Scientists may have figured out how to control intrusive thoughts
New research hints at a way to suppress certain thoughts, which could help in overcoming the intrusive and unwanted symptoms of conditions like OCD and anxiety.
Most people experience unwanted thoughts from time to time. These internal intrusions can be as harmless as the urge to touch a button that reads 'DO NOT PRESS', or as debilitating as the thought that you can't step outside or you'll be immediately judged – an experience some with social anxiety might be familiar with.
When we notice an intrusive thought, we will usually react by trying to replace it quickly with something else, something happier. But research from psychologists at the Hebrew University of Jerusalem suggests that distracting ourselves in this reactive way might actually be making the thought stronger. Instead, we should overcome unwanted thoughts using proactive thinking.
For the new study, Dr Isaac Fradkin and Dr Eran Eldar asked 80 participants to play a word game. They were shown a series of cue words, and for each they were asked to quickly give an associated word. For example, they may have been shown the cue word 'table', and come up with the response 'chair'.
Each cue was shown five different times throughout the experiment. All 80 people were told they would get paid for their participation, but half the group were told that they would get an additional bonus only if they did not repeat any words – if they used the response 'chair' for the cue 'table' more than once, they'd lose out.
The game's short time limit meant the participants that did best would be the ones who could suppress the thoughts of words they'd already said.
Fradkin and Eldar noticed that in the 40 participants who were not given the rule, any repeated responses would come faster and faster each time they were said. So, the 'chair' response to the word 'table' was given quicker the fourth time they saw it compared to the third, which was faster than the second, and so on. This, the psychologists say, suggested the association in their mind strengthened each time, and the thought took less and less time to arrive in their minds.
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People in the suppression group, still, at times and inadvertently, reported a repeated association, said Fradkin. But when they did, they took more time to think of it than the people in the group without the incentive to suppress repeated words.
So, if a person ensured that an unwanted thought – in this case, the word 'chair' – was not given any strength after its first appearance, they could actually reduce the chance of it popping up in their mind a second time.
It didn't eliminate it completely, though. "Reporting an association has always increased its strength," said Fradkin. "However, [its strength] was considerably lower among participants asked to suppress associations compared to the group in which no such suppression was requested."
How can we stop intrusive thoughts?
The findings suggest that proactively suppressing an unwanted thought (rather than reactively suppressing it by replacing it with something else) could help us reduce them happening in the first place.
"People are usually aware of their attempts to distract themselves from unwanted thoughts, or maybe suppress them in some other way, although they can rarely judge how well these attempts work. We tried to examine whether there are additional mechanisms allowing people to reduce the probability of thinking unwanted thoughts in the first place."
While participants in Fradkin and Eldar's study still experienced some intrusive thoughts, the experiment showed that there is potential for a person to reduce the self-reinforcing nature of their thoughts.
"You can have an inherent motivation to avoid a very distressing thought, however, it still comes to mind from time to time," said Fradkin. If, then, there was no mechanism in our brain that made sure this thought wasn't strengthened by its appearance every now and then, it would follow that we might expect occurrences of the thought to increase.
Eventually, the thought would become so prevalent it would be dominant. So, why doesn't that happen? "Our findings demonstrate the workings of such a mechanism, controlling – probably unconsciously, although we can't be entirely sure yet – these self-reinforcing dynamics."
Are intrusive thoughts normal?
Fradkin himself experiences unwanted thoughts "almost daily", whether it's just a brief distraction or something more unpleasant.
"For me, these thoughts often include different worries; for example – how will we, as a family, be able to keep up with the rising costs of living? Of course, considering these issues nowadays can be somewhat beneficial, even if unpleasant. Still, I often find myself overly preoccupied with them in a way that does not help me to come up with practical solutions," said Fradkin.
"I also have many intrusive and completely pointless unwanted thoughts. For example, when standing on a high bridge or balcony and looking down, I often experience my heart pounding and have this intrusive mental image of me tripping and falling somehow."
"Studying unwanted thoughts does not make you somehow impervious to them," said Fradkin. "On the contrary – you may become even more aware. However, knowing how frequent and common such thoughts are, definitely helps in not giving them too much weight."
Will this help people with conditions like OCD, PTSD and anxiety?
While in this study the unwanted thoughts were what the psychologists called 'neutral', they hope that the findings could lead to better understanding and help for people with repeated intrusive thoughts and memories.
"[These occur] in OCD, PTSD, as well as among people who are not diagnosed with any psychiatric condition but still suffer from such thoughts," said Fradkin.
Previous studies have shown that some of the ways we try to control these thoughts, like immediately replacing them with something else, can actually make the problem worse. Now that we know it is possible to give a little less power to intrusions, though, Fradkin is optimistic that the repetition of them is somewhat controllable.
"We do not yet understand exactly how people in our study were able to mitigate the self-reinforcing nature of thoughts and, more importantly, what factors or strategies can help with this," said Fradkin. "We want to examine these intriguing questions in future studies, which, we hope, might lead to practical suggestions regarding how to make sure unwanted thoughts do not become excessively repetitive."
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Amy is the Editorial Assistant at BBC Science Focus. Her BA degree specialised in science publishing and she has been working as a journalist since graduating in 2018. In 2020, Amy was named Editorial Assistant of the Year by the British Society of Magazine Editors. She looks after all things books, culture and media. Her interests range from natural history and wildlife, to women in STEM and accessibility tech.