Sex differences in changes of depressive symptoms among older adults before and during the COVID-19 pandemic: evidence from two longitudinal cohorts.

Background: Major concerns about the adverse mental health impact of the rapidly spread COVID-19 pandemic have been raised. Previous studies on changes of depressive symptoms during the COVID-19 pandemic have yielded inconsistent results regarding the sex differences. Since women have higher depressive symptoms even without the pandemic, it is essential to consider the pre-existing change of depressive symptoms of a similar period to discern the effect of the pandemic on depression. This study aimed to evaluate sex differences in depressive symptoms before and during the pandemic.

Methods: Data from the Health and Retirement Study (HRS; waves 13 to 15) and the English Longitudinal Study of Ageing (ELSA; wave 8 to COVID-19 wave 2) were analyzed. Depressive symptoms were assessed by the 8-item Center for Epidemiological Studies Depression (CES-D) scale. According to the time of COVID-19 outbreak in the US and the UK, the intervals from waves 13 to 14 surveys of the HRS and from waves 8 to 9 surveys of the ELSA were employed as pre-pandemic periods to control for the pre-existing depressive symptoms, respectively. Changes of CES-D scores during the pre-pandemic and pandemic periods were assessed by linear mixed models.

Results: Nine thousand, seven hundred thirty-seven participants (mean age: 66.7 ± 10.7 years) from the HRS and 5,098 participants (mean age: 68.7 ± 10.0 years) from the ELSA were included. CES-D scores among women were significantly higher than those among men at all waves in both cohorts. During the pre-pandemic period, no significant sex difference on changes of CES-D scores was detected in either the HRS or the ELSA. During the pandemic period, CES-D scores were increased in both men and women and the sex differences in CES-D increments of the two cohorts were both significant. Enlarged sex differences were demonstrated in increments of CES-D scores during the pandemic period.

Conclusions: Our results suggest women suffered from worse depressive symptoms in response to the pandemic, although the changes of depression were similar between men and women before the pandemic. These findings underscore the necessity to support the vulnerable populations, especially women, to manage the distress brought by the pandemic and maintain optimal mental health status.