How do we measure perinatal PTSD?

The saying “rubbish in, rubbish out” emphasizes the importance of accurate measurement in research. Simply put, if our measures aren’t right our results are not valid. Most studies of perinatal PTSD use self-report questionnaires because we need to screen a lot of women in order to identify the small proportion of women who need help. However, if our questionnaires are not accurate it undermines the results of our research.

At the risk of stating the obvious, how we measure PTSD is therefore critical. Clinical interviews are proposed to be the ‘gold standard’ of measurement and some questionnaires have been validated against interviews to determine how sensitivity and specific they are in terms of identifying women with PTSD. However, there are a number of perennial issues we need to consider. These issues include whether to use general PTSD measures or birth-specific measures. Studies suggest that postnatal women might over-report symptoms of hyperarousal and under-report symptoms of avoidance, so birth-specific measures may be more appropriate. Another issue is whether to take a diagnostic approach to PTSD as a ‘disorder’ or a continuum approach focusing on PTSD symptoms. It is clear that some women who do not fulfill diagnostic criteria for PTSD still want and need help. However, there is currently no agreement over what constitutes significant subclinical symptoms. Similarly, different questionnaires focus on a variety of symptoms or diagnostic criteria so we need to be clear about which approach we are taking before we choose our measures. A recent issue is that diagnostic criteria for PTSD changed with the publication of DSM-V but, as yet, questionnaires have not been updated to account for these changes.

The consequence of all of these issues is that it might be difficult at the current time to recommend a measure of PTSD for use with perinatal women and this probably needs to be decided according to the aims of the research. In the meantime, a compromise could be to use multiple measures and, wherever possible, to use clinical interviews. However, it is clear that we desperately need research evaluating different measures and adapting measures to conform to DSM-V diagnostic criteria.

Conferences and perinatal PTSD research

The recent ISPOG conference had a lot of research on perinatal PTSD, anxiety, and fear of childbirth, which made it a really stimulating conference for those of us working in this area. Every year it is difficult to decide which conferences to go to in order to find out more about perinatal PTSD and present our research. It was one of the reasons we set up the research network in 2005 – to facilitate discussion and exchange of ideas between researchers in this area. Similarly, coordinating efforts to attend the same conferences provides great opportunities to hear about each other’s research and discuss collaborations – as the ISPOG conference recently demonstrated.

 We have done some digging to see if we can help and have come up with a list conferences that are relevant to perinatal PTSD, or where we know people in the network are attending. This year, the Perinatal Mental Health conference in November looks particularly interesting, although the deadline for submissions has already passed. If you want to present your work to an international audience, the International Marce Society conference in 2014 is on Change in perinatal mental health so promises to be a good forum for our work.  If you know of other good conferences – especially if you are presenting perinatal PTSD research – please add them by clicking on the speech bubble.

2013 Conferences
Society for Reproductive and Infant Psychology, 17-18 September, UK
Australasian Marcé Conference, 11-12 October, Australia
Perinatal Mental Health Conference, 6-8 November, USA
International Society for Traumatic Stress Studies, 7-9 November, USA

2014 Conferences
North American Society for Psychosocial Obstetrics and Gynecology, 6-9 April 2014, USA
International Confederation of Midwives triennial conference, 2014, Prague
14th World Association for Infant Mental Health World Congress, July 2014, UK
International Marcé Society Biennial Scientific Meeting, 10-13 September 2014, UK
European Health Psychology Society conference, 2014, Austria

2015 Conferences to watch out for
6th World Congress on Women’s Mental Health, details to be announced
International Society for Psychosomatic Obstetrics and Gynaecology, Spain, details to be announced

All change… what does DSM-5 mean for perinatal PTSD?

By Susan Ayers, Centre for Maternal and Child Health, City University London

In May this year the American Psychiatric Association released version 5 of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to some controversy and criticism, including from Allen Frances, the chair of the previous DSM task force (Psychology Today, 2012). The British Psychological Society also expressed concerns about aspects of DSM-5, and the Division of Clinical Psychology published a detailed statement in response to DSM-5. So what are the implications of DSM-5 for perinatal PTSD?

