The odds are more than two to one that people whose close relatives developed chronic severe unipolar depression when they were young will have it, too, according to results of a multicenter analysis of more than 600 people and their families.
Results of the study, published in the September issue of the American Journal of Psychiatry, with Johns Hopkins psychiatrist James B. Potash, M.D., as senior author, show that siblings, parents or children of people diagnosed with chronic major depression before the age of 31 have a 2.52-to-1 chance of also having the disorder. Moreover, first-degree relatives of patients diagnosed with chronic major depression before the age of 13 have a 6.17-to-1 chance of having it. "This chronic form of major depression can be uniquely disabling because of its persistence. Our finding that this aspect of the illness runs in families suggests the value of searching for contributory genes," Potash says, although he cautions that the results also could point to environmental factors, such as loss of a parent at an early age or physical and sexual abuse.
In this study, Potash and his team looked at 638 men and women diagnosed with early-onset major depression and 2,176 of their first-degree family members. The subjects were drawn from the Genetics of Recurrent Early-onset Depression (GenRED) project, a multicenter study of patients enrolled between 1999 and 2003 by Hopkins and other researchers.
Analysis showed that the 226 people interviewed in GenRED who were diagnosed before the age of 31 with chronic major depression had 352 family members who also suffered from this form of disease (37.8%), whereas the remaining 412 had a total of 148 relatives with chronic depression (20.2%). A breakdown of these results showed that 58 people diagnosed before the age of 13 with chronic major depression had 44 family members who also had the disease (48.9%). The remaining 69 people diagnosed with major depression before age 13 had 17 relatives (15.9%) with chronic illness.
"We have known for a long time that major depression runs in families, but we are still working on determining whether certain subtypes of the illness do so more strongly than others," says Potash. Our large study allows us the numbers to examine these questions in subgroups."
Potash credits lead author Francis Mondimore, M.D., of the Department of Psychiatry at Hopkins, with observing that many of the study participants reported having been depressed "as long as [they] can remember." This led Mondimore to focus on chronic -- or persistent -- depression over time. An estimated 30 percent of those with major depressive disorder have symptoms most or all of the time, with only incomplete remissions, over many years, according to Potash.
Mondimore says a similar technique, examining a subtype of illness, was used to discover a familial relationship in breast cancer in women -- a finding that paved the way to discovering a link between the BRCA1 gene and that disease.
Data for the GenRED project and for first-degree relatives was gathered using the Diagnostic Interview for Genetic Studies (DIGS), an method that documents the onset and duration of mood episodes and the presence or absence of such symptoms as loss of interest or ability to enjoy life, feeling guilty or down, fatigue, lack of concentration, loss of appetite or weight, and thoughts of death.
Study subjects were recruited to GenRED by the University of Iowa College of Medicine, Rush University Medical College, Columbia University Medical Center, University of Pittsburgh Medical Center, University of Pennsylvania School of Medicine and The Johns Hopkins University School of Medicine.
Major depression and chronicity were diagnosed using the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) -- a standard guide for the classification of mental illness. DSM-IV criteria for major depression include the presence of five or more depressive symptoms that have lasted for two or more weeks and that significantly impair the person's life. In the current study, subjects had to have been diagnosed with major depression before the age of 31, have at least one sibling with major depression who was diagnosed before the age of 41, and have no history of schizophrenia or bipolar (manic-depressive) illness.
GenRED II, a larger study now under way at Hopkins and five other sites, is recruiting 2,700 people to identify genes for major depression. Data also is being collected on other potential contributing factors, such as early childhood trauma. J. Raymond DePaulo Jr., M.D., director of the Department of Psychiatry, is the Hopkins principal investigator.
Eric Vohr | EurekAlert!
The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses