Marginal effects of heat on high or very high distress and on receiving treatment for depression or anxiety by humidity (vapour pressure) and their 99% confidential intervals, Logit model (Model 4), 53,144 adults aged over 45 from NSW, Australia.

<p>Marginal effects of heat on high or very high distress and on receiving treatment for depression or anxiety by humidity (vapour pressure) and their 99% confidential intervals, Logit model (Model 4), 53,144 adults aged over 45 from NSW, Australia.</p

Non-linear associations between temperature (heat), vapour pressure (humidity) and mental health, Logit model, 53,144 adults aged over 45 from NSW, Australia.

<p>Non-linear associations between temperature (heat), vapour pressure (humidity) and mental health, Logit model, 53,144 adults aged over 45 from NSW, Australia.</p

Proportions of respondents by socio-demographic characteristics and humidity status.

<p>Proportions of respondents by socio-demographic characteristics and humidity status.</p

Marginal effects of humidity on high or very high distress and on receiving treatment for depression or anxiety by temperature and their 99% confidential intervals, Logit model (Model 4), 53,144 adults aged over 45 from NSW, Australia.

<p>Marginal effects of humidity on high or very high distress and on receiving treatment for depression or anxiety by temperature and their 99% confidential intervals, Logit model (Model 4), 53,144 adults aged over 45 from NSW, Australia.</p

The Importance of Humidity in the Relationship between Heat and Population Mental Health: Evidence from Australia

<div><p>Despite many studies on the effects of heat on mental health, few studies have examined humidity. In order to investigate the relationship among heat, humidity and mental health, we matched data from the Social, Economic and Environmental Factors (SEEF) project with gridded daily temperature and water vapour pressure data from the Australian Bureau of Meteorology. Logit models were employed to describe the associations among heat (assessed using temperature, °C), humidity (assessed using vapour pressure, hPa) and two measures of mental health, (i) high or very high distress (assessed using K10 scores ≥ 22) and (ii) having been treated for depression or anxiety. We found a one-unit increase in temperature and vapour pressure was associated with an increase in the occurrence of high or very high distress by 0.2% (<i>p</i> < 0.001, 99% CI: 0.1–0.3%) and 0.1% (<i>p</i> < 0.001, 99% CI: 0.0–0.3%) respectively. However, when humidity rose to the 99^<i>th</i> percentile of the sample, the estimated marginal effect of heat was more than doubled (0.5%, <i>p</i> < 0.001, 99% CI: 0.2–0.7%). Neither heat nor humidity was related to having been treated for depression or anxiety in the last month. Humidity compounds the negative association between hot weather and mental health and thus should be taken into account when reforming the health care system to respond to the challenge of climate change.</p></div

The associations between temperature (heat), vapour pressure (humidity) and mental health, Logit model for 53,144 adults aged over 45 from NSW, Australia.

<p>The associations between temperature (heat), vapour pressure (humidity) and mental health, Logit model for 53,144 adults aged over 45 from NSW, Australia.</p