Postnatal depression and appropriate screening tools for Aboriginal Australian and Torres Strait Islander peoples – a literature review

Introduction

Postnatal depressive disorder (PDD) is a non-psychotic depressive episode beginning and extending into the first postnatal year1. This unipolar depressive episode is associated with childbirth and refers to women who meet the diagnostic criteria for major or minor depression in the first postnatal year2.  It is associated with an increased risk of future depressive episodes within a 5 year period3. Some risk factors for PDD include depression and anxiety, poor social support and stressful events during pregnancy4,5.  Most estimates indicate that PDD affects between 10-15% of women worldwide6, with rates in Australian found to be at 14%7.  Antenatal risk factors for depression may predict postnatal depression8,9 . As a result, the focus of postnatal depression has broadened to include antenatal depression with the term perinatal depression now describing depressive disorders associated with pregnancy and early parenthood10.

PDD may impact the mother herself, mother-infant interaction11,12, psychological development and long-term health outcomes of the child1,13 . It may impede on a mother’s capacity to nurture her child and is associated with attachment insecurity and increased risk of psychopathological concerns14,15. In addition, as women tend to base self-esteem on their capacity to nurture others, any disruption to this may cause significant consequence on the mother’s self-regard16. It may also have consequences on a capacity to fulfil cultural ideals around the role of a mother and impacting on repercussions for the mother, child and family17.

To detect depression perinatally, the universal screening tool called the Edinborough Postnatal Depression Scale (EDPS) is currently recommended as national tool of choice7,18. This self-reported 10-item questionnaire is considered reliably capable of detecting women who may be at current risk for perinatal anxiety and depression19.  This tool, however, has not been validated for the Aboriginal and Torres Strait Islander peoples20 . Aboriginal people statistically suffer higher incidences of depression and anxiety than non-Aboriginal population21. Historical and sociocultural factors21 including but not exclusive to: colonisation, dispossession and systematic oppression22 are associated with heightened transgenerational-trauma, grief and loss among Aboriginal peoples23. High levels of mental distress, poorer physical and mental healthcare outcomes are also reported across their life24,25.

There are many social stressors and co-morbid health conditions in Aboriginal women’s pregnancy and birth that may contribute to additional risk for postnatal depression. These include but are not exclusive to: low birth weight, perinatal mortality rates twice as high as non-Aboriginal people, higher obstetric loss and bereavement26, elevated incidences of depression, anxiety and PTSD2. Additional risk factors for depression perinatally include: unemployment, low socio-economic status, childhood abuse, personality type, marital disharmony, stressful life events and social support27-29.

The prevalence of psychosocial stressors such as low partner support and major life events were significantly elevated among Aboriginal women in research literature30.  Research indicates that Aboriginal women who are pregnant also have fewer antenatal visits and less postnatal care than non-Aboriginal mothers31. These combined factors highlight the need for screening and early intervention for postnatal anxiety and depression as they could result in significant health benefits to the mother and child.

The following literature review will discuss mental health in Aboriginal peoples, the EPDS screening tool, how appropriate it is for Aboriginal people and novel screening tools such as the Kimberly Mum’s Mood Scale (KMMS). It will primarily focus on Aboriginal peoples in the Kimberley and Pilbara region of Western Australia. Aboriginal and Torres Strait Islander peoples will hereby be referred to as Aboriginal peoples as the populations in the aforementioned communities have a high proportion of Aboriginal people.

Depression and anxiety in Aboriginal and Torres Strait Islanders

Aboriginal cultural views of mental ill health is viewed as holistic, where well-being is understood in terms of the harmonised interrelations between spiritual, environmental, ideological, political, social, economic, mental and physical domains21. For Aboriginal peoples, a concept of self also encompasses the individual, together with their family, the wider tribal group and reciprocal obligations, loss or disintegration of which will to mental ill health32. Since colonisation, these traditional connections have been severely disrupted by cultural genocide, dislocation, forced removal of children, destruction of culture as well as devastating denial of basic human rights33. The consequence is an overwhelming sense of trauma, loss and grief for Aboriginal peoples.  As a result, there are two dimensions of mental health among Aboriginal Australians21. One is ‘mental distress’ resulting from collective experience as dispossessed and disadvantaged peoples and the other incorporates a range of serious psychiatric or mental disorders which are also prevalent in Aboriginal communities but may manifest differential or be understood differently34.

There is poor understanding of Aboriginal mental health including the definitions, manifestations and conceptualisations of illness which may contribute to limited epidemiological data surrounding mental illness in Aboriginal people21. Aboriginal Australians have, however, consistently been shown to have a higher prevalence of psychological distress35; ranging from 50% to 3 times higher36.  There is an associated increase in levels of distress in victims violence, discrimination or removal from natural37. Additional adverse social factors (e.g. poverty, lack of support, substance use) that are more prevalent among Indigenous peoples worldwide also cause greater risk for depression38. This is an important factor in Aboriginal suicide as depression has been documented in many settings to be a significant component of high suicide rates and both depression and suicide have been documented to be common amongst Aboriginal people39. Studies show that the rates of Aboriginal suicide are twice as high as non-Aboriginal peoples in Queensland40 and some limited research data indicates that the incidence is increasing in the Kimberley in recent decades41.

Edinborough Postnatal depression scale:

The Edinborough postnatal depression scale (EPDS) is the most widely