In any psychotherapeutic endeavour, it must be recognized that psychogenically based mental illness is generally the product of childhood experience in the context of intrafamilial interpersonal relationships. Involvement in treatment of the whole original family might therefore be considered a logical approach, if this were either possible or practicable. Rarely, however, is this the case, save when the patient happens to be a child or adolescent. On the whole, mental hospitals and psychiatric units are populated by adults, many of whom, voluntarily or otherwise, have gained a considerable degree of physical independence from their first families. Many too have already committed themselves to a second family. In these cases the selection of a spouse has often been determined by unconscious pathological needs and expectations, resulting in a ‘neurotic’ object choice, and an unsuccessful ‘sick’ marriage. Thus the second family can frequently be seen as a precipitating factor in the development of mental illness, although not ultimately as causative in the true sense of the word.