Cases of long COVID-19 are posing a new and growing challenge for medical experts, even as the eighth pandemic wave — during which the highest numbers of COVID-19 cases and deaths were recorded — appears to have peaked in recent days.

While there are still many unknowns about the disease and how its persistent form should be treated, recent Japan-based research has highlighted the aftereffects COVID-19 has on mental health.

A survey of around 4,000 infected people conducted by the city of Toyonaka in Osaka Prefecture, Osaka University and medical startup Buzzreach, released in December, found that 5.2% of the respondents had at least one symptom lingering after one month, while 3.7% did two months later. Three out of four respondents were believed to have been infected with the omicron variant.