Transient depersoruxtization refers to the momentary loss of identity: the individual feels detached from the self and does not know who he or she is. Using a sample of children and adolescents, this paper investigates aspects of the self-concept that might increase the experience of transient depersonalization. Self-esteem, self-concept stability, self-consciousness, false self-presentation, and the tendency to fantasize are hypothesized to affect transient depersonalization. A structural equations model with unobserved variables is employed to test these hypotheses. Implications for our understanding ofthe seif-concept are discussed. When Eugen Bleuler (1950), in his classic systematization of the symptons of schizophrenia, directed attention to the depersonalization syndrome, he described its central feature as the feeling that one is not onself. The patient feels detached from the self, feels different, strange, or unusual, and may think that what is happening to him or her is really happening to someone else. In contemporary terminology (de Levita, 1%5; Lichtenstein, 1977; Lopata, 1973), we could say that the individual has lost