Lessons from the past

This year is the 40th anniversary of the first appearance of the 13-item EPDS in the book Postnatal Depression: A Guide for Health Professionals,^{Reference Cox1} published by Churchill Livingstone. In the following year, the more commonly cited ten-item EPDS was published in the British Journal of Psychiatry.^{Reference Cox, Holden and Sagovsky2} Confusingly perhaps, in this 10-item scale there is a cut-off score of 13 used to flag the need for further assessment.

A greater understanding of the history of the scale may help determine, in part, what practical and linguistic revisions are necessary for its optimal use in the future, and hence the pressure for revision and why the adoption of new directions is now needed.

The EPDS is used across the world by clinicians and researchers from many different countries and is included in both national and regional perinatal services – for example, in Sweden, Germany, the USA, Australia, Italy, France and Norway – as well as in the UK Antenatal and Postnatal Mental Health Guidelines published by the National Institute for Health and Care Excellence for the National Health Service.³

The scale has been translated into over 60 languages and several dialects, even though such widespread uptake was unexpected, so why such longevity? Answers to this question include increased awareness of perinatal mental disorders, greater knowledge of their impact on infant and child development, ever-increasing dissemination facilitated by instant internet connectivity (now including artificial intelligence) and, perhaps most importantly, the brevity and face validity of the scale itself.

The EPDS was developed in Edinburgh by me in collaboration with Jenifer Holden (health visitor and psychologist) and Ruth Sagovsky (senior trainee psychiatrist). The earlier Edinburgh studies^{Reference Cox, Rooney, Thomas and Wrate4} had shown that postnatal depression was a distressing condition that impacted the mother and marked her memory. Furthermore, existing mood scales were not validated for use in this context at that time and lacked face validity.

The three of us therefore set out to develop a new screening scale and, using our clinical and research experience in the UK and Uganda, we identified 21 possible items, from which we selected 13 that were the most likely to detect postnatal depression in a self-report scale. This 13-item scale was validated against research diagnostic criteria; however, because a factor analysis revealed that 2 irritability items and the parenting item were in a different non-depression factor, a shorter 10-item scale that was found to have satisfactory psychometric properties was also later validated, as described in a paper published in the British Journal of Psychiatry.^{Reference Cox, Holden and Sagovsky2}

These 10 items that define the EPDS have remained unchanged for 40 years, yet family structure and the wider multicultural and multi-faith context of childbirth, as well as the use of language, have changed considerably. Item 10, for example, nowadays carries greater ambiguity as a measure of suicidality,^{Reference Dudeney, Coates, Ayers and McCabe5} and item 6 uses the metaphor ‘things have been getting on top of me’, the meaning of which is perhaps not always fully appreciated. Similarly, the meaning of the concept of pleasurable anticipation – ‘looking forward with enjoyment to things’ (item 2) – is also not easily grasped. Furthermore, guilt or self-blame (item 3) are unfamiliar emotions in certain African and some Western societies and are thus possibly conceptualised somewhat differently.

Therefore it is necessary to chart new directions for the use of the EPDS in contemporary societies, whether in the UK or abroad, which might include the following: developing a revised 10- (or 13)- item EPDS-R that is user-friendly, inclusive and could screen for anxiety disorders as well as depression; clarifying the present-day usage of the terms postnatal and antenatal depression in different language groups; conducting a meta-analysis of EPDS psychometric and follow-up studies; revising the wording and clarifying the concepts of some EPDS items; updating the Instructions for Users; evaluating the impact of artificial intelligence and smartphone usage; and revising the EPDS Manual to include recommendations to avoid misuse and regarding the EPDS as a diagnostic tool.^{Reference Cox6}

Depending on the findings of new research, the possibility exists that the EPDS could be renamed ‘the 13-item Edinburgh Perinatal Depression and Anxiety Scale’, to reflect the additional items and also to capture the fact that it assesses a broader range of symptoms than depression alone, and that these occur in and around the time of childbirth rather than only following birth. Awareness that antenatal anxiety is common and can adversely affect the unborn baby, and that postnatal depression – often with anxiety symptoms – can onset during pregnancy, is necessary. The use of ‘perinatal’ in the title covers both time periods.

Summary reflections

Consideration of these new directions for the EPDS is a challenging task in contemporary societies that are forever changing and in flux. It requires an awareness of the past as well as the imagination to anticipate the future, and to know what is in the best interests of new parents living in a new world. It will be for others conducting research in this field – and, specifically, colleagues at City St George’s, University of London^{Reference Dudeney, Coates, Ayers and McCabe5} – to consider in more detail what these new directions may be, and to determine the psychometrics of any new scale and how this maps onto existing research that has been derived from use of the EPDS. At the same time, proactive collaboration with the Marcé Society will be helpful, as well as with perinatal psychiatrists and parents’ advocacy and support groups, and it will be important to remain cognisant of issues such as copyright to ensure appropriate use while ensuring widespread access.

Finally, because the EPDS was developed by a team at the Department of Psychiatry in Edinburgh that had a person-centred understanding of perinatal healthcare delivery,^{Reference Holden, Sagovsky and Cox7} these humanistic, ethical and culture-based values should remain central to its further development. It could be that it is these qualities that have been the essential ingredients contributing to the effectiveness of the EPDS and its success in both research and clinical practice.

On a personal note, I anticipate maintaining my nascent collaborations that have been successfully forged in recent years with new colleagues who are based close to the London hospital where I trained. Almost half a century ago my first review paper, ‘Aspects of transcultural psychiatry’, was published in this journal.^{Reference Cox8} However, I suspect that the seeds for the germination of my ideas and subsequent research, as well as the publications that followed – including this editorial, can perhaps be traced back to my earlier work and experience as a transcultural psychiatrist, and indeed by the nature of having a multicultural marriage to Karin, a Swedish citizen.