Schizophrenia: it’s not just “in the genes”; the environment may also matter

A seismic shift in thinking is offering new hope for prevention and early intervention in schizophrenia, say two of Australia’s leading mental health specialists.

Professor Ian Hickie, Executive Director of the University of Sydney’s Brain and Mind Institute, and Professor Patrick McGorry, Executive Director of the University of Melbourne’s ORYGEN Research Centre outline the change in their opening editorial to Pathways to Schizophrenia, a special lift-out supplement in the Medical Journal of Australia.

“For the past 20 years, much of the research into schizophrenia has been based on the belief that the disorder results largely from genetically determined abnormalities in brain development,” Professor Hickie says.

“Against this background of genetic developmentalism, preventive and early intervention strategies have been discounted.

Now, however, Professor Hickie said the simplistic genetic approaches are giving way to more thorough examination of potential gene–environment interactions.

“Recent research has introduced the likelihood of a wide range of potential environmental risks.

“The challenge now lies in using new neuroscience tools to help us understand which specific environmental factors, occurring at which point in the postnatal to post-pubertal course of development, could have such a profound and debilitating impact on the function of the central nervous system.

“Postpubescent use of cannabis has been shown to have a critical role, and amphetamine use is now being closely investigated. Other factors under the microscope include infection and other inflammatory risk factors as well as the impact of oestrogen exposure.”

Professor Hickie said a clinical staging model is also challenging the dogma that each of the major psychiatric disorders has a unique pathway.

“By contrast, the staging model suggests a ‘trunk and branch’ analogy with the early stages sharing common factors that branch out into more specific symptoms later on, typically when patients are in their early 20s.  

“The exciting part of this is that it introduces the possibility that early intervention could help treat a broad range of disorders.

“Much of the social stigma and health services neglect that accompany the diagnosis of schizophrenia have been perpetuated by a ‘sterile’ clinical, research and health policy agenda.

“The policy challenge is to urgently develop a national agenda that encourages the collection of real data, properly informs consumers and carers, and demands a timely focus on reducing premature death through better attention to medical risk factors.”

^{The statements or opinions that are expressed in the MJA reflect the views of the authors and do not represent the official policy of the AMA unless that is so stated.}

CONTACT:  Professor Ian Hickie 02 9351 0810 / 0438 810 231