published_or_final_version / Clinical Psychology / Master / Master of Social Sciences

published_or_final_version / Clinical Psychology / Master / Master of Social Sciences

The mechanisms which account for the diminished responsiveness (tolerance) of an individual to a drug, as a result of prior exposure to that drug, are not yet fully understood. Recently, it has been suggested that drug tolerance is a learned adaptive response. This possibility was examined by studying the effect of ethanol on body temperature and behavioral thermoregulatory responses of Sprague-Dawley rats. Two major studies were conducted. The first study examined the initial dose-related effects of ethanol (1, 2, or 3 g/kg i.p.); the second study examined the effect of ethanol (2.5 g/kg i.p.) administered on 14 consecutive days. Rats were tested in a thermocline, a hollo plexiglass tube in which a linear temperature gradient (6-36°C) was established through local heating and cooling of opposite ends of the tube. The position of rats in the thermocline was detected by a series of infrared light emitting diodes and photocells. The body temperature of rats in the thermocline was transmitted by a temperature sensitive telemetry capsule surgically placed in the peritoneal cavity. Validation studies demonstrated that rats reliably responded to temperature cues within the thermocline. In the first experiment ethanol produced a dose-related decrease in body temperature. All rats following injection initially selected an ambient temperature cooler than baseline. Rats receiving control treatment or the high dose of ethanol eventually shifted to a warmer ambient temperature. Activity levels were depressed equally by all three doses of ethanol. In the second experiment tolerance developed to the hypothermic effect of ethanol. A diminished response to ethanol was evident by the second test day and was maximal by day 7. Ethanol treated rats selected a cooler ambient temperature than control rats throughout the 14 day period, and activity levels continued to be depressed by ethanol throughout the 14 days. On the fifteenth day all rats were given an injection of saline. Rats which had previously received daily ethanol injections exhibited a hyperthermic response to saline compared to control rats. These results suggest that ethanol altered the central control of thermoregulation by lowering and possibly broadening the thermoregulatory set point. There was evidence for a conditioned hyperthermic response, but not a learned behavioral response, which contributed to the tolerance development.

The operant model applied to geriatric settings has provided optimistic data with regard to the reversibility of behavior deficits in elderly residents. Naturalistic studies have demonstrated that one major class of resident behavioral deficiencies, dependency, tends to be encouraged by staff whereas independent functioning tends to be ignored. Only a few studies have attempted to change this interactional pattern from staff dependent-supportive to independent-supportive responses to increase residents independent functioning. The present study was a further attempt to alter these interactional patterns between staff and residents. It departs most notably from earlier studies in that cognitive and perceptual changes for residents and aides were evaluated in addition to overt behavioral changes. Specifically, the purpose of this project was to increase independent functioning and improve mood, perceptions of the environment and morale in institutionalized geriatric residents. To accomplish this, 12 nurses' aides were trained in operant principles and techniques. Self-report and behavioral measures were obtained for residents and staff in a treatment and no-intervention control group. No significant results emerged for aides and residents in the intervention condition. The failure to find significant results is discussed in terms of one or a combination of variables including: problems encountered in conducting research in naturalistic settings, deficiencies in the training program, perceptual biases of the staff and the appropriateness of the theoretical model employed. Limitations of the study and directions for future research are explored.

This study assessed the psychological problems associated with hemodialysis and included an investigation of the differences and similarities between (1) dialysis patients' and medical staff's perceptions of patients' problems, and (2) the problems of hemodialysis patients and spinal cord injury patients. Data were collected from 31 adult hemodialysis patients, 34 dialysis medical staff and 32 spinal cord injury patients at the Miami, Florida Veterans Administration Medical Center. The scaling technique of magnitude estimation was used to measure patients' and staff's perceptions of the relative seriousness of various illness-related problems. Depression and anxiety in hemodialysis patients and spinal cord injury patients were measured by standardized self-report inventories. Among the most significant findings were that: (1) Dialysis patients judged problems concerning lifestyle changes (e.g., inability to travel and work) and loss of body function (e.g., reduced levels of physical activity) to be more serious or emotionally distressing than other problems they experienced. (2) Dialysis patients and medical staff differed significantly in their perceptions of the seriousness of most problems associated with hemodialysis; moreover, there was less agreement between patients and physicians than between patients and other types of staff (e.g., nurses and technicians). (3) There were no significant differences between dialysis patients and spinal cord injury patients in their scaled problem judgments. (4) Depression in hemodialysis patients and spinal cord injury patients was greater than for the general population, with the majority of both patient groups meeting criteria for diagnosis of clinical depression. In addition, although dialysis patients and spinal cord injury patients did not differ significantly in their total mean depression scores, dialysis patients endorsed somatic components of depression more frequently and/or with greater intensity than spinal cord injury patients did. (5) Anxiety in dialysis patients was not greater than for the general population and was significantly less than for spinal cord injury patients. (6) Depression and anxiety were positively related to most problems for hemodialysis patients, while anxiety, but not depression, was significantly associated with most problems for spinal cord injury patients. A major contribution of this study is the comparison, for the first time, of patients' and medical staff's scaled problem judgments.

This study examined the reliability and the validity of the Exercise Suitability Scale (ESS). The ESS was a psychometric instrument developed to measure the suitability of four different forms of exercise (aerobics, bicycling, jogging, and swimming) for different individuals. Aspects of Exercise Suitability included in the ESS were ease, satisfaction, enjoyableness, fatigue, interest, convenience, comfort, safety, affordability, and time-involvement. Background information relating to the development of the ESS as well as methods and results of testing the instrument for reliability and validity were included in this study. Data from a student population were used for estimating the reliability and validity of the ESS. Reliability testing included computing inter-item and item-to-total correlation coefficients, Cronbach's alpha, and internal consistency coefficients (theta and omega) derived from factor analytic techniques. Several types of validity were assessed: content validity, criterion-related validity, and construct validity. Criterion-related validity was estimated by comparing scores on the ESS with information about participation in exercise. Multiple regression was also used to assess criterion-related validity. Principal components analysis was used to examine the construct and content validity of the ESS. Construct validity was also estimated by correlating ESS scale scores with a parallel instrumentation approach, a Q-Sort. Satisfactory reliability indices were obtained for all four ESS exercise scales. Criterion-related validity indices were also adequate. Factor analysis provided some evidence of content validity of the ESS, but provided little support for the construct validity of the ESS. Construct validity was supported, however by the convergence approach.

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