In an effort to push the field forward, three UCLA researchers, along with scientists from more than 20 countries, have been taking part in one of the largest collaborative efforts in psychiatry — a genome-wide study involving more than 50,000 study participants aimed at identifying which genetic variants make people susceptible to psychiatric disease.
This collaborative, the Psychiatric Genome-Wide Association Study Consortium (PGC), now reports in the current online edition of the journal Nature Genetics that it has discovered that common genetic variants contribute to a person's risk of schizophrenia and bipolar disorder.
The PGC's studies provide new molecular evidence that 11 regions on the genome are strongly associated with these diseases, including six regions not previously observed. The researchers also found that several of these DNA variations contribute to both diseases.
The findings, the researchers say, represent a significant advance in understanding the causes of these chronic, severe and debilitating disorders.
The UCLA researchers who contributed to the schizophrenia study are Roel A. Ophoff, a professor of psychiatry and human genetics and one of the founding principal investigators of the schizophrenia portion of the study; Dr. Nelson Freimer, a professor of psychiatry and director of the Center for Neurobehavioral Genetics at the Semel Institute for Neuroscience and Human Behavior at UCLA; and Rita Cantor, a professor of psychiatry and human genetics.
Schizophrenia and bipolar disorder are common and often devastating brain disorders. Some of the most prominent symptoms of schizophrenia are persistent delusions, hallucinations and cognitive problems. Bipolar disorder is characterized by severe, episodic mood swings. Both affect about 1 percent of the world's population and usually strike in late adolescence or early adulthood.
Despite the availability of treatments, these illnesses are usually chronic, and patients' response to treatment is often incomplete, leading to prolonged disability and personal suffering. Family history, which reflects genetic inheritance, is a strong risk factor for both schizophrenia and bipolar disorder, and it has generally been assumed that dozens of genes, along with environmental factors, contribute to disease risk.
In the schizophrenia study, a total of seven locations on the genome were implicated in the disease, five of which had not been identified before. When similar data from the bipolar disorder study, which ran concurrently, were combined with results from the schizophrenia study, three gene locations were identified that proved to be involved in both disorders, suggesting a "genetic overlap" between schizophrenia and bipolar disorder.
"Genetic factors play an important role in the susceptibility to develop schizophrenia," Ophoff said, "but identifying these genetic factors has been very difficult. We know that schizophrenia is not caused by a single gene that explains everything but an interplay of many genetic and non-genetic factors."
At the same time, he said, the disease itself is not uniform but manifests itself in different ways; currently, there is no objective biological marker or "sign" that can be used for diagnosis.
"This so-called heterogeneity at the genetic and clinical level is the biggest challenge for genetic studies of neuropsychiatric disorders," Ophoff said. "One way to deal with these difficulties is to increase the size of the study so there is sufficient 'power' to detect genetic effects, even amidst this clinical and genetic diversity."
The fact that even this large study resulted in a limited number of schizophrenia and bipolar genes demonstrates once again, he said, the complex nature of the disease.
Formed in 2007, the PGC is the largest consortium ever in psychiatry. Over 250 researchers from more than 20 countries have come together in an unparalleled spirit of cooperation to advance knowledge of the genetic causes of mental illness. Crucial to the success of the project was the willingness of many groups to share genetic data from tens of thousands of patients collected over many years.
The research was funded by numerous European, American and Australian funding bodies. Funds for coordination of the consortium were provided by the National Institute of Mental Health in the U.S.
The UCLA Department of Psychiatry and Biobehavioral Sciences is the home within the David Geffen School of Medicine at UCLA for faculty who are experts in the origins and treatment of disorders of complex human behavior. The department is part of the Semel Institute for Neuroscience and Human Behavior at UCLA, a world-leading interdisciplinary research and education institute devoted to the understanding of complex human behavior and the causes and consequences of neuropsychiatric disorders.
For more news, visit the UCLA Newsroom and follow us on Twitter.
Mark Wheeler | EurekAlert!
The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy