- We're kind of in this one-size-fits-all medicine and that means, especially if you have a complex illness, a lot of trial and error.

- That was a very uncomfortable feeling to have my doctors coming in and saying to me, "Well, you know, we could try this.

"We could try that, but we just really don't know."

- If you're one of the more than 16% of Americans taking a prescription mental health medication, chances are, it's been a struggle.

You may have experienced gnarly side effects, like nausea, trouble sleeping, even panic attacks, and you may have tried out multiple medications because about 50% of people with depression don't respond to their first medication.

And around 30% of patients don't respond to typical antidepressants at all.

Could personalized medicine be the relief you're all wishing for?

Personalized medicine is trying to revolutionize the field of mental health by predicting how someone will respond to a prescription medication before they have to undergo the consequences.

But here's a question.

Using personalized medicine to treat conditions, like depression or anxiety, is not that common, so how effective is it, really?

(soft upbeat music) To understand personalized medicine, we need to know what exactly it is.

And, by the way, before you think about it, I don't mean personal as in, like, up in your business, personal, I mean genetically personal, custom-tailored for you.

Some people find the term "personalized medicine" confusing.

It's also a really broad term.

Simply put, this refers to designing a treatment to match someone's individual genetic profile 'cause we're all different.

And one way to do this is to find out which medicine, specifically, will work best for each person.

This is called pharmacogenetics.

To explain more, here's Joyce, a psychiatric nurse practitioner.

- Pharmacogenetic testing can help allow you to better predict the types of medications, including the dosage, the frequency of said medications that a patient may respond better to.

So the end-goal of pharmacogenetic testing is to make devising a treatment plan for a patient much easier for the clinician, and make it much easier for the patient to find a medication that works well for their system the first time around without having to undergo many different medication trials.

- Pharmacogenetics is a valuable field of study because mental health medications affect people in different ways.

Take SSRIs, for example, which are thought to treat depression and anxiety by increasing serotonin in the brain.

Some patients on SSRIs won't feel any side effects while others really will.

And if you can't tolerate one SSRI, you may be able to tolerate another.

This is because one person may metabolize or break down certain chemicals better than another person will.

Scientists aren't sure why these inconsistencies exist, so doctors have to take educated guesses when prescribing antidepressants or other mental health treatments.

Who could benefit from personalized medicine?

Apparently, just about everyone.

In one study, more than 99% of people assessed genetically experienced high sensitivity to at least one medication.

Now, realistically, an individual may seek out personalized medicine if they're unsatisfied with a current medication plan.

On the other hand, doctors would seek genetic testing for their patients if their patients have a lower than desired response to a medication, if the medication stopped working altogether if they're really bad, unwanted side effects or in the elderly or people with liver damage who may have trouble breaking down particular medications.

Personalized medicine is being used in all kinds of fields, from cancer to nutrition to wellness and its popularity in treating mental illness is only growing.

For more on all of this, here's Dr. Holly Garriock.

- Genomics is quite good for conditions like Alzheimer's disease, Parkinson's, some breast cancers even.

It's even pretty good for some pharmacogenomic testing and antidepressant response and whether or not you will respond and how fast you metabolize a drug, for example.

It's less good for things like mental health and behavior.

Those are conditions that are really influenced by lots of environmental factors in your early childhood experiences.

And so we need to make some advances in the characterization of that in order to make some advances for the genomic analysis.

- Pharmacogenetics is taken the form of consumer products, tests that can be done at home or in a doctor's office.

Now, there's some promising results and research, but more studies need to be done to confirm their effectiveness.

Now, I'm gonna walk you through the main steps of the testing process.

Step one, a psychiatric doctor or nurse practitioner orders a test for a patient, simple enough.

Their DNA sample is then collected, mailed to a lab.

Step two, the lab processes the sample using a unique combinatorial algorithm, fancy, which evaluates how variations in clinically identified genes may influence an individual's outcome with medications.

And it looks at this for dozens of different medications.

Medications are then placed into different categories, such as no gene-drug interaction, moderate gene-drug interaction or significant gene-drug interaction.

And, finally, step three, test results are sent to the patient's physician who shares their recommended treatment plan with them and, most likely, winds up prescribing new medications or re-dosing existing ones.

