The National Adult Reading Test as a measure of premorbid IQ in schizophrenia

OBJECTIVES

To investigate the validity of the NART as an estimate of premorbid IQ in schizophrenia.

DESIGN

A within-in participants, follow-back design was adopted.

METHODS

A sample of adults with schizophrenia who had presented to psychiatric services and had a measure of IQ routinely taken during childhood were traced and subject to follow-up WAIS-R and NART IQ assessment (N = 24). Measures of current IQ and NART estimated premorbid IQ were compared with the measure of IQ taken 'premorbidly', i.e. in childhood.

RESULTS

There were no significant differences between childhood and adult measures of IQ. However there were significant differences between these two indices and NART estimated IQ, particularly where IQ deviated from general population means. The Vocabulary subtest of the WAIS-R performed better as an estimate of both premorbid and current IQ in the sample.

CONCLUSION

Use of a word-reading test such as the NART to predict past levels of intellectual function should proceed with caution, particularly where IQ does not fall in the 'average' category. Use of more than one index of prior level of function is recommended.

No association between breast-feeding and adult psychosis in two national birth cohorts

BACKGROUND

It has been proposed that breast-feeding might have a protective effect against the development of adult schizophrenia.

AIMS

To test this hypothesis.

METHOD

Using prospective data from two UK national birth cohorts, the feeding histories of those who later developed schizophrenia were compared with the remaining population at risk. Analyses in each cohort were considered to be independent tests of the hypothesis.

RESULTS

There were no differences in feeding histories. In the 1946 birth cohort (n = 4447) 30 cases of DSM-III-R schizophrenia arose by age 43; 24.1% of cases v. 23.6% of controls were entirely bottle-fed; 17.3% v. 12.3% were breast-fed for under 1 month; 58.6% v. 64.1% were breast-fed beyond 1 month. In the 1958 cohort (n = 18,856), 40 cases of CATEGO nuclear schizophrenia arose by age 28; 24.1% of cases v. 31.7% of controls were entirely bottle-fed; 27.6% v. 24.9% were breast-fed for under 1 month; 48.3% v. 43.4% were breast-fed beyond 1 month.

CONCLUSIONS

These findings provide no evidence of any effect of breast-feeding in protecting against the risk of later schizophrenia.

A new class of antituberculosis agents

Long-chain lipid envelopes are characteristic of mycobacteria such as those that cause tuberculosis and leprosy. Inhibition of fatty acid synthesis or elongation is a strategy demonstrated to be clinically effective against M. tuberculosis. A new class of compounds designed to inhibit the beta-ketoacyl synthase reaction of fatty acid synthesis has been developed. Of >30 compounds described, the most active were acetamides containing alkylsulfonyl substituents. Inhibitory activities were acutely sensitive to net charge, chain length, and degree of unsaturation. The most active compound 5 (alkyl = C(10)) contained a single methylene spacer between the sulfone and carboxamide and exhibited an MIC of 0.75-1.5 microg/mL, comparable to first-line antituberculosis drugs. These compounds are species-specific, exhibiting no significant activity against bacterial species other than M. tuberculosis and closely related strains. The synthesis, biological activity, and specificity of these compounds are described.

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.

Three-year outcome of first-episode psychoses in an established community psychiatric service

BACKGROUND

Changes in service provision, secular trends in substance misuse and changing social structures might affect outcome in psychosis.

AIMS

To assess the three-year outcome of an inception cohort of first-episode psychoses treated in a modern, community-oriented service; to compare outcomes with an earlier cohort treated in hospital-based care; and to examine the predictive validity of ICD-10 diagnostic criteria.

METHOD

Three-year follow-up (1995-1997) of an inception cohort of first-episode psychoses and comparison with two-year follow-up (1980-1982) of the Determinants of Outcome of Severe Mental Disorders (DOSMED) Nottingham cohort.

RESULTS

On most outcome measures, non-affective psychoses had a worse outcome than affective psychoses. Affective psychoses had better outcome than previously reported. Substance-related psychoses had very poor occupational outcome. Similar proportions of the current and DOSMED cohort were in remission but the former were rated as having greater disability.

CONCLUSIONS

In a modern community service, 30-60% of patients with first-episode psychoses experience a good three-year outcome. The ICD-10 criteria have good predictive validity.

Non-linear relationship between an index of social deprivation, psychiatric admission prevalence and the incidence of psychosis

BACKGROUND

Indicators of population socio-economic disadvantage expressed as weighted deprivation indices show strong relationships with mental health and underpin national funding of psychiatric services. A new index of social deprivation, the Mental Illness Needs Index, has been devised specifically to predict need for psychiatric services. Its validity has not been established outside the area in which it was developed.

