Challenge: Psychiatric disorders such as schizophrenia, bipolar disorder and major depression affect 25 million of individuals in North America. Early identification of risk factors for people with genetic predispositions remains the most promising avenue for improving the treatments for these diseases. However, there are multiple subgroups of patients within a specific disease whose condition is mediated by different molecular pathologies, and there are currently no reliable biomarkers to help establish an early diagnosis and guide treatment decisions.

Solution: The team has developed a non-invasive platform for the early and accurate diagnosis of patients with schizophrenia and bipolar disorder, thereby enabling more effective treatment, while reducing health and social costs. This approach allows for the stratification of patients using electro-retinography (ERG) profiles which exploit the retinal response to light stimulation as means to monitor the central nervous system. From a cohort of 150 schizophrenia, 150 bipolar disorder patients, 150 major depression patients as well as 200 healthy volunteers, a highly predictive ERG-based biomarker signature for the diagnosis was developed (sensitivity up to 95% and specificity up to 80% to distinguish between schizophrenia and bipolar patients). Moreover, when ERG analysis was applied to psychotic patients taking antipsychotic drugs, the team observed that these medications displayed a specific ERG signature identifying better and poorer responders with 100% sensitivity and specificity for olanzapine and up to 97% for quetiapine and lithium.

Achievements/Impact: This technology platform demonstrates that ERG profiles can predict susceptibility and treatment response in psychiatric disorders. It could also reduce patient recruitment time, leading to clinical trial cost savings while also reducing mental health costs due to earlier diagnosis. Following these successes, the team was awarded a $1 M grant from CIHR to develop a predictive test for children at high risk of developing schizophrenia and bipolar disorder. Moreover, a start-up company, diaMentis, has been created to commercialize this innovative tool to aid clinicians in early diagnosis for mental health care.