Showing papers by "Robin M. Murray published in 1984"
TL;DR: Six sets of operational criteria for diagnosing schizophrenia were applied to a systematically ascertained twin series by raters who were blind to zygosity and to the psychiatric status of the co-twin, resulting in significant monozygotic twin correlations.
Abstract: Six sets of operational criteria for diagnosing schizophrenia were applied to a systematically ascertained twin series by raters who were blind to zygosity and to the psychiatric status of the co-twin. Assuming a multifactorial/threshold model of transmission, twin correlations in liability and, where possible, approximate broad heritabilities were calculated for each criterion. All definitions resulted in significant monozygotic twin correlations. The highest heritabilities (of approximately 0.8) were given by the Research Diagnostic Criteria and by the categories "probable" plus "definite" schizophrenia according to the criteria of Feighner et al. In contrast, Schneider's first-rank symptoms defined a form of schizophrenia with a heritability of 0 and, together with the criteria of Carpenter et al and Taylor et al, proved to be excessively restrictive, identifying fewer than half of the probands as schizophrenic.
253 citations
TL;DR: In a group of schizophrenics of twin birth, no evidence of ventricular enlargement was found where there was a family history of major psychiatric disorder, but among those schizophrenics without such aFamily history, cerebral ventricular size was significantly increased (P <0.01), and there was also evidence of birth complications.
Abstract: In a group of schizophrenics of twin birth, no evidence of ventricular enlargement was found where there was a family history of major psychiatric disorder. Among those schizophrenics without such a family history, cerebral ventricular size was significantly increased (P less than 0.01), and there was also evidence of birth complications. Among normal control twins, those who reported complicated births had significantly larger ventricles.
216 citations
TL;DR: A biometrical genetic analysis was carried out on the response of 419 pairs of twins to the 42-item version of Leyton Obsessional Inventory and revealed a genetic effect on the development of obsessional personality and also the transmission of a general tendency predisposing to neurotic breakdown.
Abstract: A biometrical genetic analysis was carried out on the response of 419 pairs of twins to the 42-item version of Leyton Obsessional Inventory. Just under half the variation in both the Obsessional Trait and Symptom Scales was due to heredity. Multivariate analysis revealed a genetic effect on the development of obsessional personality and also the transmission of a general tendency predisposing to neurotic breakdown. Although the influence of heredity was outweighed by that of the environment, the latter effect showed an absence of general factors and, in particular, of any noticeable effect from the common home environment.
111 citations
TL;DR: This study illustrates that data from twins and their relatives which includes information on cohabitation history might distinguish shared genes and shared environment as causes of familial aggregation in twin family data.
Abstract: Alcohol consumption, anxiety, and depression were measured by questionnaire in 572 twin families ascertained from the Institute of Psychiatry (London) normal twin register, each family consisting of an adult twin pair, their parents, and siblings--a total of 1,742 individuals. A multivariate normal model for pedigree analysis was applied to each variable, with power transformations fitted to maximise the fit with distributional assumptions. The effect of shared twin environment was estimated by considering the measured cohabitation history of twin pairs. For log-transformed alcohol consumption, amongst current drinkers this effect was the same for MZ and DZ pairs but depended on the cohabitation status of pairs. For both anxiety and depression the effect was clearly not the same for MZ and DZ pairs. Therefore the basic assumption of the classical twin method appears to be invalid for all three traits. Estimates of heritability derived from these analyses were compared with those obtained (1) by applying the classical twin method to twin data only, and (2) by a pedigree analysis ignoring the effect of shared twin environment. For all variables there were considerable differences between estimates based on the three models. This study illustrates that data from twins and their relatives which includes information on cohabitation history might distinguish shared genes and shared environment as causes of familial aggregation. In these behavioral traits the effect of shared twin environment may depend on zygosity and play a major role in explaining familial aggregation in twin family data.
108 citations
TL;DR: Because a previous study among 385 psychiatric admissions had shown each of three rapid interviews to be far superior to each of nine laboratory tests in screening for excessive drinking and alcoholism, the separation of patients with these drinking patterns from normal drinkers was reexamined by the more sophisticated technique of discriminant analysis.
Abstract: Because a previous study among 385 psychiatric admissions had shown each of three rapid interviews to be far superior to each of nine laboratory tests in screening for excessive drinking and alcoholism, the separation of patients with these drinking patterns from normal drinkers was reexamined by the more sophisticated technique of discriminant analysis. It was thus possible to determine where there was overlap in the information provided by some tests in contrast to "new information" provided by others and whether the arbitrary cut-off points of the normal ranges of the laboratory tests were contributing to their poor sensitivity. Discriminant analysis again confirmed the good performance of the rapid interviews, particularly the Brief Michigan Alcoholism Screening Test and the Reich interview, but it also identified glutamate dehydrogenase (GDH) as the best of the laboratory tests and of comparable efficacy to the rapid interview for the group of excessive drinkers. By comparison, gamma-glutamyl transpe...
53 citations
TL;DR: 11 severely dependent alcoholics had larger ventricular volumes and ventricle/brain ratios than did their normal cotwins and these changes correlated best with the length of time the alcoholic twin had been drinking eight centilitres pure alcohol a day.
22 citations