INTREPID (International Research Programme on Psychoses in Diverse Settings) III: Deepening and Broadening Knowledge of Psychoses Globally

What is the programme about?

Psychotic disorders are frequently distressing conditions in which people experience symptoms such as hallucinations (seeing or hearing things that are not there) and false thoughts or beliefs (delusions). These disorders usually begin at a young age (in the 20s) and often (but not always) lead to long term distress and suffering.

Around 20 million people worldwide experience a psychotic disorder. However, what we know about these disorders is based on research done mainly in Europe, North America, and Australia. We do not know much about these disorders in other places, especially in the Global South. This is a problem because it means we do not know how best to treat those with a psychotic disorder in most places.

Around 5 years ago, we started a programme of research to find out more about psychotic disorders in other places, specifically India, Nigeria, and Trinidad - chosen because they are very different from each other. In this, we identified and followed over time around 200 people with a psychotic disorder and 200 people without in each place. This work has already told us much we didn't know, which can be summarised as: there are differences across places in how common psychoses are, which groups are most affected, the typical age of onset, what factors increase risk, in physical health needs, and in short term outcomes (at 2 years).

There is, however, much we still don't know: Do differences in outcome continue, over the medium and long term? What about groups typically not included in research, e.g., those who are homeless with a psychosis? Why are there such wide variations? And what about other places - do we see the same things?

This current proposed programme builds on and extends the work already to answer these questions.

What will we do?

First, we will continue and expand our research India, Nigeria, and Trinidad. We will do this in two ways.

(1) We will follow all individuals included in our previous work at 6 years after their first participation. We will collect information from them about how their symptoms and other aspects of their lives have changed over time (including those aspects of their lives they feel are most important). We will compare this information by place and by group, to see if there are similar and other differences to what we have observed before.

(2) We will identify 60 more individuals with a psychotic disorder that have not been previously treated and 60 individuals without a psychotic disorder. This will allow us to look in more detail at some possible reasons why there are differences, e.g., perhaps because of differences in responses to stress, or differences in cognition, or differences in biological age (vs. actual age) - which may explain differences in physical health and mortality.

Second, we will create a web-based catalogue of all studies of psychoses using similar approaches to ours around the world and, where possible, combine their data sets to enable researchers to conduct comparisons across a wider range of places.

Third, we will work - in each setting in India, Nigeria, and Trinidad - with people with lived experience of psychosis, carers, and others such as service providers to develop new packages of interventions, tailored to the needs of each local setting. In future work, we will test and implement these interventions.

What will the programme tell us?

This programme will tell us more about how and why psychotic disorders differ between different countries and about how to intervene more effectively. Because we have so little information at the moment about these questions, our programme promises to have a big impact, both on our understanding of psychotic disorders and on how to intervene in more diverse settings.

Over 80% of the world's population live in the Global South, but less than 10% of research on psychotic disorders is done in these settings. There is widespread acknowledgment of the need for research on psychoses to extend to more diverse contexts. Building on our prior work in INTREPID I and II in India, Nigeria, and Trinidad, the next phase of INTREPID will contribute to this by delivering programmes of research (on medium term course and outcomes, homeless populations, and mechanisms of risk and relapse), by establishing a global platform for collaborative research on psychoses, and by implementing a structured set of activities in each setting to develop bespoke packages of interventions. Our programme will be informed and shaped throughout by lived experience. We will achieve this in a 5-year programme comprising 4 Workstreams (WS).

In WS1, we will follow at 6-years cohorts of cases (~ 200 per site) and controls (~ 200 per site), constructed as part of INTREPID II, and complete a comprehensive battery of assessments to test hypotheses concerning variations between and within sites in medium term course and outcome. In WS2, we will recruit a sample of new cases and controls to refresh the INTREPID II cohorts and to enable studies of 3 mechanisms: stress sensitivity, cognitive function, and biological ageing. In WS3, we will establish a global study catalogue and data sharing platform, with the goal of including all population-based studies of psychoses, providing a unique resource for the scientific community, facilitating collaboration and data sharing. In WS4, we will develop - with individuals with lived experience - bespoke interventions in each setting.

Our programme will have a substantial impact on (1) our knowledge of variations in outcomes, homeless populations, and mechanisms, (2) global research by providing a unique platform to facilitate collaboration and data sharing, and (3) provision of services and interventions in the Global South.