The effect of abnormal structural and functional resting-state connectivity in prefrontal cortex and increased exposure to traffic-related air pollutants on schizotypy = 前額葉灰質量及功能性連結和交通有關的空氣污染物對精神分裂型人格特質的影響
Project title
The effect of abnormal structural and functional resting-state connectivity in prefrontal cortex and increased exposure to traffic-related air pollutants on schizotypy = 前額葉灰質量及功能性連結和交通有關的空氣污染物對精神分裂型人格特質的影響
Principal Investigator
Department
Grant Awarding Body
Research Grants Council
Grant Type
Faculty Development Scheme
Project Code
UGC/FDS15/H06/22
Amount awarded
HK$1,353,283
Funding Year
2022-2023
Duration of the Project
30 months
Status
On-going
Abstract
Background: Schizotypal personality traits (schizotypy) increase the risk of schizophrenia, thereby increasing the burden on the healthcare system. Mounting evidence has found reduced prefrontal cortex (PFC) gray matter volumes (GMV) and abnormal resting-state functional connectivity (rsFC) in schizophrenia. Additionally, exposure to increasing levels of traffic-related harmful pollutants (TRAPs), particularly nitrogen dioxide (NO2), is found to have a detrimental impact on schizophrenia. Furthermore, reduced prefrontal GMV and rsFC in schizophrenia is associated with exposure to these TRAPs. However, the mediation effect of environmental factors on schizotypy via PFC correlates remains unanswered.
Pilot findings: In 104 youth, exposure to NO2 levels was significantly and positively related to schizotypy after controlling for covariates.
Aims: This study aims to examine the relationship between environmental factors (NO2) and neural correlates (PFC GMV and rsFC) of schizotypy, and the mediation effect of NO2 on schizotypy via reduced PFC GMV and rsFC with a two-year longitudinal research design. Method: 130 non-clinical participants and 30 clinical patients with psychosis will be recruited from the PI’s cohort study. Sociodemographic information, psychosocial variables (e.g., loneliness and physical activity), behavioral and environmental estimates, as well as structural brain scans using magnetic resonance imaging will be assessed at baseline and one-year and two-year follow-ups. The primary behavioral assessment includes the Schizotypal Personality Questionnaire, which measures schizotypy. Environmental assessments include neighborhood-based estimates (e.g., greenspace density) computed within a radius of 300 meters surrounding the participant’s home. Estimates of individual exposure to TRAPs will also be measured. These data will be measured at four time-points in two years in order to control for any potential temporal variations due to seasonal change.
Predicted results: Both exposure to NO2 levels and PFC GMV and rsFC are hypothesized to predict levels of schizotypy respectively after controlling for covariates. Moreover, exposure to increased NO2 levels is hypothesized to predict reduced PFC GMV and rsFC and higher levels of schizotypy at the one-year and two-year follow-ups respectively while there will be no significant changes in these two variables for those with a lower level of NO2 exposure. Furthermore, more exposure to NO2 at baseline is hypothesized to predict smaller PFC GMV and reduced rsFC, which in turn lead to higher levels of schizotypy at the one-year and two-year follow-ups. These effects are predicted to be more significant in the high schizotypy individuals.
Implications: Hypothesized findings, which could show the mediating effect of increased NO2 exposure on schizotypy via reduced PFC GMV and rsFC, will have both theoretical and clinical implications. For instance, policymakers may adopt environmental measures to reduce NO2 emissions in Hong Kong in order to enhance prefrontal functioning and reduce schizotypy in youth, thereby preventing them from developing schizophrenia spectrum disorders.
Pilot findings: In 104 youth, exposure to NO2 levels was significantly and positively related to schizotypy after controlling for covariates.
Aims: This study aims to examine the relationship between environmental factors (NO2) and neural correlates (PFC GMV and rsFC) of schizotypy, and the mediation effect of NO2 on schizotypy via reduced PFC GMV and rsFC with a two-year longitudinal research design. Method: 130 non-clinical participants and 30 clinical patients with psychosis will be recruited from the PI’s cohort study. Sociodemographic information, psychosocial variables (e.g., loneliness and physical activity), behavioral and environmental estimates, as well as structural brain scans using magnetic resonance imaging will be assessed at baseline and one-year and two-year follow-ups. The primary behavioral assessment includes the Schizotypal Personality Questionnaire, which measures schizotypy. Environmental assessments include neighborhood-based estimates (e.g., greenspace density) computed within a radius of 300 meters surrounding the participant’s home. Estimates of individual exposure to TRAPs will also be measured. These data will be measured at four time-points in two years in order to control for any potential temporal variations due to seasonal change.
Predicted results: Both exposure to NO2 levels and PFC GMV and rsFC are hypothesized to predict levels of schizotypy respectively after controlling for covariates. Moreover, exposure to increased NO2 levels is hypothesized to predict reduced PFC GMV and rsFC and higher levels of schizotypy at the one-year and two-year follow-ups respectively while there will be no significant changes in these two variables for those with a lower level of NO2 exposure. Furthermore, more exposure to NO2 at baseline is hypothesized to predict smaller PFC GMV and reduced rsFC, which in turn lead to higher levels of schizotypy at the one-year and two-year follow-ups. These effects are predicted to be more significant in the high schizotypy individuals.
Implications: Hypothesized findings, which could show the mediating effect of increased NO2 exposure on schizotypy via reduced PFC GMV and rsFC, will have both theoretical and clinical implications. For instance, policymakers may adopt environmental measures to reduce NO2 emissions in Hong Kong in order to enhance prefrontal functioning and reduce schizotypy in youth, thereby preventing them from developing schizophrenia spectrum disorders.