The Jesalva Algorithm: Principle #5 - Genomic testing

Psychopharmacogenomic testing (AKA "Genomic Testing") is a new tool that has been available to clinicians during the last few years.  Armed with patient genetic information, clinicians can more quickly identify effective therapies, thus limiting the prolonged suffering and economic burden place upon many patients with chronic illness.​   This includes patients with treatment resistant depression, bipolar disorder, anxiety and attention deficit disorder (ADD).

According to genesight.com:
GeneSight® Psychotropic is a pharmacogenomic test that uses a proprietary algorithm to analyze 12 different genes to weigh their combined influence on patient response to more than 55 different psychotropic medications. Most neuropsychiatric medications are processed through multiple metabolic pathways, and genomic variants influence both metabolism and response. Unlike other tests, GeneSight uses a proprietary combinatorial pharmacogenomic approach, which measures multiple genomic variants for each patient and weights them in combination to provide comprehensive, genetically-driven recommendations for each medication.
The GeneSight® test provides information on FDA-approved medications prescribed for specific conditions such as depression and anxiety, and analyzes how your patient’s genes affect their response to these medications. This precision medicine tool can help you select the drug(s) and dosage(s) that are best suited to your patient’s condition and genetic makeup.
The test itself is very simple to do.  All it takes is a cotton swab of the inside of the cheeks which is then sent to the lab.  Results come within several days and it outlines which medications the patient can tolerate and which ones they should avoid.  It is specific for several classes of psychotropic medications including antidepressants, stimulants, antipsychotics and mood stabilizers. 
Another benefit of the test is testing for the MTHFR (methylenetetrahydrofolate reductase) gene.  This is an important gene that codes for the enzyme MTHFR.  MTHFR is an enzyme that converts folate to L-methylfolate.   L-methylfolate is important because it is a necessary component in the synthesis of monoamine neurotransmitters like serotonin, dopamine and norepinephrine. It is these neurotransmitters that are implicated to be low in states of depression and are the targets of many of the antidepressants that are used today. 
Genomic testing is a test of tolerability.  It can help in predicting which medications a patient can tolerate and which medications to avoid.  This is immensely helpful in patients who seem to be intolerant to the side effects of medications.  It narrows down the choices of medications to only a few and reduces the time to find the right medication.