In fact, they may just be different manifestations of the same underlying condition, according to a group of international researchers.
Several years ago, scientists from 19 countries formed the Psychiatric Genomics Consortium. Since then, the group has analyzed DNA from 33,000 people with major depression, bipolar disorder, schizophrenia, autism, or attention-deficit hyperactivity disorder and another 28,000 without one of these disorders.
Scientists were able to identify a handful of genes that are shared by people with these disorders. The findings may lead to new and better ways to diagnose and treat mental illness.
In the participants with mental illness, the same variations were found in four regions of the genetic code. The team’s report, published in the journal The Lancet, was led by Dr. Jordan Smoller, director of psychiatric genetics at Massachusetts General Hospital and professor of psychiatry at Harvard Medical School.
Two of the affected genes help control the movement of calcium in and out of brain cells. This movement provides a key way for brain cells to communicate.
Even subtle differences in the flow of calcium can create problems that, depending on other genes or environmental factors, could eventually lead to a full-blown mental disorder.
It’s been known for a long time that certain mental disorders run in families. This is especially true for bipolar disorder, major depression and schizophrenia. Scientists are making progress in pinpointing the genes tied to certain mental health diseases, but they still have a long way to go.
The new findings, for example, won’t immediately help clinicians either diagnose mental illness or give individuals a warning that they are at risk for it. This is because the genetic variants the researchers discovered are weak risk factors for the five diseases.
“Each one of them, by themselves, still accounts for a small amount of the risk,” said Smoller. “The fascinating thing is there might be such variants that cross our clinically distinct syndromes.”
There are many paths to mental illness. This study shows that that five seemingly different mental health disorders — major depression, bipolar disorder, schizophrenia, autism, and attention-deficit hyperactivity disorder — may be more alike than we think.
These findings could change the way we view mental illness, open the door to more effective therapies, and possibly even lead to prevention.
Source: The Lancet