Increasingly, processes which produce adaptive, behavioral change are being studied rather than discrete disorders from the medical tradition in an attempt to create a transdiagnostic model of mental health and pathology. Cognitive fusion is a construct stemming from Relational Frame Theory (RFT; Hayes, Barnes-Holmes, & Roche, 2001) which forms the basis of Acceptance & Commitment Therapy (ACT; Hayes, Strosahl, & Wilson, 1999, 2011), and is understood as a state in which one is unable to distinguish between the content of one’s own mind and what he or she is actually experiencing in the world. Both RFT and ACT are concerned with how one relates to his or her thoughts (Twohig et al., 2015), while traditional CBT emphasizes the overvaluation of specific thoughts. Individuals who are high in cognitive fusion tend to take their thoughts literally, and behave in rigid patterns in order to reduce the distress of unwanted, but seemingly “real” thoughts, as in the case of OCD.

Cognitive defusion refers to a process of separating the inner experience of thoughts and emotions from external experiencing of behaviors in context by increasing mindful awareness of intrusive thoughts and accepting thoughts as just thoughts, or random mental events (Blacklegde, 2018). Others have referred to this process in other terms, including deliteralization (Hayes, Strohsal, & Wilson, 1999), distancing (Beck, 1976), decentering (Fresco et al, 2007), mindfulness (Bishop et al, 2004), metacognitive awareness (Wells, 2008), and mentalization (Fonagy & Target, 1997). Cognitive defusion has been hypothesized to be a moderator of psychological well-being and is therefore targeted in many treatments, including in gold-standard OCD treatments like Exposure and Response Prevention (ERP).
Defusion practices allow the individual to put less stock in unhelpful or triggering thoughts in order to act in ways which are consistent with one’s values, despite the presence of potentially distressing thoughts. In ERP, individuals intentionally trigger their obsessive thoughts by exposing themselves to a feared stimuli while refraining from behaving in rigid patterns (e.g. compulsions) to reduce distress in the service of creating more behavioral flexibility. Through these exercises, the individual learns that just because a distressing thought occurs or exists does not necessarily mean the thought is true. Multiple recent studies have found that those with OCD who exhibit more avoidance behaviors (to decrease anxiety) are also higher in cognitive fusion; that is, more OCD symptoms have been found to be correlated with more cognitive fusion (Blakey, Jacoby, Reuman, & Abramowitz, 2018; Blakey, Jacoby, Reuman, & Abramowitz, 2016; Wetterneck, Steinberg, & Hart, 2014).
Given the importance of cognitive fusion as a potentially important transdiagnostic process mechanism of change, it is useful for practioners to familiarize themselves with specific cognitive defusion practices which can be used in session with clients or assigned as homework to practice defusion. Aside from ERP, other ways to foster cognitive defusion are through word repetition exercises, noting that one is “having” thoughts rather than simply stating the content of the thought as if it were true, writing thoughts on note cards, slowing speech, singing, or using silly voices to express a difficult thought. Cognitive defusion techniques all aim to deconstruct language and thought processes which most individuals with or without any mental health concerns take at face value. Many defusion practices can seem “silly” to clients, and so it is critical to build sufficient rapport prior to asking the client to fully understand and grasp what they are being asked to do. A simple defusion practice that can be used at any stage of treatment is labeling thoughts as thoughts. For instance, teaching clients to say things such as “I’m having the thought that I will crash my car and hurt someone” rather than “I will crash my car and hurt someone” to express distressing thoughts. Word repetition exercises are also an example of defusion practice. In word repetition, the health provider asks the client to distill down a distressing thought to a short phrase of only a few words. The client may be asked to state the full distressing thought and notice the emotions and physiological sensations which occur; this in itself can be a form of exposure. Then the client is asked to repeat the short phrase they have identified quickly and repeatedly for 30 seconds, until the phrase becomes meaningless. The client is again asked to note emotions and physiological sensations during and after this process.
Rather than restructuring or challenging thoughts, as with CBT, cognitive defusion practices aim to help patients distance themselves from their thoughts when the thoughts are not serving them or when they are taking their thoughts too literally. Especially with OCD, many patients are well-aware that their obsessive thoughts are excessive and have attempted to challenge them or modify their thinking patterns time and time again, with no success. Such patients with fair to good insight are able to identify that their intrusive thoughts or obsessions are irrational, yet still engage in compulsive behaviors and experience high stress due to negative and evaluative emotions (Foa & Franklin, 2001).
There is a growing body of scientific evidence suggesting that cognitive fusion is a relevant treatment target. One study indicated that after only 30 seconds of quick repetition of a brief, negative thought, individuals reported decreased distress as both emotional and physiological intensity were reduced (Masuda, Hayes, Sackett, & Twohig, 2004). Another study specifically with depressed patients (which is often a problem for individuals struggling with OCD) showed that even after mindfulness processes were controlled for, cognitive fusion had unique predictive power in the strength and amount of depressive symptoms which patients endorsed (Pinto-Gouveia, Dinis, Gregorio, & Pinto, 2018). Yet another recent study found that the amount cognitive fusion patients endorsed predicted strength and type of obsessional beliefs in OCD (Reuman, Jacoby, & Abramowitz, 2016). Several other research groups (Blackledge, 2015) have found cognitive fusion to be relevant in therapy outcome and mediational studies with various other mental health disorders, as well as in laboratory basic science experiments with healthy volunteers. Importantly, cognitive defusion exercises work by reducing the believability of unwanted or negative thoughts and reducing associated distress from thoughts (Levin et al., 2012). Taken together, this suggests that cognitive defusion is not only critical in OCD, but the ability to separate oneself from thoughts and feelings when needed rather than getting stuck “buying into” thoughts is a key skill for healthy functioning more broadly.
References
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