Journal Article Annotations
2024, 4th Quarter

Climate Change

Annotations by Mary Burke, MD
January, 2025

Association of Postpartum Temperature Exposure with Postpartum Depression: A Retrospective Cohort Study in Southern California.

Of interest:

The Climate Formulation: Addressing Climate Change in Mental Health Practice.

PUBLICATION #1 — Climate Change

Association of Postpartum Temperature Exposure with Postpartum Depression: A Retrospective Cohort Study in Southern California.

Yi Sun, Kathryne S Headon, Wajeeha Umer, Anqi Jiao, Jeff M Slezak, Chantal C Avila, Vicki Y Chiu, David A Sacks, Kelly T Sanders, John Molitor, Tarik Benmarhnia, Jiu-Chiuan Chen, Darios Getahun, Jun Wu.

Abstract: Environ Health Perspect. 2024 Nov;132(11):117004. doi: 10.1289/EHP14783. Epub 2024 Nov 27.

Background:
Postpartum depression (PPD) has been associated with biological, emotional, social, and environmental factors. However, evidence regarding the effect of temperature on PPD is extremely limited.

Objectives:
We aimed to examine the associations between postpartum temperature exposure and PPD.

Methods:
We conducted a retrospective cohort study using data from Kaiser Permanente Southern California electronic health records from 1 January 2008 through 31 December 2018. PPD was first assessed using the Edinburgh Postnatal Depression Scale (score ≥10) during the first year of the postpartum period and further identified by using both diagnostic codes and prescription medications. Historical daily ambient temperatures were obtained from the 4-km resolution gridMET dataset (https://www.climatologylab.org/gridmet.html) and linked to participants’ residential addresses at delivery. Postpartum temperature exposures were measured by calculating various temperature metrics during the period from delivery to PPD diagnosis date. A time-to-event approach with a discrete-time logistic regression was applied to estimate the association between temperature exposure and time to PPD. Effect modification by maternal characteristics and other environmental factors was examined.

Results:
There were 46,114 (10.73%) PPD cases among 429,839 pregnancies (mean±standard deviation age =30.22±5.75 y). Increased PPD risks were positively associated with exposure to higher mean temperature [adjusted odds ratio (aOR) per interquartile range increment: 1.07; 95% confidence interval (CI): 1.05, 1.09] and diurnal temperature range (aOR=1.08; 95% CI: 1.06, 1.10); the associations were stronger for maximum temperature compared with minimum temperature. The temperature-related PPD risks were greater among African American, Asian, and Hispanic mothers and among mothers ≥25 years of age compared with their counterparts. We also observed higher effects of temperature on PPD among mothers exposed to higher air pollution or lower green space levels and among mothers with lower air conditioning penetration rates.

Conclusion:
Maternal exposure to higher temperature and diurnal temperature variability during the postpartum period was associated with an increased risk of PPD. Effect modification by maternal age, race/ethnicity, air pollution, green space, and air conditioning penetration was identified. https://doi.org/10.1289/EHP14783

Annotation

The finding:
Pregnant women exposed to heat waves are at increased risk for postpartum depression (PPD). The impact of heat on pregnancy health has long been established, as have the negative impacts of air pollution and heat on mental health. This study continued the work of these researchers, finding that ambient heat increased the risk of PPD in the first year postpartum, with effects strongest for women of color (African American, Hispanic and Asian) and for women over 25 years of age. Access to air conditioning and green spaces were protective.

Strength and weaknesses:
The study had a large data base (>430,000 women) with a broad demographic. Over 10% of all subjects had a PPD based on diagnostic codes and antidepressant medications. The Kaiser System of Sothern California has a long tradition of academic study of the social determinants of health. The team used high-quality climate and urban geographical research tools.

Relevance:
As global temperatures continue to rise, climatologists predict that we will surpass the limits of the Paris Agreement (1.5o C, by 2100) unless global emissions peak now. (See most recent COP report here: https://library.wmo.int/viewer/69075/?offset=#page=3&viewer=picture&o=bookmarks&n=0&q=). Perinatal psychiatrists should be prepared to detect the impact of worsened heat on their patients. Given that increased heat and pollution also predict perinatal morbidity and infant morbidity, OB teams and mental health providers can expand their patient education to plan for heat waves, support protective measures and expect increased rates of PPD.

PUBLICATION #2 — Climate Change

The Climate Formulation: Addressing Climate Change in Mental Health Practice.

Raziya S Wang, Andreea L Seritan, Amalia Hatcher, Ali Abbas Asghar-Ali.

Abstract: Acad Psychiatry. 2024 Sep 16. doi: 10.1007/s40596-024-02040-3. Online ahead of print.

Annotation (unstructured)

This article proposes integration of an ecological/climate assessment as part of the psychiatric bio-psycho-social formulation. It demonstrates how the changing environment and its sequelae have broad health and mental health impacts. By methodically identifying these contributors, clinicians can take concrete steps to improve their understanding of patient presentations. Identifying larger ecological impacts on health can support more specific interventions, as demonstrated by the sample case. Many regions of the globe are already seeing dramatic impacts of climate change on population health. Psychiatrists in cities struck by heat waves already are aware that heat increases suicidal ideation and worsens irritability and aggression. Individuals with schizophrenia have the highest risk of heat-related mortality. Psychiatrists working with survivors of climate-related disasters understand the long-term consequences of the disruptions, losses and traumas that can result. Formalizing our climate impacts in our formulation standardizes our approach to climate-related morbidity.