Research Overview

The effectiveness of CANResT-ICU as a psychological intervention for the treatment of Post Traumatic Stress Disorder (PTSD) is currently being tested in a randomised controlled trial with survivors of Intensive Care at Addenbrooke's Hospital in Cambridge

Study Number LREC07/Q0302/20 

Study Name (Full)

A randomised controlled pilot study of the effectiveness of recreating a coherent narrative of events using novel developments in Cognitive and Behaviour Therapy for the Treatment of Post Traumatic Stress Disorder in survivors of Intensive Care Treatment

Abbreviated Name

A therapeutic intervention for the treatment of traumatic experiences in survivors of the intensive care unit


The Intensive Care Unit (ICU) can be a disorientating and frightening environment for a patient. It is exacerbated by physical and physiological trauma, pain and distressing procedures, mechanical ventilation and medication including opiates, sedation, paralysing agents and steroids. These contribute to the formation of fragmented and delusional memories. If symptoms, including anxiety, re-experiencing of the event and avoidance of stimuli related to the event develop and last for more than four weeks, the patient may be suffering from Post Traumatic Stress Disorder (PTSD). PTSD prevents patients from making a full functional recovery, even where they have made a good physical recovery. Although NICE recommends screening and where indicated treatment of patients at risk of PTSD, it is not usual practice in most ICUs.

This study aims to develop and implement an effective, as well as time and cost efficient psychological intervention that could be applied by trained, non-psychologists for the treatment of 

PTSD in 

ICU survivors.

Introduction to the study


This study aims to evaluate the efficacy of a brief psychological intervention for the treatment of ICU survivors suffering from PTSD, based on novel developments in Cognitive and Behavioural Therapy (CBT) and Narrative Exposure Therapy (NET). The study will create and implement a psychotherapeutic intervention to address the problem of fragmented and delusional memories, by creating a coherent narrative of events, which is expected to allow the ICU survivor to process their ICU experience.  The different components of the intervention proposed have been validated as an effective intervention in studies on PTSD (CBT), as well as in survivors of torture, war and displacement (NET). We believe that it may offer a treatment modality that could be applied effectively as well as time and cost efficiently by trained, non-psychologists, in ICU survivors suffering from PTSD.


Post Traumatic Stress Disorder (PTSD) is common in survivors of Intensive Care treatment (i.e., Jones, C. & Griffiths, R., 2006), the prevalence of PTSD in survivors of Intensive Care treatment is between 3 to 65% of the total population of patients discharged.   Many patients treated in Intensive Care Units (ICU) experience intense physical and emotional stress, which are a combination of the physical and physiological trauma, and the often disorientating and frightening environment of the ICU. These contribute to the formation of fragmented and delusional memories. PTSD is a treatable disorder and recent NICE (National Institute for Clinical Excellence) guidelines recommend that patients should be screened for PTSD and treatment should be offered if symptoms persist after four weeks of the traumatic event (NICE, 2005).  NICE has stated that without effective treatment, many people may develop chronic problems over many years. At present screening and offering treatment for ICU survivors is not part of the usual treatment in ICUs.

Although several recent studies have highlighted PTSD as a significant ICU related problem (i.e., Nickel, et all, 2004), no management strategy has been adopted as the gold standard for post ICU care, and in most ICUs no system for identifying and treating these patients has been created. 

Post Traumatic Stress Disorder (PTSD) was defined and classified for the first time in 1980 in the Diagnostic and Statistical Manual of Mental Disorders (DSM) III (APA, 1987). Five years later it was included in the ICD 10 (WHO,1992). The revision of causes in the DSM IV (APA, 1994) made it possible to apply the diagnosis to ICU patients, as this new definition allows a life-threatening disease as a contributing cause to the development of the disorder (APA, 1994).

