This article will cover the following points:

• History: Suppression vs Repression
• Mental processes 
• The irony behind it
• Trauma resilience

A little bit of history: Suppression vs Repression

We have all heard about Freud’s intriguing research on the mind’s (un)conscious, defense mechanisms and free will. In his work, Freud makes an interesting observation about how people “control” their thoughts: either consciously, through suppression, or unconsciously, through repression [3]. Often, these terms are used interchangeably; however, the majority of contemporary theories embrace a distinction, recognizing the large implications they have for clinical, therapeutic and cognitive contexts.

Suppression is an adaptive-control mechanism: the voluntary, conscious desire and ability to stop thinking about something [3]. It is usually a response to an obsessive thought or action: thinking about someone that hurt us (emotionally or physically), our body or social-image, or even just resisting the impulse to bite our nails. To this day, research on suppression has substantially adopted the think/no-think paradigm. This task mimics a situation in which people are confronted with a reminder about something they don’t wish to recall [6]. In short, subjects study word pairs (e.g., house-beard, table-roach) and then are instructed to exert control over their memory retrieval. In this think/no-think phase, people must retrieve the second word only for some cue words (e.g., recall “beard” when prompted with “house”), but not for others (e.g., not recall “roach” when prompted with “table”), which must be prevented entirely from entering consciousness. A final recall test shows that people fail to remember the no-think words, supporting the idea that suppression is active, and can even lead to forgetting [6]! This paradigm has given rise to mainstreams notions of “retrieval inhibition” and “intentional forgetting” [7].

Instead, repression is most commonly described as a defense mechanism: the unconscious process by which thoughts are kept out of awareness, to protect ourselves and preserve our self-image. Interestingly, repression is considered a trait: the repressive tendency [7], generally associated with avoidance, deception and rumination [7]. 

Cases of repression and suppression are frequent in victims of traumatic events, such as sexual abuse [7]. The fact that they co-occur makes it very hard to distinguish between them. Clearly, suppression is considered to be an active process, while repression is passive. Nevertheless, not everyone agrees: Erdelyi strongly believes that this distinction stems from the misinterpretation of Freud’s theories, and that the two are actually the same [8]. Still, this view is not very popular [1]. 

Mental processes

Wegner and colleagues [1, 5] have largely contributed to the study of suppression as a goal-directed mental control. Their model proposes two complementary processes:

• An operating process - which goal is to reach a desired state of mind in which the unwanted thought is absent and suppressed. It does this by effortfully looking for stimuli, distractors or other thoughts that lead to successful suppression [5].
• A monitoring process - which effortlessly looks for failures, hence all those sensations or stimuli that remind the person of the unwanted thought. The function of this mechanism is to prompt the operating process to start again [5].  

The think/no-think paradigm shows that if people engage in sufficient operating control, certain memories can be forgotten and kept out of awareness. Nonetheless, our memory system is extremely malleable and fluid, and many memory models actually posit that there is no such thing as forgetting, only failure to retrieve [7]. Indeed, suppressing a memory does not mean that it may be forever unaccessible, rather it might simply have a high tolerance for reminders. Also, because not thinking about something emotionally distressing is highly challenging and demanding, people tend to turn to else-thinking (thinking about something else), rather than no-thinking [7]. Thus, complete suppression might not even be obtained! 

The irony behind it

This downside of our mental control is elegantly described by Wegner in his Ironic Process Theory: whenever we want to focus on a task, go to sleep, or avoid certain thoughts, we find ourselves stumbling over and over again [5]. 

Operational control will look for stimuli that are in accordance with suppression: “I distract myself so I stop thinking about something sad/scary”. Our monitor does the opposite: “I perceive a reminder of the sad/scary thought, so I must tell the operating process to start again”. The heart of the flaw is precisely this: when no contradicting stimuli are around, the monitor will create a failure (e.g., exaggerate or connect non-relevant stimuli to the unwanted thought) to avoid failing as a mechanism! This is why, according to Wegner, suppression is immensely ironic. 

Trauma resilience: why is studying suppression important?

If we consider the think/no-think paradigm and theories of motivated forgetting, it sounds like suppression may actually be a powerful tool in overcoming trauma and other highly emotionally-distressing events or thoughts. Cognitive-clinical diagnosis, treatment plans and individuals with physical pain (e.g., cancer, chronic pain, etc…) may all benefit from understanding suppression. After all, what is better than forgetting or removing our negative experiences?  A lot of studies have looked at the effects of suppression on PTSD, anxiety, depression, and cravings, in order to establish whether this process is adaptive or maladaptive in the long-run. Findings are mixed, generally indicating positive short-term effects, against negative long-term effects. 