METHODS

We explored the relationship between the Mental Illness Needs Index and two alternative indicators of need for mental health services: the prevalence of psychiatric admission for electoral wards in Nottingham (calculated from Hospital Episode Statistics for the years 1992 and 1993) and ward-based incidence rates for psychosis (ICD-10 F1X-F33). Relationships were explored graphically using local regression models, and estimated using Generalized Linear and Additive Models, and Poisson regression.

RESULTS

Social deprivation was strongly related to admission prevalence and psychosis incidence (Spearman's rho 0.63 and 0.44 respectively). Neither admission prevalence, nor the incidence of psychosis were linearly related to social deprivation. Areas with above average social deprivation had both more new cases of psychoses and a higher proportion of the population admitted than expected from a linear function.

CONCLUSIONS

Application of a linear function to funding gradients may underfund high and low need areas and overfund median need areas. Improving the precision of estimates of the relationship between social deprivation and need for services is crucial to more equitable resource allocation.

Diagnostic stability of first-episode psychosis. Comparison of ICD-10 and DSM-III-R systems

BACKGROUND

The temporal stability of a diagnosis is one measure of its predictive validity.

AIMS

To measure diagnostic stability in first-episode psychosis using ICD-10 and DSM-III-R.

METHOD

Between 1992 and 1994 we ascertained a cohort of persons with first-episode psychosis (n = 168), assigning to each a consensus diagnosis. At three-year follow-up, longitudinal consensus diagnoses, blind to onset diagnoses, were made. Stability was measured by the positive predictive values (PPVs) of onset diagnoses. For onset schizophrenia, we also calculated sensitivity, specificity and concordance (kappa).

RESULTS

First-episode ICD-10 and DSM-III-R schizophrenia had a PPV of over 80% at three years. Over one-third of cases with ICD-10 F20 schizophrenia at three years had non-schizophrenia diagnoses at onset. Manic psychoses showed the highest PPV (91%). For onset schizophrenia, both systems had high specificity (ICD-10: 89; DSM-III-R: 93%), but low sensitivity (ICD-10: 64%; DSM-III-R: 51%) and moderate concordance (ICD-10: 0.54; DSM-III-R: 0.46).

CONCLUSIONS

Bipolar disorders and schizophrenia showed the highest stability. DSM-III-R schizophrenia did not have greater stability than ICD-10 schizophrenia.

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.

Specificity of developmental precursors to schizophrenia and affective disorders

Developmental precursors to adult disorder suggest that components of their causes operate in early life. Several birth cohort studies have relevant prospective data and are reporting results for schizophrenia and affective disorder. These studies suggest that developmental findings are not specific for schizophrenia, although the magnitude of effects tends to be greater compared with affective disorder. These findings are reviewed and some methodological issues discussed. Apparent lack of specificity may mask underlying unique mechanisms and causes. In terms of a future public health perspective involving prediction and prevention, a lack of specificity may be advantageous.

Early risk factors and adult person--environment relationships in affective disorder

BACKGROUND

Lower cognitive ability, higher neuroticism and symptoms of anxiety and depression in childhood predict non-psychotic disorder in adulthood. This study examined whether these early risk factors act by modifying relationships with life events close to disease onset in adulthood.

METHODS

Childhood measures of neuroticism (N) (including maternal N), cognitive ability (CA) and symptoms of anxiety and depression were measured in a national British birth cohort of 5362 individuals born in the week 3-9 March, 1946. At ages 36 and 43 years, mental state examinations were carried out by trained interviewers, and subjects were asked about the occurrence of stressful life events in the previous year (SLE).

RESULTS

The effect of aggregated SLEs on mental health was greater in women, in individuals with higher childhood N and poorer childhood mental health. Higher maternal N was also associated with greater sensitivity to SLEs, independent of subject's N, suggesting possible familial transmission of vulnerability. In addition, higher childhood N predicted, independent of later mental health, greater likelihood of reported exposure to SLEs. In general, individuals with higher childhood CA also reported more SLEs.

CONCLUSIONS

The results suggest that early risk factors for affective disorder exert effects by modifying person-environment relationships close to onset of adult symptoms. Sensitivity to life events may be transmitted from parents to offspring; psychopathological continuity over the life-span may be explained in part by continuity of altered stress sensitivity.

Precursors to schizophrenia: do biological markers have specificity?