- So the way that I use pharmacogenetic testing is if a patient is either particularly sensitive to medications, like maybe they've had a serious side effect to certain medications or if they've tried and failed a bunch of different types of medications, so they're more treatment-resistant.

There are a lot of different factors that we consider before ever prescribing any sort of medication.

Some of the other things that we take a look at are the patient's own desires.

Non-pharmacological interventions including therapy, exercise, healthy diet, sleep hygiene, family history, those are all very, very crucial for any patient's treatment plan.

And, finally, the clinician's own judgment.

I think with any sort of testing that you do, it should always be under the guidance of a healthcare provider who is properly trained on interpreting these results and understanding how to disseminate that information and work it into a treatment plan that is individualized for that patient, rather than just blanket saying, "Yes, this, no, this."

- How accessible is this testing to patients?

Is this something insurance covers?

- For some insurances, it can be covered free of charge, but for most commercial plans, as far as I understand, there is some cost to the patient.

I've heard costs anywhere from a couple hundred dollars to two to $3,000 for uninsured patients, which is an astronomical price for any patient whatsoever, let alone an uninsured patient.

- Now, let's get nerdy and talk numbers.

An analysis of data from the University of Michigan's guided study found that pharmacogenetic testing significantly improved clinical outcomes in patients taking medications with gene-drug interactions when compared to their usual treatment.

They found 70% relative improvement in remission, 42% relative improvement in response rates and 23% relative improvement in symptoms.

Relative, relative, relative.

Tell me, do these numbers sound good to you?

The bottom line is that pharmacogenetic testing works to an extent with variable results per patient.

Sometimes, it doesn't work at all.

There are a couple big limitations to keep in mind.

Number one, even if a pharmacogenetic test result encourages a patient to take a certain medication, there may still be issues with effectiveness or unwanted side effects.

These tests can only predict how a patient will respond to a particular medication.

Warning number two, potential loss of privacy.

These tests obviously gather sensitive information that some people wouldn't want floating around, but, Holly, tell it to me straight.

Is someone gonna run out and, like, take my DNA and then sell it on the black market?

- It's highly unlikely that that will happen, but it is why we take it so seriously.

Even with our program, with all of us, we take significant steps and put in place significant policies and procedures to really protect the data and privacy of the data that our participants provide.

So many data sets will remove or strip identifiable information, such as your name or other indications.

- So we've learned that personalized medicine has the ability to save mental health patients time and help them avoid negative side effects and a hassle in trying to find the right medication, but it's not a guaranteed one-stop shop.

Holly, what stands in the way of personalized medicine technology from becoming mainstream in mental health treatment?

- Yeah, the barrier is money, right, and knowledge.

So, really, we need to be able to get these tests up to a high level of validity and reliability, but also a low cost, right?

We need insurance companies to be able to cover them.

We need doctors to be able to be aware of these genetic tests for their patients and know that they can order them and gather some additional information for their patient.

- Now, this treatment model could be a threat to pharmaceutical companies who are attached to a one size-fits-all cost-effective approach to drug development.

But in 2005, the FDA issued a guide encouraging drug makers to gather genetic data.

And as we see more research and drugs approved, I would imagine more pharmaceutical companies will want to invest in personalized medicine.

Joyce, this may be a loaded, yet necessary question.

What can be done to break down these barriers, not only to pharmacogenetic testing, but to psychiatric care?

- It is very, very difficult to find a provider.

Best thing I would say and to any of my patients is, number one, check with your insurance.

Check with your local community.

Some things that I would love to see, as a clinician, are longer longitudinal studies to see if tailoring these medications based on these results are really going to have prolonged, sustained effects on patients, rather than very short-term effects.

My biggest hope is, in the future, as this research becomes more developed, is that we will see more and more patients receiving benefit for this sort of technology.

And, in the end, that this will become much more of, like, a first-line intervention.

- Okay, real talk.

I'm hopeful about the future of personalized medicine.

The world needs it and I know that you now wanna learn more.

So check out resources in our episode description and also comment below about what you think about personalized medicine and how it may benefit the world of mental health treatment.

And in the meantime, be sure to follow along for more health topics on PBS Vitals.

We will see you all soon.

(soft upbeat music)