Could genetic testing predict psychiatric illness?
Key Takeaways
Genetic testing is used for many purposes, but it is not currently confirmed to predict mental health disorders.
Some companies market genetic tests to help improve medication selection, but this is also not currently supported by research.
Physicians should continue to use family history and other factors to determine a patient’s risk for mental illness.
As mental health care becomes more mainstream, a growing number of people are wondering if it’s possible to predict psychiatric illness based on genetics.[] Research shows that by examining a patient’s DNA, doctors can identify changes in the genetic code that may result in disease or illness.
Genetic testing is already used for a variety of purposes, including carrier testing, diagnostic testing, predictive testing, and pharmacogenetics.
While this testing may be used to rule out certain diseases, it’s not yet possible to determine whether a person will develop psychiatric illness based on their genetic profile. However, such testing could possibly prove helpful in treating such illnesses.
Improving medication choice with genetic testing
Although we cannot yet predict the eventual onset of psychiatric illness based on genetic mutations alone, genetic testing may help reveal which psychiatric medications may benefit patients most.[] In general, medication selection is a trial-and-error process. However, because a person’s genetic makeup can influence the effectiveness of medications, genetic testing is being increasingly explored as a way to determine which psychiatric medications may benefit patients most.
Physicians should be cautioned that this is not yet a reliable method of psychiatric medication selection.
There may be future potential; while tests like these have not been approved by the US Food and Drug Administration, some, including GeneSight, are marketed to healthcare professionals as a method of identifying the most therapeutic drug recommendations.[]
Pharmacogenomic tests often use proprietary algorithms to assess pharmacodynamic and pharmacokinetic relationships. However, different aspects of such tests—such as specificity and sensitivity measures, metabolizer status, and blood medication levels—are not always clear.
Test results indicate which medications may be appropriate for use, but these results are also subjective. Physicians are ultimately responsible for interpreting the results correctly.
George Zubenko, MD, PhD, coauthor of a 2018 JAMA Psychiatry editorial on the use of pharmacogenetic tests for psychiatric treatment, wrote in a statement, “Doctors, patients, and family members should understand that the jury is out on whether [pharmacogenetic] testing improves good psychiatric care performed by board-certified psychiatrists.”[]
Unfortunately, consumer marketing of genetic tests may lead some to assume such tests may accurately determine which medications will work best. This concept has not been empirically confirmed in any study to date.
Family history and genetic counseling
Family history of mental health disorders remains an important risk factor for developing psychiatric problems.[] Mental health problems tend to run in families; this, coupled with the presence or absence of other variables, has a much higher predictive value than current genetic tests.
Genetic counseling may be beneficial for some patients and their families.[] Unlike genetic testing, genetic counseling helps people understand the factors in their own genetic makeup that may result in the development of disease.
In many cases, people living with psychiatric illness overestimate the possibility of others in the family developing the same disease.
Genetic counselors can help people overcome feelings of guilt that may occur if others in the family develop the same condition.
What this means for you
Currently, genetic tests cannot be used to predict a person’s chance of developing psychiatric illness with 100% certainty. Family history of illness remains a key predictive factor, and genetic counselors may help patients and their family come to terms with various factors which increase the risk of developing mental health problems.