Abstract
In-person sources of social support buffer effects of stress on mental health. However, online social support inconsistently demonstrates stress-buffering effects. Highly stressful circumstances, such as the first month of COVID-19 lockdown, may be necessary to benefit from support received from online networks. We investigated whether online support demonstrated an increased stress-buffering effect on depressive symptoms during the first month of COVID-19 lockdown. We collected cross-sectional data on three distinct groups of participants from February to April 2020-preceding lockdown (pre-COVID; n = 53), up to four weeks following university closures (initial lockdown; n = 136), and the final weeks of the semester (later lockdown; n = 127). Initial lockdown participants reported significantly more stress than pre-COVID but not later lockdown participants. The online social support by stress by COVID phase interaction was only significant for the initial versus later lockdown comparison. Online support buffered stress during initial lockdown but not later lockdown. Stress-buffering effects of offline support were observed and did not depend on COVID phase. Online support may only buffer stress when stress is heightened and offline support is less available.