Search PubMed⌕ Search

Biomedical subjects

E F Torrey

Publications and source records attributed to E F Torrey.

At least 73 records · Page 4Linked to original sources
PubMed1996

Analysis of the DRPLA triplet repeat in brain tissue and leukocytes from schizophrenics.

An expansion of the CAG triplet in the human gene called atrophin-1 or CTG-B37 causes the neuropsychiatric disease known as dentatorubral-pallidoluysian atrophy (DRPLA). We have examined the genomic DNA from brains and peripheral blood leukocytes (PBLs) of schizophrenic and non-schizophrenic individuals and PBLs from a cohort of monozygotic twins discordant or concordant for schizophrenia, for expansions of the CTG-B37 region. All samples, including non-schizophrenic/normal controls, had 7-22 CAG repeats in this region. Thus we found no evidence for an expansion of the DRPLA triplet repeat associated with schizophrenia when compared to controls. Our data suggest that an expansion in the CTG-B37 gene is not linked to or responsible for the disease schizophrenia.

Alleles↗
PubMed1996

Fluctuations in schizophrenic births by year.

BACKGROUND: It has previously been reported that births of individuals who later develop schizophrenia vary by birth year. METHOD: Birth data were analysed on 34,024 individuals diagnosed with DSM-III-R disorganised, catatonic, and undifferentiated schizophrenia using time series analysis. RESULTS: Minor yearly fluctuations were observed but did not achieve statistical significance. Thus earlier findings reported in the literature could not be replicated using a different statistical approach. CONCLUSION: The findings do not support theories which assume major yearly fluctuations in the births of individuals with schizophrenia. Such theories include the perinatal effects of influenza, temperature variation, and the effects of severe weather.

Adult↗
PubMed1995

Prevalence of psychosis among the Hutterites: a reanalysis of the 1950-53 study.

Psychiatric case records from Eaton and Weil's 1950-53 study of the Hutterites were rediagnosed using DSM-III-R criteria. The results confirmed that the Hutterites have a very low prevalence of both schizophrenia (0.9 per 1000) and bipolar disorder (0.6 per 1000). Genetic and/or environmental explanations are both possible. Because of their unusual genetics and lifestyle, the Hutterites are an invaluable potential research resource.

Alberta↗
PubMed1995

Genetic risk of neuropsychological impairment in schizophrenia: a study of monozygotic twins discordant and concordant for the disorder.

We used a paradigm involving monozygotic (MZ) twin pairs discordant for schizophrenia (n = 20) and concordant for schizophrenia (n = 8), as well as normal MZ twin pairs (n = 7) in order to study cognitive measures of genetic risk in schizophrenia. A comparison between the unaffected twins from the discordant sample and the normal twins indicated subtle attenuations in some aspects of memory and executive functioning in the unaffected group and thus provided evidence for cognitive markers of a genetic component in schizophrenia. A comparison of the affected twins from the discordant pairs and the concordant twins yielded virtually no differences, suggesting that a distinction between familial and sporadic cases is not valid in this sample. Large differences between unaffected and affected members of discordant pairs on a wide variety of variables, including IQ, attention, memory, and executive function, highlighted the magnitude of disease-specific factors.

Adult↗
PubMed1995

Could schizophrenia be a viral zoonosis transmitted from house cats?

Studies have suggested that some cases of schizophrenia may be caused by viruses. We hypothesize that such cases may be cases of viral zoonosis transmitted primarily from house cats. Epidemiological aspects of schizophrenia and a case-control questionnaire support this hypothesis.

Adolescent↗
PubMed1995

Viruses, schizophrenia, and bipolar disorder.

The hypothesis that viruses or other infectious agents may cause schizophrenia or bipolar disorder dates to the 19th century but has recently been revived. It could explain many clinical, genetic, and epidemiologic aspects of these diseases, including the winter-spring birth seasonality, regional differences, urban birth, household crowding, having an older sibling, and prenatal exposure to influenza as risk factors. It could also explain observed immunological changes such as abnormalities of lymphocytes, proteins, autoantibodies, and cytokines. However, direct studies of viral infections in individuals with these psychiatric diseases have been predominantly negative. Most studies have examined antibodies in blood or cerebrospinal fluid, and relatively few studies have been done on viral antigens, genomes, cytopathic effect on cell culture, and animal transmission experiments. Viral research on schizophrenia and bipolar disorder is thus comparable to viral research on multiple sclerosis and Parkinson's disease: an attractive hypothesis with scattered interesting findings but no clear proof. The application of molecular biological techniques may allow the identification of novel infectious agents and the associations of these novel agents with serious mental diseases.

Bipolar Disorder↗
PubMed1995

Lack of sex differences in the neuropsychological performance of patients with schizophrenia.

