Inspirations: Bringing the science of fear up to date with PTSD

  • Post-traumatic stress disorder often affects people after traumatic experiences.
  • Assault, sexual or nonsexual, is the trauma most likely to cause PTSD.
  • Men are more likely to have traumatic experiences but more women have PTSD.
  • High oestrogen levels or injections of hydrocortisone may protect against PTSD.

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(Pauline Yu [CC / Flickr])

If you’ve been watching this site over the last couple of months, you’ll have noticed that I’ve been developing an unhealthy interest in the science of fear, from William Myers’s coining of the term ‘shell-shock’ in 1915 to Solly Zuckerman’s work on British civilians during the Blitz and how the fiction writers among us might use the psychology of the Blitz to give our readers a satisfying fright.

Piers Morgan’s factchecking failures

I’d always intended to look at some more up-to-date research but it was Piers Morgan who persuaded me to get my head down to it. I won’t say he inspired me, as I can think of few less inspirational people than Piers Morgan. What he did was respond to Lady Gaga’s statement that she had post-traumatic stress disorder after been raped by tweeting that only ‘soldiers returning from battlefields have‘. He then added hypocrisy to ignorance by adding ‘I come from a big military family. It angers me when celebrities start claiming ‘PTSD’ about everything to promote themselves‘.

One wonders what his family had to say to him in 2004, when he was fired as editor of the Daily Mirror after he was taken in by faked photographs of British soldiers apparently abusing Iraqi prisoners, and published them on his front page. His disparaging tweet suggests that whatever his views on the army, he has not got any better at fact checking.

I bring this up not because I enjoy commenting on celebrity twitter spats or even because I enjoy being rude about Piers Morgan, though the latter is a fringe benefit. I comment because Morgan’s grasp of the science of fear appears to be where I left it in my last few articles, when it was still focused on the effects of combat. The story of PTSD brings the science up to date, via some very dark places. Before you follow me any further into them, it’s only fair to warn you that sexual assault is going to be a major theme.

The common misconception that PTSD is only caused by combat may be due to its being the intellectual offspring of shell-shock. As the diagnoses of psychiatric disorders are usually based on clusters of symptoms, definitions inevitably evolve over time. Hence

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(Michelle Robinson [CC / Flickr])

‘shell-shock’ was replaced with ‘combat stress response’ by the beginning of the Second World War and revised again in the late 1970s, when American psychologists noticed similar symptoms were very common among soldiers returning from the Vietnam War.

What is PTSD?

The first proper definition of PTSD was in the third edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-III to its friends, published in 1980. It described a diagnosis of PTSD based on symptoms including anxiety, depression, isolated, disconnected, panic attacks brought on by a psychological trauma. While most people are likely to have some of those symptoms after a trauma, PTSD is defined by their lasting more than a month and being severe enough to cause ‘functional impairment’: if you find it distressing to do things you had no problem with before experiencing a trauma, it’s PTSD.

The definition and diagnosis were revised for the DSM-IV in 2000 and the current definition was published in the DSM-V in 2013. It is now considered to be more of a mood disorder than an anxiety disorder, and the need for an objective sense of fear and horror has been dropped to recognise the fact that PTSD can be brought about by a vicarious trauma. Most of the studies I quote here were using the DSM-III or DSM-IV definitions, though the revisions are unlikely to have made any difference to the findings.

While research on PTSD may have started with American Vietnam veterans, it was quickly recognised that you don’t have to go to war to be traumatised. In fact, psychiatrist Fran Norris showed that being assaulted, sexually or otherwise, is about six times as likely to cause PTSD as combat some 25 years ago. Norris’s study was one of the first indications that PTSD is not necessarily combat-related, and that most cases are in fact caused by interpersonal violence, sexual or otherwise.

Hunting the definitions

Surveys of PTSD are notoriously difficult to do, and Norris’s study illustrates some of the difficulties. For one thing, there’s the question of how serious an incident must be to count as traumatic. Norris’s work identified motor accidents as a significant cause of PTSD, but how serious is a serious motor accident? In a survey, someone who had PTSD from an accident would say they had experienced a serious accident. Someone else may have shrugged off an identical accident, and answer that they had never been in a serious accident. Norris’s survey question was whether they had been in an accident serious enough to injure at least one person, but that just shifts the question to how serious a knock counts as an injury. Does a cut scalp that bleeds all over everyone and requires stitches count as an injury? Ask different people and you’re likely to get different answers.

