The effect of life events on blood pressure and body mass index in children

In Conroe, Texas, 492 students ages 5 to 15 participated in a screening examination for cardiovascular risk factor study. Among 492 students, 141 elementary and junior high students participated in the present sub-study to investigate the effect of the number of recent life events on blood pressure and on body mass index. Using the elementary and junior high school Coddington scales, life events occurring in the past 12 months were measured for students ages 9 to 14 years, no significant differences in life events were observed by age and sex. The number of life events was not related to blood pressure but was positively correlated to body mass index in children and adolescents. ^

Stressful life events and their contributions to symptoms of anxiety and depression in adolescents

There are several innovative aspects to this thesis that extend our current knowledge of the relations between stress and psychiatric symptoms in adolescents. First, distal and proximal stressors are differentiated. This approach allows one to specifically examine the role of early childhood stressors as well as stressors experienced more recently as they impact the expression of depression and anxiety during adolescence. Second, a state-of-the-art assessment instrument was used to examine proximal stressors, helping to distinguish several aspects of stress, including objective stress and subjective stress. Third, the parent study from which these data were derived was designed to examine the role of familial risk for depression and related risk factors for the initial development of depression and alcohol use disorders. This allowed for a very thorough collection of demographic characteristics of the study population. Accordingly, this thesis examines the initial prodromal expression of anxiety and depressive symptoms as they are originally expressed prior to the development, if any, of a full-blown psychiatric disorder.^

THE EFFECT OF PERSON-ENVIRONMENT INTERACTION ON ANXIETY, DEPRESSION, AND SUBJECTIVE DISTRESS OF OPTOMETRY STUDENTS

The purpose of this study was to investigate whether an incongruence between personality characteristics of individuals and concomitant charcteristics of health professional training environments on salient dimensions contributes to aspects of mental health. The dimensions examined were practical-theoretical orientation and the degree of structure-unstructure. They were selected for study as they are particularly important attributes of students and of learning environments. It was proposed that when the demand of the environment is disparate from the proclivities of the individual, strain arises. This strain was hypothesized to contribute to anxiety, depression, and subjective distress.^ Select subscales on the Omnibus Personality Inventory (OPI) were the operationalized measures for the personality component of the dimensions studied. An environmental index was developed to assess students' perceptions of the learning environment on these same dimensions. The Beck Depression Inventory, State-Trait Anxiety Inventory and General Well-Being schedule measured the outcome variables.^ A congruence model was employed to determine person-environment (P-E) interaction. Scores on the scales of the OPI and the environmental index were divided into high, medium, and low based on the range of scores. Congruence was defined as a match between the level of personality need and the complementary level of the perception of the environment. Alternatively, incongruence was defined as a mismatch between the person and the environment. The consistent category was compared to the inconsistent categories by an analysis of variance procedure. Furthermore, analyses of covariance were conducted with perceived supportiveness of the learning environment and life events external to the learning environment as the covariates. These factors were considered critical influences affecting the outcome measures.^ One hundred and eighty-five students (49% of the population) at the College of Optometry at the University of Houston participated in the study. Students in all four years of the program were equally represented in the study. However, the sample differed from the total population on representation by sex, marital status, and undergraduate major.^ The results of the study did not support the hypotheses. Further, after having adjusted for perceived supportiveness and life events external to the learning environment, there were no statistically significant differences between the congruent category and incongruent categories. Means indicated than the study sample experienced significantly lower depression and subjective distress than the normative samples.^ Results are interpreted in light of their utility for future study design in the investigation of the effects of P-E interaction. Emphasized is the question of the feasibility of testing a P-E interaction model with extant groups. Recommendations for subsequent research are proposed in light of the exploratory nature of the methodology. ^

Distribution of quality adjusted life expectancy: A systems approach

Statistical methods are developed which assess survival data for two attributes; (1) prolongation of life, (2) quality of life. Health state transition probabilities correspond to prolongation of life and are modeled as a discrete-time semi-Markov process. Imbedded within the sojourn time of a particular health state are the quality of life transitions. They reflect events which differentiate perceptions of pain and suffering over a fixed time period. Quality of life transition probabilities are derived from the assumptions of a simple Markov process. These probabilities depend on the health state currently occupied and the next health state to which a transition is made. Utilizing the two forms of attributes the model has the capability to estimate the distribution of expected quality adjusted life years (in addition to the distribution of expected survival times). The expected quality of life can also be estimated within the health state sojourn time making more flexible the assessment of utility preferences. The methods are demonstrated on a subset of follow-up data from the Beta Blocker Heart Attack Trial (BHAT). This model contains the structure necessary to make inferences when assessing a general survival problem with a two dimensional outcome. ^

The chronobiology of the menstrual life sequence of American women

Seasonal variation in menarche, menstrual cycle length and menopause was investigated using Tremin Trust data. Too, self-reported hot flash data for women with natural and surgically-induced menopause were analyzed for rhythms.^ Menarche data from approximately 600 U.S. women born between 1940 and 1970 revealed a 6-month rhythm (first acrophase in January, double amplitude of 58%M). A notable shift from a December-January peak in menarche for those born in the 1940s and 1950s to an August-September peak for those born in the 1960s was observed. Groups of girls 8-14 and 15-17 yr old at menarche exhibited a seasonal difference in the pattern of menarche occurrence of about 6 months in relation to each other. Girls experiencing menarche during August-October were statistically significantly younger than those experiencing it at other times. Season of birth was not associated with season of menarche.^ The lengths of approximately 150,000 menstrual intervals of U.S. women were analyzed for seasonality. Menstrual intervals possibly disturbed by natural (e.g., childbirth) or other events (e.g., surgery, medication) were excluded. No 6- or 12-month rhythmicities were found for specific interval lengths (14-24, 25-31 and 32-56 days) or ages in relation to menstrual interval (9-11, 12-13, 15-19, 20-24, 25-39, 40-44 and 44 yr old and older).^ Hot flash data of 14 women experiencing natural menopause (NM) and 11 experiencing surgically-induced menopause (SIM) did not differ in frequency of hot flashes. Hot flashes in NM women exhibited 12- and 8-hr, but not 24-hr rhythmicities. Hot flashes in SIM women exhibited 24- and 12-hr, but not 8-hr, rhythmicities. Regardless of type of menopause, women with a peak frequency in hot flashes during the morning (0400 through 0950) were distinguishable from those with such in the evening (1600 through 2159).^ Data from approximately 200 U.S. women revealed a 6-month rhythm in menopause with first peak in May. No significant 12-month variation in menopause was detected by Cosinor analysis. Season of birth and age at menopause were not associated with season of menopause. Age at menopause declined significantly over the years for women born between 1907 and 1926, inclusive. ^