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.]
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.
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.
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.
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.
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.
There is no disease mongering.
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.
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.
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.
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.
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.