GeneSight Testing in St. George at Zion Mental Health

Many doctors, many medicines

Snowbirds and full-time retirees in St. George often take prescriptions from doctors in two states. Add a psychiatric medicine that causes dizziness or does nothing, and it is hard to know whether the cause is the medicine, the dose, an interaction, or something about your body. GeneSight, a genetic test from Myriad Genetics, helps answer the last part.

How it works

A cheek swab is sent to the lab. It checks genes like CYP2D6 and CYP2C19, which build liver enzymes that clear many antidepressants and other medicines. A slow version can let medicine build up and cause side effects at normal doses. A fast version can clear it before it helps.

The report in your hands

Each common psychiatric medicine lands in one of three columns: no expected gene issue, a moderate one, or a significant one. Picture a trail sign at Snow Canyon: a caution marker does not close the trail, it just tells your provider to take a different route, start with a smaller step, or check in more often.

Who it helps most

• People who have tried two or more medicines for depression or anxiety without relief
• People who had unusual side effects at ordinary doses
• People who take many medicines, where interactions are a concern

For a first psychiatric medicine, standard choices usually work fine without testing.

Heart, pain, and stomach medicines

The same enzymes process many medicines from other doctors. CYP2D6 turns codeine and tramadol into their active forms, and CYP2C19 affects clopidogrel, a common heart medicine. With your consent, results can be shared with your cardiologist, primary care doctor, or pain specialist.

What the studies say

In a large trial called GUIDED, people whose care used GeneSight results improved and reached remission more often than those who did not, though the study fell short of its main goal for average symptom change. Separately, panels of pharmacogenetics experts publish dosing advice for several antidepressants based on CYP2D6 and CYP2C19 status. So the test shifts the odds in your favor without making promises.

Its limits

A report will not tell you whether you have depression, and it cannot name the one medicine that is sure to work. It also has no FDA approval as a tool for picking antidepressants. Your provider reads it alongside your full psychiatric evaluation, your medicine history, and what matters most to you.

A St. George example

Picture a retired schoolteacher in Bloomington who felt wobbly and queasy on two antidepressants, even at the smallest doses. Her report might show she clears those medicines slowly through CYP2D6, so modest doses built up far higher than expected. Her provider could switch to one handled by a different enzyme, or begin lower and climb slowly, which also lowers her risk of a fall.

Keeping it private

The report lives in your protected medical record. A federal law from 2008, the Genetic Information Nondiscrimination Act, bars most employers from basing job decisions on genetic results.

How it works here

First, you and your provider talk about whether results could change the next decision. If so, a soft swab is rubbed inside your cheek during your visit. When the report comes back, your provider sits down with you, walks through it column by column, and explains what changes.

When testing can wait

If you have tried only one medicine for a few weeks, a proper trial usually comes first. Your provider will be straight with you about whether a report would change anything right now.

Good for life

Genes do not change, so the report stays useful. Keep a copy for doctors in both of your homes.

Getting started

Ask about testing at any visit. It becomes part of your ongoing medication management. Visit us at 169 W 2710 S Cir in St. George. Become a patient to ask whether it fits.