The symptoms experienced by PTSD sufferers are grouped into (1) persistent re-experiencing of the trauma, (2) a continuous avoidance of stimuli and (3) increased physiological arousal (DSM IV-TR, APA, 2000). Although the presentation varies, sufferers of PTSD tend to ruminate obsessively about the circumstances concerning the traumatic event and can suffer from hyperarousal, hypervigilance, irritability, difficulty with sleep and concentration, as well as emotional numbing which could lead to social isolation and the breakdown of relationships  (NICE, 2005, p7).

The most common co-morbid disorders presented with PTSD are

(1) affective disorders (almost 50% of cases for major depression, 20% for dysthymia) and anxiety disorders in general (16% GAD, 9% panic disorder, 30% specific phobia, 28% social phobia, 19% agoraphobia);

(2) substance misuse disorders (52% alcohol and 34% drugs in men, 28% alcohol and 27% drugs in women);

and (3) conduct disorder (43% in men and 15% in women) (Kessler et al., 1995).


CANResT- ICU Study Objectives

The main objective of this study is to develop and evaluate the efficacy of a specialised brief CBT intervention for the treatment of PTSD in survivors of ICU. We also aim to evaluate the effect of a specialised brief CBT intervention vs. normal care, on the progression or resolution of anxiety, depression and psychological well-being, in ICU survivors who have developed PTSD.

In order to determine the incidence of PTSD in our critically ill population we will be employing several diagnostic tools including PTSS-14 (Twigg et al, 2008), SCID-I (First et al., 1996), Memory Intensity Questionnaire (Talarico, Labar and Rubin, 2004) and the HADS scale (Zigmond and Snaith, 1983) which evaluate the incidence of anxiety and depression.

We will also study the various factors before and during ICU admission associated with the development of PTSD.  By identifying these factors, we hope to develop a prediction score that can be used to identify the patients at risk of PTSD at an early stage using the PTSD scoring system combined with a risk factor score.

Ultimately we will aim to create a protocol-based treatment for PTSD in ICU survivors, suitable for use in Addenbrooke’s hospital.


Study Methods

Study Design,

Treatment, Randomised, Single Blind, Control Group, Efficacy Study


Eligibility: All ICU survivors who meet criteria for PTSD from 4 weeks after discharge; 16 years or over; Cognitive and physically able to understand written materials and elaborate a narration of events

Sample: The study will be conducted in an 15 bed ICU / HDU at Addenbrooke’s Hospital.

Participants: All survivors of ICU who meet eligibility criteria for the trial would be included in the study.


Research participants will receive a pre-randomisation assessment for PTSD at three months post discharge from the ICU. If they meet criteria for the disorder, they will be ransomised to one of two conditions: Treatment as usual, or receiving CANResT-ICU treatment


Participant Involvement

All participants would be asked to,

1.     Complete a set of screening questionnaires after discharge from the ICU or high dependency area, as allowed by patient physical and cognitive recovery. The questionnaires would take approximately 20 minutes to complete and would evaluate their levels of anxiety, depression and possible symptoms of PTSD

2.    A research nurse would contact the participant again, by phone or in person four to six weeks after their discharge date. The telephone conversation would take approximately 20 minutes and participants would be asked to complete the same set of questionnaires

3.    If the results of the screening questionnaires indicate that the participant is at risk of PTSD we will proceed to contacting them again three months later to administer the same questionnaires and a more detailed questionnaire, which will take approximately one hour (SCID). This may be done over the phone or in person.

4.    We will then be able to determine whether the participant has been diagnosed to be at risk of PTSD and we will let them know of the outcome by letter.

  1. If a participant is diagnosed to be at risk of PTSD, he or she will be invited to participate in the second part of the study. All participants who have been diagnosed to be at risk of PTSD, and agreed to continue taking part of the research study, would be randomly allocated to one of two treatment strategies: treatment as usual or the specialist intervention that we have developed.


Whether the participant receive treatment as usual or the intervention arranged as part of the study, we would contact them again at approximately four months after discharge from ICU (one month post intervention), to ask them to complete the screening questionnaires again to monitor their progress

       6.   Finally, we would contact them again one year after their discharge from the ICU to complete the same set of screening questionnaires

Although the questionnaires, that we would ask the participants to complete, are routine questionnaires for the evaluation of PTSD, they are not usually administered in the standard care of ICU patients. Furthermore, although the elements of therapy that are involved in the intervention that we propose have been validated and found helpful for the treatment of PTSD in different groups, it is a novel and therefore experimental intervention specific for patients that have experienced an ICU admission.


