Characterizing Response to Antipsychotics in Schizophrenia

Overview

The goal of this research project is to develop MRI-based biomarkers to identify patients with schizophrenia who are most likely to benefit from first-line antipsychotic or clozapine treatment. The MRI sequences (NM-MRI, MRS and rsfMRI) will be created by translating the best scientific evidence into a potential clinical product that has the highest chance of being clinically relevant predictor of treatment response. This study has the potential to significantly improve patient outcomes and reduce unnecessary interventions and costs at the Royal's Integrated Schizophrenia Recovery Program.

Currently, we cannot predict who will get better on first-line antipsychotic versus clozapine treatment. Although much evidence shows that dopamine and glutamate function are related to treatment response in schizophrenia, the utility of neuromelanin sensitive MRI (NM-MRI) as a measure of dopamine and magnetic resonance spectroscopy (MRS) as a measure of glutamate \& glycine (a co-agonist of glutamate receptors) in predicting response to treatment have never been measured in the same sample. The evidence suggests that the function of these two neurotransmitter systems partially determines the response to antipsychotic medications. Additionally, an emerging type of resting-state functional MRI (rsfMRI), naturalistic movie-watching, has been shown to outperform traditional rsfMRI for functional connectivity-based prediction of behaviour and will be explored in the current study. Given the background information, our hypotheses are: 1.1) First-line antipsychotic users will have higher dopamine turnover resulting in a higher NM-MRI signal in the substantia nigra relative to clozapine users. 1.2) First-line antipsychotic users will have lower glutamate and/or glycine concentration as indicated by the MRS signal in the dorsal anterior cingulate relative to clozapine users.

Conditions