In which type of mental health disorder is derealization commonly experienced?

Derealization is most commonly experienced in dissociative disorders. This phenomenon involves a significant alteration in the perception of the external world, where individuals may feel detached from their surroundings, as if the world is unreal or dreamlike. In dissociative disorders, such as dissociative identity disorder or depersonalization/derealization disorder, these symptoms are central to the condition and may arise as a response to trauma, stress, or overwhelming emotional experiences.

While derealization can also be noted in anxiety disorders, particularly during panic attacks or high anxiety states, it is not the primary feature as it is in dissociative disorders. In depressive disorders, feelings of detachment may occur, but they are generally tied to the mood symptoms rather than a distinct dissociative experience. Similarly, personality disorders may have aspects of altered perception, but derealization is not a hallmark symptom. Thus, the association of derealization with dissociative disorders is what makes this the correct answer.