“We’re hoping our findings will eventually lead to tests that can identify those at high risk for attempting suicide,” says Virginia Willour, Ph.D., an assistant professor in the Department of Psychiatry at the Johns Hopkins University School of Medicine and lead author of the study. An estimated 4.6 percent of Americans ages 15 to 54 have tried to take their lives, according to Willour.
The investigators conducted a family linkage study in which they searched for commonalities in the genomes of family members with bipolar disorder and a history of attempted suicide. The same gene region on chromosome 2 that was identified by this bipolar disorder and attempted suicide study was recently identified by two complementary family studies that looked at attempted suicide in families with major depression and alcohol dependence.
“Family linkage studies are not always consistent, so the fact that all three studies, including ours, point to the same region of the genome is a good indication that we are on the right track toward identifying a gene or genes that play a role in why a person chooses to take his or her own life,” says Willour.
In the multi-institutional study, results of which appear in the March issue of Biological Psychiatry, the researchers examined data from 162 families with bipolar disorder. They looked at attempted suicide in this sample because it is an important clinical problem that tends to occur more often in some of these families than in others, suggesting a distinctive genetic basis, according to senior author James B. Potash, M.D., M.P.H., of the Department of Psychiatry at Hopkins. This technique, of looking at sub-types of illness, is used by genetic researchers as a way to reduce genetic complexity.
From the 162 families, the researchers selected 417 subjects who were diagnosed with schizoaffective/bipolar disorder, bipolar I disorder or bipolar II disorder.
These subjects were asked whether they had ever attempted suicide and the degree of intent of the most serious attempt. One hundred fifty-four subjects said they had attempted suicide, and 122 stated that they had “definite” intent. For the purpose of this study, the latter were considered to have a history of attempted suicide.
Data for all 417 subjects was entered into a computer program that looks for genetic similarities between subjects with similar psychological profiles. Results indicated that family members with a history of attempted suicide and bipolar disorder showed a high degree of genetic similarity at a specific area -- DNA marker D2S1777 -- on a section of chromosome 2 referred to as 2p12. This is the same marker implicated in a 2004 study from the University of Pittsburgh School of Medicine that looked at attempted suicide and major depression. And it is close to another marker, D2S1790, located in the 2p11 region of chromosome 2, which was identified in a 2004 study from the University of Connecticut School of Medicine that looked at alcoholism and attempted suicide.
Willour says that although the Hopkins-led study does not pinpoint a specific gene responsible for attempted suicide, it does suggest a “neighborhood” in which the gene might be found. She adds that the next step is to further narrow the search and find the “address.” “Once we have located the specific gene,” she says, “we can better identify people who might be at risk of suicide and offer drug companies a target for possible therapies.”
The data used by Willour and her team -- DNA samples, medical histories and psychiatric evaluations -- came from an independent study, CHIP, conducted at the University of Chicago, Johns Hopkins, and the National Institute of Mental Health (NIMH) Intramural Program. The purpose of CHIP, initiated in 1988 and funded through at least 2010, is to find genes that predispose people to developing bipolar disorder or particular subtypes of the illness.
Eric Vohr | EurekAlert!
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).
The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
16.08.2017 | Physics and Astronomy
16.08.2017 | Materials Sciences
16.08.2017 | Interdisciplinary Research