One category that is not subject to so much vagary is sexual assault. The question asked was, ‘did anyone ever make you have sex by using force or threatening to harm you? This

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Causes of PTSD after Norris (1992)

includes any type of unwanted sexual activity’. Under current definitions, that’s not sexual assault but violent rape. It places the definition of ‘sexual assault’ at the more serious end of the scale than the other traumas, but also excludes a lot of serious, and hence traumatic, experiences of being sexually assaulted. It risks over-estimating the percentage of people who have been sexually assaulted who have PTSD, but under-estimating the percentage of people within the population who have PTSD after being sexually assaulted.

Another problem that arises is that Norris’s survey assessed current PTSD but asked about any and all traumatic events the respondents had ever experienced, so there were probably people who did have PTSD but had recovered from it. It’s a problem particularly pertinent to the experience of combat. The survey was carried out in the USA, presumably in 1990 based on the fact that it was carried out after Hurricane Hugo in 1989 and submitted in 1991. Most of the combat would have been experienced during the Vietnam War around two decades earlier, while the other traumatic experiences mentioned could have been long before that or could have been a few weeks before the survey. Based on the figure that around two thirds of people with PTSD recover from it, it’s possible that the lifetime rate for combat-related PTSD was as high as 6.6%, but we can’t make a similar calculation for other traumas because we don’t know how recent they may have been.

Frustrating as they are, these problems are impossible to avoid in population-based surveys and they are not damning criticisms of Norris’s methodology so much as a description of necessary constraints. As it’s not ethical to deliberately traumatise people to see how they react, such surveys are the best available way to the truth.

Why do more women have PTSD than men?

Perhaps for these reasons,  different studies tend to report different figures for how many people have experienced trauma and how many have PTSD, although studies from the UK, USA and Australia are in broad agreement that between 1% and 4% of people have PTSD at any given time. They also agree that around three times as many people have experienced

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(Moonlight 徐宇峰 [CC / Flickr])

PTSD in the past than will have had it at the time they are asked. That’s good news in that: two thirds of people with PTSD recover from it. It’s also bad news: a third of cases become ‘chronic’, meaning that they persist for years or in some cases, decades.

Why do more women have PTSD than men?

While the precise estimates vary, one pattern that emerges consistently: men are more likely to have experienced a traumatic event, but women are more likely to have PTSD.

Likely reasons for that fall into two categories: either there is a biological difference between men and women that affects their response to trauma, or they tend to experience different types of trauma.

The latter possibility was tackled by clinical psychologists David Tolin and Edna Foa in a 2006, when they combined the results from 290 earlier studies. They found that different types of traumatic event were not equal. The most traumatic trauma was sexual assault which, for the purposed of the study, included rape. Women were far more likely to have been sexually assaulted than men, which the authors concluded accounted for the discrepancy between PTSD prevalence between men and women. Women who had survived a sexual assault were no more likely than men to have PTSD, but women were around six times more likely to have been sexually assaulted as adults and around two-and-a-half times more likely to have been sexually assaulted as children, so women were simply more likely to have been traumatised by sexual assault.

However, as Norris showed that physical assault was almost as traumatic as sexual assault and Tolin and Foa showed men were more likely to be assaulted nonsexually than women,

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A good way to get PTSD (ER24 EMS (Pty) Ltd. [CC / Flickr])

sexual assault is not a complete answer.

When Tolin and Foa considered different types of trauma, they found that women were more likely to develop PTSD after some types of non-sexual trauma, specifically serious accidents, nonsexual assaults, combat, major fires and witnessing death or injury. However, they did acknowledge that even within their categories of trauma, men and women may not have equivalent experiences. For example, the nonsexual assault experienced by women was more likely to be domestic violence by a family member or partner, which may be more traumatic.

The veterans of Somalia

Another study looked at men and women who had been part of the American military deployment to Somalia in 1993-1995. Women were more likely to have symptoms of PTSD even though they saw less combat, but overlaying their experiences was a great deal of sexual harassment. In fact, 52% of women and 12% of men were sexually harassed while they were deployed. Combined with the Tailhook and Aberdeen scandals of the early to mid-1990s, it’s evident that the American military had some serious problems with sexual abuse at the time. Given that more of the women who experienced combat also experienced sexual harassment, which is potentially traumatic in itself, we can’t conclude that the higher prevalence of PTSD among women was due to their reacting to combat differently to men.

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(Marines from Arlington, VA, United States [Wikimedia Commons])

The Somalia veteran study started in the same place as many studies of PTSD: for soldiers and emergency services, potentially traumatic situations are part of the job description so it would be useful to know how to prepare people in such a way that they don’t develop PTSD. The study then ran into a commonly encountered stumbling block: there are so many ways for different people to have different experiences that it’s impossible to isolate one to work on, beyond the obvious: if you don’t want your soldiers to get PTSD, stop sexually harassing them.

