Preventing PTSD, depression and associated health problems (A Case Study)
Dr. Jennifer Wild
Emergency workers carry a threefold increase, compared with the general population, in risk for major depression (MD) and post-traumatic stress disorder (PTSD) and an associated increased risk of poor physical health.1 To date, interventions aimed at reducing risk of ill mental health in this population have been unsuccessful. Randomised controlled trials (RCT) found that trauma risk management, a peer support system widely available to the police and ambulance services in England2; critical incident stress debriefing widely used by UK fire-services,3 and the charity Mind’s six-session group-based resilience intervention had no effect on resilience or rates of mental ill health.4 More effective preventative interventions for emergency workers are urgently needed.
Established interventions may have been unsuccessful because they fail to target predictors of mental ill health and are offered to emergency workers after rather than before repeated exposure to the stresses linked to their work. Moreover, cognitive strategies that could help them cope with characteristic stressors are not included as part of the training. For example, our and others’ research has demonstrated that exposure to trauma or stressful scenarios through imagery reduces anxiety for police officers and other at risk populations.5 6 Development of more effective interventions requires identification of predictors of mental disorders and an understanding of how to modify them.
In a series of experimental and prospective studies, we identified two cognitive factors that are robust predictors of poor mental health in emergency workers: rumination (repetitive negative thinking) and resilience appraisals. Those who reported ruminative thoughts during critical incidents were more likely to experience poor levels of coping.7 Adaptive appraisals during analogue trauma led to more successful attempts to regulate emotions and fewer PTSD symptoms.8 Our large-scale prospective study of newly recruited paramedics investigated predictors of PTSD and MD derived from cognitive theories of PTSD and depression.1 Rumination at the start of paramedic training uniquely predicted PTSD; low resilience uniquely predicted an episode of MD.
We then developed an intervention to modify peritraumatic ruminative thinking (ie, thinking repetitively in an abstract way during trauma). Training to think in a concrete style (eg, focusing on objective details and the sequence of events) led to significantly fewer intrusive memories and PTSD symptoms than individuals trained in a ruminative style.9 We also applied one of the core techniques of a successful treatment for PTSD (cognitive therapy for PTSD10), updating the memory of the stressful event with helpful information, as a preventative strategy for dealing with analogue trauma and found that it is more helpful in reducing repetitive thinking and PTSD symptoms than control interventions including exposure.11
Research has further demonstrated that exposure to trauma or stressful scenarios through imagery reduces anxiety for police officers and other at risk populations, and that internet-based cognitive treatment that includes attention training as a core component significantly reduces anxiety.
Genetic and longitudinal studies suggest that inflammation is a pre-existing vulnerability factor for the development of PTSD in trauma-exposed individuals rather than simply a correlate of subjective distress, disease severity or maladaptive coping strategies following PTSD onset.13 14 For example, brain imaging studies have shown that high inflammation levels may increase threat perception (negative valence). Peripheral administration of lipopolysaccharides residues from bacterial cells’ components known to elicit a strong systemic inflammatory response, potentiates amygdala activity in response to socially threatening stimuli (fear faces).15 In turn, greater pretreatment amygdala reactivity to threat predicts less symptom reduction during cognitive behaviour therapy.16 Additionally, inflammation is an important risk factor for depression and cardiovascular disease, which frequently accompany PTSD.17–19 Our study will investigate the link between inflammation and the development of PTSD and MD in trauma-exposed student paramedics. We will investigate whether or not internet cognitive training for resilience (iCT-R) can reduce levels of clinically relevant inflammation levels, such as C-reactive protein (CRP), known to increase risk of psychiatric as well as cardiovascular and metabolic conditions comorbid with PTSD and MD.
Given the wealth of literature supporting a relationship between the stress hormone, cortisol and PTSD and MD, we will also systematically assess the cortisol awakening response (CAR) and diurnal cycle. The CAR is an endocrine marker, defined as the change in cortisol concentration that occurs during the first hour after waking from sleep.20 A meta-analysis of 62 studies concluded that increases in the CAR were associated with job stress and life stress and linked to greater fatigue, burnout and exhaustion and risk for later health states, such as coronary heart disease.21 A recent study found that higher CAR predicted future episodes of MD within a 2.5-year period.20 We anticipate that iCT-R will reduce the CAR and cortisol throughout the day and protect against the development of PTSD and MD.
To assess potential moderators of outcomes, we will measure psychiatric, personality, trauma and social support factors at baseline (social support, trauma exposure, anxiety, age, gender, education, neuroticism, past and current psychiatric status, immune function). The neuroticism subscale (12 items) of the Eysenck Personality Questionnaire has excellent psychometric properties and is a measure of emotionality.42 We will use an adapted version of a brief measure of social support, to assess perceived support from and closeness to friends, family and work colleagues, as well as use of social support.43 Trauma exposure will be measured using a 19-item unpublished trauma questionnaire relevant to emergency workers, which includes items from the Life Events Checklist.44 We will also collect demographic information (age, gender, and level of education), information on the duration, frequency and distress linked to the Intrusions Questionnaire,45 and questions about concrete and abstract thinking based on an existing assessment tool.46 Participants will be asked to think about a problem they are having and write questions that may go through their minds in relation to the problem. They will then be presented with four problem scenarios and asked to select from a list the likely thoughts they would have if faced with the problem. The list consists of a range of concrete and abstract thoughts. We will investigate whether or not changes in resilience-related factors (rumination, responses to intrusions, concrete thinking, resilience appraisals, practice of iCT-R/Mind-Online tools) mediate symptom levels of PTSD and MD at 1-year and 2-year follow-up with iCT-R and Mind-Online.