Others might disagree, but to me, usage dictates that there is a slight distinction in meaning between "to trifle with" and "to be trifled with" that goes beyond a question of passive vs active". It might be putting too fine a point on it, but for me "to trifle with something" has a fairly broad meaning that includes that of "to fiddle with something" in the sense that there is physical contact and or interference involved, while "to be trifled with" has a rather more restricted sense of "to be not taken seriously", and does not carry the same implication of physical contact and/or inteference.
Thus though I would myself much prefer
depression is not something to be trifled with as it is a serious medical condition
over
depression is not something to trifle with as it is a serious medical condition,
I don't like
depression is not something to be trifled with as it is a serious medical condition and should be taken seriously
as to my mind it contains a redundancy (ie not something to be trifled with = should be taken seriously).