J. Daniel House

Depression, Cortisol Metabolism and Lymphocytopenia

Depression is often associated with hypercortisolemia. Because high levels of cortisol influence the distribution of different types of leukocytes in the blood stream, we examined the percentages and absolute numbers of circulating neutrophils and lymphocytes in 29 depressed patients who were nonsuppressors on the Dexamethasone Suppression Test (DST), 28 depressed patients who were suppressors on the DST, and 52 schizophrenic controls. We found no significant differences in either RBC or WBC counts in the 3 groups. There were, however, significant differences in the percentages of both neutrophils and lymphocytes as well as the absolute number of lymphocytes among the groups. These differences were mostly due to significantly lower lymphocyte percentages and absolute counts in the depression-nonsuppressor group. We also found a significant negative association between post-dexamethasone plasma cortisol concentrations and blood lymphocyte counts. These data suggest a close interaction between cortisol metabolism and lymphocyte regulation in major depression.

Immune function in mania

There is now a large body of evidence suggesting a close interaction between the central nervous system and the immune system. More specifically, immunological abnormalities have been described in relation to psychological stress (Jemrnott and Locke 1984) and in patients with psychiatric illness (DeLisi and Crow 1986). We have earlier reported a decrease in mitogen-induced lymphocyte proliferation in hospitalized depressed patients compared to normal controls (Kronfol et al. 1983). These findings have been replicated by independent investigators (Schleifer et al. 1984). Negative life events and depression have been associated with immunological impairment, as evidenced by decreased responsivity to mitogen stimulation and reduced natural killer cell activity (Bartmp et al. 1977; Locke et al. 1984). On the other hand, to the best of our knowledge, the immune status of patients with manic illness has never been investigated. We now report an impairment in immune regulation in manic patients similar to what has been described in patients with major depression. Subjects

PREDICTIVE VALIDITY OF THE GRADUATE RECORD EXAMINATION FOR PERFORMANCE IN SELECTED GRADUATE PSYCHOLOGY COURSES

A number of studies have evaluated the predictive validity of the GRE across several settings. The purpose of this study was to assess the predictive validity of the GRE for performance in selected graduate courses in psychology. Each of the three sections of the GRE aptitude test was evaluated. The predictive validity coefficients observed were comparable to those noted previously. Present results suggest that, while over-all predictive validity of the GRE may be relatively low, there may in fact be some courses for which validity coefficients are considerably higher.

Effects of Restriction of Range on Predictive Validity for the Graduate Record Examination

Several discussions of the effects of restriction of range on predictive validicy have been presented (1. 3). Generally, the presence of restriction of range on a predictor test will produce lower than expected predictive validity for the performance measure. T o estimate more accurately true predictive validity when restriction of range is present, several correction formulas have been presented (1 , 2 ) . A common area in which restriction of range becomes of interest is in psychological measurement, such as the relationship between Graduate Record Examination (GRE) scores and subsequent graduate grade point average. Although restriction effects have been widely discussed, relatively few studies have determined the magnitude of the effects. This study assessed the effects of the extent of restriction of range in a common measurement situation, the effects o n the predictive validity of the GRE. Graduate grade point averages and GRE scores were obtained for 8 5 students who were accepted for graduate smdy in a Masters level program in psychology at a large midwestern university. GRE scores were also obtained for an additional 72 s u b jects who were denied admission. Using a formula to correct for restriction which was presented by Givner and Hynes ( I ) , both corrected and uncorrected predictive validities were computed. The uncorrected predictive validity of the GRE was .15, and che predictive validicy corrected for restriction effects increased slightly to .17; neither correlation is significant. There is no evidence that improvement in a correlation corrected for restriction is dependent upon the magnitude of the original predictive validity. The relatively small increase in predictive validity in this study suggests that, in many actual measurement siruations, effects of restrictions of range may be slight.

Numerical relationships for temperature integrals with temperature dependent frequency factors

Abstract Temperature integrals having a negative exponent (m) on temperature have been evaluated for m= − 1 2 . −1. − 3 2 . and −2 with E=30–100 kcal mole−1 and T = 300–1000 K. For a given value of m. −log I is linearly related to E and l/T. The slopes and intercepts of these linear equations have been found to be functions of E and T. Also, a linear relationship exists between −log I and m for given values of E and T. By combining these results with those previously published for temperature integrals having positive values of m, equations have been obtained that permit accurate evaluation of temperature integrals for any combination of m. E. and T values.

A new iterative method for determining kinetic parameters from TG data

Abstract An iterative method is described which computes n and E from nonisothermal TG data. The method which requires only three (α, T ) data pairs as input, involves successive iterations of E/R and n using data pairs where Δα is first small, then large. A complete algorithm for implementation of the method on a programmable calculator is presented as well as results of analysis of calculated and experimental (α, T ) data.

Immunologic Abnormalities in Depressive Illness

There is now a large body of evidence suggesting strong and complex interactions between the central nervous system and the immune system (Ader, 1981). Lesions in certain areas of the brain are accompanied by specific immune changes (Stein et al., 1976). Several immunologic phenomena are accompanied by increased neuronal firing in specific areas of the brain as well as a disturbance in neuroendocrine regulation (Besedovsky and Sorkin, 1977). Stressed animals exhibit an increased susceptibility to a variety of immune-related disorders such as allergy and cancer (Riley, 1981) as well as impairment in specific immunologic functions such as lymphoblast transformation and granulocyte phagocytosis (Monjan and Collector, 1977).

Perception of Voluntary Control of Cardiac Function in Distance Runners and Non-Runners

6 non-runners and 6 distance runners were compared for ability to increase heart rates voluntarily using biofeedback. There was no difference between the groups on that ability, but runners were significantly more accurate in ability to estimate the magnitude of the cardiac changes which occurred.

Numerical integration of Euler's integral and numerical relationships involving E and T

Abstract Numerical integration has been carried out for p( x ) = ʃ ∞ x x −2 e − x d x where x = E/RT with E = 20, 25, …, 100 kcal mole −1 and T = 300, 350, …, 1000 K. Using the values of -log p( x ), numerical equations have been obtained that enable calculations of -log p( x ) at other values of E and T .

Methodological issue in cardiovascular feedback research.

In a recent review Bandiera, Bouchard, and Granger (1) contend that research on voluntary control of heart rate has generally been biased in favor of group methodologies over individual methodologies. However, the authors feel that individual approaches to such research are particularly warranted because intrasubject variability is smaller than intersubject variability. This study examined the assertion that smaller intrasubject than intersubject variability is present on a voluntary cardiac control task. Eleven subjects participated; all were male undergraduate students. Using methods previously described ( 2 ) , subjects were instructed to increase their heart rates for four 120-beat trials while seated in a reclining chair and avoiding irregular breathing or excessive muscular tension. Heart rates were recorded in beats per minute. Intrasubject variability was assessed by subtracting the lowest heart rate of the four trials from the highest rate for the four trials for each subject. Intersubject variability was determined by subtracting the lowest heart rate from the highest heart rate for the 11 subjects on each of the four trials. The mean intrasubject variability across the four trials for all subjects was 13.32 (SD = 8.39) while the mean intersubject variability for the four trials was 36.57 (SD = 7.56). This difference was significant ( t = 4.85, df = 13, p = .0003). It appears that the contention of Bandiera, Bouchard, and Granger ( 1 ) is accurate and that individual subject methodologies could prove to be more sensitive to small changes in cardiovascular function.