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Biomedical subjects

A M Reveley

Publications and source records attributed to A M Reveley.

At least 19 recordsLinked to original sources
PubMed1999

Heritability estimates for psychotic disorders: the Maudsley twin psychosis series.

BACKGROUND: Previous twin studies have supported a genetic contribution to the major categories of psychotic disorders, but few of these have employed operational diagnostic criteria, and no such study has been based on a sample that included the full range of functional psychotic disorders. METHODS: A total of 224 twin probands (106 monozygotic, 118 dizygotic) with a same-sex co-twin and a lifetime history of psychosis was ascertained from the service-based Maudsley Twin Register in London, England. Research Diagnostic Criteria psychotic diagnoses were made on a lifetime-ever basis. Main-lifetime diagnoses of DSM-III-R and International Statistical Classification of Diseases, 10th Revision schizophrenia were also made. Probandwise concordance rates and correlations in liability were calculated, and biometrical model fitting applied. RESULTS: A substantial genetic contribution to variance in liability was confirmed for the major diagnostic categories except Research Diagnostic Criteria depressive psychosis and unspecified functional psychosis, where familial transmission was confirmed, but the relative contribution of genetic and common environmental factors was unclear. Heritability estimates for Research Diagnostic Criteria schizophrenia, schizoaffective disorder, mania, DSM-III-R schizophrenia, and International Statistical Classification of Diseases, 10th Revision schizophrenia were all between 82% and 85%. None of the estimates differed significantly from any other. CONCLUSIONS: Heritability estimates for schizophrenia, schizoaffective disorder, and mania were substantial and similar. Population morbid risk estimates were inferred rather than directly measured, but the results were very similar to those from studies where morbid risks were directly estimated.

Adult↗
PubMed1998

Minor physical anomalies in familial and sporadic schizophrenia: the Maudsley family study.

OBJECTIVES: (1) To test the hypothesis that minor physical anomalies are increased in patients with schizophrenia and (2) to investigate differences in the prevalence of minor physical anomalies in patients with familial and sporadic schizophrenia and their first degree relatives. METHODS: A weighted Waldrop assessment was carried out on 214 subjects in five groups: schizophrenic patients from multiply affected families; first degree relatives of these familial schizophrenic patients; sporadic schizophrenic patients; first degree relatives of these sporadic schizophrenic patients, and normal controls. Broad and narrow criteria for abnormality were defined based on the distribution of minor physical anomalies in the control group. RESULTS: (1) The total schizophrenic group did not have a significant increase in minor physical anomalies using a narrow criterion of abnormality, but did when a broader criterion was used. (2) A significant increase in the proportion of subjects with an abnormally high number of minor physical abnormalities was shown in the group of sporadic schizophrenic patients (uncorrected p<0.01). Separate analyses for males and females showed a significant increase in the male sporadic group (uncorrected p<0.05), and a smaller non-significant increase in the female sporadic group. Neither the familial schizophrenic group nor either group of first degree relatives showed any significant increases in the proportion of patients with high abnormality scores. CONCLUSION: This work supports prenatal developmental abnormality as a mechanism for sporadic, but not familial, schizophrenia.

Adult↗
PubMed1993

A twin study of psychosis and criminality.

Lifetime criminal and psychiatric histories were examined in a consecutive series of 280 individuals of twin birth with a diagnosis of major functional psychosis who were seen and followed up at the Maudsley Hospital between 1948 and 1988. Their 210 co-twins, 35% of whom had a similar diagnosis, were ascertained and followed up over the same period. In the absence of reliable general-population estimates for lifetime conviction rates, co-twins were used as case controls. Among the 220 complete pairs, significantly more probands (25.7%) than co-twins (14.0%) were convicted, although there was no evidence for an independent genetic basis for criminal behaviour. Criminal conviction was significantly related to psychiatric diagnosis. There were specific patterns of offending, particularly among the schizophrenic men, who were also significantly more often convicted (48.6%) than the men with affective psychosis (19.4%), and more likely to receive a prison sentence. The schizophrenic patients were younger at their first conviction (mean age 22.6 years v. 30.8 years) and they had committed more violent offences than the affective group. In both diagnostic groups, ages at first psychiatric contact and first conviction were highly correlated.

Adolescent↗
PubMed1992

A controlled study of 99mTc-HMPAO single-photon emission imaging in chronic schizophrenia.

Regional cerebral blood flow (rCBF) during a word fluency task was compared in twenty-five male, right-handed, medicated schizophrenic patients and twenty-five age-matched male, right-handed healthy volunteers, using 99mtechnetium-HMPAO multidetector single-photon emission tomography. Increased rCBF in caudate and thalamus was found in patients, probably secondary to neuroleptic medication. Patients showed decreased rCBF in left frontal cortical regions and increased rCBF in left posterior cortical regions, compared to controls. Patterns of left-sided frontal rCBF dominance in controls were reversed in patients, as were normal patterns of right-sided parietal rCBF dominance. Negative symptom score correlated inversely with mesial frontal rCBF, particularly on the left.

Adult↗
PubMed1992

The association between triple X and psychosis.

Two cases of psychotic illness in association with the karyotype triple X showed specific diagnostic and management problems as well as obstetric complications, EEG abnormalities, and lack of a family history of psychiatric disorder. Routine karyotyping during the investigation of psychosis is becoming relevant to psychiatric practice as research reports increasingly feature genetic and chromosome anomalies in association with schizophrenic psychoses.

