Genetics of Mental Illness

A genetic disposition can be established for several mental diseases, including Alzheimer's, schizophrenia, Huntington's and autism. Deletions, mutations, translocations and other alterations in genes or chromosomes are responsible for many mental illnesses. Therefore, doctors can diagnose some mental illnesses by identifying the genetic abnormalities involved.

Genes can cause organic changes in a person that ultimately develop into mental illness. People who have blood relatives with these diseases are at risk for inheriting the genetic mutations that cause disease. Genetic testing for mental illness can be beneficial to these at-risk individuals.

Benefits of Genetic Testing for Mental Illness

Benefits of testing for mental illness include diagnosis of major illnesses, genetic counseling and medication selection. Since anomalies in known genetic markers correspond to certain diseases, comparing the chromosomal makeup to an individual with normal chromosomes allows diagnosis of these diseases.

Once a mental illness diagnosis has been made, an individual can act to try to control his or her environment and take precautions to prevent instigating episodes. In addition, many people would prefer to know if they are carriers of certain genes. They can then make informed decisions about having children who might be at risk for mental illness.

Genetic counseling is recommended when parents have a high risk of conceiving a child with major disorders. Risk assessment includes the mother's age and relatives or previous children with disorders. Genetic counselors give parents the information they need to make informed decisions after receiving genetic test results.

Certain diseases like schizophrenia require medication. Since specific genes are related to schizophrenia, DNA testing can help doctors assess which medications and dosage would be best for the patient. Testing a gene for a serotonin receptor allows them to predict how the patient would react after taking antipsychotic drugs. Another genetic test predicts which children with asthma will respond positively to an inhalant. Tests like these are prescribed on a wait-and-see basis.

Limitations of Genetic Testing for Mental Illness

Determining a genetic cause for mental illness has its complications. Most mental illnesses involve more than one gene. They can be caused by more than one gene on more than one chromosome in different populations. This means that different sets of genes are responsible for mental disorders in different families and ethnicities.

Also, environmental factors have an influence on disorders as well. Merely having a gene does not mean that a person will actually have the disorder. It depends on the circumstances surrounding the individual. One example of this is the gene associated with susceptibility to alcoholism.

Ethical Concerns over Mental Health Genetic Testing

Ethical concerns increase as the number of genetic tests available for diseases, illnesses and abnormalities rises. Concerns over genetically inherited mental disorders include:

• Confidentiality: People are concerned that a hospital or laboratory will not keep their test results confidential. Insurance companies can have access to genetic testing results and the patient might not realize it.
• Discrimination: People may be discriminated against for jobs or insurance once genetic tests label them with an illness.
• Regulation of testing: Testing should be regulated by the federal government to ensure adequate validity and support. Genetic counseling should be made mandatory.
• Reproductive issues: There is a possibility of mainstreaming the future populations by aborting all "different" fetuses. It could even become mandatory to perform genetic testing so the government can choose what types of people have the privilege of living.

Resources

Frey, Rebecca J. (2007). Genetic factors and mental disorders. Retrieved September 22, 2008, from the Mind Disorders Web site: http://www.minddisorders.com/Flu-Inv/Genetic-factors-and-mental-disorders.html.

Hannaford, Richard (1998). Genetic testing could bring stigma to children. Retrieved September 22, 2008, from the BBC News Web site: http://news.bbc.co.uk/1/hi/health/178301.stm.