Can training to suppress thoughts improve mental health? Study challenges century-old wisdom

By Neha MathurReviewed by Benedette Cuffari, M.Sc.Sep 26 2023

Conventional psychotherapies often advise people with anxiety, post-traumatic stress disorder (PTSD), and depression to avoid suppressing their thoughts. In a recent article published in Science Advances, researchers describe the effects of thought suppression on mnemonic, affective, positive, or negative mental health indices.

Study: Improving mental health by training the suppression of unwanted thoughts. Image Credit: YURII MASLAK / Shutterstock.com

About the study

The study protocol combined active forgetting of distressing imagery with the controlled recruitment of extinction circuitry considered critical in adjusting emotional responses to threat. In other words, researchers let people confront reminders that reactivated their fearful thoughts and suppressed awareness of the associated memory.

Researchers recruited participants from the Cognition and Brain Sciences Unit of the United Kingdom Medical Research Council (MRC), as well as through online websites like Twitter and word of mouth from other participants. 

A total of 120 participants, 93 of whom were females, were recruited to participate in three days of online thought suppression training, which helped them suppress fearful or neutral thoughts. Three months later, follow-up sessions were conducted during the coronavirus disease 2019 (COVID-19) pandemic. 

Study participants were randomly assigned to conditions that differed in the valence of the events. Primary analyses involved comparisons between the primary intervention ‘Suppress-Negative’ and ‘Suppress-Neutral’ control groups, which comprised 61 and 59 people, respectively.

Each participant generated 76 future events, in which they mentioned 20, 20, and 36 negative (fears and worries), positive (hopes and dreams), and neutral (routine scenarios) events, respectively. 

Each event was generated with four conditions, of which included a short tagline of eight words or less, a cue word that evoked the event during training, a key detail that described the event, and a brief but more elaborate description of the event to help the experimenter verify the event’s compliance with the rules. Eight events were allocated to each condition and were described as Imagine, Baseline Imagine, Baseline No-Imagine, and No-Imagine.

The researchers rated event attributes of vividness, likelihood of occurrence, distance in the future, frequency of thought, degree of current concern, and mood to assess mental health. A three-day retrieval suppression practice ensued, wherein each session had 12 No-Imagine and Imagine repetitions in response to No-Imagine and Imagine cues, respectively. These assessments were repeated after three months.

Analyses of event and mental health measures focused on changes in memory and the effect of each event after pretraining, post-training, and follow-up.

Mental health questionnaires were administered using an online survey tool 'Qualtrics.’ These scores were converted to the percent of maximum possible score (POMP) scores calculated as POMP = 100 ∗ (raw−min)/(max-min). 

Study findings

Training people to suppress distressing thoughts did not increase rebound risk on all assessed mnemonic, affective, or mental health indices. The risk did not increase, regardless of the affective intensity of feared events, delays, anxiety, depression, or post-traumatic stress at the outset of training. Rather, retrieval suppression interrupted the progression from cues to unwelcome thoughts and better-captured thought suppression as it occurs naturally.

Molecular mechanisms underlying the current benefits of thought suppression training remain unclear. However, this experiment provided an alternative view of the origins of intrusive thinking in these disorders. 

A three-day training regimen improved all symptoms, thus implying that the study participants had minimal structural or neurochemical deficits within notable brain structures, such as the prefrontal cortex. The training likely increased the participants’ awareness of thought suppression and, as a result, was crucial for regulating distressing fears.

The researchers speculate that this training approach eliminated a metacognitive gap or altered false beliefs about the dangers of thought suppression restricting its use.

Conclusions

The study findings challenge the century-old notion that thought suppression is maladaptive and a key mediator in the pathogenesis of mental health disorders. Rather, suppression training reduced memory for suppressed fears and reduced their vividity and anxiety-provoking potential.

These findings indicate that this training improved mental health for those suffering from symptoms of anxiety and PTSD. Importantly, these post-training benefits persisted after three months.