What’s the worst thought you’ve ever had? Exploring intrusive thoughts

Research shows people across varied cultures experience so-called intrusive thoughts. Where do they come from? Do they mean anything?

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Research shows people across varied cultures experience so-called intrusive thoughts. Where do they come from? Do they mean anything? (Dan Bolshakov/ Big Stock Photo)

Research shows people across varied cultures experience so-called intrusive thoughts. Where do they come from? Do they mean anything? (Dan Bolshakov/ Big Stock Photo)

This story is from The Pulse, a weekly health and science podcast.

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What’s the absolute worst thought you’ve ever had?

“I drove past some sand volleyball courts and my first thought was, ‘What if I threw razor blades in the sand?’”

Not great.

“Sitting on a ledge with a friend, ‘I could push them off and end their life right now and say they slipped.’”

These are from a Reddit thread where users shared their worst. Both were among the milder ones. It got more horrific.

“I’m holding a newborn, what if I just … threw it as hard as I could at the ground. It would be so easy to break this little baby.”

Noah Berman, a psychologist and assistant professor at the College of the Holy Cross in Worcester, Massachusetts, has heard some version of these countless times. They’re known as intrusions, and there’s a bunch of them.

“I’m talking like 50 to 80 different types of intrusions,” he said.

The thing about intrusions is that basically everyone has them, even if they don’t share them online. Berman talked about a recent study from Concordia University.

“I think it was in 15 different cities, 13 different countries, and they found an estimate of around 92% to 94% of people report these thoughts.”

When Berman works with patients, he often goes through a checklist of intrusions to comfort people — a lot of them come in thinking they’re alone with their wild thoughts. The checklist shows such thoughts are common enough to, well, be on a checklist.

Most of us just brush these thoughts away, but Berman treats people with obsessive compulsive disorder. Intrusive thoughts often get them stuck in a loop.

“The presence of these obsessions causes such increased anxiety or distress that it leads them to want to do something to make themselves feel better,” he said.

So they do some kind of ritual. Maybe it’s something mental, like repeating The Lord’s Prayer in their heads; or maybe it’s something physical, like touching a doorknob in a certain way over and over again. These rituals may bring them a bit of relief.

“But the more that you do that, it becomes a stronger and stronger process and more difficult to break,” Berman said.

Rituals can steal hours out of a patient’s day.

Berman breaks the cycle in what may seem like a counterintuitive way. A patient comes in chased by a thought, he said, “it keeps flashing in their head, `Stab Mom, you’re going to stab Mom.’” So Berman responds with an assignment.

“I’m going to have them cut vegetables for dinner with their mom every day of the week while paying attention to their internal experience and not trying to push any of it away,” he said.

That’s kind of basic exposure therapy: Put yourself in the feared situation, see that you come through it not a murderer. Berman’s whole thing is making patients OK with their thoughts, but he can’t exactly get rid of them. Some inner something still says, “Stab Mom,” or whatever.

Where does that voice come from? To try to answer that, you have to look into the strange world of inner speech.

Capturing your ‘inner speech’

Charles Fernyhough has been researching that for years as part of a team at Durham University in the UK. It’s very, very tricky, trying to take stock of our inner dialogue, he said.

“You have to sort of be attending to your own experience, and [the] fact that you’re attending to yourself is probably gonna mess up your experience,” he said.

It’s as if someone asks you, “What are you thinking right this second?”

You’ll probably draw a blank. Just thinking about what you were just thinking — changes what you think you were just thinking. (Does your head hurt yet?)

Fernyhough uses a beeper to train people to capture their thoughts better. “It’s attached to your belt, and it goes off randomly,” he said.

When it beeps, you write down what you were just thinking, right before it went off. People get better at charting their own thoughts over time.

“Watching that process unfold is really fascinating,” Fernyhough said. “You see people sort of come face-to-face with their own experience almost for the first time.”

Fernyhough and his team are among the few researchers who are doing the basic science of inner speech. They’ve found it’s very different from what we say out loud. But it probably does start with spoken language.

“It starts as social speech, and over time, over childhood, it becomes internalized. It’s a developmental process,” he said.

Before inner speech, you get private speech.

“So you see children talking to themselves, but out loud, in a way that you and I might talk to ourselves silently in our heads,” Fernyhough said. “That’s the stage known as private speech.”

As early private speech becomes internalized, he said, it also changes, and becomes increasingly personalized.

“If I were able to stick a microphone into your brain and somehow, you know, miraculously pick up on your inner speech, a lot of the time I think I wouldn’t understand it,” Fernyhough said.

A lot of it becomes a kind of shorthand you create for yourself.

“Just like if I picked up your notebook and tried to make sense of it, you’re writing information for yourself where you already know half the story because it’s you speaking,” he said.

And partly because of that, inner speech is also super fast.

“Our inner speech is highly compressed, highly condensed, and that actually chimes with a little bit of research suggesting that we talk to ourselves much faster than we can speak out loud,”  Fernyhough said.

Research shows our inner speech is maybe 10 times faster than anything we could hope to say out loud. And it’s not just one track sped up, it’s multiple tracks all going at once, like maybe a subject is thinking about their next vacation at the same time they notice a tear in the wallpaper.

“They’re both going on at the same time,” Fernyhough said. “It’s not that they’re flipping between them, they seem to both be in their experience at the same time.”

And to further complicate things, inner speech is a misnomer. It’s not always talking or, so to speak, a voice. There’s also inner seeing: imagining or picturing something, an inner feeling like happiness or anger, or it’s sensory (“the carpet is soft.”)

And then there’s something called unsymbolized thinking. It’s hard to describe, like a ghost of thought — it’s there, but you don’t capture it in language or images.

“There’s no language involved. There is also not a visual image. It doesn’t have any sensory component. You can’t feel it in your body anywhere,” Fernyhough said. “It’s just a pure abstract thought that conveys that meaning.”

And he has a hunch that this weird space, without language or anything, is where a lot of intrusive thoughts start — though his group has not explicitly studied the question yet.

“You might just have a completely abstract thought about dropping the baby that doesn’t come in words,” Fernyhough said.

In the absence of knowing where these come from or why, just don’t assign too much weight to them, Fernyhough said.

Like most of us, he is able to let the bad thoughts go.

“My brain is just this kind of factory chucking out stuff all day long. It’s just churning out different scenarios. It’s churning out ideas, it’s just, you know, it’s constantly on the go,” Fernyhough said. “And a lot of what it chunks out is absolute rubbish. It’s just noise. A lot of what it chucks out is really nothing to do with me.”

That last point is something psychologist Fred Penzel, executive director of Western Suffolk Psychological Services in New York state, drives home in his practice.

“We do not consider the content of obsessive thoughts to be significant. In other words, we don’t analyze what they mean,” he said.

He doesn’t even care what your particular intrusive thought is.

“We don’t try to figure out where they came from. We just accept that people get whatever they get,” Penzel said. “There’s no rhyme or reason.”

Researchers know there’s some neurochemical basis for intrusive thoughts, because certain antidepressants seem to alleviate them. But a lot of it is still a mystery.

What’s clear, however, is that even though these thoughts come from somewhere deep inside your head, they don’t say anything about who you are, or what you’re capable of.

Editor’s note: In a previous version of this story, Noah Berman’s affiliation was misidentified. Berman is an assistant professor at the College of the Holy Cross in Worcester, Massachusetts.


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