This study briefly reviews both historical and recent conceptualizations of dependency. In particular, it focuses on this concept's applicability to patients with chronic illnesses, especially those with allergies. Type and degree of dependency were seen as an important factor in the approach to the medical and psychological treatment of clinical ecology patients. The purpose of the study was to develop an objective measure of dependency which could quickly identify patients whose dependency conflicts interfere with the treatment process. The study was divided into three phases. In the first phase test responses by 84 inpatients to the CAQ, MMPI, and the HAT as well as historical and demographic data were analyzed by a series of stepwise discriminant analysis. The 53 resulting items were examined for those which most concisely discriminated between the two identified groups (pathologically dependent and nonpathologically dependent). These 15 items were used to test 120 additional patients in phase II. Fourteen items were retained and the coefficients obtained classified the patients in phase I and II with a 98.81 percent and 94.17 percent degree of accuracy respectively. These classification coefficients were used to classify another 30 patients in phase III with a 96.67 percent rate of accuracy. These results provide exceptionally strong support for the hypothesis that group classification can be obtained through the use of an objective screening instrument. The pathologically dependent patients tend to focus on disease, frequently are unemployed, have histories of childhood illnesses, have limited emotional controls, are depressed, ambivalent, and distrustful. Additionally, they experience difficulty establishing goals or accepting personal responsibility. Those patients identified as nonpathologically dependent exemplify the more positive aspects of these traits. The pathologically dependent patients appear to be caught in a dilemma between wellness and satisfaction of dependency needs. While all patients need an organized approach to treatment, the pathologically dependent require an extremely structured repititious approach and may require long term psychological intervention in order to make positive steps toward wellness.