leads the research group behind the work. “This study proposes a shift in the field to directly explore live cellular function as a model for disease.”

Using a high-content single-cell screening process, the researchers analysed cells from 42 schizophrenia patients and screened thousands of potential compounds for new drugs. ̽��ֱ��team have focused on discovering new psychiatric uses for drugs which are routinely prescribed for other conditions, such as high blood pressure.

This drug ‘repurposing’ strategy can reduce the time and cost it takes to bring a new drug to the clinic tenfold. With an average drug development cost of $2-3 billion over 12 years, this represents an efficient alternative to deliver new potential treatments to patients in considerably less time. ̽��ֱ��approach could also lead to a reduction in animal testing.

They can also test existing psychiatric treatments on patient blood cells and may be able to predict how effective those treatments will be for each individual. This overcomes a major hurdle in clinical psychiatry as many patients do not respond to first-line treatments. To accomplish this, the team tested rare blood samples from schizophrenia patients before and after clinical treatment, collected via a network of international collaborators.

As a final step, the team confirmed that the activity of new drugs was shared between blood cells and brain cells, by testing those drug compounds on human nerve cells.

“This is the most in-depth, functional exploration of primary psychiatric patient tissue to date and has the potential to substantially accelerate drug discovery and personalised medicine for neuropsychiatric disorders and other human diseases,” said lead author Dr Santiago Lago, who developed the technology with Dr Jakub Tomasik.

̽��ֱ��research was funded in part by the Stanley Medical Research Institute, the Engineering and Physical Sciences Research Council and the European Union.

Reference:
Santiago G. Lago et al. ‘Drug discovery for psychiatric disorders using high-content single-cell screening of signalling network responses ex vivo.’ Science Advances (2019). DOI: 10.1126/sciadv.aau9093

Researchers have developed a method that could drastically accelerate the search for new drugs to treat mental health disorders such as schizophrenia.

Psychiatric disorders are increasingly recognised as disorders of the whole body

Sabine Bahn

Santiago Lago

Drug target in neurons

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State of Madness: Psychiatry, Literature, and Dissent After Stalin

sjr81 — Thu, 25 Apr 2019 08:02:57 +0000

Towards the end of the 1960s, rumours began to spread that nonconformist citizens of the USSR were being diagnosed with mental illnesses and confined to psychiatric hospitals.

Carrots and sticks fail to change behaviour in cocaine addiction

cjb250 — Thu, 16 Jun 2016 18:00:35 +0000

“Addiction does not happen overnight but develops from behaviour that has been repeated over and over again until individuals lose control,” said Dr Karen Ersche from the Department of Psychiatry, who led the research.

In a study reported today in the journal Science, Dr Ersche and colleagues tested 125 participants, of whom 72 were addicted to cocaine and 53 had no history of drug addiction, on their inclination to develop habits. They found that people with cocaine addiction were much more likely than healthy participants to make responses in an automatic fashion, but only if they had previously been rewarded for responding in the same way. ̽��ֱ��addicted individuals simply continued repeating the same responses they had previously learned, regardless of whether their actions made sense or not.

In a different context, however, where participants had to perform an action to avoid electrical shocks, people with cocaine addiction did not develop habits. In fact, they were much less inclined than the control participants to make an effort to avoid the electric shock in the first place.

“Our experiments highlight the particular difficulties faced when it comes to changing behaviour in people with cocaine addiction: they are highly responsive if their behaviour is rewarded – for example a ‘high’ from drug use – but then quickly switch to autopilot, becoming unable to change that behaviour in light of different consequences,” said Dr Ersche. “By contrast, when cocaine users are facing adversity, they are less inclined than healthy people to do something about it.

“These findings have significant implications for the treatment of people with cocaine addiction. Clearly punitive approaches are ineffective, as the prospect of something bad happening to them won’t make cocaine users more likely to change their behaviour. Interventions that build on their particular strength in developing habits, by training the implementation of more desirable habits to replace drug-taking habits, are likely to be more effective. Our findings also suggest that cocaine users would need to be actively protected from – rather than simply warned about – adverse consequences, because they will likely fail to avoid them if left to their own devices.”

There is currently no medical treatment for cocaine addiction – most individuals are treated with talking or cognitive therapy. According to Dr Ersche, the results show that a different approach to treating cocaine addiction might be of enhanced benefit to cocaine users. ̽��ֱ��researchers are now aiming to better understand the brain systems underlying cocaine users’ proneness to habits and their lack of avoidance, and to use this knowledge to develop more effective treatments for cocaine addiction.

In the first experiment conducted by Ersche and her colleagues, participants were asked to learn the relationship between pictures, and a correct response was rewarded with points. After a long training period, participants were informed that some pictures were no longer worth any points. Participants with cocaine addiction were less likely to take on board the information about the change in reward, and were also more likely to continue responding in an automatic way, regardless of whether they were rewarded or not.

