Identification of biomarkers for risk of major psychiatric disorders in vulnerable populations to develop new strategies for early interventions and prevention.

Dr. Pierre Marquet's research aims to identify and detect risk biomarkers for major psychiatric disorders such as schizophrenia, bipolar disorder and recurrent severe depression, in vulnerable children, well before the appearance of the first clinical symptoms. The detection of an infantile risk syndrome from these biomarkers would allow the implementation of early management strategies, which are known for their effectiveness.  Early intervention is likely to delay or even prevent the onset of these diseases in their most disabling forms as they are known today.

Dr. Pierre Marquet is a psychiatrist, physicist engineer and the chairholder of the Canada Excellence Chair in Neurophotonics. He uses his various expertise to characterize the early development of severe psychiatric diseases both in their neurobiology and their alteration of psyche. Ultimately, this multidisciplinary approach aims to detect the presence of discrete alterations of neurodevelopment in children, which would predict the appearance, many years later, of major psychiatric disorders and who could then act as biomarkers of risk to guide the implementation of early interventions.

One of the approaches favored by Dr. Marquet to identify risk biomarkers at the cellular level, is to study, using multimodal optical microscopy techniques, the maturation of human neuronal cells cultured from pluripotent stem cells taken from vulnerable patients or young children. His team has developed an innovative approach using very high resolution optical microscopy based on a holographic principle, which allows to visualize, in three dimensions and with a nanometric sensitivity, the dynamics of the maturation process of human neural cells. His team also uses neuroimaging techniques such as structural and functional MRI to better understand the brain mechanisms that underlie these psychiatric disorders.

As a psychiatrist, Dr. Marquet also participates in the clinical part of these studies, which are conducted primarily in children of patients, who are unfortunately at risk of developing mental disorders. The transdisciplinarity of his team, bringing together expertise in areas such as mathematics, physics, neurobiology, and clinical psychiatry, has recently allowed him to identify very promising candidate biomarkers.