He is a professor of Biostatistics at Paris-Saclay Medical University, the Director of the CESP (INSERM centre for research in epidemiology and population health), and the former President of the IACAPAP (International Association for Child and Adolescent Psychiatry and Allied Professions).

This representation preserves the topological structure of the correlation matrix and is more accurate than the more classical Principal Components Analysis.

"[11] After that he engaged more in the epistemology of mental health research, and took many positions in the national media (the questionable place of genetics studies in psychiatric research,[12] the potential misuse of medications in child and adolescent psychiatry,[13] the insufficiency of health policies in child and adolescent psychiatry, the inappropriate importance of the place of neurosciences in psychiatric training.

[15] Falissard published a series of papers addressing psychiatric disorders, disability, mental health or subthreshold manifestations.

[14] In his interview with Juliette Parmentier, he discussed the impact of the COVID-19 crisis on the mental health of young people, and stated that for the 16-25 year old "The main problem for this age group is the total lack of recognition of their sacrifices.