In a second experiment, the same participants were shown two different pictures on a screen, which they learned to associate with receiving an electric shock. Participants were then taught a strategy on how they could avoid the shocks by pressing a foot pedal. Those participants with cocaine addiction were less good at avoiding the electric shocks in the first place, possibly due to learning and/or motivational impairment, and subsequently did not develop avoidance habits.

̽��ֱ��work was funded by the Medical Research Council and was conducted at the NIHR Cambridge Biomedical Research Centre and the Behavioural and Clinical Neuroscience Institute.

Reference
Ersche, KD et al. Carrots and sticks fail to change behavior in cocaine addiction. Science; 17 Jun 2016; DOI: 10.1126/science.aaf3700

People who are addicted to cocaine are particularly prone to developing habits that render their behaviour resistant to change, regardless of the potentially devastating consequences, suggests new research from the ̽��ֱ�� of Cambridge. ̽��ֱ��findings may have important implications for the treatment of cocaine addiction as they help explain why such individuals take drugs even when they are aware of the negative consequences, and why they find their behaviour so difficult to change.

CB Du Rietz

Sträng

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Living with adversity: What Tupac and Eminem can tell us about risk factors for mental health

cjb250 — Tue, 12 Apr 2016 08:40:56 +0000

Tupac Shakur and Eminem are often touted as two of the greatest rappers of all time. While Tupac, who was shot dead in 1996, is African American and Eminem is Caucasian, their lyrics have similar narrative story telling styles that are filled with anguished suffering and anger conveyed in their hip-hop songs. ̽��ֱ��characters they portray in their lyrics are often surrounded by challenging environments – alcohol and drug addiction, parental abuse and gun crime, for example.

Two songs that describe important issues of adversity reflecting strong emotional turmoil in their lyrics are ‘Death around the corner’ from Tupac Shakur’s album, ‘Me Against ̽��ֱ��World’, and ‘Cleaning out my closet’ by Eminem from his album, ‘ ̽��ֱ��Eminem Show’. In both songs, whether knowingly or unwittingly, the artists’ characters reveal many of the symptoms of mental illness – and also paint a picture that suggests why these problems have arisen.

In ‘Death around corner’, Tupac portrays a fictional character preoccupied with paranoia about a perceived threat to his own life and to his family. He feels the need to protect himself and his family from perceived targeted violence.

Straight away, the song opens with a skit, a dialogue between Tupac’s character, his partner, and their son. Tupac’s character is standing by the window with an AK47 firearm. His son is confused about his father’s strange behaviour and his wife is exasperated with her partner and feels he is consumed by his paranoia. She refers to Tupac’s character as “being crazy” and notes that he is neglecting his family (“you don’t work…you don’t do a…thing”). It is apparent that she does not share his concerns about their family’s safety and appears very irritated that he is preoccupied by his worries. What is particularly concerning is that the character – who is likely paranoid without justification – is carrying a potentially loaded gun at home whilst a vulnerable child and partner present and witnessing this behaviour.

̽��ֱ��first verse makes reference to his need to stay ‘high’, probably through use of either a stimulant or cannabis, which are both risk factors for developing psychosis and paranoia.

̽��ֱ��character describes his harsh urban environment as being where the “skinny” people “die” – in other words, where the weak are killed or exploited. ̽��ֱ��environment appears to be a place where vulnerable individuals can develop social defeat, which research has shown is a risk factor for psychosis.

Tupac’s character alludes to his daddy being “madder than a motherfucker”, which may indicate that the character has an increased risk of developing psychosis due to genetic factors, as we know people with a family history – particularly a parent or sibling – are at increased risk. He subsequently goes to bed “with my pistol in my sheets” due to feeling paranoid.

In the first verse, Tupac mentions his character’s use of “endo” (cannabis) and how it relieves his stress and paranoia. In the next verse, though, he mentions how smoking “…too much weed got me paranoid, stressed”. Is he contradicting himself here? Not necessarily: it depends on the type of cannabis that Tupac’s character has smoked which could explain both the increases in his paranoia and his relief from it – while some forms of cannabis are relatively benign, others, such as ‘skunk’, have been shown to increase the risk of psychosis.

Later, Tupac goes on to describe how his character was “raised in the city, shitty” at an early age, “drinking liquor out my momma’s titty” (a reference to his mother’s excessive alcohol use during early childhood whilst breast feeding), and possibly being exposed to second-hand cannabis smoke from an early age. All these risk factors highlight a chaotic household, which may have had an adverse effect on his developing brain – again leading to the development of psychosis in later life.

