Globally, at least one in eight people live with a mental illnessand according to the World Health Organization (WHO), depression is a leading cause of disability.
WHO also estimates that the number of people with anxiety and depression increased by up to 25% in the first corona year.
Therefore, there is a great need to understand and treat these common and serious conditions.
Now researchers from the University of Oslo, among others, question whether it is true that we see schizophrenia and bipolar disorder as different disorders, for example, because the genetic overlap is so large.
The supercomputer calculates millions of variations
The research, published in The American Journal of Psychiatry,studied the genetic data of more than 200,000 people with a mental disorder.
The genetic overlap between bipolar disorder, ADHD, depression and schizophrenia was initially examined. A team of 30 math, statistician and computer science experts used advanced math to analyze millions of genetic variations.
Using a supercomputer, which is thousands of times more powerful than ordinary computers, the researchers studied the genetic variants associated with bipolar disorder and compared them to the variants associated with schizophrenia.
Another look
They discovered 10,000 genetic variants associated with mental disorders, many of which are common to multiple disorders.
One finding was that bipolar disorder and schizophrenia have an overlap of 8,500 genetic variants, while ADHD and depression have an overlap of 4,500 genetic variants.
Depression risk is influenced by 14,500 genetic variants, of which 7,500 may also influence bipolar disorder risk. Lead author Guy Hindley explains:
‘The findings may represent an important shift in our view of the genetic basis of mental disorders. Our research shows that thousands of genetic variants likely play a role in schizophrenia risk, rather than a small number of genes specifically affecting that risk,” she says.
It can prevent side effects
It’s not the first study to show that many mental disorders have similar genetic causes. Samples have previously been collected from more than 100,000 people and numerous genetic variants have been found that can increase the risk of a mental disorder.
But this is one of the first studies to provide a rough estimate of the number of genetic similarities between different mental disorders.
Hindley hopes that with this discovery, we’ll be able to better define disorders in the future, narrow down the number of causes, and then tailor a treatment so that the large group of people with depression, for example, don’t just end up in the same box.
“The reason we still have the current system, with psychiatric diagnoses, is that there are no better alternatives. But I hope that with these more biological measures we can classify patients into more similar groups. For example, we can also avoid people who don’t benefit from drugs having to live with side effects,” she says.
