Study sheds light on genetic overlap between major psychiatric disorders

February 8, 2018, University of California, Los Angeles
Dr. Daniel Geschwind. Credit: UCLA Health

Most medical disorders have well-defined physical characteristics seen in tissues, organs and bodily fluids. Psychiatric disorders, in contrast, are not defined by such pathology, but rather by behavior.

A UCLA-led study, appearing Feb. 9 in Science, has found that autism, schizophrenia and bipolar disorder share some physical characteristics at the , specifically, patterns of gene expression in the brain. Researchers also pinpointed important differences in these disorders' gene expression.

"These findings provide a molecular, pathological signature of these disorders, which is a large step forward," said senior author Daniel Geschwind, a distinguished professor of neurology, psychiatry and human genetics and director of the UCLA Center for Autism Research and Treatment. "The major challenge now is to understand how these changes arose."

Researchers know that certain variations in genetic material put people at risk for psychiatric disorders, but DNA alone doesn't tell the whole story. Every cell in the body contains the same DNA; RNA molecules, on the other hand, play a role in in different parts of the body, by "reading" the instructions contained within DNA.

Geschwind and the study's lead author, Michael Gandal, reasoned that taking a close look at the RNA in human brain tissue would provide a molecular profile of these psychiatric disorders. Gandal is an assistant professor of psychiatry and biobehavioral sciences at UCLA.

Researchers analyzed the RNA in 700 tissue samples from the brains of deceased subjects who had autism, schizophrenia, bipolar disorder, or alcohol abuse disorder, comparing them to samples from brains without .

The molecular pathology showed significant overlap between distinct disorders, such as autism and schizophrenia, but also specificity, with major depression showing molecular changes not seen in the other disorders.

"We show that these in the brain are connected to underlying genetic causes, but we don't yet understand the mechanisms by which these genetic factors would lead to these changes," Geschwind said. "So, although now we have some understanding of causes, and this new work shows the consequences, we now have to understand the mechanisms by which this comes about, so as to develop the ability to change these outcomes."

Explore further: Study identifies biological mechanisms for schizophrenia, bipolar disorder and depression

More information: M.J. Gandal el al., "Shared molecular neuropathology across major psychiatric disorders parallels polygenic overlap," Science (2018). science.sciencemag.org/cgi/doi … 1126/science.aad6469

Related Stories

Study identifies biological mechanisms for schizophrenia, bipolar disorder and depression

January 29, 2015
Common psychiatric disorders such as schizophrenia, bipolar disorder and major depression share genetic risk factors related to immune function and DNA regulation, according to new findings by a large collaborative research ...

Shared genetics in schizophrenia and bipolar disorder

October 2, 2017
A genetic variant associated with multiple psychiatric disorders drives changes in a brain network that may increase an individual's risk of developing bipolar disorder and schizophrenia, finds a study published in Journal ...

Brains of people with autism spectrum disorder share similar molecular abnormalities

December 5, 2016
Autism spectrum disorder is caused by a variety of factors, both genetic and environmental. But a new study led by UCLA scientists provides further evidence that the brains of people with the disorder tend to have the same ...

Family study emphasizes distinct origins for bipolar disorder subtypes

January 10, 2018
The most common subtypes of bipolar disorder, bipolar I and bipolar II, stem—at least in part—from different biological causes, according to a new study published in Biological Psychiatry. Despite genetic overlap between ...

Researchers map out genetic 'switches' behind human brain evolution

January 11, 2018
UCLA researchers have developed the first map of gene regulation in human neurogenesis, the process by which neural stem cells turn into brain cells and the cerebral cortex expands in size. The scientists identified factors ...

Increased brain acidity in psychiatric disorders

August 8, 2017
The body's acid/alkaline homeostasis, or maintenance of an adequate pH balance in tissues and organs, is important for good health. An imbalance in pH, particularly a shift toward acidity, is associated with various clinical ...

Recommended for you

People with family history of alcoholism release more dopamine in expectation of alcohol

May 23, 2018
People with a family history of alcohol use disorder (AUD) release more dopamine in the brain's main reward center in response to the expectation of alcohol than people diagnosed with the disorder, or healthy people without ...

Why we fail to understand our smartphone use

May 23, 2018
Checking your phone dozens of times a day indicates unconscious behaviour, which is "extremely repetitive" say psychologists.

Study confirms that men and women tend to adopt different navigation strategies

May 23, 2018
When navigating in a known environment, men prefer to take shortcuts to reach their destination more quickly, while women tend to use routes they know. This is according to Alexander Boone of UC Santa Barbara in the US who ...

Early life trauma in men associated with reduced levels of sperm microRNAs

May 22, 2018
Exposure to early life trauma can lead to poor physical and mental health in some individuals, which can be passed on to their children. Studies in mice show that at least some of the effects of stress can be transmitted ...

Training compassion 'muscle' may boost brain's resilience to others' suffering

May 22, 2018
It can be distressing to witness the pain of family, friends or even strangers going through a hard time. But what if, just like strengthening a muscle or learning a new hobby, we could train ourselves to be more compassionate ...

Study finds popular 'growth mindset' educational interventions aren't very effective

May 22, 2018
A new study co-authored by researchers at Michigan State University and Case Western Reserve University found that "growth mindset interventions," or programs that teach students they can improve their intelligence with effort—and ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.