U. Pittsburgh researchers find link between gene, depression

05 декабря, 2002
U-WIRE-2002 U-Wire - http://www.uwire.com U-WIRE-12/04/2002-U. Pittsburgh: U. Pittsburgh researchers find link between gene, depression 2002 The Pitt News Via U-WIRE U-WIRE via NewsEdge Corporation : U-WIRE-(C)2002 U-Wire - http://www.uwire.com U-WIRE-12/04/2002-U. Pittsburgh: U. Pittsburgh researchers find link between gene, depression (C) 2002 The Pitt News Via U-WIRE By Michelle Scott, The Pitt News (U. Pittsburgh) PITTSBURGH -- According to Dr. George Zubenko, major depression will affect 5 to 15 percent of Americans and is a leading cause of disabling disorders worldwide. Moreover, 10 to 15 percent of those hospitalized for major depression commit suicide. Though doctors have developed some treatments for this disorder, the recent discovery of a gene that may influence major depression may help produce even more effective diagnosis methods and treatments, particularly for women, who are twice as likely to suffer from depression as men. Researchers at the Molecular Neurobiology and Genetics Lab at the University of Pittsburgh Medical Center have uncovered a great deal of evidence linking the susceptibility gene known as CREB1, to unipolar mood disorders in women. This 15-year-long study, led by Zubenko, professor of psychiatry at Pitt's medical school, and an adjunct professor of biological sciences at Carnegie Mellon University, was sponsored by the National Institute of Mental Health. The team's study suggests that CREB1 contributes to the high risk of women in families that exhibit recurrent, early onset major depression disorder. Men with the same genetic background do not have an elevated risk for such disorders. In order to isolate the basis for major depression, the research team used multiple approaches, including varied methods of psychiatric analysis and classification for 400 participants from 81 families affected by recurrent, early onset depression disorder. The team also studied the phenotypes, or genetic makeups, for the 400 study participants with the help of the Center for Inherited Disease Research. The team's examinations encompassed 19 regions of the genome that are related to major depression and turned up significant results on a narrow region of eight genes on chromosome 2, where the gene CREB1 is located. Examinations of the brains of those who died with major depression disorder, those of animals who experienced animal models of major depression and those treated with anti-depressants all revealed alterations in CREB 1 behavior. According to Zubenko, CREB1 acts as a regulatory gene that influences what other genes in the brain do and how they behave through their effects on DNA transcription. "It helps to modulate the brain's reward systems, which influence people's enjoyment of certain activities," he said. "It also can cause abnormalities in neuronal plasticity, which effects cognition, emotional responses, sensory experiences, and long-term memory, which are common symptoms of those suffering major depression disorder, or may cause the onset or recurrence of the disease." The CREB1 gene may also help explain the high depression rate for females, since it only affects women. Zubenko and his team published a study in March, which revealed that of the 19 regions linked to recurrent early onset depression disorder, 16 were specific to either men or women only. He explained CREB1's sex specificity by saying that sex in human beings is primarily hormone-based, and CREB1 has an influence on estrogen receptors. "Studies such as this one are providing us with a better understanding of the biology of complicated disorders such as major depression, which is unlikely to represent a single disease with a unitary cause," Zubenko said. "Instead, clinical depression is probably more like anemia. Both of these disorders are defined by a collection of clinical features that result from different causes in different people." The team's study also revealed a trend of accelerated mortality rate among family members of those affected by recurrent early onset depression disorder, though these individuals were affected by the same disorders that cause death in most Americans, like heart disease and cancer. "[The depression-related genes] probably don't just put the brain at risk. They probably affect other organ systems as well as the brain," Zubenko said. ##30## ((Distributed via M2 Communications Ltd - http://www.m2.com )) <> << Copyright ©2002 M2 Communications Ltd >>