Professor Cannon has an ongoing research programme which centres on investigating early life risk factors for later adult psychiatric disorders, with a particular focus on psychosis. She has collaborators in the UK, US and Finland and has published in high-ranking psychiatry journals.

Her main programme of work at present involves investigating epidemiological, neurocognitive, neuroimaging and electrophysiological correlates of psychotic-like experiences in adolescence. This work was funded by a Clinician Scientist Award from the Health Research Board.

She is also carrying out an programme of research on the association between prenatal and perinatal complications and early developmental delay as both independent and interactive risk factors for later psychosis. Her group have been the first to report an additive interaction between prenatal infection and genetic vulnerability in increasing risk for later schizophrenia.

A further strand to her work is the publication of systematic reviews of observational studies on risk factors for psychosis, such as epilepsy and traumatic brain injury. Professor Cannon's other main strand of research is the area of youth mental health. She has carried out a large school-based survey of psychopathology in early adolescence with both questionnaire and detailed clinical interview. She is Secretary of the Special Interest Group on Youth Mental Health (affiliated to ACAMH) and, is on the organising committee for the first National Research Conference in Youth Mental Health, held in RCSI in October 2011.

Top World Rankings 2014
Professor Mary Cannon appeared in the Thomson Reuters Highly Cited Researchers website,, and 2014 World's Most Influential Scientific Minds report which was launched in July 2014.

Professor Cannon has been ranked among the world's top 3,000 by the multinational media body Thompson Reuters. Inclusion means the person's research is listed in the top 1 per cent for the number of times their work has been cited by other scientists.

Not only is Professor Cannon just one of 11 Irish academics to make this outstanding achievement, she is the only woman in Ireland to achieve this.