As previously mentioned, some psychologists believe that forgetting is possible [6]. Suppression may reduce the activation of the amygdala and hippocampus, the brain regions associated with emotions and memory respectively, limiting negative emotional responses to aversive scenes or stimuli. 

But in cases in which forgetting through suppression occurs, there is still a problem. Intentional forgetting seems to impede emotional processing of traumas by disrupting cognitive processes responsible for the reactivation of unwanted memories [4] and the integration of events in autobiographical memory [2]. This maladaptive version of suppression is common in people suffering from PTSD (post-traumatic stress disorder), preventing them from processing the trauma. Naturally, a vicious cycle begins where the persistence of symptoms maintains the person in a suppressive loop, further strengthening the symptoms and so on [4]. This role of suppression as symptom-enhancer is seen also in Depression, Obsessive-Compulsive Disorder and Anxiety Disorders. Emotional sensitivity to threatening stimuli increases, inciting stronger emotional reactions, or physical pain, and reinforcing suppression. These thoughts we so wish to keep out ironically become intrusive, creating a never-ending cycle of suppression and rumination. 

A study investigating suppression in PTSD among survivors of the 2015 Paris terrorist attacks puts forth an interesting perspective [4]. An excessive amount of suppression when the trauma is yet to be processed may block the effects of a psychotherapeutic treatments, such as exposure therapy. Because of this, the authors advise strengthening coping skills and restoring the cognitive capacities prior to treatment. Once these have been refurbished, suppression can be employed as an adaptive mechanism to cope with obstacles during treatment and residual memories, promoting trauma resilience. This view incorporates both positive and negative side-effects of suppression, dependent on other factors rather than suppression per se [4]. This idea is backed-up by other research highlighting the fact that suppression is especially harmful among psychopathologies that compromise cognitive processes, such as OCD, addictions and Schizophrenia, and so that one must work on restoring these rather than removing suppression.

Lastly, studies comparing suppression to acceptance-based coping or mindfulness demonstrate a restricted potential of this mental control mechanism, stressing the importance of redirecting one’s attention to bodily sensations, feelings and thoughts in a non-judgmental way [9]. After all, it seems like when we suppress our negative memories, we are simply making them less accessible and draining in the short term, but counterproductive in the long-run.

:( Imagine this: You keep telling yourself “stop thinking about this”. The monitoring process will consider the fact that you are repeatedly saying this as a failure. Then, it signals to your operating process to start again, because the desired mental state was not achieved. The more you tell yourself, the more you are thinking about it… 

:) Try this: Next time be accepting and mindful towards your sad and scary thoughts: make them your friends and not your enemies! 

References

1.  Wegner, D. M., & Zanakos, S. (1994). Chronic thought suppression. Journal of personality, 62(4), 615-640.
2. Schönfeld, S., Ehlers, A., Böllinghaus, I., & Rief, W. (2007). Overgeneral memory and suppression of trauma memories in post-traumatic stress disorder. Memory, 15(3), 339-352.
3. Garssen, B. (2007). Repression: Finding our way in the maze of concepts. Journal of behavioral medicine, 30(6), 471-481.
4. Mary, A., Dayan, J., Leone, G., Postel, C., Fraisse, F., Malle, C., ... & Gagnepain, P. (2020). Resilience after trauma: The role of memory suppression. Science, 367(6479).
5. Wegner, D. M. (1994). Ironic processes of mental control. Psychological review, 101(1), 34.
6. Anderson, M. C., & Levy, B. J. (2009). Suppressing unwanted memories. Current Directions in Psychological Science, 18(4), 189-194.
7. Schmidt, R. E., & Van der Linden, M. (2006). Towards a post-Freudian theory of repression: Reflections on the role of inhibitory functions. Behavioral and Brain Sciences, 29(5), 530-531.
8. Erdelyi, M. H. (2001). Defense Processes Can Be Conscious or Unconscious. American Psychologist, 56(9), 761–762. 
9. Masedo, A. I., & Esteve, M. R. (2007). Effects of suppression, acceptance and spontaneous coping on pain tolerance, pain intensity and distress. Behaviour research and therapy, 45(2), 199-209.