Key changes in DSM-5 criteria for PTSD are outlined in an APA factsheet. Frustratingly, getting access to the complete diagnostic criteria seems to be difficult unless you purchase the manual. Nonetheless, the key changes outlined by the APA factsheet and gleaned from a few other sources are as follows:

  • PTSD is now classified as a ‘trauma and stressor-related disorder’ rather than an anxiety disorder.
  • Event criteria have changed so the person has to directly experience or witness “actual or threatened death, serious injury or sexual violation”. Previous criterion A2 about individuals responding to this event with intense fear, helplessness or horror has been removed. In addition, certain events are excluded from qualifying as a traumatic event, including the unexpected death of a family member by natural causes. 
  • There are now four symptom clusters of PTSD instead of three: (1) intrusions, (2) avoidance, (3) arousal and (4) negative cognitions and mood. The new category of ‘negative cognitions and mood’ includes some symptoms of numbing that were previously included with avoidance symptoms, in addition to new symptoms such as persistent blame of self or others.
  • Arousal symptoms now include more aggressive or self-destructive behaviours.
  • Two subtypes have been added of PTSD in children and PTSD with dissociative symptoms.

For perinatal PTSD the changes to event criteria are critical. Traumatic births still fit criteria because women can directly experience the threat of death or injury. Similarly, fathers and birth partners may fit criteria by witnessing such events. However, the exclusion of death of a family member by natural causes could (arguably) exclude death of the infant before, during or after birth, depending on how ‘natural causes’ is defined. This raises the question of whether psychological problems arising from perinatal infant death are more appropriately conceptualised as PTSD or complicated grief.

This tightening of event criteria to potentially exclude infant deaths, coupled with the necessity for parents to have four types of symptoms rather than three, means prevalence rates of postpartum PTSD could reduce. On the other hand, the removal of criterion A2 where the person has to respond to the event with intense fear, helplessness or horror could increase prevalence rates of postpartum PTSD. The rationale behind this change is that people respond to traumatic events in different ways (e.g. anger, shame, guilt) and that inclusion of A2 “proved to have no utility in predicting the onset of PTSD” (see APA factsheet).

Postpartum PTSD research certainly supports the notion that women respond to traumatic birth with a wide range of negative emotions (e.g. Ayers, 2007).  However two large studies carried out in the UK and Australia suggest the removal of A2 is likely to inflate prevalence rates of postpartum PTSD because many women perceive a threat of injury or death during birth. In the UK, Ayers et al (2009) looked at prevalence of postpartum PTSD in 502 women in community studies and found 35% of women reported perceived threat of injury or death. Similarly, 35% of women reported feeling intense fear or horror at some point during birth. However, only 19.7% of women reported both perceived threat of death or injury and feeling intense fear, helplessness or horror. This was also the case in an Australian study where Boorman et al (2013) looked at criteria for a traumatic birth in 890 women and found that prevalence of traumatic birth doubled from 14.3% to 29.4% when women’s emotional responses (criterion A2) were removed.

It is therefore not clear whether changes to PTSD diagnostic criteria in DSM-5 will reduce or increase prevalence rates of postpartum PTSD. In other populations the indications are that DSM-5 criteria result in lower prevalence rates (Miller et al, 2012). Research is needed to examine whether this is also the case in perinatal samples. However, before we do this we need to consider how best to measure perinatal PTSD, given the changes introduced by DSM-5. Finally, these diagnostic changes also have implications for screening and access to treatment that we haven’t considered here.

If you have any comments on this article or related issues, such as the measurement of perinatal PTSD, please let us know or leave a reply below. We are keen to publish blog posts or articles from any of our members – just get in touch with Ellinor (ellinor.olander@city.ac.uk) or Susan (susan.ayers.1@city.ac.uk).