Executive function and genetic predisposition to schizophrenia--the Maudsley family study.

Executive cognitive impairment has been found in families affected by schizophrenia and is a putative endophenotype. We wished to explore its genetic basis further by studying the association between impairment and genetic loading for schizophrenia. We studied 30 schizophrenia patients with a family history of schizophrenia, 53 of their nonpsychotic first-degree relatives (familial), 32 patients with schizophrenia but no known family history of psychosis, 52 of their first-degree relatives (nonfamilial), and 47 normal controls. They were tested using the National Adult Reading Test (NART), Trails A and B, Verbal fluency tasks, and a computerized version of the Wisconsin Card Sorting Test (WCST). Familial, but not nonfamilial, relatives were impaired on NART, letter fluency, Trails B, and WCST total errors. They were inferior to nonfamilial relatives on letter fluency and Trails A. Both sets of relatives were impaired on Trails B controlling for Trails A, and on WCST categories achieved. There were no significant differences between schizophrenia patients with and without a family history. Our results suggest that executive deficits qualitatively similar to those seen in those with schizophrenia reflect familial susceptibility, even taking early IQ and education into consideration, consistent with a genetic mechanism.

Gas-phase methylation of [60]fullerene.

Direct methylation of [60]fullerene via a gas-phase reaction in a CH4/H2 atmosphere was performed using a modified hot filament chemical vapor deposition method. Pressures were varied from 10 to 60 mbar and the substrate was maintained at 690 degrees C. High-resolution matrix-assisted laser desorption ionization (MALDI) mass spectrometry analysis showed signals corresponding to C60H18-2n(H,CH3)n. Collision-induced dissociation experiments confirmed a maximum of 18 ligands possible to the [60]fullerene cage.

Reaction time and sustained attention in schizophrenia and its genetic predisposition.

Sustained attention is affected by schizophrenia. The simplest form of Continuous Performance Test (CPT-X) is a purer test of vigilance than more demanding variants but widely thought too insensitive to detect abnormalities in those with genetic predisposition to schizophrenia. We used a 7-minute CPT to compare 61 patients diagnosed with schizophrenia, 45 of their never-psychotic relatives, and 47 control subjects. We found a significant impairment in stimulus discrimination in both patients (p=0.001) and their relatives (p=0.006). There was no difference in stimulus discrimination between relatives of patients with impaired and unimpaired stimulus discrimination. Relatives of patients with unimpaired stimulus discrimination were still inferior to controls (p=0.02). Reactions slowed in all groups equally as the test progressed. Patients showed increased mean reaction time (p<0.0001) and interquartile range (p=0.003). Relatives showed slower reaction times (p=0.01) but normal interquartile range. Groups did not differ in respect of individuals' fastest reaction times. We conclude that genetic predisposition to schizophrenia reduces performance even during a task placing minimal cognitive load on working memory and perceptual processing, suggesting impaired vigilance. Increased reaction time in the disease and its predisposition appear to be due to changes in response distribution rather than by a limitation of maximum speed. Our results raise the possibility of separating the cognitive components of vigilance, working memory and perceptual processing tapped by more demanding variants of the CPT, and draw attention to the need for consideration of dynamic neurocognitive processes in schizophrenia.

Photophysical properties of the ground and triplet state of four multiphenylated [70]fullerene compounds.

The particular chromophoric structure of C(70)Ph(10), which consists of two cage-centered π-electron systems, makes its photophysical properties an exception to those found for other phenylated [70]fullerenes C(70)Ph(2n) (n=2-4). For these other C(70)Ph(2n) species, their intrinsic photophysical properties undergo smooth transitions as a function of n.

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.

Early intervention in psychiatric emergencies: a controlled clinical trial.

In the UK, psychiatric care of patients with acute and chronic disorders has increasingly moved from hospital to the community. We have evaluated in a controlled trial patients with severe mental illness, who were assigned to early intervention by community services or to standard hospital treatment. 100 patients aged 16 to 65 years presenting as psychiatric emergencies to an inner London teaching hospital were randomly allocated to a multidisciplinary community-based team (n = 48) or conventional hospital-based psychiatric services (n = 52) and assessed over a 3-month period. Ratings of psychopathology and social functioning were made before treatment and after 2, 4, and 12 weeks by independent assessors. 85 patients completed all assessments, and all patients had evaluable data beyond 2 weeks. 3 patients died during the study, 2 from natural causes and 1 from an accident. Patients referred to the community service showed greater improvement in symptoms and were more satisfied with services than those in the hospital-based service. Patients treated in the hospital-based service spent eight times as many days as psychiatric inpatients as those treated in the community-based service. Patients both prefer and seem to benefit from community-based psychiatric care, and our early-intervention community service might be a good model for such care.