Adult↗
PubMed1991

Obsessive-compulsive disorder and schizophrenia in three identical twin pairs.

Three monozygotic twin pairs are described who are concordant for DSM-III-R obsessive-compulsive disorder while being discordant for schizophrenia or schizoaffective disorder. Follow-up interview showed the non-psychotic co-twins to have schizotypal personality disorder. It is concluded that obsessive-compulsive and schizophrenia-spectrum disorders can truly co-exist, thus supporting diagnostic changes introduced into DSM-III-R, and may in some cases be inherited together.

Adult↗
PubMed1989

Hand preference in psychotic twins.

In an attempt to replicate the influential study of Boklage (1977), hand preference for writing was examined in a new series of 30 monozygotic (MZ) and 30 dizygotic (DZ) twin pairs in whom the proband had suffered a functional psychosis. In contrast to the original report, no increased rate of left-handedness was found in MZ compared to DZ twins, or psychotic compared with nonpsychotic twins. In particular, no relationship between within-pair left-handedness and discordance for psychosis emerged. Possible reasons for the disagreement between the two studies are examined.

Adult↗
PubMed1988

Twin birth and adult psychiatric disorder. An examination of the case records of the Maudsley Hospital.

We compared the general distribution of diagnoses in 20,895 patients at the Maudsley Hospital with that of 504 patients born twins, including 117 twins where the co-twin had died before the age of 15. Significant differences in diagnostic distribution were found in the co-twin-dead compared with the co-twin-alive group; the former received diagnoses of schizophrenia, personality disorder, or substance abuse more often than the latter. While there were no overall differences between twins and non-twins, there were relatively more twins in the above three diagnostic groups. We suggest that the factors leading to the death of one twin are implicated in the later psychiatric morbidity of the survivor.

Adult↗
PubMed1987

Left cerebral hemisphere hypodensity in discordant schizophrenic twins. A controlled study.

Eleven identical (monozygotic) twin pairs discordant for schizophrenia and 18 unselected control monozygotic twin pairs received a computed tomographic scan. Brain absorption density was determined on quadrants at five slice levels using a fully automatic program that eliminated cerebrospinal fluid spaces from analysis. There was no difference in brain density among schizophrenics, co-twins, and controls. There was a significant difference in right vs left hemisphere asymmetry of density across diagnostic groups. Overall, the left hemisphere was less dense than the right in the schizophrenics, while the reverse was found for the co-twins and controls. These results support the hypothesis of left hemisphere dysfunction in schizophrenia and suggest that it is an environmentally acquired, rather than genetic trait.

Absorptiometry, Photon↗
PubMed1987

The relationship of twinning to the familial-sporadic distinction in schizophrenia.

Cerebral ventricular enlargement in schizophrenia may occur more often in the absence of a family history of the disorder, suggesting that it is related to some non-genetic component of aetiology. This paper shows the finding to be much more apparent in a group of twins than in a similar group of singletons. Previous studies have shown twins in general to have larger cerebral ventricles than non-twins; we suggest that it is the greater susceptibility of twins to obstetric complications that is responsible for both the larger cerebral ventricles found in normal twins, and the very marked increase in ventricular size found in family history negative schizophrenic twins. We go on to consider evidence relating to a possible increased susceptibility of twins to develop schizophrenia.

Adult↗
PubMed1987

The familial/sporadic distinction as a strategy in schizophrenia research.

The rationale and limitations of discriminating between cases of schizophrenia with and without a family history are reviewed. It is concluded from the evidence available that, by identifying subgroups of greater aetiological homogeneity, the strategy can be a useful starting point for research into likely causes.

Brain↗
PubMed1986

Genetic vulnerability to schizophrenia.

The genetic contribution to schizophrenia is the most clearly established etiologic factor. This article briefly reviews the evidence for a genetic influence as well as recent challenges to that evidence. It discusses the possible modes of transmission and outlines current efforts to identify more precisely the genetic and environmental factors contributing to schizophrenia and the nature of the gene-environment interaction.

Adoption↗
PubMed1985

Towards an aetiological classification of schizophrenia.

The genetic contribution to schizophrenia is widely accepted, yet none of the proposed models of transmission has been convincing. Schizophrenia is generally viewed as aetiologically homogeneous with the exception of supposedly rare "phenocopies" associated with organic brain lesions and without a family history. However, up to one-third of schizophrenics have enlarged cerebral ventricles, and this appears to be a consequence of environmental damage. Although the aetiology of schizophrenia comprises genetic and environmental components acting in variable proportions, a simple division into familial and sporadic cases would facilitate research. Families with several ill members will be most valuable for molecular genetic studies, while the new brain imaging techniques should be particularly directed towards sporadic cases.

Birth Injuries↗
PubMed1984

Twin concordance for operationally defined schizophrenia. Confirmation of familiality and heritability.

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.

Adult↗
PubMed1984

The genetic basis of cerebral ventricular volume.

Cerebral ventricular volume, assessed by computed tomography, is a genetically determined trait. In a series of 18 monozygotic and 18 dizygotic twins, heritability values ranged from 82% to 85% depending on the method of calculation.

Adult↗