Up close with one of ‘world’s most influential scientific minds’, Mary Cannon

29 Aug 2014

Mary Cannon, consultant psychiatrist at Beaumont Hospital and associate professor in the Department of of Psychiatry at the Royal College of Surgeons in Ireland

Prof Mary Cannon is exploring risk factors in young people for later psychosis, and she is among the top researchers globally in the field.

Last June, Cannon opened her email to find a couple of interesting messages from colleagues. The Thomson-Reuters list of The World’s Most Influential Scientific Minds 2014 was just out, and Cannon was named among them. “I didn’t know I was on it and people were emailing saying, ‘Look at this – you are the only Irish woman on this list’,” she says.

Early risk factors

Indeed she was – 11 researchers in Ireland were recognised and Cannon was included for her research on exploring risk factors in adolescence and youth for developing psychosis later in life.

“(I see) two key periods of interest for mental health risk factors – one is the prenatal and infancy years, and the other is through early adolescence and into the 20s,” she explains. “Someone might have vulnerability very early in life, maybe a genetic variation or an environmental issue, and then in adolescence and youth there can be a ‘second hit’, where a vulnerability could be converted into a disorder. I have a strong interest in the risk factors that we can identify in this period of adolescence and emerging adulthood.”

An associate professor in the Department of of Psychiatry at the Royal College of Surgeons in Ireland (RCSI) and a consultant psychiatrist at Beaumont Hospital, Cannon splits her time between clinical and research work.

Her discoveries about how adolescents hear voices in their heads and the long-term impacts of early life bullying and neglect are opening new perspectives on how risks might be mitigated. “We want to be able to identify vulnerable people early on and protect them through emerging adulthood,” explains Cannon. “That approach has very good potential for prevention.”

Hearing voices and early trauma

One of Cannon’s main research interests is in hearing voices inside the head, or ‘auditory hallucinations’, and she admits she has been surprised by the results in young people. “A big turning point for me was finding out that one person in five in early adolescence hears voices,” she says. “It was a surprise that so many kids were having this experience.”

Yet the evidence was there once the RCSI researchers went looking for it, both in the scientific literature that detailed so-called psychotic symptoms in childhood and adolescence and also in their own surveys of adolescents in Ireland.

“People had thought of hearing voices as a symptom of psychosis, which affects adults,” says Cannon. “But we found that having auditory hallucinations is not an uncommon thing to happen in adolescence. My feeling would be that if kids have an ability to hear voices, it’s not necessarily pathological but within that group of children who hear voices there will be those at risk of later psychosis and we need to keep an eye on them.”

For the wider public, Cannon wants to challenge the stigma attached to auditory hallucinations in this age group, which could make it harder for those who experience them to talk about it. “We have to break that down and say it’s not unusual, this is something that a lot of people experience,” she says. “And there is a more complex picture here – for some people hearing voices may be linked to depression and anxiety – and we are now looking at whether there are other risk factors for psychosis that come into play on top of this ability to hear voices.”

Her research also looks at the effects of early life trauma (such as severe neglect) and bullying on the risk of psychosis, and the findings suggest that if bullying is stopped, it reduces the risk of psychosis later on. “It is grounds for really focusing on young people and the stresses they can be under,” she says.

Seeing the bigger (and earlier) picture

Cannon emphasises that risk factors for psychosis need to be seen as part of a bigger picture, and she wants to see more research effort on the interplay between factors, be they genetic or environmental. “There is a whole range of risk factors for psychosis, but what we haven’t figured out yet is how they all interact,” she says.

She would also like to remove the boundary between child and adult designations in mental health, both in research and provision of services. “There’s a movement now towards ‘youth mental health’, to remove this artificial division that comes up at age 18,” she says, recalling how during her own training as a clinician she saw that mental health issues in adults didn’t just spring up fully formed. “These illnesses and their risk factors can start way earlier than age 18, and to have any chance of preventing these illnesses you need to look back.”

Early inspirations

Cannon’s perspective may well have been influenced by her mother, a primary school teacher and principal who could pick up on subtle clues about her pupils. “My mother could predict which kids would have difficulties and which ones would do well,” recalls Cannon. “I always found it interesting that the the seeds are sown so early.”

Cannon went on to study medicine at University College Dublin and trained in psychiatry at St John of God Hospital with the late Prof Eadbhard O’Callaghan. “He inspired me to go into research,” she recalls.

That inspiration led her to the Institute of Psychiatry in London where she worked with Prof Sir Robin Murray through a Wellcome Trust fellowship before returning to Ireland in 2004 to a research position with the RCSI, where she secured a Health Research Board clinician-scientist fellowship.

“That funding gave me five years to focus on my research and I think that really has been the key to help me get on (the Thomson-Reuters) list, because I had that time to get a research group up and off the ground,” she says. “It’s so important to provide research funding for clinicians early in their careers so they can build up their research skills – by the time you get to a senior consultant post, it is hard to start a clinical research group.”

New answers from data

Much of Cannon’s research depends on mining into data from large cohort studies that have gathered data from individuals – either as a snapshot for a cross-sectional study, or even more tellingly if the researchers have followed up with people over time in a longitudinal study.

“I have been very lucky to be able to draw on data from larger international studies in places such as Dunedin (New Zealand) and Finland, and studies are being built up in Ireland,” says Cannon, who has started to develop cohorts here.

“But there is a danger now that new data protection legislation coming through in the EU is going to hamper this kind of work and I am very concerned about this – it will stop us being able to do this kind of research in not just psychiatric illness but heart disease or cancer.”

As for her next steps in research, she wants to further explore the period of emerging adulthood when a person’s situation often changes. “In late adolescence and into the early 20s, people may have less structure in their lives and they may move out of the family home, and I think that needs more focus in mental health research,” she says. “I’m also interested whether early life stress and trauma could be linked with later symptoms, what is going on physically in the brain and how we might be able to influence it.”

Women Invent Tomorrow is Silicon Republic’s campaign to champion the role of women in science, technology, engineering and maths. It has been running since March 2013, and is kindly supported by Accenture Ireland, Intel, the Irish Research Council, ESB, Twitter, CoderDojo and Science Foundation Ireland.

Dr Claire O’Connell is a scientist-turned-writer with a PhD in cell biology and a master’s in science communication