Scientific understanding of the connection between genetics and mental illness is accelerating, offering hope for treating and preventing such problems as depression, schizophrenia, Alzheimer's disease, and alcoholism, according to a new book, Mending Minds.
"Recognition of the importance of genes in psychiatric disease represents an about-face from the view that prevailed a couple of decades ago," says author Leonard L. Heston, a professor of psychiatry at the University of Washington Medical School. He notes that solid evidence favoring genetics' role comes from studies of adopted children and identical twins.
As scientists gain greater understanding of the physical and chemical properties of genes, they are also gaining the ability to apply that understanding to treating genetic-based diseases. We now know, for instance, that DNA - the genetic code - can and does change within the course of a lifetime, which means that "inheritance is not rigid, unchanging, or unforgiving," says Heston.
Only in the last few years has direct study of human DNA become possible, and the idea of mapping the human genome was first seen as a remote possibility in 1978. Locating the genes that cause a specific mental illness will radically alter the psychiatric profession, Heston suggests. Already, Huntington's disease can be located genetically, and the mapping of other disease will soon come. Once mapped, the diseases could eventually be prevented by manipulating the structure of DNA.
Meanwhile, scientist will have to try to understand how environment interacts with DNA to cause mental diseases. "We cannot expect to understand what DNA does wrong until we understand what it is responding to," Heston writes. …