Clearing the mind of fearful thoughts, rather than processing them, may sometimes be good for our mental health.
In the late 1980s, scientists found that people who were first asked to avoid thinking about white bears, and later to think about them, had more thoughts about the animals than people who were only asked to think about white bears. This led to the common belief that blocking out unwanted thoughts ironically causes them to reoccur more often.
As a result, some forms of therapy aim to boost mental health by guiding people to recall and explore difficult experiences rather than suppress them.
Now, Zulkayda Mamat and Michael Anderson at the University of Cambridge have found that some forms of thought suppression can actually be helpful.
“When you avoid a thought by doing or thinking of something else, yes, you tend to attract that thought again,” says Mamat. “But we found that suppressing thoughts by making sure your mind is without any thought – for example by imagining a blank space or imagining pushing that thought out of your mind – can be beneficial.”
The researchers recruited 120 people and asked them to imagine future scenarios that might occur in their lives over the next two years. The participants weren’t asked whether they had been diagnosed with any mental health conditions, but surveys they took revealed some symptoms.
Each participant came up with 20 negative scenarios they were afraid of, such as losing a loved one, and 36 neutral scenarios such as hanging out the laundry. For each scenario, participants had to provide a cue word that could be used to evoke the thought.
Each event had to be specific to them and something they had vividly imagined occurring. For each scenario, they were to provide a cue word (an obvious reminder that could be used to evoke the event during training) and a key detail (a single word expressing a central event detail). For example:
Negative – visiting one’s parents at the hospital as a result of COVID-19, with the cue ‘Hospital’ and the detail ‘Breathing’.
Neutral – a visit to the opticians, with the cue ‘Optician’ and the detail ‘Cambridge’.
Positive – seeing one’s sister get married, with the cue ‘Wedding’ and the detail ‘Dress’.
Participants were asked to rate each event on a number of points: vividness, likelihood of occurrence, distance in the future, level of anxiety about the event (or level of joy for positive events), frequency of thought, degree of current concern, long-term impact, and emotional intensity.
Participants also completed questionnaires to assess their mental health, though no one was excluded, allowing the researchers to look at a broad range of participants, including many with serious depression, anxiety, and pandemic-related post-traumatic stress.
Then, over Zoom, Dr Mamat took each participant through the 20-minute training, which involved 12 ‘No-imagine’ and 12 ‘Imagine’ repetitions for events, each day for three days.
For No-imagine trials, participants were given one of their cue words, asked to first acknowledge the event in their mind. Then, while continuing to stare directly at the reminder cue, they were asked to stop thinking about the event – they should not try to imagine the event itself or use diversionary thoughts to distract themselves, but rather should try to block any images or thoughts that the reminder might evoke. For this part of the trial, one group of participants was given their negative events to suppress and the other given their neutral ones.
For Imagine trials, participants were given a cue word and asked to imagine the event as vividly as possible, thinking what it would be like and imagining how they would feel at the event. For ethical reasons, no participant was given a negative event to imagine, but only positive or neutral ones.
At the end of the third day and again three months later, participants were once again asked to rate each event on vividness, level of anxiety, emotional intensity, etc., and completed questionnaires to assess changes in depression, anxiety, worry, affect, and wellbeing, key facets of mental health.
Dr Mamat said: “It was very clear that those events that participants practiced suppressing were less vivid, less emotionally anxiety-inducing, than the other events and that overall, participants improved in terms of their mental health. But we saw the biggest effect among those participants who were given practice at suppressing fearful, rather than neutral, thoughts.”
Following training – both immediately and after three months – participants reported that suppressed events were less vivid and less fearful. They also found themselves thinking about these events less.
Suppressing thoughts even improved mental health amongst participants with likely post-traumatic stress disorder. Among participants with post-traumatic stress who suppressed negative thoughts, their negative mental health indices scores fell on average by 16% (compared to a 5% fall for similar participants suppressing neutral events), whereas positive mental health indices scores increased by almost 10% (compared to a 1% fall in the second group).
In general, people with worse mental health symptoms at the outset of the study improved more after suppression training, but only if they suppressed their fears. This finding directly contradicts the notion that suppression is a maladaptive coping process.
Suppressing negative thoughts did not lead to a ‘rebound’, where a participant recalled these events more vividly. Only one person out of 120 showed higher detail recall for suppressed items post-training, and just six of the 61 participants that suppressed fears reported increased vividness for No-Imagine items post-training, but this was in line with the baseline rate of vividness increases that occurred for events that were not suppressed at all.
“What we found runs counter to the accepted narrative,” said Professor Anderson. “Although more work will be needed to confirm the findings, it seems like it is possible and could even be potentially beneficial to actively suppress our fearful thoughts.”
Although participants were not asked to continue practising the technique, many of them chose to do so spontaneously. When Dr Mamat contacted the participants after three months, she found that the benefits in terms of reduced levels of depression and negative emotions, continued for all participants, but were most pronounced among those participants who continued to use the technique in their daily lives.
“The follow up was my favourite time of my entire PhD, because every day was just joyful,” she said. “I didn’t have a single participant who told me ‘Oh, I feel bad’ or ‘This was useless’. I didn’t prompt them or ask ‘Did you find this helpful?’ They were just automatically telling me how helpful they found it.”
One participant was so impressed by the technique that she taught her daughter and her own mother how to do it. Another reported how she had moved home just prior to COVID-19 and so felt very isolated during the pandemic.
“She said this study had come exactly at the time she needed it because she was having all these negative thoughts, all these worries and anxiety about the future, and this really, really helped her,” said Dr Mamat. “My heart literally just melted, I could feel goosebumps all over me. I said to her ‘If everyone else hated this experiment, I would not care because of how much this benefited you!’.”
The research was funded by the Medical Research Council and the Mind Science Foundation.
Reference
Mamat, Z, and Anderson, MC. Improving Mental Health by Training the Suppression of Unwanted Thoughts. Sci Adv; 20 Sept 2023; DOI: 10.1126/sciadv.adh5292
