Oh, wouldn't it be great if life could be so black and white.

Let us assume that being around a depressed person depresses you and shortens your life. (it is true, but quite a bit more complex)

So, you are depressed (because of childhood trauma, or some horrible accident in the family...) but you carry on, and go to work each day. Your work mate is going to have a shorter life from being around you.
This is not outright killing them, but at what percentage?

Being depressed makes you much more likely to get into an accident.
So, your work mate, being depressed from work, and being near you, steps out in front of a bus, because they weren't being fully aware.
Did you just kill them?

You see, people kill all the time. Is it better to have someone who knows what they are doing, or someone who kills by accident?

In my opinion a person who knows they are a monster is much more preferable than a person who does not know.
A wise enemy is better than a foolish friend.

We are about to enter a time where you will have to make a choice of standing on your human rights as a free person, or cowering as a slave. Thus, it would be nice not to kill, but we are no where near a place in our evolution where we can hold it as anything more than a goal that we should strive for.