Cluster Headaches: The Worst Possible Pain?

The rare "suicide headache" is lesser-known than migraines, widely misunderstood, and often described as the worst pain known to humans. Psychedelic drugs are being explored as a treatment, but research is still scarce.

An artist's interpretation of a cluster headache (Wikimedia)

The “worst pain known to medical science” is an impossible thing to quantify, though many sufferers of cluster headaches are quick to describe their condition according to this elusive empiric standard.

Here are some the ways the pain of clusters has been described to me:

  • “Like a really really strong pressure, and then there’s a kind of burning sensation.”
  • “Someone’s jabbed a white-hot poker into your eye socket and is holding it there for 45 minutes to an hour and a half.”
  • “Like I just got shot in the face.”
  • “It’s like a papercut in my eye, in the center of my head.”
  • “A pain that's so sharp and excruciating, there's no talking or doing anything other than just screaming to try to get out of it."
  •  “It makes you want to get up and literally run from the pain.”

Sufferers and doctors alike want to make clear the distinction: though they’re called “headaches,” clusters are not like migraines. The pain of a cluster headache is one-sided, typically concentrated around the eye and the temple, but can sometimes spread to other areas. On the affected side, the eye tears up and may droop, the nose can get congested. A headache will last between half an hour and two hours, and true to their name, they come in clusters—one or more times a day, often at the same time each day for a cycle that can last a few weeks, or a few months. Episodic sufferers get breaks of 30 days or more between their cycles; chronic sufferers get shorter breaks, or sometimes, no break at all.

It’s not a new disorder—in 1745, the Dutch-Austrian physician Gerhard van Swieten described a patient who seems to be suffering from cluster headaches:

“A healthy, robust man of middle age was, each day, at the same hour troubled by pain above the orbit of the left eye, where the nerve leaves through the bony frontal opening; after a short time the left eye began to redden and tears to flow; then he felt as if his eye was protruding from its orbit with so much pain that he became mad. After a few hours all this evil ceased and nothing in the eye appeared at all changed.”

“There’s something very rhythmic about cluster,” says Dr. Mark Green, professor of neurology at the Mt. Sinai School of Medicine and director of the school’s Center for Headache and Pain Medicine. “Someone may come in and say ‘at 4:15 a.m. every morning, I get an attack.’ We used to call them alarm clock headaches, they were so regular.” Though scientists don’t know exactly what causes cluster headaches, the condition seems to involve the hypothalamus—the part of the brain responsible for circadian rhythms.

According to the World Health Organization, the condition affects one in 1000 adults—clusters usually start for people when they’re in their 20s, or older.

Cindy Reynolds got her first cluster headache a little earlier than most. “I was 15,” she says. “It was a wonderful day, I had just made cheerleading. I was super excited. I spent the night with a girlfriend and woke up in excruciating pain, screaming.” After about a year, which included many trips to the hospital for MRIs and CT scans, she was diagnosed with episodic cluster headaches. Today, Cindy, now 52 years old, has been chronic for five and a half years.

Due to the rarity of the condition, “so many of the people I see with clusters are misdiagnosed,” Green says. “They’re told they have migraines or they’re told they have sinus headaches or some other thing.”

Mike Scott, 42, thought for years that he was suffering from sinus headaches. “It typically happened in the fall or the spring, and they would happen day after day for a while, so I assumed there was some kind of pollen or allergen or something that I was reacting to,” he says. In his 30s, his formerly manageable headaches got worse, and he found out about clusters by Googling his symptoms.

Cluster headaches are also known, colloquially, as “suicide headaches.” Green confirms that “most headache doctors have had patients with cluster headaches who have committed suicide from the pain…That’s more likely in the chronic form, [when] they know that they’re going to get one or two or three of these headaches, every day, forever. It’s pretty awful to anticipate that.”

Green remembers one 80-year-old cluster headache patient of his who also had heart disease. Because of that, he didn’t want to prescribe a certain type of injection that can sometimes stop the pain. “He owns a gun and threatened suicide without them,” Green says. The patient has since “done well, and understands the risks,” he says.

Of the notion that it’s the “worst pain known to medical science,” though, Green says, “I think they’re terrible. I think sometimes people can get a little carried away.”

Even in less extreme circumstances, sufferers say the severity of the pain has changed their lives. Both Scott and Reynolds say their bosses are understanding of their conditions, and allow them to work from home. But they, and Green, know people who are unable to work because of the headaches.

Scott has had attacks while driving—particularly dangerous because of the tearing and blurring of vision that occurs. And, he says, “it’s really affected my daughter. Now any time I grimace or put my hand to my face or anything, she says, ‘Dad, are you getting a cluster?’ She’s so worried about it, it just breaks her heart to see me suffering.”

Reynolds, a chronic patient, says, “if I could write a book on how to get through this, I would model it after the Alcoholics Anonymous guidebook…It’s just too hard to explain the severity of the pain and how it takes over your life [when] you’re in a cycle. I would incorporate the five stages of grief, for sure. And then how you come to understand how to live with this.”

