When people accept difficult situations, they WORRY LESS about their problems, which improves their mental health. This is because they would THEN spend less time thinking about possible solutions and (SPEND) more time focusing on the positive aspects of their lives.


I also feel that it is better to omit the 2nd "spend"


I discovered that THEN means IN THAT CASE, so please I want to know if I used it correctly

onose34I also feel that it is better to omit the 2nd "spend"

Right.

onose34I discovered that THEN means IN THAT CASE, so please I want to know if I used it correctly

There's no need for it. I would omit it.