The PRECOGNITION Project
In this piece, we are excited to introduce a new project which we have been working on, called PRECOGNITION. We are Barbora Rehák Bučková and Giulia Cattarinussi, a statistician and a psychiatrist interested in predicting the onset and the course of psychosis. Our main goal is to build cognitive growth charts. These charts are similar to those used to track a child’s physical development. But rather than height and weight, we will track a person's cognitive development. Sounds complicated? It is, but let’s proceed step by step!
Cognitive impairments in psychosis
As you may already know, cognition is the set of thinking skills that enable us to understand, learn and solve problems. These are also commonly referred to as “thinking skills”. Cognitive impairments, including difficulties in memory, attention and problem-solving, are commonly seen in people with mental disorders. In psychosis, a severe mental illness characterised by loss of contact with reality, these deficits are frequently present early in the course of the disorder, sometimes even before symptoms start.
Cognitive impairments in psychosis have a dramatic impact on quality of life. For example, they might affect school performance or the ability to get and hold a stable job. As a consequence, cognitive impairments are very distressing, and they affect self-confidence and the everyday life of people with psychosis. This is a crucial issue since functioning in areas such as employment is considered by young people with psychosis to be a major treatment goal, even more important than the alleviation of psychotic symptoms, such as hearing or seeing things that others cannot hear or see (hallucinations) and believing things that are not actually real (delusions). In addition, we need to keep in mind that cognitive impairments in psychosis come with a huge burden for caregivers, as well as societal and economic costs.
We are now starting to understand that keeping track of changes in one’s thinking skills can help us catch and treat psychosis as soon as the first symptoms appear. However, even though we understand that someone developing psychosis will show changes in their thinking skills, these changes are also common in many other mental health disorders. This overlap makes it harder to accurately predict and treat psychosis.
Most research so far has focused on finding differences between groups of people with psychosis and those without. While we can see that thinking skills are different in people with psychosis compared to those without, these differences are often not clear enough to make a diagnosis of psychosis. It is like knowing that men are usually taller than women, but not being able to guess someone's biological sex just because they are 178 cm (5'10") tall.
To move the field forward, we need to improve our understanding of how our individual thinking skills develop and change over time. This will allow us to identify factors that vary across individuals and that aggregate and interact in complex ways, ultimately enabling us to understand and predict the course of psychosis. However the more intricate the changes, the more data we need to understand them. Thus, we have to tackle this problem by gathering more data and developing approaches that would help us understand the specifics of the condition for each person individually.
Normative models: Tracking growth to keep us healthy
Although new to neuroscience and psychiatry, the concept of 'normative models' has been used in other branches of medicine for quite some time. Many of you may be familiar with baby growth charts.
Once baby Lisa is born, a paediatric doctor assesses her weight and height. And because thousands of babies are born every day, scientists were able to estimate that while an average newborn weighs around 3.2 kg, only 3% of newborns weigh less than 2.3 kg.
As Lisa gets older, her weight and height increase. This is where the growth charts come into play. During periodic check-ups, a doctor can track how Lisa is doing compared to other children. She was born at an average weight; however, in two months she weighed half a kilogram less than what was expected based on her weight as a newborn. Noticing a difference from her “expected growth trajectory” the doctor can perform a deeper examination to eliminate the risk of disease. In short, having a reference of how our body or mind is expected to develop provides a powerful tool to monitor our health and indicate our “wellness”.
The idea of normative models of cognition follows the above principles. Unfortunately, unlike weight and height, it is more complicated to make a “growth chart” of cognition as it is much harder to measure. Hundreds of tests have been developed to quantify some aspects of cognition such as intelligence, memory, or attention but there is no single test best suited for this task. Moreover, different tests are measured in different circumstances in different countries, so we have to be very careful about how to combine information across them. Thus, our challenge is to unify and combine different tests to have a measure of cognition we can model. In other words, we would have a cognition analogue like Body Mass Index (BMI), a single number combining two other measures of weight and height.
The PRECOGNITION Project
The goals of the PRECOGNITION project are very ambitious! We first need to gather a lot of cognitive tests measured across different hospitals and countries to have a sample big enough to study and distil the best measures of cognition to be modelled. So far, we have collected data from four European countries (the Czech Republic, Denmark, Norway and the United Kingdom), and we are working to gather new data from other continents. Once we understand how cognition develops in healthy people, we can then study how psychosis disrupts those healthy processes. Ultimately, this knowledge could enable us to design mechanisms to catch those early signs and prevent the disease from progressing.
In addition, since we believe that the involvement of people with lived experience is crucial to conducting good research, we will have one-to-one interviews with people with lived experience of psychosis who have or have had problems with thinking skills, as well as focus groups with their caregivers. This will allow us to gain a wide range of perspectives and it will help us to determine the cognitive impairments and functional outcomes that are the most meaningful to people with psychosis.
You can find out more about our progress on our website, https://precognition-project.org/.
We will also be recruiting for one-to-one interviews with people with lived experience of psychosis and cognitive impairments and a focus group with their caregivers, so please feel free to email us at precognition@kcl.ac.uk if you would like more information.