The rapid advancement of the technologies in genetics has prompted genetic testing to become an essential component in clinical practice and research. In the past decades, we have seen how genetics was studied to unravel its relationship to underlying psychiatric disorders.
Genetics is one of the most critical factors as to how well a patient responds to medication and whether they have side effects. Before prescribing an antidepressant or an antipsychotic, psychiatrists are trained to ask whether any of their family members are taking drugs in the same class, and which medications they responded to. So if any of your family members responded well to Zoloft and became more anxious with Lexapro, it is more likely you will respond to Zoloft and feel anxious with Lexapro.
Genetic Testing or ‘Pharmacogenomics,’ is the process of looking at a person’s DNA, and based on their DNA sequences predicting which medications they are more likely to have a good response to and which medications are more likely to give them side effects. It is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder. More than 1,000 genetic tests are currently in use, and more are being developed.
Several methods can be used for genetic testing:
- Molecular genetic tests study single genes or short lengths of DNA to identify variations or mutations that lead to a genetic disorder.
- Chromosomal genetic tests analyze whole chromosomes or long lengths of DNA to see if there are substantial genetic changes, such as an extra copy of a chromosome, that cause a genetic condition.
- Biochemical, genetic tests study the amount or activity level of proteins; abnormalities in either can indicate changes to the DNA that result in a genetic disorder.
Genetic testing is voluntary. Because testing has benefits as well as limitations and risks, the decision about whether to be tested is a personal and complex one. A geneticist or genetic counselor can help by providing information about the pros and cons of the test and discussing the social and emotional aspects of testing.
The algorithms are created by looking at the DNA sequences of other patients with similar DNA sequences and receptor structure, looking at data as to how well they responded to particular medications, and which medication they have had side effects too. This information is used to predict which drugs you are likely to respond well to, and if there are any medications, you may be at risk of having an adverse reaction to.
It is important to note that response to medication is multifactorial, and genetic testing is used with regards to giving us more information but is not one hundred percent accurate. We still need to deny on clinical presentation, history, and response to past treatments as the essential factor in our decision making.
Indications for genetic testing include if a patient has failed trials of medication before, if a patient cannot decide what medication they wish to start, or if they want the information.