Around the anniversary, someone might feel triggered, and there's a spectrum of reactions ranging from feeling bummed out for a day or two to having "significant psychiatric or medical symptoms." The symptoms that come with anniversary reactions aren't all that different from those associated with PTSD , and can include intrusive thoughts that occurred at the time of the event; avoidance of the place or situation where the trauma happened; feelings of sadness, shame, and guilt; and nerves. For what it's worth, "being transported to the Upside Down" is not usually a hallmark symptom, but everyone's experience with PTSD is different, and much of it has to do with the individual's personality. Maybe, the Upside Down is just a metaphor for a dark depression, in which case this could be totally accurate.