Introduction to Genetics in PsychologyGenetic techniques are a central pillar of research in the neurosciences. The ability to manipulate genes in model organisms, such as the mouse, has shed light on gene function and hence the biology of many basic neurobiological processes. Together with the power of genetics to find genetic changes that cause psychiatric disease, these advances are leading to novel therapies for common conditions. For psychologists, genetics is influencing the way work is done from the bench to the bedside. An understanding of genetic methodologies is crucial if psychologists are to take advantage of the new possibilities opened up by genetic research.Perhaps the most fundamental advance has been the identification of all human genes through the sequencing of the human genome. This information can now be put to use in a number of ways with current and novel genetic technologies. Understanding the biology of psychological processes Many neurobiological phenomena in humans can be studied in model organisms. Genetic techniques make it possible to find out which genes are involved in these processes. A basic method has been the ability to mutate genes at will in the mouse, so that in principle it is possible to investigate the function of all known genes. Newer approaches make more subtle changes possible. There is little doubt that transgenic technologies will continue to revolutionize our understanding of neuroscience for years to come. Helping patients Genetic mapping studies have already led to the identification of disease genes in a number of disorders of interest to psychologists. Childhood conditions, such as X-linked mental retardation, as well as late onset disease, such as dementia, have been shown to be due to abnormalities in a single gene. Soon the genetic bases of common psychiatric disorders, such as schizophrenia and depression, are likely to be unraveled. With this knowledge will come a better understanding of the cause of psychological disorders, the starting point for the development of effective therapy. For example, treatment of Alzheimer's disease is already changing because of genetic research. Treatment Our ability to treat patients is limited by our ignorance of how psychopathology arises. Yet we do know that there is great variation in the response to treatment and that some of this variation is due to genetic factors. Our ability to look at all our genes opens up new possibilities. On one hand, we can seek to identify which genetic variants confer susceptibility to particular drugs or to psychotherapeutic interventions. On the other hand, using methods that monitor the expression of genes in response to treatment (either by pharmacology or psychotherapy,) we can investigate the response of a patient and target therapies appropriately. These new approaches are likely to make existing therapies safer, by reducing side effects, more effective, by targeting the best therapy to the individual needs of a patient, and lead to the discovery of entirely new treatment regimens. Jonathan Flint, M.D. |
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