Recent research has revealed that differing bodies may metabolize the same drug differently. Why and how does this occur? Investigation into the burgeoning field of pharmacogenomics can help answer those important questions. Pharmacogenomics is the study of all genes in the genome that may determine drug response.1 Looking into studies where psychiatric patients have been diagnosed with the same disease, we can see a large sample of patients that react differently to similar or the same medications. In pharmacogenomics of the psychiatric population, drugs are divided into three categories based on safety and effectiveness: red category, yellow category, and green category; red-zone, yellow-zone, and green-zone. The subjects of the studies cited herein are a sampling of those who took either red, yellow, or green categorized FDA-approved drugs. There is also a small sample of subjects who took a combination of yellow and green drugs simultaneously. However, there are no subjects that took a combination of red and yellow or a combination of red and green; and there are also no subjects that took drugs from all three categories. Drugs that treat depression are the focus of this research, as psychiatric medicines, such as antidepressants, have a large sampling of patients who have or have not done well with the various medications. Pharmacogenomic testing will help treat patients more effectively with medication that correspond better to the patient’s genetic makeup. This results in a more personalized approach to medicine.

Keywords: gene, personalized medicine, pharmacogenomics, psychiatric

ADHD, Attention Deficit Hyperactivity Disorder; CPGx, Combination Pharmacogenomics; DNA, Deoxyribonucleic Acid; JRA, Juvenile Rheumatoid Arthritis; MTHFR, Methylenetetrahydrofolate Reductase; OA, Osteoarthritis; OCD, Obsessive-Compulsive Disorder; PMDD, Premenstrual Dysmorphic Disorder; PTSD, Post-Traumatic Stress Disorder; RA, Rheumatoid Arthritis; SNRI, Serotonin And Norepinephrine Reuptake Inhibitors; SSRI, Selective Serotonin Reuptake Inhibitor; URM, Ultra-Rapid Metabolizer

Individual patients can respond differently to the same or similar medication. The differences can be due to a multitude of factors: age, ethnicity, body mass, nutrition, metabolizing enzymes, and/or genetics. Studying the effects of genetic factors on medications might help physicians select the best medication for a particular patient. The study of human genes and how they affect medication and efficacy is termed, pharmacogenomics. One of the most important features of pharmacogenomics is that it can be used to predict, and thus prevent, adverse drug reactions that can seriously affect a patient’s quality of life.² Pharmacogenomics can also be used to look into toxicity levels in patients, thus reducing overdosing on a prescribed medication. Pharmacogenomics is a piece of what is called, “personalized medicine” which could change the paradigm of medical care for individual patients for the better. The more specific patient treatment can become the more likelihood for improved outcomes. The Golden Helix Institute of Biomedical Research has deployed several genomic databases as a web service so that healthcare providers and researchers can access the many studies and results.³ This type of intercommunication and sharing of information is essential to the field of pharmacogenomics as it goes forward. The research reviewed herein is focused on psychiatric patients and the medications that are typically used. But first, a brief review of the “basics” follows.

What is DNA?

Deoxyribonucleic acid (DNA) is a genetic material sequence that contains a unique configuration in every individual; even identical twins develop genetic mutations specific to the individual. Individual DNA consists of 3 million base pairs, which is called a human genome. DNA’s information is stored by codes made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). The purine and the pyrimidine bases are linked together in pairs to form a double helix; as such, purine (A,G) and pyrimidine(C,T). DNA purine base A pairs with pyrimidine T and purine base G pairs with