Puffing with the dragons 9 Depersonalization vs. Derealization: What's the Difference? Derealization is a mental state where you feel detached from your surroundings, as if the world isn't real, is foggy, or you're in a dream or movie, often with distorted perceptions of objects, time, and depth, even though you know it's a subjective feeling. It's a dissociative symptom often triggered by severe stress, anxiety, or trauma, and can occur alone or with depersonalization (feeling detached from you