Like everyone else, I wouldn't say they were the cause of my M problems at all. I do believe they contributed. For a while she lost all objectivity.
From December 2011 thru May 2012 my W was a completely different person. Her mother and sister both said if they didn't know her from her physical appearance, they would have no idea who she was.
Something happened in May that caused a crash of sorts. Not sure what it was since she doesn't want to discuss what all happened. That was when she realized the Lexapro might have been having a negative impact. She's brought it up several times since, but, thus far has not acted on weaning herself off. I recommended she talk to her doctor first before she does, though...