Could Uncontrollable Crying And Paranoia Be Due To Severe Depression?

yes, my daughter experienced something today that to me was unexplainable. She had paranoia and uncontrollable crying spells. I have a son that is diagnosed bipolar/schizophrenic and he had some of these signs before being diagnosed. She was scared of everyone including her father. This went on for several hours and then she was ok, but something happened and something triggered what happened. I had a son that drowned almost 4 years ago and she was there when it happened. She was the last person to touch him trying to save him. She went through some therapy for about a year and seemed to be ok, but she hasn t had any since this time. Could it be deep depression causing this? I need and want some answers. Clearly something happened and can it happen again?