Mental health: Suppressing unwanted thoughts can improve well-being

For this study, researchers from the Medical Research Council (MRC) Cognition and Brain Sciences Unit recruited 120 participants from 16 countries to take part in their study, some through social media sites. They collected data on their mental health and the cohort included participants with and without a history of mental health problems.

Participants were asked to list 20 negative “fears and worries” that might come to fruition in the next two years that they were currently worried about, as well as 20 positive “hopes and dreams” and 36 neutral events. They were then asked to each give a cue that reminded them of the event and a key detail in the fictional scenario.

They underwent 20 minutes of thought suppression training via video conference, during which participants were confronted with their cue for 4 seconds. Of the participants, 61 were in the suppress-negative group and were asked to first imagine the event and then suppress any thoughts about it. Meanwhile, 59 participants in the suppress-neutral group were asked to vividly imagine the event. Participants were asked to do this 12 times a day for three days.

The researchers then measured how well the thoughts were stored and rated the participants’ mental well-being after they went through the training. They then followed the participants up to three months later.

Immediately following the suppression exercise, participants who were asked to suppress unwanted thoughts were found to recall a key detail of the event that was troubling them less frequently and less vividly. This was not the case for all participants.

However, of the 61 participants who were asked to suppress unwanted thoughts, six reported increased vividness of unwanted thoughts after training.

At a three-month follow-up, the researchers found that participants who were asked to suppress their thoughts had lower vividness and recall of details when they thought about the event that worried them.

People with worse mental health symptoms at the start of the study were found to have a greater improvement in their mental health three months later only if they were asked to suppress the thoughts.

The mental health index scores of the PTSD participants who suppressed these thoughts increased by nearly 10%, compared to a 1% decrease for those who did not suppress them. These indices of mental health included both negative impacts (e.g., anxiety, depression, worry) and positive impacts (e.g., positive impact on well-being).

How people manage stressful thoughts, how different approaches affect mood and behavior, and whether or not this can be changed has been a subject of debate for over a century.

One of the most famous forefathers of psychoanalysis, Sigmund Freud, popularized the concept that our motivations and behavior are influenced by unconscious thoughts. He proposed that psychoanalysis could help people by making them aware, and so the idea that confronting troubling thoughts was good for mental well-being became popular.

Whether or not you can actively suppress thoughts was explored more than 30 years ago by Professor Daniel Wegner, a Harvard social psychologist who pioneered thought suppression research. In his famous experiments with polar bears, he found that people who were asked to avoid thinking about a polar bear for five minutes later thought about it more often than those who were told to think about it for the same amount of time.

He suggested that consciously suppressing thoughts starts a process that makes the thought appear more often, and that people who want to avoid unwanted thoughts should consider distraction, exposure therapies that aim to give the individual a sense of control over the fear, and mindfulness therapies that promote the ability to neutrally accept unwanted thoughts.

One researcher, Professor Michael Anderson, Principal Scientist and Program Leader at Cambridge Neuroscience, University of Cambridge, UK, focused on implementing research showing that suppressing the retrieval of unwanted memories can reduce memory frequency.

In 2014, he published research showing that repressing memories can slow their effect on a person’s awareness of and ability to recall them, challenging the assumption that repressed memories remain intact over time.

When the COVID-19 pandemic hit in 2020, his then-Ph.D. student Dr. Zulkayda Mamat was unable to do the research she needed. He and she recognized that there was a mental health pandemic alongside the COVID-19 pandemic, and if they could develop an online tool to help people with the many difficult scenarios the pandemic presents, they could potentially make a difference. However, they wondered if they were wrong about the potentially beneficial effect of suppressing unwanted thoughts.

“We had to overcome this hesitation like: what if we really screw people up? [W]hat as training [trying] getting them to suppress their fears actually failed and made them exacerbate those fears and make them more mentally maladjusted? [N]something in our research over the last 20 years suggests that this will happen. So we thought, let’s take a chance,” said Professor Anderson Medical News Today in the interview.

The fact that many participants benefited from the training did not surprise Dr. Abigael San, a chartered clinical psychologist and spokeswoman for the British Psychological Society, who was not involved in the study.

“I didn’t think what they did was that different from what happens in some types of therapy,” she said MNT. She said this was likely because participants were encouraged to confront the negative thought and then encouraged not to think about it, which is known to cause problems.

The study’s results may not be generalizable, she added, because the cohort was made up of “a sample that is not necessarily representative of what we see in clinical populations.”

She said the results were not “necessarily generalizable as these were people taking part in studies at the MRC”, and the small group of participants was recruited through online study adverts on Facebook and Twitter and word of mouth from previous participants.

The team now plans to conduct larger studies, including a clinical trial.

“Our immediate plans would be to possibly conduct a larger clinical trial of this intervention. So it was an initial feasibility study. It wasn’t exactly small; we have a decent number of people. But I think for this to qualify as a current clinical trial, we need to look at more formalities than we currently have. So I think this is my first order,” said Prof. Anderson.