A study led by Trinity researchers has, for the first time, shown a shared genetic origin for the conditions Motor Neuron Disease and schizophrenia, revealing that both conditions are genetically linked.
Previous studies have revealed a clear link between schizophrenia and other neuropsychiatric illness including bipolar affective disorder and autism but this is the first time that any overlap between Motor Neuron Disease and a psychiatric condition has been shown.
The Trinity team collaborated with Motor Neuron Disease experts in the University of Utrecht in the Netherlands as well as in King’s College London. Collaboration also occurred between Trinity and the Psychiatric Genome Consortia, which unites investigators around the world, to discover if these observations of the diseases in terms of its incidence, distribution and how it is controlled, could be due to an overlap between the two conditions.
The study was in part prompted by earlier studies by researchers at Trinity which revealed that people with Motor Neuron Disease are more likely to have family members with schizophrenia or to have a family member who has committed suicide.
This research was produced by obtaining family histories from people suffering from Motor Neuron Disease from the National Amyotrophic Lateral Sclerosis Clinic – Amyotrophic Lateral Sclerosis is the term Motor Neuron Disease is also known by – and was subsequently investigated as part of case control studies in which 192 Motor Neuron Disease sufferers participated. Details of over 12,000 relatives from this study were obtained and the rates of neurological disorders in these relatives were subsequently analysed.
This latest study analysed the genetic profile of some 13,000 Motor Neuron Disease sufferers and 30,000 schizophrenia cases, revealing that many of the genes associated with the two conditions are the same. A 14 per cent overlap in genetic susceptibility between adult-onset Motor Neuron Disease and developmental schizophrenia was found.
Orla Hardiman, Professor of Neurology at Trinity and Consultant Neurologist at the Natural Neuroscience Centre at Beaumont Hospital and lead author of this project, commented in a press release: “Our recent observations of links with psychiatric conditions in some families have led us to think differently about how we should study [Motor Neuron Disease].”
She stated the the the results show Motor Neuron Disease “is not just a disorder of individual nerve cells but a disorder of the way these nerve cells talk to one another as part of a wider network”.
Hardiman explain that now researchers need to look at Motor Neuron Disease the same way they do schizophrenia, Instead of thinking of it “as a degeneration of one cell at a time, and looking for a magic bullet treatment that works”, they should consider looking to drugs that help stabilise brain networks that are failing as part of new treatments going forward. Schizophrenia is when there is a problem or disruptions in connectivity different parts of the brain.
Hardiman also stated that the team noted the knock-on effects of their research going forward: “The other significant issue that this research brings up is that the divide between psychiatry and neurology is a false one. We need to recognise that brain disease have various different manifestations and the best way to develop new treatments is to understand the biology behind what is happening.”
“This will have major implications on how we classify diseases going forward and how we train our future doctors in psychiatry and neurology. That in itself will have knock-on effects on how society understands, approaches and treats people with psychiatric and neurological conditions”, Hardiman commented.
Dr Russell McLaughlin, Ussher Assistant Professor in Genome Analysis at Trinity and lead author of this paper said: “This study demonstrates the power of genetics in understanding the causes of diseases. Our work has shown that the biological pathways that lead to these diverse conditions have much in common.”
Following on from this study, the Trinity group will continue to work alongside their partners in the University of Utrecht in analysing the links between Motor Neuron Disease and other psychiatric conditions with the help of modern genetics, neuroimaging and epidemiology and in doing so, will work to develop new and more effective treatments that will help in stabilising disrupted brain networks.
