Neuropsychological performance of psychotic patients in community care: results from the UK700 study.

OBJECTIVE: To compare cognitive performance in chronic schizophrenic and affective psychotic patients maintained in community care. METHOD: We studied a sample of community-based patients (n = 707) with chronic psychotic disorders. Neuropsychological assessment was completed using the National Adult Reading Test (NART) and the Trail Making Test (TMT). RESULTS: Affective psychotic patients had higher premorbid IQ than schizophrenic patients before adjustment for confounding factors (P=0.03); however, after adjustment for ethnic group and social class this became non-significant (P=0.19). There were no significant differences between groups on the TMT, parts A or B. CONCLUSION: Unlike studies suggesting that schizophrenic patients are more cognitively impaired than affective psychotic patients, our study suggests a degree of cognitive homogeneity between those patients who develop a chronic illness. Measures of premorbid IQ suggest that this cognitive homogeneity exists prior to the onset of illness.

Verbal fluency in patients with schizophrenia and affective psychoses and their first-degree relatives.

BACKGROUND: Schizophrenic patients are known to have neuropsychological deficits including impaired verbal fluency, but it is not clear whether this latter deficit is: (a) a consequence of overall intellectual deficit; (b) shared with affective psychotic patients; or (c) shared by the relatives of schizophrenic patients; and (d) shared by the relatives of affective psychotic patients. METHODS: We administered Thurstone's Verbal Fluency Test to 45 schizophrenic patients and 72 of their relatives, and 30 affective psychotic patients and 53 of their relatives. Subjects were asked to generate as many words as possible beginning with the letters 'C' and 'S' and the total was taken as the dependent variable. Subjects also completed the National Adult Reading Test (NART) to provide a measure of (pre-morbid) IQ. RESULTS: Schizophrenic patients generated significantly fewer words than affective psychotic patients, however adjusting for NART this became non-significant. Schizophrenic (but not affective psychotic) patients generated significantly fewer words than their relatives; again adjusting for NART this became non-significant. Patients who had been exposed to obstetric complications (OC+) and those who had not (OC-) had similarly poor verbal fluency scores. Relatives of OC+ schizophrenic patients had superior verbal fluency than relatives of OC- schizophrenic patients and this remained significant after adjustment for NART. CONCLUSIONS: The results suggest that some families transmit impairment in verbal fluency as part of a pattern of lower overall IQ. However, in other families, relatives show largely normal neuropsychological function, and the poorer verbal performance of the schizophrenic member appears to have arisen secondary to his/her exposure to OCs.

Neuropsychological performance and spectrum personality traits in the relatives of patients with schizophrenia and affective psychosis.

Neuropsychological deficits are found in both schizophrenic patients and their relatives, and some studies have shown similar, but less severe, deficits in affective psychotic patients and their relatives. We set out to establish: (a) whether schizophrenia spectrum personality traits are more common in the relatives of schizophrenic patients than, in the relatives of affective psychotic patients; and (b) what the relation is between spectrum personality traits and neuropsychological deficits in these relatives. Relatives were interviewed using the International Personality Disorder Examination (IPDE), and also completed the National Adult Reading Test (NART), the Trail Making Test (TMT; Parts A and B) and Thurstone's Verbal Fluency Test (TVFT). Spectrum personality traits were equally common in 129 relatives of schizophrenic patients and 106 relatives of affective psychotic patients, but the performance of the former group was inferior to that of the latter on the NART and the TVFT. Relatives with high paranoid traits had lower NART scores than relatives without such personality traits; similarly, those with high schizoid traits took longer to complete the TMT, part B, than those without such traits; and relatives with high schizotypal traits generated significantly fewer words on the TVFT than those without such traits. We conclude that relatives of schizophrenic and affective psychotic patients share a propensity to schizophrenia spectrum traits, but relatives of the former have poorer neuropsychological performance. Furthermore, there exists an association between neuropsychological deficits and spectrum traits in both groups of relatives; in particular those with high paranoid traits have lower IQ scores than their less paranoid counterparts.

Childhood schizotypy and positive symptoms in schizophrenic patients predict schizotypy in relatives.

BACKGROUND: Schizotypy is one phenotypic expression of the familial-genetic liability to schizophrenia, but its precise relationship to frank psychotic symptoms remains unclear. We, therefore, set out to examine the relationships between (a) premorbid personality in schizophrenic patients, (b) the psychopathology they showed, and (c) schizotypal traits in their relatives. METHOD: Ninety consecutively admitted schizophrenic patients were interviewed with the Present State Examination (PSE). Their mothers were interviewed concerning their childhood personality and social adjustment, and 121 of their well relatives were evaluated with three different schizotypal scales. Factor analyses were carried out on (a) the nine main psychotic symptoms from the patients' PSE interview, and on (b) the schizotypal features derived from the scales completed by the first-degree relatives. Correlation coefficients were calculated between premorbid personality traits, and factor scores in probands and in relatives. RESULTS: No relationship was found between childhood schizoid-schizotypal personality traits and any particular dimension of psychopathology in patients. The positive syndrome in patients was correlated with higher scores for relatives on the three schizotypy scales, but did not predict any specific pattern of schizotypy in the relatives. Premorbid schizoid-schizotypal traits were also correlated with schizotypy in the relatives. CONCLUSIONS: Schizotypy in relatives has a familial relationship with schizoid-schizotypal traits in the childhood, and with positive symptoms during the illness, of schizophrenic patients.

