Article in the Irish Times from 24th March:

TCD researchers’ findings cast doubt on divide between psychiatry and neurology.

Irish-based researchers have shown for the first time that motor neurone disease and schizophrenia are genetically and biologically linked.

The finding, which casts doubt on traditional assumptions about the divide between psychiatry and neurology, could have major implications for the treatment of these conditions and the training of doctors in related specialties.

The researchers from Trinity College Dublin (TCD) discovered the association after analysing the genetic profiles of almost 13,000 motor neurone and more than 30,000 schizophrenia cases.

Their analysis showed a 14 per cent overlap in genetic susceptibility to adult onset neurodegenerative condition, motor neurone disease or amyotrophic lateral sclerosis, and the developmental neuropsychiatric disorder, schizophrenia.

Senior author of the study, Dr Orla Hardiman, professor of neurology at TCD, said the research showed motor neurone disease was 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 larger network.

“So instead of thinking of motor neurone disease as a degeneration of one cell at a time, and looking for a ‘magic bullet’ treatment that works, we should think about it in the same way that we think about schizophrenia, which is a problem of disruptions in connectivity between different regions of the brain, and we should look for drugs that help to stabilise the failing brain networks.”

The research, published in the journal Nature Communications, pointed to the divide between psychiatry and neurology being a false one, Dr Hardiman added.

“We need to recognise that brain disease has many different manifestations, and the best way to develop new treatments is to understand the biology of what is happening.

“This will have major implications for how we classify diseases, and in turn how we train our future doctors in both psychiatry and neurology.

“That will have knock-on consequences for how society understands, approaches and treats people with psychiatric and neurological conditions.”

Earlier TCD studies showed people with motor neurone disease were more likely to have family members with schizophrenia, and to have had a family member who took their own life.

This finding prompted the latest research, in order to establish whether this link was due to a genetic overlap between the two conditions.