21 April 2020
Examination of the neural basis of psychotic-like experiences in adolescence during processing of emotional faces
We caught up with Dr Evan Papanastasiou from King's College London to find out why he chose CANTAB to examine the neural basis of psychotic-like experiences in adolescence during processing of emotional faces.
Can you tell us more about your research group?
This research was conducted as part of my PhD in Psychosis Studies, at the Institute of Psychiatry, Psychology and Neuroscience at King’s College London. As a member of the Cognition Schizophrenia and Imaging Laboratory (CSI Lab), I have developed a special interest in the link between cognition and schizophrenia. The CSI lab, headed by Professor Sukhi Shergill, specialises in studying cognition in various presentations of the psychosis spectrum, by employing state-of-the-art assessments and neuroimaging techniques.
The present research was conducted in collaboration with the IMAGEN study, a European research project examining how biological, psychological, and environmental factors during adolescence may influence brain development and mental health.
What is the rationale behind your study?
Occasional psychotic-like experiences (PLEs) are relatively common in healthy adults and adolescents, but when these experiences become highly frequent this can indicate the beginning of a psychotic illness. Late adolescence is a critical time for the onset of psychotic illness, as this is when psychotic symptoms typically begin to manifest. The aim of the study was to examine whether PLEs in adolescence are associated with altered activation of frontal and limbic areas of a brain network, which have shown perturbed activation during facial emotion processing in subjects with psychosis.
Which methods did you use?
To investigate long-term changes in brain activation, 298 healthy adolescents underwent functional magnetic resonance imaging, whilst performing a facial emotion processing task, at the age of 14 years old and again at 19 years old. Neurocognitive measures were obtained by employing the CANTAB battery, specifically the Affective Go/No-go Task, to complement our neuroimaging findings.
What are your key findings?
Adolescents with a higher frequency of PLEs at age 19, showed an enhanced response in right insular cortex and decreased response in right prefrontal, right parahippocampal and left striatal regions at the same age. Also, the same group showed a gradient of decreasing response to emotional faces with age, from 14 to 19 years, in the right parahippocampal region and left insular cortical area.
What are the implications of your study?
In accordance with a previous study of ours from the same population, our findings are consistent with the neurodevelopment model of psychosis, which advocates that abnormal brain development from early childhood through adolescence to adulthood can be linked to the development of psychosis. In addition, our present study emphasises the role of frontal and limbic areas in the aetiology of psychotic symptoms, in subjects without the illness phenotype and the confounds introduced by antipsychotic medication.
An improved understanding of these compensatory changes during adolescence would be very helpful in developing strategies to reduce the transition to illness.
Why did you choose CANTAB?
We were very lucky that CANTAB was the neurocognitive battery of choice for the IMAGEN study team. This battery offers a variety of cognitive tasks, which can be administered easily and reliably via a digital platform and can reveal a multitude of deficits in brain function, suitable to study a wide range of clinical and sub-clinical populations, including the prodromal psychosis phenotype.
What are the next steps for your research?
Biological markers (biomarkers) accompanied by PLEs, such as the ones discovered in this study, as well as our previous one, may prove useful for improving early diagnosis of psychotic illness. Currently there are no biomarkers for psychosis, but in the future there is hope to combine data from patient interviews, neuroimaging studies, and possibly genetic testing to increase the accuracy of predictive diagnoses.
Dr Evan Papanastasiou MD MSc PhD – King's College London