OBJECTIVE: While a number of studies have suggested that women with schizophrenia have a less severe form of the disorder than men, the issue has been examined with neuropsychological measures only infrequently. METHOD: The authors compared neuropsychological test performances of men and women from four independent schizophrenic cohorts: two groups of inpatients with chronic courses at a research hospital (N = 128 and N = 63), one group of consecutive admissions to a private psychiatric hospital (N = 57), and one group of schizophrenic twins from discordant monozygotic pairs (N = 20). Nearly 100 comparisons of neuropsychological test performances were made between men and women. RESULTS: Not one comparison significantly favored women, and few were even significantly different between the sexes. CONCLUSIONS: It cannot be ruled out that the disproportionate number of men in the chronic cohorts may have reflected either more frequent intellectual deterioration in men or a bias toward more severely impaired women. Yet, men and women in all groups performed similarly, including the groups in which the sex ratios were nearly equal and were not skewed toward chronicity. These results provide little support for the hypothesis that gender is associated with a unique pathogenesis of schizophrenia or is a marker for a distinct subtype of schizophrenia, at least to the extent that cognitive impairment is a primary manifestation of the underlying disease process. However, given the lack of female patients with later ages at onset and more affective symptoms, the results in this study should be considered relevant only for chronic patients with onset of schizophrenia before age 30.

Adult↗
PubMed1995

A national survey of the use of outpatient commitment.

OBJECTIVE: To determine the extent of use of outpatient commitment, a survey was undertaken of each state and the District of Columbia. METHODS: One of the authors, an attorney, reviewed pertinent state statutes, then conducted telephone interviews with individuals in each state who were knowledgeable about the use of outpatient commitment. RESULTS: Thirty-five states and the District of Columbia have laws permitting outpatient commitment. Georgia, Hawaii, and North Carolina use different criteria for outpatient commitment than for inpatient commitment. In only 12 states and the District of Columbia was use of outpatient commitment rated as very common or common. Reasons for not using it include concerns about civil liberties, liability, and fiscal burden as well as lack of information and interest, the failure of some states to set enforceable consequences for noncompliance, and criteria that are too restrictive. Some states use alternative formal or informal mechanisms to encourage treatment compliance; conditional release is widely used in New Hampshire and conservatorship-guardianship in California. Within many states the availability of outpatient commitment varies considerably by locale. CONCLUSIONS: To clarify the role of outpatient commitment in psychiatric services, more research is needed to identify optimal candidates for its use. Research is also needed on its overall effectiveness compared with conditional release and conservatorship-guardianship and on the consequences of not using such mechanisms to improve treatment compliance.

Ambulatory Care↗
PubMed1994

Relations between neuropsychological performance and brain morphological and physiological measures in monozygotic twins discordant for schizophrenia.

Correlational approaches that examine the relation between neuropsychological measures and brain morphology or physiology in schizophrenia have yielded inconsistent results. This may be due in part to difficulties in ascertaining precisely to what degree each measure deviates from its genetically and environmentally determined potential level. We attempted to surmount this problem in a paradigm involving monozygotic twin pairs discordant for schizophrenia. In this paradigm, the difference score between the unaffected member and affected member of a twin pair should represent the degree of pathologic involvement irrespective of actual level. In correlating intrapair difference scores of anatomic structures measured from magnetic resonance imaging (n = 15) and prefrontal regional cerebral blood flow (rCBF) (n = 10) with cognitive abilities (after partialing IQ), we found strong associations between (1) the left hippocampus and a parameter of verbal memory, and (2) prefrontal rCBF with symptom scores and perseveration on the Wisconsin Card Sorting Test. These results support other research implicating medial temporal and prefrontal regions as important in the symptomatic expression and cognitive failures of schizophrenia. Overall, however, there was a relative paucity of significant associations between neuroanatomic and neurocognitive variables. This may have been due to the relatively restricted ranges of hippocampal size or cognitive ability found in this sample.

Adult↗
PubMed1994

Prenatal origin of schizophrenia in a subgroup of discordant monozygotic twins.

Neuropathological, obstetrical, and epidemiological evidence increasingly suggest that some cases of adult-onset schizophrenia have prenatal or neonatal etiological roots. We evaluated the developmental histories of 23 monozygotic twin pairs discordant for schizophrenia to determine when they markedly and permanently began diverging from each other in motor skills or unusual behavior. Seven of the twins (30%) who later developed schizophrenia had become permanently different from their cotwins by age 5 years. The early divergence group differed from the others by multivariate tests (p = 0.002) for within-twin pair effects and by univariate tests for physical anomaly scores (p = 0.01), total finger ridge counts (p = 0.001), family history of psychosis (p = 0.004), and serious perinatal complications or low birth weight (p = 0.05). It is concluded that some cases of adult-onset schizophrenia are associated with prenatal events, which may include neurodevelopmental abnormalities or specific insults such as anoxia or infectious agents.

Adolescent↗
PubMed1994

Obstetric complications in histories of monozygotic twins discordant and concordant for schizophrenia.