This review addresses childhood antecedents and biological markers of schizophrenia within a neurodevelopmental framework. General-population birth-cohort studies illustrate delays in developmental milestones, abnormalities in social functioning, and cognitive deficits throughout childhood, adolescence, and early adulthood. Abnormal neurology and motor dysfunction have been measured in children prior to the onset of schizophrenia, at first onset of disease, and in those with chronic schizophrenia. Minor physical anomalies, a static marker of developmental disturbance, are also increased in schizophrenia. None of these factors has high specificity for this disorder. This review examines the associations between these precursors and some etiological factors for schizophrenia, comments on their lack of complete specificity to this psychotic syndrome, and considers their usefulness as predictors of risk.

Schizophrenia as a long-term outcome of pregnancy, delivery, and perinatal complications: a 28-year follow-up of the 1966 north Finland general population birth cohort

OBJECTIVE

The 1966 North Finland general population birth cohort was studied to determine whether abnormalities during pregnancy, delivery, and the neonatal period are associated with adult-onset schizophrenia.

METHOD

The authors included all 11,017 subjects alive in Finland at age 16. For each individual, standardized assessments made during pregnancy, delivery, and infancy were linked to national psychiatric case registers covering the period up to age 28. Subjects with DSM-III-R schizophrenia were identified by using a two-stage screen that included perusal of individual case records. Associations (adjusted odds ratios) between schizophrenia and specific pregnancy, delivery, and neonatal characteristics were calculated.

RESULTS

Within this cohort, 76 cases of DSM-III-R schizophrenia arose by age 28 years; 51 (67.1%) of these persons were men. Demographic characteristics and previous obstetric histories of the mothers were similar in the case and unaffected comparison groups, although the former were more likely to have been more depressed than usual during pregnancy. Low birth weight (< 2500 g) and the combination of low birth weight and short gestation (< 37 weeks) were more common among the schizophrenic subjects. Being small for gestational age (< 10th percentile) was not more common. Of 125 survivors of severe perinatal brain damage, six (4.8%) later developed schizophrenia.

CONCLUSIONS

The spectrum of adverse outcomes after fetal and perinatal insults unfolded beyond childhood and included adult-onset schizophrenia. The findings have implications for understanding the mechanisms involved in the development of schizophrenia and, possibly, for its prevention.

In vivo photoactivation of caged-thrombin

Aberrant ocular neovascularization is a major cause of blindness in the world. Abnormal blood vessels in the eye may produce corneal opacification, corneal transplant rejection, neovascular glaucoma, vitreous hemorrhage, traction retinal detachment, and subretinal scars from choroidal neovascular membranes (1-5). Light-induced clotting of blood within these abnormal vessels could provide a novel method for the ablation of deleterious neovascularization. Thrombin is a serine proteinase that participates in the final stages of the coagulation cascade. An inhibitor of thrombin, p-Amidinophenyl-(E)-4-diethylamino-2-hydroxy-alpha-methylcinnamate hydrochloride, MeCINN (1), covalently attaches to the active site serine hydroxyl, inhibiting or caging, the enzyme. Photolysis of the caged-thrombin in vitro causes a trans-cis isomerization of MeCINN which leads to regeneration of active enzyme and cleaving of fibrinogen into fibrin (6). Using a rabbit model of corneal neovascularization, we found that light at 366 nm safely and effectively photoactivates intravenous caged-thrombin and produces localized thrombosis in vivo. These results suggest that intravascular photoactivation of caged-thrombin could be used to occlude abnormal blood vessels in the human eye.

Schizophrenia and the myth of intellectual decline

OBJECTIVE

The authors' goal was to investigate the issue of intellectual deterioration in schizophrenia.

METHOD

They examined the childhood IQs of adult patients with schizophrenia who had attended a child psychiatry service where measurement of intelligence was routine. Follow-up IQs of 34 of these patients were obtained an average of 19.4 years later.

RESULTS

The mean child and adult IQs were greater than one standard deviation lower than those of the general population. There were no significant differences between the child and adult IQs, however, suggesting that the impairment in intelligence during childhood was stable over the follow-up period.

CONCLUSIONS

The deficit in intellectual function observed in these patients, and reported in the literature, is lifelong and predates the onset of schizophrenia.

