Drawing upon their studies of physicians' responses to the recommendations and diagnosis of psychiatric consultants, the authors propose that the psychiatric consultant is most often invoked when the primary physician experiences an inappropriate interpersonal distance in the relationship with the patient. Sensing the threat or the reality of the patient as too close or too distant, the physician seeks the presence of the consultant. In the subsequent triadic constellation, the psychiatric consultant is suggested to function principally as buffer between the physician and the patient, restoring, or effecting a more optimal interpersonal distance in the original dyad. This construct helps to explain the consultees' "selectivity" in requesting consultation and the marked disparity between reported prevalence of psychiatric disorders in the medically ill and referral rates. It also calls attention to the role of the psychiatric consultant in assuring that the medical care of the patient with psychiatric features is not compromised or abbreviated.