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Biomedical subjects

J E Overall

Publications and source records attributed to J E Overall.

210 records · Page 12Linked to original sources
PubMedDate not supplied

Brain interactions in chronic schizophrenics under resting and activation conditions.

The metabolic patterns of correlation among brain images obtained during resting conditions and during an eye tracking task were investigated in 12 controls and 18 chronic schizophrenics using positron emission tomography (PET) and deoxy[11C]glucose. Analyses of the interaction between brain regions revealed highly significant differences between groups under both test conditions. Schizophrenics showed lower correlations between anterior and posterior areas and between thalamus and cortical areas than the normals and less change between the baseline and the task than the normals. The schizophrenic subjects showed derangements in the pattern of interactions among brain areas, both under baseline and under activation as compared to the control group.

Adult↗
PubMedDate not supplied

Survival analysis with unreliable endpoints.

There exists a current interest in the application of survival analysis methodology to evaluate differences in latencies of response to psychological or psychopharmacological treatment modalities. However, unreliability in the measurement of treatment responses in such research poses a problem. Two methods of defining the "discrete endpoint" that is required for survival analysis are compared regarding power of tests of significance for differences in survival curves. Discrete endpoints defined by regression equations fitted to all available data for each subject provided greater power when entered into survival analysis than did endpoints dependent only on individual measurements. While this may not surprise statisticians, no examples of the use of regression estimates for survival analysis endpoints have been identified in reports of previous clinical trials nor in discussions concerning potential applications of survival analysis methodology in psychiatric research.

Analysis of Variance↗
PubMedDate not supplied

Persistence of depression in detoxified alcoholics.

Although many alcoholics appear depressed upon entry into an alcoholism treatment program, the depressive features tend to disappear in most cases after only a few weeks of sobriety in an appropriate treatment setting. This report is concerned with understanding factors that mediate for persistence of depression in some detoxified alcoholics. Among four relatively independent aspects of alcohol-related behavior measured by the Drinking Behavior Interview, only one factor, that related to disruption in close personal relationships, was found to correlate significantly with level of self-reported depression at the end of a 4-week treatment program. These results and those from a previous study are discussed in terms of the loss of social support.

Adult↗
PubMedDate not supplied

The SKT neuropsychological test battery.

The SKT is a brief neuropsychological test battery that includes nine performance subtests that define two independent factors of memory and attention deficit. It requires no more than 15 minutes to administer and has five parallel forms. Developed in Germany, it has been used successfully to document improved performance of patients in trials of antidementia drugs in that country. This article addresses factor structure and scoring, dementia profile classification, reliability, and validity data. The SKT appears to hold promise for efficient assessment of objective performance changes to supplement clinical evaluations of therapeutic efficacy of new drugs for treatment of senile dementia.

Aged↗
PubMedDate not supplied

Empirical scaling of the stages of cognitive decline in senile dementia.

A 30-item questionnaire concerned with signs and symptoms of cognitive decline was completed by a relative or caregiver for each of 115 elderly patients seen in the gerontology outpatient clinic of our institution. Twelve different preliminary scale values were calculated to locate each of the 30 clinical manifestations along a continuum of increasing severity. Principal components analysis was then used to combine the 12 preliminary indices into a single composite scale that more reliably represents distances between the 30 clinical manifestations. The scale scores for the clinical manifestations were observed to cluster into relatively discrete groups, suggesting naturally occurring stages or phases. Objective cluster analysis methods further suggested the presence of distinct thresholds for occurrence of new impairments along the cognitive decline continuum. Utility of the empirically derived scale values in staging the course of primary degenerative dementia is suggested.

Aged↗
PubMedDate not supplied

Factor structure and reliability of the Alzheimer's Disease Assessment Scale in a multicenter trial with linopirdine.

The Alzheimer's Disease Assessment Scale (ADAS) has assumed a primary role in assessment of treatment responses in large-scale multicenter trials of drugs being evaluated for treatment of dementia in elderly patients. Data from 280 patients with Alzheimer's disease were analyzed to evaluate factor structure and reliability. Results confirm the presence of three primary factors interpreted as mental status, verbal fluency, and praxis. The presence of a large general factor underlying those more specific dimensions also supports the utility of the composite ADAS cognitive score that has been used as a primary outcome measure in previous drug trials. Test-retest reliability of the factor scores were calculated to be 0.83, 0.78, and 0.87. Test-retest reliability of the composite ADAS cognitive score was 0.90. Statistics useful for estimation of sample sizes for future multicenter trials are provided.

Aged↗