[Double suicide and symbiontic psychosis (suicide à deux and folie à deux)]

Symbiontic psychoses (induced delusions) are marked by 'solitude by twos'--together in alienation to the environment. This special psychological situation is dangerous and the foundation to develop 'suicides by twos' (double suicides). The relations between the psychotic partners (domination-subordination) change over to relations of double suicide (instogator-participant). The presuicide syndrome of such double suicides is described with two cases, one at the psychopathological borderline to a symbiontic psychosis, the other on the culmination of it (delusion of influence and reference).