No normal or usual care will be withheld from the participants at any part of the study.


Two main questionnaires will be used to assess the incidence of PTSD and a further two to enquiry about variables related to mood and psychological wellbeing. Demographic as well as information regarding previous history of mental and physical health problems will be collected.

Ethical Considerations

Foreseen risk or disadvantages for the participants

We do not anticipate any additional risks or disadvantages of taking part in this study compared to other alternatives for treatment.

The treatment of PTSD involves talking about the patient’s experience of the ICU and describing memories of the ICU, which can be distressing or frightening. This could cause the participant personal stress and evoke feelings of anxiety and frustration.

Expenses and payments

We do not expect that participation in this research study would result in any specific expenses on the side of the participant. If a participant were diagnosed to be at risk of PTSD, we would ask he or she to attend the hospital for one appointment, in addition to any other regular appointments that they might attend as part of their usual treatment.

We are unable to offer payments or reimbursement of expenses incurred while taking part in this study.

Benefits of taking part

We cannot promise the study will help the participant but the information we get might help improve the treatment of patients that have experienced an ICU admission, who suffer from PTSD.

If a particular participant suffer from PTSD symptoms, this study could help to diagnose this disorder and offer them a treatment that might alleviate their symptoms of PTSD.



All information collected during the course of the research, will be kept strictly confidential.  If applicable, any information about a particular participant, which leaves the hospital, will have their name and address removed so that they cannot be recognised from it.

We would like to notify a participant’s GP of their participation in this trial and we would ask them for consent to do so. We would not disclose sensitive information without a participant’s consent. We would like to inform their GP if we believe that a participant suffers from PTSD, or a mood disorder, which could need further input from other service. Finally, we would inform the GP if we believe that a particular participant are at risk of harming themselves or others.



The total duration of the participation in the study will be twelve months for each patient.

The participants will have a telephone interview approximately one month post discharge with brief psychological intervention within the following three months.

All patients will be followed up by phone at four and twelve months after being discharged from the ICU. The same screening measures for PTSD and mood (anxiety and depression) (UK-PTSS-14, SCID-I and HADS) will be administered.  The participants will have completed the study after the final follow up telephone interview at twelve months



Patients will receive a written patient information sheet at or soon post ICU discharge. If they give their consent, they will be screened for PTSD symptoms. The screening would involve the completion of a PTSD screening scale, which will be administered by the physician leading the ward follow-up or research nurse. The objectives of the study would be explained to the patient and telephone follow-up arranged for four weeks later.

The follow-up at one month would involve a face-to-face interview, or if they have been discharged home, a telephone conversation of approximately 15-20 minutes, with a research nurse. The telephone conversation will be followed by a letter giving the patients feedback on issues arising from the interpretation of their scores, and advice regarding the steps to follow where there is an indication of severe anxiety and / or depression, which would require help. Patients will also be advised by telephone if issues of risks are detected, and their GPs will be written to. They will also be advised if they meet criteria for being at risk of PTSD.

Patients who meet criteria for being at risk of PTSD after the questionnaires administered during the interview at four to six weeks, will be invited, by the research nurse, to participate in the second stage of the research study. They will be invited to an interview for a second time to establish a diagnosis of PTSD, and would then be randomised to: CANResT ICU or treatment as normal.



Patients may withdraw from the study at any time without providing a reason.  If they withdraw, they will be offered the opportunity to have data already collected to be excluded from the study.  However, if no such request is made, data collected up to the point at which the patient withdraws will be included in analyses.


Dissemination & Outcome

We would like to publish the results of this study for scientific purposes. The personal details of the participants would be kept confidential and would not be identifiable in any report or publication produced as a result of this study.

If the participant wishes, they could also receive a report on the outcome of the study.