Purpose : To assess gender differences in COVID-19 related changes in home and work responsibilities longitudinally, and determine whether these differences, together with other potential risk and protective factors, are associated with depression, anxiety, and post-traumatic stress disorder (PTSD) symptomatology. Method: Symptoms of depression, anxiety, and PTSD were measured using an online survey instrument, between May 2020 and April 2021, in four waves completed at 3-monthly intervals. Analyses were based on data from the COvid MEntal healTh (COMET) survey which investigated the mental health effects of the COVID-19 outbreak spanning 13 countries on five continents in N = 7,909 participants. Results: From the first to the last wave, women reported a greater increase in home and work responsibilities, and had higher depression, anxiety and PTSD scores compared to men. Women who reported a reduction in income due to the pandemic had higher depression scores. Working harder and experiencing a reduction in income were also associated with higher anxiety scores in women but not in men. Women were more likely to score above the cut-off for depression (32.5% vs 23.6%, p <.001), anxiety (21.2% vs 14.4%, p <.001) and PTSD (21.2% vs 14.4%, p <.001) than men during the first wave. Stronger reliance on socially supported coping mechanisms was a risk factor for depression, anxiety and PTSD in men and women. Conclusion: Women were more likely to report mental health problems which may be related to the gender disproportionate increase in home and work responsibilities but not necessarily due to COVID-19 stressors.