The importance of social support and food insecurity in improving outcomes for perinatal depression: A causal mediation analysis of the AFFIRM-SA trial

Nadine Seward; Emily Garman; Thandi Davies; Charlotte Hanlon; Angus MacBeth; Robert C. Stewart; Ahmad Waqas; Ricardo Araya; Crick Lund

doi:10.1016/j.jad.2025.03.159

The importance of social support and food insecurity in improving outcomes for perinatal depression: A causal mediation analysis of the AFFIRM-SA trial

Nadine Seward^*, Emily Garman, Thandi Davies, Charlotte Hanlon, Angus MacBeth, Robert C. Stewart, Ahmad Waqas, Ricardo Araya, Crick Lund

^*Corresponding author for this work

Health Service & Population Research

Research output: Contribution to journal › Article › peer-review

Abstract

Background: Understanding the mechanisms through which psychological interventions influence symptoms of perinatal depression can inform the development of interventions for improving maternal mental health. The AFFIRM-SA trial, conducted in an underserved settlement on the outskirts of Cape Town, was a task-shared psychological intervention designed to improve symptoms of perinatal depression. We aim to estimate indirect effects of mediators through which the AFFIRM-SA intervention reduced perinatal depressive symptoms. Methods: Interventional Effects, a robust causal inference framework, was used to decompose the total effect of randomisation to the intervention on symptoms of perinatal depression reducing by at least 40 % on the Edinburgh Postnatal Depression Scale (EPDS) at 12 months postpartum in women with complete data (n = 310), into the following indirect effects at three months postpartum: experienced violence, presence of moderate or severe levels of food, and mean levels of perceived social support. Results: Of the total effect of the intervention measured through the difference in EPDS scores improving by at least 40 % between treatment arms (mean difference in probability between intervention and control arm: 0.139, bias-corrected 95 % CI −0.056 to 0.224), 8 % was mediated through reduced levels of severe food insecurity (0.011; bias-corrected 95 % CI 0.003, 0.029) and 9 % through increased levels of perceived social support (0.012: bias-corrected 95 % CI: 0.001, 0.032). There was no evidence to support the mediating role of reduced levels of violence. Limitations: The main limitation is the sample size (n = 310) which reduces the certainty of our findings where mediators are uncommon (e.g., domestic violence). Conclusions: Our findings suggest that psychological interventions that combine psychological components with interventions that directly target social determinants of mental health (such as food insecurity and social support) could substantially improve perinatal depression.

Original language	English
Pages (from-to)	552-560
Number of pages	9
Journal	Journal of Affective Disorders
Volume	380
Early online date	3 Apr 2025
DOIs	https://doi.org/10.1016/j.jad.2025.03.159
Publication status	Published - 1 Jul 2025

Keywords

Causal mediation
Food insecurity
Interventional effects
Perinatal depression
Postnatal depression
Psychological interventions
Social support

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.jad.2025.03.159

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@article{3484639638be406cb2a496b294b50800,

title = "The importance of social support and food insecurity in improving outcomes for perinatal depression: A causal mediation analysis of the AFFIRM-SA trial",

abstract = "Background: Understanding the mechanisms through which psychological interventions influence symptoms of perinatal depression can inform the development of interventions for improving maternal mental health. The AFFIRM-SA trial, conducted in an underserved settlement on the outskirts of Cape Town, was a task-shared psychological intervention designed to improve symptoms of perinatal depression. We aim to estimate indirect effects of mediators through which the AFFIRM-SA intervention reduced perinatal depressive symptoms. Methods: Interventional Effects, a robust causal inference framework, was used to decompose the total effect of randomisation to the intervention on symptoms of perinatal depression reducing by at least 40 % on the Edinburgh Postnatal Depression Scale (EPDS) at 12 months postpartum in women with complete data (n = 310), into the following indirect effects at three months postpartum: experienced violence, presence of moderate or severe levels of food, and mean levels of perceived social support. Results: Of the total effect of the intervention measured through the difference in EPDS scores improving by at least 40 % between treatment arms (mean difference in probability between intervention and control arm: 0.139, bias-corrected 95 % CI −0.056 to 0.224), 8 % was mediated through reduced levels of severe food insecurity (0.011; bias-corrected 95 % CI 0.003, 0.029) and 9 % through increased levels of perceived social support (0.012: bias-corrected 95 % CI: 0.001, 0.032). There was no evidence to support the mediating role of reduced levels of violence. Limitations: The main limitation is the sample size (n = 310) which reduces the certainty of our findings where mediators are uncommon (e.g., domestic violence). Conclusions: Our findings suggest that psychological interventions that combine psychological components with interventions that directly target social determinants of mental health (such as food insecurity and social support) could substantially improve perinatal depression.",

keywords = "Causal mediation, Food insecurity, Interventional effects, Perinatal depression, Postnatal depression, Psychological interventions, Social support",

author = "Nadine Seward and Emily Garman and Thandi Davies and Charlotte Hanlon and Angus MacBeth and Stewart, {Robert C.} and Ahmad Waqas and Ricardo Araya and Crick Lund",

note = "Publisher Copyright: {\textcopyright} 2025",

year = "2025",

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doi = "10.1016/j.jad.2025.03.159",

language = "English",

volume = "380",

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T1 - The importance of social support and food insecurity in improving outcomes for perinatal depression

