(part 4 Botox)
The studies using Botox for depression, like other research into Botox’s off-label potential, were so encouraging that they caught the attention of Allergan. In Rosenthal and Finzi’s research, 74 people with major depressive disorder were randomly assigned to receive Botox injections or a placebo. Six weeks later, 52% of the people who received Botox experienced a drop in reported symptoms, compared with 15% of the people given a placebo. “Over 50% of people responding is a high number,” says Finzi. “These are people who have already tried other treatments, and they are significantly depressed.”Now Allergan hopes to replicate the findings on a larger scale, and the company is currently running its own Phase 2 clinical trial. If its results are in line with Rosenthal and Finzi’s, it would be huge, paving the way for Botox to obtain official approval for the drug as a depression treatment. That wouldn’t change anything for doctors, of course–they can already prescribe it off-label, and some do, with great results–but it would allow Allergan to begin marketing Botox for depression, a change that could dramatically increase its adoption and sales.
Still, Botox’s use for depression raises a question that confounds some researchers. In some cases, how Botox works is evident: the toxin can block the signals between nerves and muscles, which is why it can help calm an overactive bladder, say, or a twitching eye, or the facial muscles that make wrinkles more apparent. In other cases, however (with migraines as well as with depression), scientists are flummoxed. They may have noticed that the drug works for a given condition, but they aren’t always sure why–in sciencespeak, they don’t know what the mechanism is.
With depression, Rosenthal and Finzi think it may relate to what’s known as the facial-feedback hypothesis, a theory stemming from research by Charles Darwin and further explored by the American philosopher and psychologist William James. The theory posits that people’s facial expressions can influence their mood. Lift your face into a smile and it may just cheer you up; if you can’t frown or furrow your brow in worry, perhaps you won’t feel so anxious or sad.
But it could be something else altogether. In 2008, Matteo Caleo, a researcher at the Italian National Research Council’s Institute of Neuroscience in Pisa, published a controversial study showing that when he injected the muscles of rats with Botox, he found evidence of the drug in the brain stem. He also injected Botox into one side of the brain in mice and found that it spread to the opposite side. That suggested the toxin could access the nervous system and the brain.
“We were very skeptical,” says Edwin Chapman, a professor of neuroscience at the University of Wisconsin–Madison, after reading Caleo’s study. But in August 2016, Chapman and his graduate student Ewa Bomba-Warczak published a study in the journal Cell Reports showing similar spreading effects in animal cells in the lab. For Chapman, it explained what he was hearing anecdotally from doctors: that Botox might be influencing the central nervous system and not just the area where it’s being injected.
Ironically, it’s the off-target effects of Botox that have some researchers most excited. “Botox may be working in a way that is different from what we think,” says Bomba-Warczak. “It may be even more complex.”
Chapman and Bomba-Warczak both think Botox is safe when used correctly, but they say their inboxes quickly filled with messages after their study was published. “We were startled by the number of people who feel they were harmed by these toxins,” says Chapman. “We feel these were pretty safe agents. Now it seems that for some people, they believe the toxin can sometimes cause something that may be irreversible. And that’s a total mystery.”
Allergan says Botox is well established as a drug and that the benefits and risks of toxins are well understood. “With more than 25 years of real-world clinical experience … approximately 3,200 articles in scientific and medical journals, marketing authorizations in more than 90 markets and many different indications, Botox and Botox Cosmetic are [among] the most widely researched medicines in the world,” an Allergan rep wrote in an emailed statement.
Even if Botox’s mechanism isn’t always well understood and some of its off-label uses are still unproven, interest in the drug isn’t likely to wane. “Botox is a big cash cow for the physicians’ practices,” says Ronny Gal, an investment analyst at Sanford C. Bernstein who has watched the drug closely for more than a decade. “When I talk to physicians, they say, ‘Botox is not a problem. It works and gives you the result you want.’ If it works for depression and atrial fibrillation, it could be massive.”
In November, the FDA held a two-day hearing asking for expert comment on the agency’s rules concerning off-label drug use and marketing. Some said the practice paves the way for scientific progress and gives doctors and their patients much needed alternatives for hard-to-treat medical conditions. Others said that off-label drug use is primarily financially motivated and that it poses a serious threat to public health, particularly when drugs are used experimentally on children.
Off-label use is a topic the FDA has been eyeing for some time. “There have been many instances where unapproved uses of a drug, even when commonly accepted by the medical community, have later been shown to be unsafe or ineffective or both–sometimes with devastating consequences to public health,” says the FDA’s Peddicord.
It’s unclear how the FDA’s focus will pivot with the next Administration. President-elect Donald Trump has pledged that in his first 100 days, he would be “cutting the red tape at the FDA,” and insiders have speculated that a Trump Administration would loosen the agency’s already limited oversight on off-label use.
But even if the laws remain unchanged, as long as off-label uses are permitted by law, expect doctors to keep pushing the boundaries of Botox’s applications–sometimes in the name of medical progress and sometimes with remarkable results.
Norman Rosenthal, the Maryland psychiatrist who recommended Botox for his suicidal patient, says he’s seen the upside firsthand. The patient, persuaded by Rosenthal, did indeed get Botox shots on his forehead and between his brows. Days later, Rosenthal got an email from the patient. It was a thank-you note. Finally, the patient wrote, he was feeling better.
This appears in the January 16, 2017 issue of TIME.