Schizophrenic patients and their first-degree relatives show an excess of mixed-handedness.

An excess of mixed-handedness in schizophrenia has been reported. However, it is not established whether this excess is manifest in non-schizophrenic psychoses, nor whether the underlying etiology is genetic or environmental. We investigated these issues in a group of patients with schizophrenia (n=94), affective psychosis (n=63), other psychosis (n=26); their respective first-degree relatives (total n=183) and a control group (n=85). A narrow definition of mixed-handedness was used corresponding to groups 5 and 6 as defined by the Annett Handedness Questionnaire. We found an excess of mixed-handedness in the schizophrenic group compared with controls (OR=5.2, 1.4-18.6, p<0.006). There was no difference between the other psychotic groups and controls. There was a trend for an excess of mixed-handedness in the first-degree relatives (n=99) of schizophrenic patients (p=0.055), but not in the relatives of affective or other psychotic patients. There was a striking linear trend in the proportion of mixed-handedness between controls, the relatives and the schizophrenic patients (chi2=7.0, p=0.008). There was no association between mixed-handedness and a history of pregnancy or birth complications in the schizophrenic group. There was some evidence for impaired sociability in the mixed-handed schizophrenic patients. Our results indicate that the excess of mixed-handedness in schizophrenia may have a genetic basis.

Life events, ethnicity and perceptions of discrimination in patients with severe mental illness.

BACKGROUND: Whilst it is commonly believed that black and ethnic minority (B&EM) people living in the UK experience social disadvantage compared with the white British (WB) population, no study has specifically addressed this issue in patients with severe mental illness. We sought to test the hypothesis that B&EM patients experience more negative life events than their WB counterparts, and to examine the extent to which they attribute these events to discrimination. METHOD: Thirty-four WB, 78 African Caribbean (AC) and 35 other ethnic minority patients with psychotic illnesses, defined using Research Diagnostic Criteria, were asked to complete a Racial Life Event Questionnaire examining life events and perceptions of discrimination at baseline and 12 and 24 months later. RESULTS: African Caribbean patients experienced more 'Financial' life events across the study period, otherwise there were no significant differences between patient groups in number of life events experienced. The B&EM group collectively (n = 113), however, were significantly more likely than the WB group (n = 34) to attribute 'Assault', and 'Legal' life events to discrimination. The AC patient group were significantly more likely than the other two ethnic groups to attribute the 'Financial' and 'Health' life events they experienced to discrimination. The B&EM group was also significantly more likely, and particularly the AC patient group, to report that members of their own ethnic group are adversely affected by discrimination. Further analyses showed skin colour rather than ethnicity or nationality to be the major contributing factor to perception of discrimination; thus, the Irish (n = 11) had similar scores to the WB while Africans (n = 16) scored like the ACs. CONCLUSION: Our study shows that B&EM patients do not experience significantly more life events than WB patients; however, their perception of these events is clearly different, and significantly more often attributed to racism. It is reasonable to suppose that patients may be disinclined to utilise services they believe to be prejudiced against them on the basis of their skin colour, and service providers need to be aware of this in order to create health care services that B&EM patients feel confident to use.

Autoimmune diseases in the pedigrees of schizophrenic and control subjects.

Autoimmune diseases aggregate in individuals and within pedigrees, and it has been postulated that autoimmune mechanisms may account for a proportion of schizophrenia. Structured questionnaires were used to interview the mothers of 121 DSM-III-R schizophrenic patients and the mothers of 116 controls in order to determine the prevalence of schizophrenia and of autoimmune diseases in their pedigrees. Patients with a schizophrenic first degree relative were significantly more likely to also have a parent or sibling with an autoimmune disease (60% vs. 20%, OR = 6.1, 95% CI = 2.3-6.5, p = 0.0003). A significant excess of insulin dependent diabetes mellitus (IDDM) was present in the parents and siblings of schizophrenic patients (OR = 9.65, 95% CI = 1.3-429.2, p = 0.009). These findings suggest that autoimmune mechanisms may play a role in the aetiology of schizophrenia, particularly familial schizophrenia. Associations have been established between autoimmune diseases and the HLA encoding genes of the major histocompatibility complex on chromosome six, and it may be that some of the genetic liability to schizophrenia involves these genes.

Family history of autoimmune diseases in psychosis.

The mothers of 101 psychotic patients and 116 normal controls were interviewed using a semi-structured questionnaire designed to determine the presence or absence of autoimmune disorders in first degree relatives of the probands. Thyrotoxicosis and insulin-dependent diabetes mellitus were significantly more common in the relatives of the psychotic patients than in the control relatives; in particular thyrotoxicosis was more frequent in the mothers of patients (11%) than the mothers of controls (2.6%). None of the examined characteristics of the patients, including RDC-diagnosis, family history of psychosis, age at onset of psychosis and winter birth, was predictive of thyrotoxicosis and insulin-dependent diabetes mellitus in relatives.