VoL 1, No. 1, 1966 D. MECHANIC:Response Factors in Illness: The Study of Illness Behavior 11 Response Factors in Illness: The Study of Illness Behavior ::" DAVID MECHANIC University of Wisconsin, Madison, Wisconsln/U.S.A. Summary. Illness behavior -- the manner in whi& people differentially perceive, evaluate and respond to symptoms -- may be viewed from at least three general perspectives. Such patterns of behavior may be seen (a) as a product of social and cultural conditioning, (b) as part of a coping repertoire or (c) in terms of their usefulness for the patient who obtains certain advantages from the "sick role". -- The importance of such factors in determining whether people recognize symp- toms, make contacts with doctors, accept or reject advice about treatment, and remain under or discontinue medical supervision, is reviewed; with particular reference to the ana- logies between such patterns, responses to various types of pain and placebo reactions. The implications of con- sidering "secondary" social and psychological components of disease, as well as "primary" biological aspects, are discussed in terms of their value for the patient and their relevance to planning medical services. RdsumL Le comportement pathologique -- les mani~res diverses dent les gens s'apercoivent des sympr6mes, les dva- luent et y r~agissent -- peut ~tre envisag~ d'au moins trois points de rue. On peut considErer de tels types de comporte- ment (a) comme consdquences de leur condition sociale et culturelle (b) comme faisant partie de l'attitude usuelle du malade (c) dans le sens de leur utilit4 pour le patient qui retire certains avantages de son ~r61e de malade,,. -- On passe en revue ces facteurs pour determiner si les gens re- connaissent leurs symptgmes, entretiennent des contacts avec des mddecins, acceptent ou rejettent des conseils concernant leur traitement, restent sous contr61e medical ou l'inter- rompent, ceci en relevant les analogies entre ces comporte- ments et les rdactions k l'dgard de diffdrentes sortes de dou- leurs et de reactions ~ placebo. -- Les implications entre les composantes sociales et psychologiques ,,secondaires,, de la maladie, aussi blen que les aspects biologiques ~,primaires>, considErEs, sent discutdes en termes de leur valeur pour le patient et de leur utilitd dans l'organisation des services mEdicaux. Zusammenfassung. Das Verhalten Kranker, d.h. ihre un- terschiedliche Auffassung, Verarbeitung und Reaktion auf Symptome, l~i~t sich zumindest unter drei Gesichtspunkten betrachten. Man kann solche Verhaltensmuster als Ergebnis einer soziokuhurellen Konditionierung (a), als Tell einer An- passungsstrategie (b) oder als Technik eines Krankheitsgewinns betrachten. Das Gewicht dieser Faktoren far die Symptom- verarbeitung, fiir die Kontaktbeziehung des Patienten zum Arzt, ffir seine Annahme oder Ablehnung iirztlichen Rates und filr seine Bereitschaft, unter ~irztlicher Aufsicht zu bleiben oder diese zu durcbbrechen, wird diskutiert. Dabei werden die Beziehungen solcher Verhahensmuster zu der Verarbeitung verschiedenartiger Schmerztypen und zu Placebo-Reaktionen besonders berficksichtigt. ,,Sekund~ire" soziale und psycholo- gische Komponenten der Krankheit und ,,prim~ire" biologische Aspekte der Krankheit haben ftir das Verhahen des Patien- ten in gMcher Weise Bedeutung und verdienen bei der Planung medizinischer Dienste berii&sichtigt zu werden. Medicine has three principal tasks -- to under- stand how particular symptoms, syndromes, or disease entities arise either in individuals or among groups of individuals; to recognize and cure these or to shorten their course and minimize any residual impairment; and to promote living conditions in human populations which eliminate hazards to health and thus prevent the occurrence of disease. Each task can only be pursued with maximal effec- tiveness if the integral importance of social and psychological, as well as biological, factors is ap- preciated. Much medical activity -- whether in research, clinical practice, or preventive work -- requires an understanding of the cultural and social pressures which influence an individual's recognition that he needs advice, his decision whether to seek it, his choice of counsellor, his cooperation in carrying out any measures that are suggested and his willingness to remain in contact should there be any recom- mendation that further supervision is needed. Unless our knowledge of these processes is taken into ac- count in training doctors, dealing with patients and designing sociomedical services, we shall continue to make grave errors in all three fields. * This work was supported in part by a Public Heahh Service Special Fellowship (MH--8516) from the National Institute of Mental Health. During the period of the fellow- ship the author was affiliated with the Medical Research Council Social Psychiatry Research Unit, Maudsley Hospital. The author is indebted to Dr. JOHN W~NG for his helpful comments. In this paper, I shall consider only one aspect of these problems: that concerning response factors in illness. Although there is a good deal to learn in this area, considerable knowledge is already available. Data about illness, whether clinical or epidemio- logical, usually contain two kinds of information: one on the state of the patient (for example, a description of symptoms or dysfunctions); and the other on his reactions to his condition. The physi- cian's diagnosis is influenced by each of these kinds of information. He obtains data from physical ex- amination and laboratory studies and also from a clinical history, which usually includes the patient's reactions to his condition. Within the traditional medical model, the patient lodges a complaint and the physician attempts to account for, explain, or find justification for it through his investigation. Logically, if not empirically, the diagnostic situ- ation involves two sets of facts: historical data and symptoms reported by the patient or other infor- mants about his condition, and data obtained by the physician through a systematic examination for abnormal signs and through laboratory investi- gation if necessary. Thus it is logically possible for physicians to hypothesize that some patients are hypochondriacs or malingerers if they note sub- stantial discrepancies between the patient's com- plaints and other findings elicited through an in- dependent investigation of the complaints.