Evidence suggests that there are cross-cultural variations in the distribution, presentation, aetiology, and outcome of psychotic disorders, although the majority of research on psychotic disorders has been conducted in a small number of high-income countries. This evidence may therefore give us a distorted view of these conditions, and it is unclear whether this knowledge base is generalisable to the rest of the world in order to develop locally appropriate services. Increasing the diversity of settings and populations in psychosis research can therefore provide new insights into psychotic disorders, but can also generate robust local data to inform service planning in contexts where evidence is currently scarce. INTREPID II is generating evidence in India, Nigeria and Trinidad, with regard to:
- Incidence, presentation and risk factors
- 2-year course and outcome
- Impact and help-seeking
- Physical health
Further, biological samples will investigate genetic biomarkers of psychosis.
There are major challenges to conducting this type of research in diverse settings where a large proportion of people with psychosis do not access formal mental health services. To ensure that the cohorts are as representative as possible, we have developed comprehensive case-finding methods that encompass the professional sector (e.g. mental health services), the folk sector (e.g. traditional and faith healers) and the popular sector (e.g key informants in the community).
Previous research has rarely included controls, to compare data from people with psychosis with local population norms, and so we have developed strategies for recruiting matched controls from the same local area. Attrition is another common problem encountered in existing research of this sort, and so the INTREPID teams are regularly checking in with participants and have trialled methods of reducing loss to follow-up. We have also established close coordination between the three sites to ensure that the data collected are directly comparable.