Depersonalization-Derealization Disorder is a dissociative syndrome characterized by a sense of disconnectedness from one’s own self and the world around. People suffering from the condition report feeling like external observers, cut off from their own bodies, emotions and thoughts; their surroundings are perceived as unreal. The present thesis analyses DDD by sustaining the view that its phenomenology can be understood through Metzinger’s notion of phenomenal transparency. This idea is not entirely new: recent contributions have framed the dramatic experiences of depersonalization (...) and derealization as instances of highly opaque mental states. However, more detailed discussions of phenomenal transparency are sparse. My contribution wishes to partially fill in this gap. To elucidate the concept of transparency, I will first highlight the distinction between the classical representationalist notion of transparency and the metzingerian, phenomenal account of it. I will then argue that phenomenal transparency adequately describes the associated depersonalized phenomenology. Finally, I will attempt to present and dissipate ambiguities contained in the concept and address potential criticism regarding the redundancy of transparency as an explanatory tool for dissociative phenomena. (shrink)