It’s clear from these lyrics that Tupac’s character has a family history of psychosis, that he abuses stimulants or cannabis, and that he lives in a harsh environment. All of these factors we know alter an individual’s brain chemistry and in particular how it responds to the key neurotransmitter dopamine, which research has shown leads people to fixate on or give too much emphasis to things in our environment or within our own thoughts, feelings or senses – and hence drive mental health issues such as paranoia and psychosis.

There is another way of looking at Tupac’s character, though: it’s possible that he is experiencing some form of Post Traumatic Stress Disorder (PTSD) following experiencing and witnessing life threatening situations from living in a violent hood “..I guess I seen too many murders…”. His behaviour certainly seems to match some of the common symptoms for PTSD: the frequent looking out of the window and paranoia could be seen as hypervigilance and hyperarousal which are prominent symptoms. His mention of seeing death around the corner could be referencing intensive flashbacks, ‘reliving’ of murders he has witnessed, and his use of “weed” might reflect the use of cannabis for ‘self-medication’.

Eminem’s song 'Cleaning out my closet' follows a similar trend of highlighting early adverse experiences. ̽��ֱ��song deals with Eminem’s angst against his mother.

In the first verse, Eminem highlights how he can’t keep his emotion in check and describes them as “the oceans exploding” attributing it to his parents relationship, their “tempers flaring”.

̽��ֱ��chorus indicates that Eminem wishes to exorcise his emotional demons by voicing his angst in his lyrics. He uses the metaphor “but tonight I’m cleaning out my closet” to acknowledge that he would rather reveal his “skeletons” than allow them to eat away at him.

It appears he is trying to reach out to listeners as though they are psychotherapists. His character discloses his secrets in order to feel free from torment. Sigmund Freud described depression as anger turned inwards, often towards traumatic childhood experiences, hence we can see Eminem’s psychotherapy with the listeners as an opportunity to let go of the buried anger in an attempt to protect himself from depression.

̽��ֱ��rest of the second verse involves Eminem making accusations against his detached, absent father, and Eminem promises to be different by being present for his daughter. It also reveals Eminem avoiding killing his ex-girlfriend and her partner (for the sake of his daughter), therefore he’s able to control his angry impulses.

̽��ֱ��next verse explores his mother’s addiction to prescription pills, which echoes Eminem’s self-declared battle with addiction to prescription pills. This also highlights his increased risk of substance misuse partly due to his familial genetic predisposition.

Eminem’s character accuses his mother of Munchausen’s syndrome by proxy – where a mother fakes her child’s symptoms (or even worse, causes real symptoms) to make the child seem sick – describing himself as a “victim of Munchausen’s syndrome”. In this syndrome, it is believed that the intention of the caregiver is to gain attention and to receive commendation as the rescuer of the child for saving the child in their care from the illness. They do this to fulfill their need for attention by placing the sick role on to their child.

Eminem ends the song by accusing his mother of being jealous of his success and reveals his intention of not allowing her access to his daughter to protect her from becoming a victim of the abuse he experienced.

Interestingly, in a song released by Eminem later in 2013, entitled ‘Heights’, he regrets these harsh views toward his mother as previously written in ‘Cleaning out my closet’ and instead acknowledges his mother’s difficulty raising him as a single parent.

̽��ֱ��suffering and painful feelings revealed by Tupac and Eminem’s characters offer us a valuable insight to examine mental health themes related to psychosis and social adversity. By utilising the interests of individuals who listen to hip-hop music – especially young people – we aim to enhance their understanding about mental health by delivering medical information in a context-enhanced manner. Perhaps this urban influenced approach will help empower and encourage individuals to examine what adversity is around the corner for them personally, and to explore what risk factors may still be locked away in their own closets.

Hip-hop artists Tupac and Eminem are among the most iconic music artists of the past two decades, and as Dr Akeem Sule and Dr Becky Inkster, co-founders of HIP-HOP-PSYCH, write, their lyrics can provide a valuable insight into the lives of some of the people most at risk of developing mental health issues.

̽��ֱ��suffering and painful feelings revealed by Tupac and Eminem’s characters offer us a valuable insight to examine mental health themes related to psychosis and social adversity.

Eminem - Cleanin' Out My Closet

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How hallucinations emerge from trying to make sense of an ambiguous world

cjb250 — Mon, 12 Oct 2015 19:00:41 +0000

Take a look at the black and white image. It probably looks like a meaningless pattern of black and white blotches. But now take a look at the image at the bottom of this article and then return to the black and white picture: it’s likely that you can now make sense of the black and white image. It is this ability that scientists at Cardiff ̽��ֱ�� and the ̽��ֱ�� of Cambridge believe could help explain why some people are prone to hallucinations.

A bewildering and often very frightening experience in some mental illnesses is psychosis – a loss of contact with external reality. This often results in a difficulty in making sense of the world, which can appear threatening, intrusive and confusing. Psychosis is sometimes accompanied by drastic changes in perception, to the extent that people may see, feel, smell and taste things that are not actually there – so-called hallucinations. These hallucinations may be accompanied by beliefs that others find irrational and impossible to comprehend.

