After the decade of the 80’s, Aids has become an unavoidable fact of life for teenagers and young adults. This may be indeed more psychological than real. It has become a social phenomenon with obvious quantitative and statistical aspects. How therefore is the psychological reality articulated in the individual confronted to Aids ? Such an articulation seems to depend upon the psychological structure of adolescence thus becoming some kind of ” revelator ” of this deep down structure. Through the analysis of a young borderline individual, the author tries to show its significance for such a youth, its place in her psychological economy and the benefits that may be, or have been, drawn from it. In the theoretical analysis that follows, the focus lies in the pertinence of the concepts of death instinct and life instinct in the clinical approach of borderline patients.