Amyotrophic lateral sclerosis (ALS) — also known as Lou Gehrig’s disease or motor neuron disease (MND) — appears to share a genetic origin with schizophrenia, according to a new study published in the journal Nature Communications.
ALS/MND is a rare group of progressive neurological diseases that cause the death of nerve cells (neurons) involved in controlling voluntary muscle movements, such as walking, breathing, chewing, and talking. Currently there is no known cure or treatment that can reverse the damage.
“This study demonstrates the power of genetics in understanding the causes of diseases. While neurological and psychiatric conditions may have very different characteristics and clinical presentations, our work has shown that the biological pathways that lead to these diverse conditions have much in common,” said Dr. Russell McLaughlin, Ussher Assistant Professor in Genome Analysis at Trinity College Dublin, and lead author of the paper.
The study was prompted by earlier epidemiological findings by Trinity researchers, revealing that people with ALS/MND were more likely than expected to have family members with schizophrenia and to have had another family member who had committed suicide.
This earlier work investigated the rates of various neurological and psychiatric conditions among more than 12,000 relatives of ALS/MND participants and controls. The findings were subsequently published in 2013 in the journal Annals of Neurology.
For the new study, researchers from the University of Utrecht, Kings College London and members of the Project MinE and Psychiatric Genome Consortia analyzed the genetic profiles of almost 13,000 ALS/MND cases and over 30,000 schizophrenia cases. They found that many of the genes associated with these two distinct conditions are the same.
In fact, the research shows an overlap of 14 percent in genetic susceptibility to the adult onset neurodegenerative condition ALS/MND and schizophrenia.
While overlaps between schizophrenia and other neuropsychiatric conditions including bipolar affective disorder and autism have been shown in the past, this is the first time that an overlap in genetic susceptibility between ALS/MND and psychiatric conditions has been shown.
“Our work over the years has shown us that ALS/MND is a much more complex disease than we originally thought,” said senior author Dr. Orla Hardiman, professor of neurology at Trinity and consultant neurologist at the National Neuroscience Centre.
“So instead of thinking of ALS/MND as a degeneration of one cell at a time, and looking for a ‘magic bullet’ treatment that works, we should think about ALS/MND 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 stabilize the failing brain networks.”
Hardiman added that the dividing line between psychiatry and neurology is a false one. “We need to recognize that brain disease has many different manifestations, and the best way to develop new treatments is to understand the biology of what is happening,” she said.
Hardiman said these findings will have major future implications regarding how we classify diseases, and in turn how doctors will be trained in both psychiatry and neurology.
Source: Trinity College Dublin