SAITAMA (Kyodo) -- The last retired military personnel or civilian employee who received Japanese government medical benefits for trauma or other mental conditions developed in the line of duty died in 2021, government records showed Wednesday.

With the passing of the individual in Shimane Prefecture, western Japan, the number of firsthand witnesses to the Second Sino-Japanese War and World War II has further dwindled, making it increasingly difficult to fully grasp the psychological impact of the conflicts.

Ahead of the 80th anniversary of the end of World War II, the Japanese government is continuing its investigation into mental illnesses that developed under the harsh conditions of the battlefield.

Under the Law for Special Aid to the Wounded and Sick Retired Soldiers enacted in 1963, the number of recipients of medical benefits for mental illness peaked at 1,107 in fiscal 1978, according to government statistics on welfare administration.

The number, which includes both hospitalized and non-hospitalized patients, decreased to 444 in fiscal 1995, to 117 in fiscal 2005, and to 11 in fiscal 2015.

According to the Shimane prefectural government, the last recipient was not hospitalized and died in January 2021. The prefectural government has declined to disclose any details about the individual or their cause of death due to privacy concerns.