Suicidal ideation as a presenting complaint. Associated diagnoses and characteristics in a casualty population.

A prospective study was conducted of all referrals to the emergency psychiatric service of an inner-London hospital over one year. There were 53 individuals who presented with the specific and spontaneous complaint of suicidal ideation without any accompanying act of self-harm. The main diagnoses in this group were personality disorders (40%) and alcohol dependence (15%); only 13% were suffering from depressive illness. Members of the group differed from the other 369 presenters to the service in that they were less likely to be accorded a diagnosis of a defined mental illness, twice as likely to have a criminal record, and more likely to have a previous history of deliberate self-harm. A quarter of the suicidal complainants were admitted to hospital following assessment.

Laterality, order of report and attention in a dichotic CV syllable task.

Lateralisation was measured on a dichotic CV syllable-pairs task under 4 conditions: (1) free attention and report; (2) as in (1) but with subjects required to report location of items; (3) random pre-stimulus and (4) random post-stimulus cuing of the ear to be attended to and reported first. In (1) there were accuracy advantages for the right ear and for first reports after controlling right ear starting bias. After excluding intrusions there was an REA in accuracy for (2) but no starting bias; a similar REA was observed for (3) and (4) but the first report advantage for (2) and (3) was absent for (4) and (4) was less accurate overall. There were more intrusions for (4) and more from the right ear for (2), (3) and (4). Subjects with the highest intrusion rates from the right ear were also the most lateralised to this ear on the measure which excluded intrusions.

Familial handedness and sex differences in strength of hand preference.

Handedness inventory scores and details of familial handedness were obtained for 54 males and 71 females. For males the handedness distributions of subjects with and without familial sinistrality (FS) did not differ significantly. For females more extreme handedness scores were observed for subjects with FS in both left and right handed ranges of the handedness distribution. Sex differences in handedness were apparent only in subjects with FS, where females displayed more extreme scores at both ends of the distribution. These results are discussed in terms of possible genetic, environmental and other influences on the expression of manual asymmetry and it is concluded that at present we have insufficient information to be able to adequately explain variations in handedness in terms of one or more such influences.

Theory and practice in the measurement of laterality.

Using data from a divided visual field task, it is shown that correlations between laterality measures and overall accuracy are not a consequence of the level of accuracy constraining the achievable range of laterality, but depend on the design of current laterality measures and on the differential correlation of each hemisphere's scores with total accuracy. Comparing four laterality measures on 125 subjects shows that, although the laterality distributions differ in dispersion, the four measures are significantly intercorrelated and give nearly identical indications of average lateralisation. It is concluded that laterality measures may be of some limited use in comparing experimental results from different sources rather than in evaluating theories of cerebral asymmetry.

Hemisphere differences in the recognition of nonsense shapes: cerebral dominance or strategy effects?

A tachistoscopic visual half-field task involving delayed recognition of nonsense shapes did not prove to rely disproportionately on either cerebral hemisphere. However, subjects at either extreme of the laterality distribution were more accurate at recognition overall, relative to subjects displaying indeterminate laterality. These results are discussed in terms of subjects' preferred processing strategies and it is concluded that until we possess a detailed knowledge of task requirements and of subjects' strategies, the results of laterality studies will remain ambiguous.

The Comprehensive assessment and Referral Evaluation (CARE)--rationale, development and reliability.

The Comprehensive Assessment and Referral Evaluation (CARE) is a new assessment technique which is intended to reliably elicit, record, grade and classify information on the health and social problems of the older person. The CARE is basically a semi-structured interview guide and an inventory of defined ratings. It is designated comprehensive because it covers psychiatric, medical, nutritional, economic and social problems rather than the interests of only one professional discipline. The style, scope and scoring of the CARE makes it suitable for use with both patients and non-patients, and a potentially useful aid in determining whether an elderly person should be referred, and to whom, for a health or social service. The CARE can also be employed in evaluating the effectiveness of that service if given.