To live with her headaches, Cindy uses breathable oxygen, as needed. She is a believer in alternative medicine, she says. Though other cluster patients may use oxygen, too, they typically also use some sort of preventative medication, such as verapamil, and something to try to stop the pain while they’re having it. Scott stockpiles Imitrex injections for this purpose—he says his insurance company gives him a limited number each month, which isn’t enough if he’s having multiple headaches every day during a cycle. So he gets his prescription filled even when he’s in an off period, and saves the injections for when he needs them.

For Bob Wold, founder of the non-profit cluster headache research and advocacy organization, Clusterbusters, none of the medications he tried worked. “All of the different medications that people use for clusters are hand-me-downs, usually from migraine treatments, anti-seizure medications, or blood pressure medications…I had pretty much tried all of the different medications that were available, and so I was contemplating having gamma knife surgery. They clamp your head down and shoot radiation into your brain, killing off part of your brain. I had been approved for that surgery at Northwestern.”

He decided to try one last thing first, something he’d read about online. A couple doses of psilocybin mushrooms, which are classified as a Schedule I drug, broke a cycle he says he’d been stuck in for months, when nothing else could.

“I canceled the surgery and haven’t looked back since,” he says.

Clusterbusters was born from this idea, and anecdotal evidence of many cluster patients who used psilocybin or LSD to successfully stop their headaches. The organization incorporated in 2002, with the goal, Wold says, of starting more research into this treatment option, which the community calls “busting.”

“Over the last 10 years, I have talked to thousands of people that have used these treatments, and for the most part, when people try them, they usually never go back to conventional medication,” Wold says. He also notes that the dose required for treatment is not enough to cause someone to hallucinate—“it’s normally starting off at approximately a quarter of a recreational dose,” he says.

Clusterbusters partnered with researchers at Harvard University, and published a case series in the journal Neurology, in which they interviewed 53 cluster patients who used LSD or psilocybin to treat their headaches. Most found the treatment effective in stopping the headaches and lengthening the remission periods between cycles. A small pilot study—just five people—followed, in Germany, where researchers used bromo-LSD, a non-hallucinogenic form of the molecule. It was 100 percent successful, Wold says.

Green is slightly less enthusiastic about the treatment. “No one should quote the efficacy of the trials, because they’re ongoing,” he says.

Research on hallucinogenic treatments is now at the point where it would need a larger clinical trial, and Clusterbusters has branched out into other research, including working with Yale University on surveying the efficacy of the many medications cluster headache patients use. The organization is also working on getting a genetic study underway to investigate the possibility that the headaches come from expression of a certain gene. Wold says some of the researchers he’s worked with “think it may be an epigenetic effect, that [the psychedelics are] actually changing the way the genes express themselves, telling your body to stop sending the signal for cluster headaches.”

Clusterbusters has become a hub for the cluster headache community’s advocacy work as well. The organization worked with the Substance Abuse and Mental Health Services Administration (SAMHSA) to develop a fact sheet on cluster headaches for workers on their suicide hotlines. Partnering with the Alliance for Headache Disorders Advocacy, Clusterbusters has sent a delegation to an event in Washington, D.C. called “Headache on the Hill” for the past two years. There they arrange visits with senators, congressmen, and government agencies, asking for more funding for research.

Wold says the group is also seeking orphan drug designation from the Food and Drug Administration, a status that provides incentives for developing drugs for rare diseases. According to the FDA website, orphan drug status is for "diseases/disorders that affect fewer than 200,000 people in the U.S., or that affect more than 200,000 persons but are not expected to recover the costs of developing and marketing a treatment drug." Wold says there are more than 200,000 cluster headache sufferers, but not enough to be particularly attractive to pharmaceutical companies without orphan drug status.

"Our numbers are in a real grey area. It's just a real bad area for us to be in," he says.

Reynolds, who has attended Headache on the Hill, says she thinks the event also serves to ease patients’ feelings of isolation.

“Cluster headache patients get empowered by a bond with another cluster headache patient because we can finish each other’s sentences, when others can’t understand,” she says.

“Everyone hears the word ‘headache’ and they say ‘migraine.’” Scott agrees. “There’s a whole set of assumptions that they make. The first thing they’ll say is, ‘You need to take something and go lie down in a dark room.’ Lying down actually makes it worse. Light and sound have no effect on these, whereas for migraines, people are very sensitive to light and sound.”

Clusterbusters’ guide for SAMHSA cautions people not to compare clusters to migraines. “Just the mention of a connection can cause the caller increased anxiety and anger,” it reads.

Reynolds takes a different view of misunderstandings she’s encountered. “When you share something with a familiar word [like ‘headache’], the person that you’re having a conversation with wants to acknowledge that they understand. So they’ll say, ‘I’ve had a cluster headache,’ or, ‘Have you tried Advil?’ It’s very discouraging, probably, to the patients, but the people that we’re sharing with are trying to be helpful. This is just wonderful human nature, isn’t it?”