Histories of obstetric complications (OCs) during pregnancy, labor-delivery and the neonatal period were investigated by detailed maternal report for 23 monozygotic (MZ) twin pairs discordant for schizophrenia, 10 MZ twin pairs concordant for schizophrenia and 7 normal MZ control pairs. Statistically significant differences in OC rates were found across these 3 groups. OCs being most frequent in discordant pairs and least frequent in normal control pairs. Labor complications were significantly more frequent in discordant than concordant pairs. OC rates were equivalent in sick and well discordant twins. The results provide evidence for the role of OCs in the development of schizophrenia, complications at the time of birth being especially associated with the development of schizophrenia in discordant twins.

Adult↗
PubMed1994

Link between pregnancy complications and minor physical anomalies in monozygotic twins discordant for schizophrenia.

OBJECTIVE: The aim of the current study was to explore the relevancy of early pregnancy complications for the development of minor physical anomalies in monozygotic twins discordant and concordant for schizophrenia. METHOD: Pregnancy complications and minor physical anomalies were independently assessed in 22 discordant, 10 concordant, and six normal comparison monozygotic twin pairs. RESULTS: Complications occurring during early pregnancy were associated with a higher frequency of minor physical anomalies in the total group and in the discordant twin pairs particularly. While no significant differences in anomaly rates were observed among the discordant, concordant, and normal comparison groups, the discordant ill twins showed a trend toward having more anomalies than their well co-twins. CONCLUSIONS: Complications occurring early in pregnancy are relevant for the development of minor physical anomalies and may be of particular importance for the development of these anomalies in twin pairs discordant for schizophrenia.

Adult↗
PubMed1994

Violent behavior by individuals with serious mental illness.

OBJECTIVE: The perceived association between violent behavior and serious mental illness was explored to determine the validity of claims by mental health advocates that individuals with serious mental illness are no more dangerous than members of the general population. METHODS: The author reviewed recent studies and media accounts of violent behavior by individuals with serious mental illness, with emphasis given to the most recent studies. RESULTS AND CONCLUSIONS: Although the vast majority of individuals with serious mental illness are not more dangerous than members of the general population, recent findings suggest the existence of a subgroup that is more dangerous. A history of violent behavior, noncompliance with medications, and substance abuse are important predictors of violent behavior in this subgroup. The findings imply that the criteria for involuntary hospitalization, involuntary medication, outpatient commitment, the monitoring of medication compliance, and other mandated follow-up procedures may need to be revised. The existence of a subgroup of seriously mentally ill patients who exhibit violent behavior undermines efforts by mental health advocates to reduce the stigma of mental illness by denying an association with violence. Until the problem of violence by this subgroup is addressed, it will be difficult to substantially decrease the stigma associated with serious mental illness.

Family Health↗
PubMed1993

Sylvian fissure asymmetries in monozygotic twins: a test of laterality in schizophrenia.

To address prior reports that schizophrenia is associated with loss of normal brain asymmetry and that it might be linked to a defect of a gene controlling cerebral lateralization, we measured on three-dimensional cortical renderings from magnetic resonance imaging (MRI) scans the lengths and angles of the sylvian fissures in 10 normal monozygotic (MZ) twin pairs (n = 10 pairs) and in 10 MZ pairs discordant for schizophrenia (n = 10 pairs). We confirmed in both sets of twins the expected normal asymmetries of length and angle of the sylvian fissure. We also confirmed that the length asymmetry occurs solely in the region of the planum temporale. In the discordant twins, affected and unaffected twins did not differ in asymmetry measures, thus failing to support an association between illness per se and diminished asymmetry. Moreover, the discordant twins as a group did not differ from the normal twins as a group, thus failing to confirm the hypothesis of a genetic association with abnormal asymmetry. The implications of variations in methodology and patient samples are discussed.

Adult↗
PubMed1993

Increased serum soluble interleukin-2 receptors in schizophrenic monozygotic twins.

There is a confusing history of immune findings associated with schizophrenia. At least some of these discrepant results may be artifacts caused by heterogeneity. In an attempt to decrease heterogeneity, we studied three groups of monozygotic twins who were either discordant for schizophrenia, concordant and ill, or concordant and well. This comparison minimizes environmental and genetic variance, and heightens differences that are actually due to the disorder. Overall, schizophrenic subjects had higher levels of serum soluble interleukin-2 receptors (SIL-2Rs) than unaffected individuals (480.8, SD 238.6 U/ml vs 380.9, SD 170.6 U/ml; F = 5.256, df = 1.61, P = 0.02). When data from discordant and concordant twin groups were analysed separately, both the discordant ill twins (P = 0.06) and concordant ill twin pairs (P = 0.08) showed trends towards higher serum SIL-2R levels than their respective control groups. These data contribute to the growing body of evidence that immune activation is associated with some forms of schizophrenia.

Adult↗