How much greater are the negative effects of depression, anxiety, substance abuse and cognitive difficulties including memory issues for older adults who have lost a spouse than other older adults who have not lost spouses?

The negative effects are much greater for older adults who have lost a spouse than other older adults who have not lost spouses.

Explanation:

The effects are felt much greater for older adults who have lost a spouse due to it being compounded on the grief that the older adult is feeling from the loss of their spouse. Also the absence of the spouse brings forth a sense of loneliness and a loss of companionship, thus further amplifying the negative effects being inflicted.