T2 - A causal mediation analysis of the AFFIRM-SA trial

AU - Seward, Nadine

AU - Garman, Emily

AU - Davies, Thandi

AU - Hanlon, Charlotte

AU - MacBeth, Angus

AU - Stewart, Robert C.

AU - Waqas, Ahmad

AU - Araya, Ricardo

AU - Lund, Crick

PY - 2025/7/1

Y1 - 2025/7/1

N2 - Background: Understanding the mechanisms through which psychological interventions influence symptoms of perinatal depression can inform the development of interventions for improving maternal mental health. The AFFIRM-SA trial, conducted in an underserved settlement on the outskirts of Cape Town, was a task-shared psychological intervention designed to improve symptoms of perinatal depression. We aim to estimate indirect effects of mediators through which the AFFIRM-SA intervention reduced perinatal depressive symptoms. Methods: Interventional Effects, a robust causal inference framework, was used to decompose the total effect of randomisation to the intervention on symptoms of perinatal depression reducing by at least 40 % on the Edinburgh Postnatal Depression Scale (EPDS) at 12 months postpartum in women with complete data (n = 310), into the following indirect effects at three months postpartum: experienced violence, presence of moderate or severe levels of food, and mean levels of perceived social support. Results: Of the total effect of the intervention measured through the difference in EPDS scores improving by at least 40 % between treatment arms (mean difference in probability between intervention and control arm: 0.139, bias-corrected 95 % CI −0.056 to 0.224), 8 % was mediated through reduced levels of severe food insecurity (0.011; bias-corrected 95 % CI 0.003, 0.029) and 9 % through increased levels of perceived social support (0.012: bias-corrected 95 % CI: 0.001, 0.032). There was no evidence to support the mediating role of reduced levels of violence. Limitations: The main limitation is the sample size (n = 310) which reduces the certainty of our findings where mediators are uncommon (e.g., domestic violence). Conclusions: Our findings suggest that psychological interventions that combine psychological components with interventions that directly target social determinants of mental health (such as food insecurity and social support) could substantially improve perinatal depression.

AB - Background: Understanding the mechanisms through which psychological interventions influence symptoms of perinatal depression can inform the development of interventions for improving maternal mental health. The AFFIRM-SA trial, conducted in an underserved settlement on the outskirts of Cape Town, was a task-shared psychological intervention designed to improve symptoms of perinatal depression. We aim to estimate indirect effects of mediators through which the AFFIRM-SA intervention reduced perinatal depressive symptoms. Methods: Interventional Effects, a robust causal inference framework, was used to decompose the total effect of randomisation to the intervention on symptoms of perinatal depression reducing by at least 40 % on the Edinburgh Postnatal Depression Scale (EPDS) at 12 months postpartum in women with complete data (n = 310), into the following indirect effects at three months postpartum: experienced violence, presence of moderate or severe levels of food, and mean levels of perceived social support. Results: Of the total effect of the intervention measured through the difference in EPDS scores improving by at least 40 % between treatment arms (mean difference in probability between intervention and control arm: 0.139, bias-corrected 95 % CI −0.056 to 0.224), 8 % was mediated through reduced levels of severe food insecurity (0.011; bias-corrected 95 % CI 0.003, 0.029) and 9 % through increased levels of perceived social support (0.012: bias-corrected 95 % CI: 0.001, 0.032). There was no evidence to support the mediating role of reduced levels of violence. Limitations: The main limitation is the sample size (n = 310) which reduces the certainty of our findings where mediators are uncommon (e.g., domestic violence). Conclusions: Our findings suggest that psychological interventions that combine psychological components with interventions that directly target social determinants of mental health (such as food insecurity and social support) could substantially improve perinatal depression.

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KW - Food insecurity

KW - Interventional effects

KW - Perinatal depression

KW - Postnatal depression

KW - Psychological interventions

KW - Social support

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DO - 10.1016/j.jad.2025.03.159

M3 - Article

AN - SCOPUS:105001565567

SN - 0165-0327

VL - 380

SP - 552

EP - 560

JO - Journal of Affective Disorders

JF - Journal of Affective Disorders

ER -

The importance of social support and food insecurity in improving outcomes for perinatal depression: A causal mediation analysis of the AFFIRM-SA trial

Abstract

Keywords

UN SDGs

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