Feasibility study for a randomised controlled trial of trauma processing techniques with new police recruits

Randomised Control Trial Status


Trial Hypothesis

The feasibility study was designed in 2017 to firstly ascertain proof-of-concept that hippocampal-dependent processing techniques were translatable into a training environment for operational policing. Secondly, the study serves as a pilot for a longer term Randomised Controlled Trial to assess the extent to which the techniques could mitigate against longer term exposure –and ultimately to assess their potential to prevent complications from unprocessed trauma, such as Post-Traumatic Stress Disorder (PTSD) and Complex Post-Traumatic Stress Disorder (CPTSD).

The study assesses: in-session efficacy of trauma processing techniques and between group (and between session) trauma impact monitoring.

We would not expect to see large effect sizes due to the number of environmental and genetic conditions which influence trauma processing capacity and which cannot be controlled in this study. We do expect feedback to reflect self-reported trauma processing improvements and higher confidence than with the control group after the first 12 months.

Geographical area

​Greater Manchester.

Research Institution / Organisation

University of Cambridge

In Collaboration With

Police Care UK (formerly Police Dependants' Trust)

Project Start Date

May 2017

Participants - inclusion criteria

  • PCL-5 below PTSD threshold (no current diagnosis or probable levels of post-traumatic stress) 
  • Not currently suffering from anxiety or depression 
  • Only 'manageable' difficult experiences to be used in training, not extreme trauma exposure.

Target Sample Size

  • n = 75
  • trial group n = 46
  • control group n = 29

Study Design

Feasibility study to demonstrate proof-of-concept and in doing so to assess process, resources, study management and scientific assessment in preparation for the design of a larger RCT. Includes basic randomised comparing treatment to control as well as within-group differences pre and post treatment.

Session One training collected data free-form, using qualitative coding and interpretive analysis. Session Two (and control group training) collected data using workbooks with specific questions enabling more structured analysis.


Post-Incident Trauma Processing Techniques based on hippocampal dependent spatial and episodic memory consolidation using maps and timelines, supported by grounding techniques to protect against trauma re-exposure or unnecessary stressing.

Outcome Measures

  • PCL-5 Score monthly
  • Self-reported changes in a) emotional response to traumas to which the techniques are applied (using a Visual Analogue Scale) and b) recall detail of traumas to which the techniques are applied
  • Ability to shift overhead view and commit representation to paper (advanced allocentric processing as an indicative measure of hippocampal integrity)

Summary of Findings

Session One data suggested 75% of trial participants felt an improvement in emotional response to the event processed as a direct result of applying the techniques and 46% reported improvement in recall of the event (ie new information reported). 50% showed initial capacity for the more advanced hippocampal processing task.

Session Two data indicates a statistically significant improvement in ‘ease of feeling’ about a traumatic event after applying the techniques, which was independent of the impact of age and current trauma on such feeling. 71% of participants used the techniques in between sessions without prompting and 81% said they’d pass them on. 68% reported new recall of events after having applied the techniques.  Longer term between group data showed the control group to be more unsure about whether they had experienced trauma exposure during their first year, and both groups were more likely to check in to report exposure when impact was low. 

Jessica K Miller, Alexandra Peart, Magdalena Soffia, "Can police be trained in trauma processing to minimise PTSD symptoms? Feasibility and proof of concept with a newly recruited UK police population"; The Police Journal: Theory, Practice and Principles; July 2019 

Date last updated

Thursday 08 August 2019
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