This article reports the authors' observations on 22 families in which a young adult member has been diagnosed as manic-depressive, and on 11 families in which a member has been diagnosed as suffering from major schizoaffective disorder. All families could be described as extremely rigid and bound-up systems. Many of them were characterized by a "restrictive parental complementarity" and reciprocal delegation, and they shared certain cognitive features and assumptions. "Manic-depressive" families showed similarities as well as differences when compared with families in which there were schizophrenic and serious psychosomatic disorders.