Last week we woke to the news that a passenger ferry had sunk off the coast of South Korea, with at least four people confirmed dead and 280 unaccounted for, evoking the grim memory of the Costa Concordia disaster in 2012. Meanwhile, though the search has continued for the missing Malaysia Airlines plane, relatives' hopes of a safe landing have long since been extinguished.
Human tragedies like these are the stuff of daily news, but we rarely hear about the long-term psychological effects on survivors and the bereaved, who may experience the symptoms of post-traumatic stress disorder for years after their experience.
Although most people have heard of PTSD, few will have a clear idea of what it entails. The American Psychiatric Association's Diagnostic and Statistical Manual (DSM) defines a traumatic event as one in which a person "experienced, witnessed, or was confronted with an event or events that involved actual or threatened death or serious injury, or a threat to the physical integrity of self or others". PTSD is marked by four types of responses to the trauma. First, patients repeatedly relive the event, either in the form of nightmares or flashbacks. Second, they seek to avoid any reminder of the traumatic event. Third, they feel constantly on edge. Fourth, they are plagued with negative thoughts and low mood.
According to one estimate, almost 8% of people will develop PTSD during their lifetime. Clearly trauma (and PTSD) can strike anyone, but the risks of developing the condition are not equally distributed. Rates are higher in socially disadvantaged areas, for instance. Women may be twice as likely to develop PTSD as men. This is partly because women are at greater risk of the kinds of trauma that commonly produce PTSD (rape, for example). Nevertheless – and for unknown reasons – when exposed to the same type of trauma, women are more susceptible to PTSD than men.
What causes it? In one sense, the answer is obvious: a specific trauma. Yet this is only part of the story, because not everyone who is raped or badly beaten up develops PTSD. Of the contemporary psychological attempts to answer that question, the most influential is the one formulated by the clinical psychologists Anke Ehlers and David Clark at the University of Oxford. They argue that PTSD develops when the person believes they are still seriously threatened by the trauma they have experienced. Why should someone assume they are still endangered by an event that happened months or even years previously? Ehlers and Clark identify two factors.
First is a negative interpretation of the trauma and the normal feelings that follow, for example believing that "nowhere is safe", "I attract disaster", or "I can't cope with stress". These interpretations can make the person feel in danger physically (the world seems unsafe), or psychologically (their self-confidence and sense of well-being feel irreparably damaged).
Second are problems with the memory of the trauma. Partly because of the way the person experiences the event, the memory somehow fails to acquire a properly developed context and meaning. As a result, it constantly intrudes. Ehlers and Clark liken the traumatic memory to "a cupboard in which many things have been thrown in quickly and in a disorganised fashion, so it is impossible to fully close the door and things fall out at unpredictable times".
These factors change the way people behave. They may avoid situations that might spark a memory of the trauma, and will sometimes try to deaden their feelings with drink or drugs. Yet these strategies tend to entrench and exacerbate the problem.
PTSD can be treated with antidepressants or various kinds of psychotherapy, including prolonged exposure therapy and eye movement desensitisation and reprocessing. However, a recent meta-analysis of 112 studies conducted over the past 30 years found that cognitive behavioural therapy (CBT) was the single most successful type of treatment.
CBT typically comprises three main strands. First, it evaluates the individual's excessively negative thoughts about the trauma and its aftermath – for example by helping them understand that they are not to blame or that their feelings are normal and natural. Second, the treatment works on the person's memory of the trauma: the individual might be asked to write a detailed account of the event; relive it in their imagination; revisit the site of the trauma; or be shown how to cope with the kind of objects or situations that trigger the traumatic memory.
The final strand involves tackling the kind of behaviours that tend to fuel PTSD, for example by demonstrating that attempting to suppress a thought is futile (if you doubt it, try right now not to think of a white bear) or that avoiding a situation only strengthens one's fear.
A course of CBT for PTSD normally involves meeting with a therapist once or twice a week over several months. Given how debilitating the problem can be, that can seem like a very long time to wait to get one's life back on track. However, pioneering research published in last month's issue of the American Journal of Psychiatry suggests that there may be an alternative. Instead of months, it may be possible to tackle the symptoms of PTSD in just seven days.
Anke Ehlers at the University of Oxford and her colleagues randomly assigned 121 patients with PTSD (about 60% female, 40% male) either to a seven-day course of intensive CBT; weekly sessions of CBT for three months; a type of psychotherapy known as emotion-focused supportive counselling; or to a 14-week waiting list. Participants in the first three groups all received the same amount of therapy (18 hours).
The results were striking. The intensive CBT proved almost as successful as the standard three-month course, with respective recovery rates from PTSD of 73% and 77%, and the intensive version produced its effects more quickly. For the supportive counselling group, recovery was 43% (another finding that undermines the idea that all types of psychotherapy are equally effective). Among the waiting list group, just 7% had recovered. Both courses of CBT also led to large reductions in levels of anxiety and depression.
Most importantly, the benefits lasted: 40 weeks after entering the study, about two-thirds of the CBT patients were still free from the symptoms of PTSD. The therapy isn't easy – it confronts highly distressing events and feelings, after all – but it works.
Daniel and Jason Freeman are the authors of Anxiety: A Very Short Introduction. On Twitter they are @ProfDFreeman and @JasonFreeman100. A version of this blog first appeared in The Guardian: http://www.theguardian.com/science/blog/2014/apr/17/post-traumatic-stress-disorder-ptsd-cbt?CMP=twt_gu