Six weeks after starting an antidepressant, your daughter still sleeps until noon on weekends, skips dinner, and says the pills make her feel “flat.” A friend in your parent group says her son had a cheek swab that showed which medications his body might struggle with, and you start wondering whether that test would have saved your family some of these weeks.
Two questions usually follow. Is the medication failing, or does it need more time? And would a genetic test help the prescriber choose better? A rushed switch or an abrupt stop can cause its own problems, so both deserve a careful answer.
What Pharmacogenomic Testing Is
Pharmacogenomic testing looks at genes that affect how the body processes certain medications. Most panels used in mental health focus on liver enzymes, especially CYP2D6 and CYP2C19. Variants in these genes can make a person a poor, intermediate, normal, rapid, or ultrarapid metabolizer of a given drug. A poor metabolizer may build up higher levels of a medication on a standard dose and notice more side effects. An ultrarapid metabolizer may clear it so quickly that it has little effect.
A clinician swabs the inside of the cheek, a lab analyzes the DNA, and the report goes back to the prescriber who ordered it. When a teen has already had a rough time with one or two medications, some parents ask whether they can get accurate genetic tests from Genesight or a similar lab before the next change. According to the company, its report sorts more than 60 mental health medications into three groups based on predicted gene-drug interactions, and results typically reach the provider in about three days.
Give the Current Medication a Fair Look First
Before assuming the medication or your teen’s genes are the problem, check the timeline. The National Institute of Mental Health notes that antidepressants usually take 4 to 8 weeks to work, and that sleep, appetite, energy, and concentration often improve before mood does. A teen who is sleeping a little better at week five may be on the right track even if they still seem low.
Missed doses are another common reason a medication seems to fail. Teens forget, run out, or quietly stop because of side effects they are embarrassed to mention, so ask directly and without judgment. If you are looking for ways to open that conversation, this guide on how to support your teen battling depression covers talking without shame and keeping your teen connected.
There is also a safety reason to stay closely involved. All antidepressants carry an FDA boxed warning, the most prominent warning a drug label can have, about suicidal thoughts and behaviors in young people. NIMH explains that children, teenagers, and young adults under 25 may have an increase in suicidal thoughts or behavior, especially in the first few weeks of treatment or after a dose change. Watch closely during those periods, and call the prescriber right away if you see new or worsening agitation, withdrawal, or talk of self-harm. The 988 Suicide & Crisis Lifeline is available by call or text at 988.
What the Test Can and Can’t Tell You
Some gene-drug links appear in FDA drug labeling. The agency’s Table of Pharmacogenetic Associations lists atomoxetine, a nonstimulant ADHD medication often prescribed to teens, as reaching higher levels in CYP2D6 poor metabolizers, with a higher risk of side effects. It lists a 20 mg maximum dose of citalopram for CYP2C19 poor metabolizers because of heart rhythm risk.
The same FDA page adds that including a gene-drug pair in the table does not necessarily mean the agency advocates testing before prescribing. It also says a patient’s genetic makeup is only one of many factors that affect drug levels and response.
Test makers say much the same. The company behind that test states that its results do not diagnose any condition, do not cover drug-drug interactions, and do not show which medication will work best. A medication in the “use as directed” group is not guaranteed to help your teen, and one in a caution group is not off limits. Much of the outcome research on these tests has also involved adults, so evidence in teenagers is thinner.
Genes are also only part of what affects drug levels. Other prescriptions, supplements, and smoking can change how the body handles some medications. Teens sometimes borrow pills from friends, and antidepressants are among the medications young people commonly share, as this piece on teens sharing prescription drugs describes. The prescriber needs to know everything your teen takes, or even a carefully read report can point the wrong way.
Questions to Ask the Prescriber
Bring a short list of what you have noticed since the medication started, including sleep, appetite, school, mood, and side effects, with rough dates. Then consider asking some of these questions.
Is it too early to judge this medication, and what would a fair trial look like? Could the dose, timing, or missed doses explain what we are seeing? Would pharmacogenomic testing change what you do next, or would you make the same choice without it? If we test, will you go over the results with us and our teen? What does the test cost with our insurance, and how long until we have results?
Ask about privacy too. The federal Genetic Information Nondiscrimination Act limits how health insurers and employers can use genetic information, but it does not cover life, disability, or long-term care insurance.
Include your teen whenever you can. A 15-year-old who understands why a medication is being adjusted is more likely to take it consistently and speak up when something feels wrong.
Whatever you decide about testing, keep your teen on the current medication until the prescriber says otherwise. NIMH advises against stopping a prescribed medication without a provider’s help, even when someone feels better, because a slow and supervised taper avoids unpleasant or harmful effects. A pharmacogenomic report can add useful information to that plan, and the prescriber is the right person to decide how much weight it carries.
Also read:
How to Choose the Right Therapeutic Boarding School
5 Benefits of Residential Therapy for Troubled Teens
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