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Biomedical subjects

D Schopflocher

Publications and source records attributed to D Schopflocher.

12 recordsLinked to original sources
PubMed2004

A multivariate study of predictors of repeat parasuicide.

OBJECTIVE: To identify variables which differentiate future repeaters of parasuicide from non-repeaters in a multivariate analysis. METHOD: Interviews were conducted with 507 parasuicide cases; data were collected on precipitating factors for the index parasuicide, psychiatric and medical history, stressful life events, prior history of parasuicide, hopelessness, anger, self-esteem and social adjustment. Individuals were followed for 1-2 years to determine if a repeat parasuicide occurred. RESULTS: A logistic regression model identified four significant predictors of repeat parasuicide: prior history of parasuicide, a history of depression, a history of schizophrenia and poor physical health. A risk factor scale constructed from these four variables showed that the risk of repeat parasuicide increases as the number of risk factors increases. CONCLUSION: This study identifies four key predictors of repeat parasuicide, and provides evidence that the risk of repeat parasuicide increases when multiple risk factors are present.

Adolescent↗
PubMed2001

Toward measuring the impact of ecological disintegrity on human health.

Ecological integrity refers to the ability of environmental life-support systems to sustain themselves in the face of human-induced impacts. We used a correlational, aggregate-data study design to explore whether life expectancy, as a general measure of population health, is linked to large-scale declines in ecological integrity. Most of the data were obtained from World Resources Institute publications. Selected surrogate measures of ecological integrity and gross domestic product (GDP) per capita (as a socioeconomic confounder) were modeled, for the first time, using linear regression techniques with life expectancy as the health outcome. We found a modest relation between ecological integrity and life expectancy, but the direction of the association was inconsistent. When GDP per capita was controlled, the relation between ecological integrity and life expectancy was lost. GDP per capita was the overwhelming predictor of health. Any relation between ecological integrity and health may be mediated by socioeconomic factors. The effect of declines in ecological integrity may be cushioned by the exploitation of ecological capital, preventing a direct association between measures of exposure and outcome. In addition, life expectancy may be too insensitive a measure of health impacts related to ecological decline, and more sensitive measures may need to be developed.

Cross-Sectional Studies↗
PubMed1998

A comparative approach to identify unsafe older drivers.

The identification of unsafe older drivers is a current and important challenge. In the present research, a comparative approach was used in which the on road driving errors and expert evaluations of older drivers with clinically significant declines in mental abilities (N = 155) were compared to the errors and evaluations of a normal elderly control group (N = 68) and a normal younger control group (N = 30). The results indicate that the conventional criteria used in North America for licensing new drivers is inappropriate for license removal in experienced drivers. The results also indicate that hazardous errors were the single best indicator of membership in the group of older drivers with clinical impairment. This group also differs from the two normal control groups on turn positioning errors, minor positioning errors and overcautiousness. All groups differ from each other on scanning errors. A regression analysis further indicated that the five driving errors listed above accounted for over 57% of the variance associated with global ratings provided by expert driving instructors.

Accidents, Traffic↗
PubMed1998

Central executive function in working memory: event-related brain potential studies.

Visual event-related brain potentials (ERPs) were recorded during a running memory task, in which subjects dynamically revised (updated) memory stores, and a control task not requiring maintenance of a changing memory set but utilising identical stimulus sequences and response patterns. In three experiments, ERPs associated with cognitive processes were isolated through subtraction of control potentials from ERPs acquired during updating. We provide evidence that resultant difference ERPs primarily reflected processing or processing control, as opposed to storage. These findings are consistent both with Baddeley's working memory model, which postulates separate storage and control modules, and Morris and Jones' behavioral evidence for specific involvement of Baddeley's central executive in memory updating. In addition, our ERP data indicate that updating requires processes not suggested by Morris and Jones' behavioural studies; possibly control processes engaged to reduce the effects of proactive interference. Overall the data are consistent with the discovery of an ERP correlate of central executive activity.

Adult↗
PubMed1989

Speech Sounds Perception Test: nonrandom response locations form a logical fallacy in structure.

The response format of the Speech Sounds Perception Test confounds speech perception with irrelevant method variance. To rectify this problem the response format was revised by randomizing the response locations. An empirical comparison of the revised and original forms was undertaken with forensic (n=59) and psychiatric (n=67) samples. The empirical results coupled with the logical problem in the original form indicates that a revision is necessary.

Adult↗
PubMed1985

Long-term brain impairment in chronic alcoholics: N2-P3 cognitive potentials in a template-matching memory task.

