July 12, 2018 Read Original Story

Genetic testing to guide antidepressant choices: Big news coverage, but limited evidence

Reviewed By

Rating

Which antidepressant is right for you? This genetic test could help

Our Review Summary

This Philadelphia Inquirer article looks at two companies’ direct-to-consumer genetic tests designed to help doctors rely less on trial-and-error, and more on genetic markers, in guiding their medication choices for patients who’ve proven difficult to treat for depression.

The article offers balance through two patient anecdotes. One patient says the genetic testing helped guide her to an effective antidepressant, while the other isn’t convinced. An outside expert is also tapped who points to specific treatments rather than genetic testing for higher chances of success.

Although this article was cautious about the touted benefits, it would have served readers better by exploring some of the limitations of the research studies. The evidence doesn’t appear to come from gold-standard, randomized controlled trials. The only study we found through an online search was an abstract presented at a May 2018 medical conference.

Why This Matters

The majority of patients with major depression who choose antidepressant therapy do not achieve remission with the first medication they try. Even among those who do, many relapse. That’s why many patients end up frustrated — and still suffering with symptoms — as they endure a subsequent trial-and-error approach until an effective medication or combination of medications is found.

One promise of precision medicine — that has yet to be proven — is that genetic testing may help guide this process and make it more “personalized” and efficient. It’s important to make it clear (as this article does) that these genetic tests cannot predict which medicines will work, and it’s arguable if they can even identify those that will not.

Furthermore, because the financial stakes are high, it’s important for journalists to scrutinize (and be transparent) about the funding of studies on these genetic tests, potential conflicts of interest, and whether the results are expressed in more meaningful absolute terms, rather than more eye-catching (and potentially misleading) relative terms. For more on this, see our primer on evaluating relative vs. absolute numbers.

Criteria

Does the story adequately discuss the costs of the intervention?

Satisfactory

The article notes that the GeneSight test is covered by Medicare if a patient is being treated by a psychiatrist and that some insurance plans also cover the test. It also tells us that the Genomind Genecept Assay is covered by Medicare and Medicaid.

We aren’t provided out-of-pocket costs for the GeneSight test, though. Nor could we find the full price of Genomind’s ‘Genecept Assay’ on its website or elsewhere.

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

On the one hand the article is appropriately cautious in stating:

But while genetic testing offers tools to better guide patients’ treatment, it cannot tell doctors which medicines will work — or necessarily provide the key to enduring remission from depression.

On the other hand, the results of Myriad’s recently published “large-scale test” on outcomes are given as “patients were 30 percent more likely to respond to treatment” when guided by their GeneSight test.

But, as we wrote back in May in a review of a Wall Street Journal article on the test, there’s problems with that percentage:

“No absolute numbers are given … just a relative improvement in ‘response’ to medication (ie. 30% greater response to the medicine when the test was applied).”

The Philadelphia Inquirer story quotes an independent source saying he’s impressed by the response rate (50%) and remission rate (40%) at six months, but again, these are relative numbers. Myriad did not provide the absolute numbers at 6 months … only at 8 weeks …. at which time the absolute difference in achieving remission between those who did and did not receive genetic testing was only 5%.

Does the story adequately explain/quantify the harms of the intervention?

Not Satisfactory

Although harms from a cheek swab are unlikely there is a potential harm in framing the genetic testing results as guiding the choice of one antidepressant over another. Patients may focus solely on pharmaceutical options, to the exclusion of non-pharmaceutical ones.

Antidepressants have well-documented side effects and drug interactions.

Does the story seem to grasp the quality of the evidence?

Not Satisfactory

The only data cited in the article comes from unpublished data presented at a medical conference. The research has not been peer-reviewed.

Does the story commit disease-mongering?

Satisfactory

No disease mongering.

We were glad to see the article include this relevant context:

As many as two-thirds of people with depression aren’t helped by the first antidepressants they try, leaving many to spend months after they are diagnosed without real help …. [genetic testing] is meant to help avoid the painful trial-and-error process many depression patients endure in the search for the right medicine.

Does the story use independent sources and identify conflicts of interest?

Not Satisfactory

As noted above, it should have been made clear that the May 2018 “large-scale test” is unpublished and funded by the test sponsor.

The same goes for the Genecept paper that is cited by the company’s VP: it’s an industry-sponsored review paper — not original research — and cannot make claims about improved clinical outcomes or reduced overall medical costs from genetic testing.

We were pleased to see two independent sources cited, one of which provided a critical perspective.

Does the story compare the new approach with existing alternatives?

Satisfactory

An independent source is included who mentions transcranial magnetic stimulation (TMS) and electroconvulsivetherapy (ECT) as alternatives to antidepressants in the treatment of resistant depression.

One alternative that is not mentioned is cognitive behavioral therapy.

Does the story establish the availability of the treatment/test/product/procedure?

Satisfactory

It’s clear that both GeneSight from Myriad Genetics, and Genecept from Genomind, are commercially available.

Does the story establish the true novelty of the approach?

Satisfactory

By featuring both the work of Myriad Genetics and Genomind, the reporter makes it clear that this is already a competitive arena within so-called “precision medicine.”

Does the story appear to rely solely or largely on a news release?

Satisfactory

This article does not rely solely on a news release and quotes outside sources.

Total Score: 6 of 10 Satisfactory

Comments

We Welcome Comments. But please note: We will delete comments left by anyone who doesn’t leave an actual first and last name and an actual email address.

We will delete comments that include personal attacks, unfounded allegations, unverified facts, product pitches, or profanity. We will also end any thread of repetitive comments. Comments should primarily discuss the quality (or lack thereof) in journalism or other media messages about health and medicine. This is not intended to be a forum for definitive discussions about medicine or science. Nor is it a forum to share your personal story about a disease or treatment -- your comment must relate to media messages about health care. If your comment doesn't adhere to these policies, we won't post it. Questions? Please see more on our comments policy.

COMMENTS button We welcome comments, which users can leave at the end of any of our systematic story reviews or at the end of any of our blog posts.

But before leaving a comment, please review these notes about our policy.

You are responsible for any comments you leave on this site.

This site is primarily a forum for discussion about the quality (or lack thereof) in journalism or other media messages (advertising, marketing, public relations, medical journals, etc.) It is not intended to be a forum for definitive discussions about medicine or science.

We will delete comments that include personal attacks, unfounded allegations, unverified claims, product pitches, profanity or any from anyone who does not list a full name and a functioning email address. We will also end any thread of repetitive comments. We don”t give medical advice so we won”t respond to questions asking for it.

We don”t have sufficient staffing to contact each commenter who left such a message. If you have a question about why your comment was edited or removed, you can email us at feedback@healthnewsreview.org.

There has been a recent burst of attention to troubles with many comments left on science and science news/communication websites. Read “Online science comments: trolls, trash and treasure.”

The authors of the Retraction Watch comments policy urge commenters:

“Shed light, not just heat. Facts, challenges, disagreements, corrections — those are all fine. Attacking the person, instead of the idea or the interpretation, is neither acceptable nor helpful.”

We”re also concerned about anonymous comments. We ask that all commenters leave their full name and provide an actual email address in case we feel we need to contact them. We may delete any comment left by someone who does not leave their name and a legitimate email address.

And, as noted, product pitches of any sort – pushing treatments, tests, products, procedures, physicians, medical centers, books, websites – are likely to be deleted. We don”t accept advertising on this site and are not going to give it away free.

The ability to leave comments expires after a certain period of time. So you may find that you’re unable to leave a comment on an article that is more than a few months old.

Getty Images