Observed on March 20, this year's International Day of Happiness came amid unprecedented challenges posed by the COVID-19 pandemic, and psychologists believe many people have lowered their expectations from life.

Zhang Xichao, professor of psychology at Beijing Normal University, said cases of depression have been on the rise since the onset of the pandemic – something that could not be ignored. He also said that the world would need a different measurement of happiness if the pandemic carried on for another year or two.

Data from the World Economic Forum shows that 114 million people lost their jobs in 2020 due to the pandemic and the subsequent lockdowns, and according to figures compiled by Johns Hopkins University, the total confirmed cases worldwide have surpassed 122 million, with more than 2.6 million people losing their lives.

With a fear of the unknown, losing of family members and friends, economic crises and lockdown fatigue, a large number of people across the world are suffering mentally and emotionally.

Zhang said that after the pandemic hit, overall level of happiness among people dropped for sure, and due to lockdowns and quarantine, people meet, talk and exercise less than usual, which increases irritability, anxiety and fear.

With governments around the world working to get their economies back on track, finding a sense of calm will matter just as much for many people.

To improve the sense of happiness, Zhang said perseverance and regular physical exercise are necessary. It's also important to take part in more social activities and maintain good interpersonal relationships, he said.