堕落 (duò luò): для деградации

After graduating from university, he became addicted to video games and refused to look for a job, and his life gradually went downhill.

That official was corrupted by embezzlement and bribery, and eventually was sentenced to prison.

Under the influence of friends, he got into drugs and fell into depravity from then on.

She used to be a good student, but after hanging out with those bad kids, she gradually went astray.

War made many people lose their moral底线, and the whole society became degenerate.

He was once full of ideals, but faced with the temptation of money, he eventually degraded into a criminal.