Nausea. Fatigue. Weight gain. Sexual side effects. Insomnia. Dry mouth.

Not a pleasant list. It can be summarized in one word: Yuck.

These are just some of the side effects that can be caused by antidepressants, according to the Mayo Clinic.

A lot of people experience side effects when taking depression medication. According to a study published in the journal, Psychiatry: “38 percent of the approximately 700 patients surveyed reported having experienced a side effect as a result of taking a selective serotonin reuptake inhibitor (SSRI) antidepressant; the most common side effects mentioned were sexual functioning, sleepiness, and weight gain.”

But side effects shouldn’t be a reason to not start or to stop taking antidepressants. The Mayo Clinic writes:

“If side effects seem intolerable, you may be tempted to stop taking an antidepressant or to reduce your dose on your own. Don’t do it. Your symptoms may return, and stopping your antidepressant suddenly may cause withdrawal-like symptoms. Talk with your doctor to help identify the best options for your specific needs.”

The consequences of not treating depression can be significant: risk of suicide, relationship trouble, and serious additional health issues. So recognizing and managing side effects is an important part of depression treatment.

How Metabolism & Side Effects Are Connected

Everyone’s metabolism is different. Your genes can affect how quickly your body breaks down (metabolizes) medicine . No two people have identical genetic profiles – unless they are identical twins.

There are more than 20,000 genes in your body. Mostly found in the liver, the Cytochrome P450 system is a family of about 60 genes that produce enzymes that metabolize medications, including antidepressants. Six of those enzymes metabolize about 90 percent of medications.

Your unique genetic profile determines the rate at which your body may metabolize a medication. Research has found that people typically fall into one of four general metabolizer “types”:

1. Poor metabolizer – medication is broken down very slowly. May experience side effects at standard doses.
2. Intermediate metabolizer – slow rate of metabolism. May have too much medication at standard doses, potentially causing side effects.
3. Extensive (or normal) metabolizer – normal rate of metabolism. Has normal amount of medication at standard doses.
4. Ultra-rapid metabolizer – medication is rapidly broken down. Medication may be removed from your system too quickly to provide any symptom relief.

Based on your genetic profile, you may be a poor metabolizer for one medication but an ultra-rapid metabolizer for another.

Side Effects You Shouldn’t Ignore

Any side effect that causes you discomfort, pain or concern should not be ignored. If taking an medication for a psychiatric condition causes a side effect, you should first share your concerns with your doctor.

Additionally, some people may experience a side effect when they start taking a medication, but then it won’t bother them as much. Everyday Health reports that “when you first begin antidepressant treatment, depression medication side effects can be physical symptoms like headache, joint pain, muscle aches, nausea, skin rashes, or diarrhea. These symptoms are usually mild and temporary.”

“Many people build up a tolerance to these early side effects, and they rarely require discontinuation of medications,” Madhukar Trivedi, MD, a psychiatry professor and director of the Depression Center at the University of Texas Southwestern Medical Center in Dallas, told Everyday Health.

You should report any mild or temporary side effect to your doctor.

Where to Find Side Effects Information

Every FDA-approved medication comes with a warning about side effects. You can find these on our website by clicking on each of the FDA-approved medications included in our panels. After choosing the type of test, scroll down into the list of medications. When you click on one of the medications, it will take you to more detailed information about that medication, including its uses, potential side effects, precautions, interactions and overdose information.

Your pharmacy should provide this information when you fill your prescription. You can also go to the manufacturer’s website for additional information.

Genetic Testing Can Help

Pharmacogenomic tests, like the GeneSight® Psychotropic test, can help determine how your body metabolizes or responds to medications commonly prescribed to treat depression, anxiety, ADHD and other psychiatric conditions.

And keep in mind that while genetics provides an important piece of the puzzle, there are several factors that can influence medication response and susceptibility to side effects other than the genes that are tested on the GeneSight panel, including drug/drug interactions, food/drug interactions, and environmental factors such as lifestyle. The GeneSight test can serve as an objective tool that can be used in concert with these other factors to help guide medication selection.

If you are frustrated with side effects, the GeneSight test may be able to help.