Comparison of the family history with the family study method: report from the Camberwell Collaborative Psychosis Study

We assessed the accuracy of the family history (FH-RDC) and family study (SADS-L) methods for obtaining information about the presence of psychopathology in 274 first-degree relatives of patients with psychotic disorders. The family history method had only modest sensitivity, 40.8% for affective disorders and 58.6% for psychotic disorders, but high specificity, 94.1% for affective disorders and 98.7% for psychotic disorders. For both disorders, sensitivity was higher for relatives who had had previous psychiatric admissions. However, with the family study method, we found that relatives with affective disorder were more likely to be interviewed than those relatives with other disorders. Hence, the family study method may be prone to selection bias that distorts morbid risk estimates. We conclude that the best way of collecting information regarding family psychopathology is to interview directly as many relatives as possible and to collect supplementary family history information on unavailable relatives.

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.

Do obstetric complications cause the earlier age at onset in male than female schizophrenics?

We compared the age at onset of 184 patients with functional psychoses with and without a history of obstetric complications (OCs) as defined by the scale of Lewis et al. (1989). OCs had no significant influence on the age at onset in those patients who had affective psychoses or were non-white. There were 73 white patients with a DSM-III-R diagnosis of schizophrenia. The mean age at onset of those 25 who had a history of at least one definite OC was 2.6 years earlier than that of the 48 patients with no history of OCs. This effect was entirely due to the male patients with histories of OCs who had, on average, a 3.5 years earlier age at onset. There were no gender differences in age at onset among schizophrenics without a history of OCs. We suggest that a subgroup of male patients with a history of OCs is responsible for the earlier age at onset in male compared to female schizophrenics.

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.

Mixed-handedness in patients with functional psychosis

BACKGROUND

An excess of non-right-handedness has been shown among patients with schizophrenia. However it is not clear whether this finding can be accounted for by an increase in left-handedness, mixed-handedness or both. It is not known whether atypical patterns of hand preferences occur in other functional psychotic illnesses.

METHOD

The Annett hand preference questionnaire was administered to patients with schizophrenia (n = 120); affective psychosis (n = 55); schizoaffective psychosis (n = 41), and control subjects (n = 86). Handedness was classified into three categories: right, mixed and left-handedness.

RESULTS

The hand preference patterns of patients with functional psychotic illnesses were not significantly different from controls. Patients with schizophrenia showed a non-significant excess of mixed-handedness compared with controls. Patients with schizophrenia and affective psychosis showed a non-significant decrease in left-handedness compared with controls.

CONCLUSIONS

Although our results showed a trend in the hypothesised direction, we failed to demonstrate that patients with psychotic illness differed from controls on self-reported hand preference patterns.

A factor analytic study of symptoms in acute schizophrenia

The three-syndrome model of schizophrenic phenomenology has been well established in chronic illness. We report an attempt to replicate this concept in a sample of acutely unwell schizophrenic patients. Factor analysis was performed using PSE data collected within a week of admission from 114 patients who met DSMIII(R) diagnostic criteria for schizophrenia. Four main factors accounted for 58% of the variance. The first two factors closely resembled Liddle's disorganisation and psychomotor poverty syndromes. Hallucinations and delusions loaded separately under the third and fourth factors. To examine the validity of these four syndromes, the relationships between factor scores and other clinical data were examined. The disorganisation syndrome was associated with a history of multiple past admissions and a longer lifetime duration of in-patient treatment.

Minor physical anomalies in psychoses: associations with clinical and putative aetiological variables

This study of patients with functional psychoses set out to examine associations between minor physical anomalies (MPAs) and demographic, clinical, CT scan measures, and putative aetiological variables. 157 psychotic patients had minor physical anomalies assessed using a modified Waldrop scale. RDC diagnoses for these patients were: schizophrenia (n = 79), schizoaffective disorder (n = 31), mania (n = 24), major depression (n = 13), unspecified functional psychosis (n = 8), other organic psychosis (n = 2). 63 healthy white controls were also assessed with the modified Waldrop scale. Minor physical anomalies were not associated with any particular diagnosis. For white subjects, patients had significantly more MPAs than well controls. Anomalies of the palate were the most frequent item reported in patients and controls. For males, there was a weak association between the presence of MPAs and positive family history of a major psychiatric disorder. Those with MPAs required more frequent and longer psychiatric admissions, and showed impaired ability on a test sensitive to left parietal system function. Within the patient group, there were no associations between MPAs and gender, age at onset, negative symptoms, premorbid level of functioning, estimated premorbid intelligence, pregnancy and birth complications, and selected CT variables. Minor physical anomalies are found in a range of functional psychoses. There may be overlap between the various genes that predispose to psychiatric illness (especially in males) and those genes that predispose to developmental instability.