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Summary of early Parkinson’s drug study claims there’s proof, but that’s misleading

Longtime antidepressant could slow Parkinson's

Our Review Summary

Researchers at the University of Michigan observed by looking at medical records a correlation between patients taking anti-depressants known as tricyclics and what appeared to be a delay in the worsening of Parkinson’s disease symptoms. Using rats and then test tubes full of cells, they experimented to see if the drug nortriptyline would slow the creation of alpha-synuclein protein, a hallmark of Parkinson’s. They did not do experiments on people.

The release does not give us any metric for the “slowing” that they observed. We wish there had been some numbers putting the results in context to help us judge the importance of such a small early study, or perhaps that the University had waited to issue a release until more was known.

[Editor’s note: The summary was revised to refer to alpha-synuclein protein, not amyloid plaque.]


Why This Matters

This “early concept” study does not prove that the anti-depressant known as nortriptyline will “slow” Parkinson’s disease in people. We fear the headline and lead sentence of the news release will mislead most readers into thinking there is proof where there is none. About 50,000 people are diagnosed each year in the United States, according to the National Institutes of Health and the economic and emotional burden of this degenerative disease is massive. Health news releases and stories should carefully avoid such quick fix reporting on preliminary research.


Does the news release adequately discuss the costs of the intervention?

Not Satisfactory

The story is about a proof-of-concept study, which is the very earliest step in research. But if it’s not too soon to issue a news release, it’s not too soon to address cost impacts. The release could have mentioned the cost of the medication, nortryptiline, or alternatively, the economic burden of Parkinson’s.

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

Not Satisfactory

No numbers are offered in the release. We don’t know how many patient records were examined. We don’t know the number of rats in the animal studies. We don’t know the number of test tubes in the cell-only stage of this early proof-of-concept study.

The release includes this statement on benefits:

“In a proof-of-concept study, published in the journal Neurobiology of Disease, the drug nortriptyline, which has been used to treat depression and nerve pain, stopped the growth of abnormal proteins that can build up in the brain and lead to the development of the disease.”

What does “stopped the growth” mean if we don’t have a measurement of growth in the absence of nortriptyline? For how long was the growth stopped? Was the impact temporary or permanent?The release doesn’t say.

The research was not done in humans but only in rats and in cells. The release should have included this information early in the text and in the headline.

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

The drug nortriptyline has side effects. These include nausea, rare allergic reactions and liver toxicity in some patients. The release should have made some reference to potential harms, even if these are not well-known for this new therapy yet.

Does the news release seem to grasp the quality of the evidence?

Not Satisfactory

The release does not provide enough detail about the work to give us a sense about the quality of the evidence. As we explained in the Benefits section above,  the release does not give any numbers for the patient records analyzed, or the rats in the laboratory or the test-tubes of cells. Without any numbers, we can’t judge evidence.

Reports on early animal research must be handled carefully. Only about 1 out of 500 compounds that look promising in mice make it to human use.

Does the news release commit disease-mongering?


There is no disease mongering.

Does the news release identify funding sources & disclose conflicts of interest?

Not Satisfactory

The release says this about the funding of the study: “The National Institutes of Health, as well as the Michael J. Fox and St. Mary’s Foundations, funded the study.” But the release does not identify any potential conflicts of interest. In our own reading of the material, we found that two of the study’s authors — C. Justman and P. Lansbury — are on staff with a for-profit biotech company, Lysosomal Therapeutics, of Cambridge, Mass.That should have been disclosed in the release.

Does the news release compare the new approach with existing alternatives?

Not Satisfactory

Parkinson’s disease is complex, unfolds over many years, and has many dimensions. It is often misdiagnosed. The release should have included some description of treatments available. Besides the drug levadopa, surgery and other therapies have been used to ease symptoms.

Does the news release establish the availability of the treatment/test/product/procedure?

Not Applicable

The release is about a “proof of concept” and no therapy is available based on this research. We’ll rate this Not Applicable but note that the release should have been more clear in the headline and lede that this therapy hasn’t been tested in humans.

Does the news release establish the true novelty of the approach?


The release suggests researchers have taken a novel approach to finding a new treatment strategy for Parkinson’s. It states:

“The idea that this clustering effect is controlled by how fast or slow a protein reconfigures itself is typically not a standard way of thinking in research on proteins, but our work has been able to show these changes.”

“Understanding how these proteins can clump together could point researchers in new directions and help them find other possible drugs that could potentially treat Parkinson’s.”

But as already noted above under Benefits, without testing the drug in humans, the claim of a novel finding seems unwarranted.

Does the news release include unjustifiable, sensational language, including in the quotes of researchers?

Not Satisfactory

The headline and lead sentence suggest there is “proof” that nortriptyline slows progression of Parkinson’s in people. Here’s the first sentence:

“Michigan State University scientists now have early proof that an antidepressant drug that’s been around for more than 50 years could slow the progression of Parkinson’s.”

The most we can say is based on this study is that researchers established an association between nortriptyline and Parkinson’s progression, and that the drug seems to affect proteins related to the disease in mice.

That’s not proof — early or late — that the drug could slow Parkinson’s in people, and the statement is unjustified.

Total Score: 2 of 9 Satisfactory

Comments (3)

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September 12, 2017 at 2:29 pm

Note: the drug inhibited the formation of misfolded alpha-synuclein, not amyloid plaques.


    Kathlyn Stone

    September 13, 2017 at 10:50 am

    Thank you for bringing that to our attention. A correction has been made and a note left in the Summary explaining the change.
    Kathlyn Stone
    Associate Editor


    Gary Schwitzer

    September 13, 2017 at 11:04 am

    Next time, please adhere to our comments policy. As stated, we usually delete comments left by anyone who doesn’t leave an actual first and last name and an actual email address. We made an exception this time.

    Gary Schwitzer