The ideal experiment would be to assess people before and after they are exposed to a trauma. Unfortunately, militaries tend to take a dim view of their soldiers being experimented on while on deployment and research ethics committees take a dim view of experiments that turn their subjects into gibbering wrecks.

Oestrogens and fear conditioning

The closest that has been possible was in a set of experiments led by Mohammed Milad. He designed an experiment in which volunteers were conditioned to expect an electric shock when a coloured light came on. Their level of fear was measured by the conductivity of their skin. While there are obvious limitations in studying PTSD using a protocol specifically designed not to cause PTSD – the electric shock is described as ‘highly annoying but not painful’ – he could at least look into whether there were biological differences between men and women.

As expected, the appearance of the light heightened the fear response in people who had been conditioned to associate it with the electric shock but for women, whether the

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(Philippe Put [CC / Flickr])

conditioning stuck or not depended on where they were in their menstrual cycle. Women in the middle of the cycle, when oestrogens are high, were less conditioned than women in the early stage of the cycle who were not different to men.

Milad went further, showing that women with a naturally high oestrogen level were less likely to retain the conditioning. His experiments suggest a biological difference between how men and women respond to fear, but there is a problem: high levels of oestrogens apparently make women less likely to be conditioned to fear, which contradicts the epidemiological evidence that more women have PTSD. Here again, the limitations raise their head: Milad’s experiments were designed to elicit a mild fear response, while the traumas that cause PTSD usually include many other emotions such as horror, grief and violation.

To extrapolate from Milad’s experiments to the lived experience of PTSD, we have to assume that conditioning someone to an annoying electric shock is a milder form of the process by which traumatised people develop PTSD. If we accept the assumption, Milad supports Tolin and Foa’s inference that the difference between men and women is not that

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Who is likely to be comforting who? (marc cornelis [CC / Flickr])

women are more prone to PTSD but that they are more likely to experience sexual violence which is inherently more traumatic than anything else.

Can oestrogen protect from PTSD?

Milad’s results lead to a further question: if high levels of oestrogens prevent women becoming conditioned to fear, could raising a woman’s oestrogens protect her from PTSD after trauma? Raising oestrogens is something that many women habitually do with hormonal contraception and in fact, women taking contraceptives do suffer less post-traumatic stress symptoms after sexual assault than women who didn’t. To be clear, that’s not to say they did not suffer at all. The study assessed a range of symptoms rather than whether or not the women met the criteria for PTSD and six months after the assault, they all had at least some of the symptoms of PTSD even if they didn’t qualify for the full diagnosis.

Once again, the problem of confounders raises its head: women on contraception were more likely to have been drinking at the time of the assault and also more likely to seek therapy after it. Any or all of the three factors, hormonal contraception, alcohol or therapy, could have alleviated their suffering less six months later. What was more clear was that women who took emergency contraception, the so-called ‘morning after’ pill, suffered less PTSD symptoms than women who did not.

Steroids and psychotherapy

There is therefore an argument for offering women an injection of oestrogens as part of the emergency treatment for a trauma, but it’s unlikely to be of much help to men who would respond to them in a different way. It does beg the question of whether testosterone, which is a chemically similar steroid hormone, may be of some help. I cannot find any research on testosterone levels at the time of the trauma, although there is no difference in PTSD levels between men with and without PTSD. There are websites advertising testosterone injections as a treatment for PTSD, but then there are websites offering testosterone as a panacea for any ailment you could think of without any evidence. Based on the information available, treating PTSD with testosterone probably does nothing at all, and is as likely to make things worse as better.

More encouragingly, a team at the Chaim Sheba Medical Centre in Tel Aviv, Israel, tried injecting accident victims with hydrocortisone when they were still in the Emergency Department. Three months after the accident, no one who received the hydrocortisone had PTSD while 30% of people who received the placebo did. It’s a considerably better

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Should this be where treatment for PTSD is started? (Paul [CC / Flickr])

result than was observed with emergency contraception, although it’s also true that accidents are far less likely to induce PTSD than sexual assault. It was a small study, but it does look like a straightforward treatment that could benefit a lot of people.

It’s not widely available in most places so anyone with PTSD is left depending on psychotherapy and possibly antidepressants. It’s not clear that medication adds much to psychotherapy, but PTSD often goes hand in hand with depression. As around two thirds of people with PTSD recover from it, anyone who has it can take some comfort that it’s probably not a life sentence.

 

Addendum: Revised on 10th Feb 2017 to incorporate the suggestions of a mental health professional who prefers to remain anonymous.

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Posted in Inspirations, Wednesday Pontification

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