In research published today in the journal Proceedings of National Academy of Sciences (PNAS), a team of researchers based at Cardiff ̽��ֱ�� and the ̽��ֱ�� of Cambridge explore the idea that hallucinations arise due to an enhancement of our normal tendency to interpret the world around us by making use of prior knowledge and predictions.

In order to make sense of and interact with our physical and social environment, we need appropriate information about the world around us, for example the size or location of a nearby object. However, we have no direct access to this information and are forced to interpret potentially ambiguous and incomplete information from our senses. This challenge is overcome in the brain – for example in our visual system – by combining ambiguous sensory information with our prior knowledge of the environment to generate a robust and unambiguous representation of the world around us. For example, when we enter our living room, we may have little difficulty discerning a fast-moving black shape as the cat, even though the visual input was little more than a blur that rapidly disappeared behind the sofa: the actual sensory input was minimal and our prior knowledge did all the creative work.

“Vision is a constructive process – in other words, our brain makes up the world that we ‘see’,” explains first author Dr Christoph Teufel from the School of Psychology at Cardiff ̽��ֱ��. “It fills in the blanks, ignoring the things that don’t quite fit, and presents to us an image of the world that has been edited and made to fit with what we expect.”

“Having a predictive brain is very useful – it makes us efficient and adept at creating a coherent picture of an ambiguous and complex world,” adds senior author Professor Paul Fletcher from the Department of Psychiatry at the ̽��ֱ�� of Cambridge. “But it also means that we are not very far away from perceiving things that aren’t actually there, which is the definition of a hallucination.

“In fact, in recent years we’ve come to realise that such altered perceptual experiences are by no means restricted to people with mental illness. They are relatively common, in a milder form, across the entire population. Many of us will have heard or seen things that aren’t there.”

In order to address the question of whether such predictive processes contribute to the emergence of psychosis, the researchers worked with 18 individuals who had been referred to a mental health service run by the NHS Cambridgeshire and Peterborough Foundation Trust, and led by Dr Jesus Perez, one of the co-authors on the study, and who suffered from very early signs of psychosis. They examined how these individuals, as well as a group of 16 healthy volunteers, were able to use predictions in order to make sense of ambiguous, incomplete black and white images, similar to the one shown above.

̽��ֱ��volunteers were asked to look at a series of these black and white images, some of which contained a person, and then to say for a given image whether or not it contained a person. Because of the ambiguous nature of the images, the task was very difficult at first. Participants were then shown a series of full colour original images, including those from which the black and white images had been derived: this information could be used to improve the brain’s ability to make sense of the ambiguous image. ̽��ֱ��researchers reasoned that, since hallucinations may come from a greater tendency to superimpose one’s predictions on the world, people who were prone to hallucinations would be better at using this information because, in this task, such a strategy would be an advantage.

̽��ֱ��researchers found a larger performance improvement in people with very early signs of psychosis in comparison to the healthy control group. This suggested that people from the clinical group were indeed relying more strongly on the information that they had been given to make sense of the ambiguous pictures.

When the researchers presented the same task to a larger group of 40 healthy people, they found a continuum in task performance that correlated with the participants’ scores on tests of psychosis-proneness. In other words, the shift in information processing that favours prior knowledge over sensory input during perception can be detected even before the onset of early psychotic symptoms.

“These findings are important because they tell us that the emergence of key symptoms of mental illness can be understood in terms of an altered balance in normal brain functions,” says Naresh Subramaniam from the Department of Psychiatry at the ̽��ֱ�� of Cambridge. “Importantly, they also suggest that these symptoms and experiences do not reflect a ‘broken’ brain but rather one that is striving – in a very natural way – to make sense of incoming data that are ambiguous.”

̽��ֱ��study was carried out in collaboration with Dr Veronika Dobler and Professor Ian Goodyer from the Department of Child and Adolescent Psychiatry at the ̽��ֱ�� of Cambridge. ̽��ֱ��research was funded by the Wellcome Trust and the Bernard Wolfe Health Neuroscience Fund. It was carried out within the Cambridge and Peterborough NHS Foundation Trust. Additional support for the Behavioural and Clinical Neuroscience Institute at the ̽��ֱ�� of Cambridge came from the Wellcome Trust and the Medical Research Council.

Reference
Teufel, C et al. Shift towards prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals. PNAS; 12 Oct 2015

Why are some people prone to hallucinations? According to new research from the ̽��ֱ�� of Cambridge and Cardiff ̽��ֱ��, hallucinations may come from our attempts to make sense of the ambiguous and complex world around us.

August Natterer

Meine Augen zur Zeit der Erscheinungen

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