Evolving Concept Of Abnormal Illness Behavior & Clinical Implications ASEAN Journal of Psychiatry, Vol. 16 (2), July - December 2015: XX-XX REVIEW ARTICLE EVOLVING CONCEPT OF ABNORMAL ILLNESS BEHAVIOR & CLINICAL IMPLICATIONS Sujita Kumar Kar*, Rajesh Kumar** *Department of Psychiatry, King George’s Medical University, Lucknow- 226003, Uttar Pradesh, India; **Institute of Human Behavior and Allied Sciences (IHBAS), Delhi- 110095, India. Abstract Objectives: The concept of “Abnormal illness behavior (AIB)” has been evolved to a greater extent in the last century. Henry Sigerist introduced the concept of “illness behavior” in 1929. Mechanic & Volkart defined and further conceptualized the impression on illness behavior. Talcott Parson had given the concept of “Sick role,” and Issy Pilosky had familiarized the notion of “abnormal illness behavior.” The main objective of this article is to review the conceptual evolution on “abnormal illness behavior” and to analyze its current clinical implications. Methods: Extensive search of literature was performed regarding abnormal illness behavior, illness behavior and sick role in online web searching sites like – Google Scholar, PubMed and individual journal sites as well as google books. The literature was critically reviewed with personal inputs from authors. Results: Abnormal illness behavior ranges from denial of illness in one extreme to conscious amplification of symptoms on the other. Abnormal illness behavior is noticed in various clinical conditions like stress-related disorder, stress-related disorders, factitious disorder and malingering. Conclusions: Identifying abnormal illness behavior can prevent unnecessary and excessive utilization of medical aids for the same. ASEAN Journal of Psychiatry, Vol. 16 (2): July – December 2015: XX XX. Keywords: Illness Behavior, Sick Role, Abnormal Illness Behavior, Somatoform Disorder, Stress Related Disorders Introduction Presentation of a particular illness in an individual may differ from another individual suffering from the same illness. Differential presentation of illnesses in different individuals depends upon several important factors, which can be broadly categorized as – illness-related factors, individual specific factors and contextual factors. The illness- related factors may be - the nature of illness, severity of illness, chronicity of illness and response to treatment. Similarly individual specific factors like – personality of the individuals, coping skills, defense mechanisms used also play a role in coloring the illness expression. Socio-economic status, stigma, secondary gains are some important contextual factors, which are also liked to influence the presentation of an illness. When the presentation of an illness is perceived to be out of proportion to the clinical expectations and underlying pathophysiology, the possibility of abnormal illness behavior is more likely. “Abnormal illness behavior (AIB)” term was introduced by Issy Pilowsky. Pilowsky defined the term “Abnormal Illness Behavior” as – “An inappropriate or maladaptive mode of experiencing, evaluating or acting in relation to one’s own state of health, which persists, despite the fact that a doctor (or expert) has