Neuropsychological measurements and N2-P3 visual cognitive potentials evoked by a template-matching visual-memory task were collected from seemingly intact chronic alcoholics and normal controls. Psychometric results were not significantly different between alcoholics and controls, but the N2-P3 cognitive potentials of the alcoholic population showed a decreased amplitude and an atypical interhemispheric pattern of latencies that point to alcohol-related deficits. The different functional nature and possibly separate intracranial origin of N2 and P3 suggest respective cortical and hippocampal localisation of these deficits. Cognitive brain potentials were a more sensitive indicator of cerebral impairment than psychometric data.

Adult↗
PubMed1984

Neuropsychological test performance in depressed patients before and after drug therapy.

Sixty psychiatrically depressed patients (female = 39, male = 21), classified as psychotic or neurotic, were neuropsychologically assessed on an expanded Halstead-Reitan battery before antidepressant medication. Extant normative data from a large control group (N = 142) were employed for comparative purposes. Statistical analysis of the pretreatment data revealed a selective impairment in the processing of visuospatial material and retention of both nonverbal and verbal information by both the Neurotic and Psychotic groups, with greater impairment shown by the latter group. Separation of the Psychotic group from the Neurotic and Control groups was possible using these data. Posttreatment data analysis, although tentative due to the high attrition rate (female = 19, male = 14), indicated significant improvement in those abilities most impaired initially and did not allow separation of the Neurotic and Psychotic groups from the Normal group. These results are consistent with previous research which suggest greater perturbation of the nondominant hemisphere in depressive disorders, attenuation of cognitive deficits with amelioration of symptomatology, and the presence of residual deficits after treatment in older subjects.

Adolescent↗
PubMed1981

A neuropsychological study of the stable syndrome of hysteria.

Ten patients with the stable syndrome of hysteria were matched for age, sex, handedness, and full-scale WAIS IQ with ten controls, ten psychotic depressives and ten schizophrenics. All were subjected to an extensive neuropsychological test battery. Compared to the controls, the hysteria group exhibited bifrontal impairment (R = L) and, globally, greater dysfunction of the nondominant hemisphere. A G analysis provided a complete separation between the hysteria and controls. However, a D-index analysis showed that the hysteria group was more impaired than normals and depressives because of greater dysfunction of the dominant hemisphere, whilst schizophrenia showed greater nondominant hemisphere dysfunction than hysteria. Further, a cluster analysis on the 40 subjects produced three clusters: normal controls, depressives, and a schizophrenia-hysteria grouping. These findings are interpreted as suggesting that dominant hemisphere dysfunction is fundamentally related to the syndrome of hysteria and that the dysfunction of the nondominant hemisphere is brought about by associated features: the female excess, the emotional instability and dysphoric mood, the presence of asymmetrical pain, and conversion symptomatology. It is further argued, in view of the familial associations, that hysteria in the female is a syndrome equivalent to psychopathy in the male (who also exhibits dominant hemisphere dysfunction) and might represent in the female a (relatively benign) variant of schizophrenia characterized by imprecise verbal communications, a subtle form of affective incongruity, together with the conversion parameter.

Adult↗
PubMedDate not supplied

Characteristics of PAHs, PCDD/Fs and PCBs in sediment following forest fires in northern Alberta.

Extensive forest fires occurred in northern Alberta, Canada, in 1998. Polynuclear aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were studied following these forest fires in order to explore natural and anthropogenic influences on the affected forest fire area. Specifically, concentrations and profiles of these compounds were determined in sediment samples. A predominance of alkylated PAH derivatives over parent PAHs were observed at the burned and reference sites. Naturally dervied PAHs were abundant at all sites. A high proportion and concentration of retene was observed at the totally burned site and indicates some inputs from forest fires. Very low concentrations of PCDD/Fs and PCBs were observed at all sites, and the profiles were very similar. This likely reflects common atmospheric contributing sources to the study area.

Air Pollutants↗
PubMedDate not supplied

Characteristics of preterm delivery and low birthweight among 113,994 infants in Alberta: 1994-1996.

This study examined the impact of infant and maternal factors on preterm delivery and low birthweight (LBW) in Alberta between January 1, 1994 and December 31, 1996. Data on 113,994 births were collected from vital statistics registration birth data. Logistic regression models for preterm and LBW delivery suggested the key risk factors were multiple and still birth (odds ratios > 22.0). Other characteristics included female gender, birth defects, nulliparous women, maternal age 35 and greater, unmarried, history of abortion, maternal smoking, maternal street drug use, and having less than 4 prenatal visits (odds ratios 0.86-2.54). Interactions between smoking and alcohol, and smoking and parity were noted. Efforts to improve the currently low rates (8.2%) of smoking cessation during pregnancy are required. Social, economic and medical factors associated with delayed childbearing and birth outcomes should be investigated.

Adolescent↗