This paper describes a very malignant type of self-destructiveness seen in a small group of patients. It is active in the way that they run their lives and it emerges in a deadly way in the transference. This type of self-destructiveness is, I suggest, in the nature of an addiction of a particular sado-masochistic type, which these patients feel unable to resist. It seems to be like a constant pull towards despair and near-death, so that the patient is fascinated and unconsciously excited by the whole process. Examples are given to show how such addictions dominate the way in which the patient communicates with the analyst and internally, with himself, and thus how they affect his thinking processes. It is clearly extremely difficult for such patients to move towards more real and object-related enjoyments, which would mean giving up the all-consuming addictive gratifications.