The clinical treatment of adolescents who display serious intellectual deficiencies raises a number of questions concerning the possibilities of the work of adolescence within its double trajectory of access to genital sexuality and new temporal order, insofar as access to symbolization seems to be “ barred ” by lasting instrumental inadequacies which hinder overall development. Most often reduced to the space of the small child, the space-time of the mentally deficient youth does remain marked by very archaic modes of psychical functioning which tend to freeze all temporal unfolding and all otherness. Nevertheless, pubescent sexuality is not absent; but its elaboration follows paths that are skewed in relation to the usual paradigm of the neurotic theater. Contributions from theorization about childhood autism and recent work on the psychosomatic offer a field of research on the heterogeneity of symbolic modes that on encounters in certain forms of deficiency pathology, and opens up the impasse of mere deficiency to the complexity of these types of organization, particularly at the time of adolescence when the investment of the body in its drive and sensory dimension is at the forefront of the time of the other.