Dissociation CBT Studies

1. What is dissociation?

   "I was in a totally different world; it was going on all around me. I thought that I might have died and was in hell, and I was thinking maybe that's what it was." -- "Maria"

   Dissociation involves confusing and upsetting feelings of unreality, unfamiliarity, or disconnection in relation to your mind, body, or surroundings. For example, some people describe being detached from their own emotions, including affection for loved ones, or feeling profoundly 'strange', as though they are living life from behind a thick pane of glass. These experiences can cause significant distress, and have been linked with risk of self-harm or suicide, and with increased severity and incomplete treatment-response of comorbid mental health diagnoses. Many dissociative experiences considered transdiagnostic. For example, dissociation is present at a very high rate in psychotic disorders (potentially up to 50%). Crucially, in this context, it may even be instrumental in the development and maintenance of key psychotic symptoms, such as paranoid delusions and auditory hallucinations.

   However, dissociation has traditionally been considered within the context of post-traumatic responses. As a result, a fuller understanding of dissociation as an independent construct - rather than simply as another post-traumatic symptom - has yet to be achieved.

   This 'neglect', and extensive debate within the field, has also resulted in a lack of clarity about the precise accepted definition of 'dissociation' as a construct. Therefore, in previous work, our research group delineated a subgroup of common dissociative experiences unified by a core phenomenological experience of a 'felt sense of anomaly' (FSA). Thus, the term 'dissociation' is operationalised within this project by focusing on this specific type of dissociative experiences (FSA-dissociation), since this has been demonstrated to be common and transdiagnostic.

2. What are the psychological maintenance mechanisms of dissociation?

   Understanding the psychological mechanisms of a pathological presentation is vital to developing an effective intervention for it. Seminal work developing (now gold standard) cognitive behavioural therapy (CBT) interventions for anxiety disorders and PTSD have demonstrated the clinical efficacy of identifying, verifying, and then precisely targeting the underlying causal mechanisms of the problem to be treated. However, much remains unknown about the psychological mechanisms underpinning dissociation. To date, only two experimental studies inferring causality in dissociation have been carried out: one of which was by our group.

   In our recent work, we began the process of identifying plausible mechanisms of FSA-dissociation, resulting in a provisional cognitive model of the problem. This model suggests that dissociative experiences are maintained by a two feedback loops. The first is caused by catastrophic appraisals (negative interpretations or beliefs about the dissociative experience), which lead to rumination and counterproductive 'safety behaviours' (actions intended to mitigate potential harm), both of which serve to keep attention focused on the dissociation and reinforce interpretations of this experience as threatening. This first loop therefore proposes three possible maintenance mechanisms: catastrophic appraisals of dissociation, perseverative thinking (rumination), and counterproductive safety behaviours.

   The second hypothesised feedback loop explains why the appraisals of dissociation are catastrophic in nature - as opposed to benign or benevolent. Across two large studies of online survey and NHS patient (psychosis) respondents, previous data has indicated relationships between dissociation and both high affect intolerance and low self-efficacy. In essence, people who feared shifts or peaks in their mood, and simultaneously felt powerless to manage or cope with challenges, were more likely to have FSA-dissociative experiences - as was indicated by previous qualitative evidence. This second feedback loop therefore suggests two further plausible mechanisms of dissociation: affect intolerance and self-efficacy.

   In this project, the researchers have chosen to focus on the three mechanisms with the largest effect sizes from this research: negative cognitive appraisals of the dissociative experience (causal effect 0.73 in a non-clinical group; 0.72 in a psychosis group), perseverative thinking (rumination) (0.31; 0.52), and affect intolerance (0.26; 0.41).

3. The current study

The aim of this project is therefore to test the three largest psychological contributors to FSA-dissociation as identified in this previous research: cognitive appraisals, rumination, and affect intolerance. Whilst there is evidence that these are all associated with dissociative experiences in the context of psychosis, to date there has been no experimental manipulation of these factors to demonstrate their role in maintaining dissociative difficulties. Evidence of their causal effect on dissociation is required before a translational psychological intervention can be developed.

Using an interventionist-causal approach (experimentally manipulating the factor of interest via attempting to ameliorate it with therapeutic techniques) allows researchers to combine an experimental test of causal relationships with the first stages of treatment development. This project constitutes an intermediate stage along the trajectory of treatment development, in that the primary aim of these three studies will be to demonstrate proof-of-concept for the interventions, in order that a larger study with adequate statistical power to test for causal relationships and treatment efficacy may be carried out.