In the last 10 years a consensus has developed that the symptoms of psychosis may be better understood by linking the steps between the phenomenological experiences and social, psychological and neurobiological levels of explanation. Cognitive models of psychosis are an important link in this chain. They provide a psychological description of the phenomena from which hypotheses concerning causal processes can be derived and tested; social, individual, and neurobiological factors can then be integrated via their impact on these cognitive processes. In this paper, we set out the cognitive processes that we think lead to the formation and maintenance of the positive symptoms of psychosis and we attempt to integrate into our model research in social factors. If this model proves useful, a fuller integration with the findings of biological research will be required (Frith, 1992).

Background. Although poor language test performance has been documented in schizophrenia, its relationship to formal thought disorder remains unclear.

Method. Forty schizophrenic patients were administered eight language tests and, under blind conditions, rated for formal thought disorder. Measures of general intellectual function were also obtained.

Results. Performance on all language tests was significantly correlated with the general intellectual measures. Three language test scores also showed significant correlations with formal thought disorder scores. Multiple regression and analysis of intellectually preserved patients suggested particular associations of formal thought disorder with semantic comprehension and picture description.

Conclusions. General intellectual impairment is an important determinant of poor language test performance in schizophrenia, but presence of formal thought disorder may also contribute. A higher-order semantic deficit may be particularly relevant to both linguistic impairment and formal thought disorder.

Background. Several studies have examined the ability of schizophrenic patients to represent mental states (‘theory of mind'; ToM). There is consensus that some patients have impaired ToM, but there is disagreement about the relation between ToM and symptomatology, and about the severity and specificity of the deficit.

Methods. Two first-order and one second-order false belief tests of ToM were given to groups of schizophrenic patients and psychiatric and normal controls. The relation between ToM and symptomatology was explored using regression and symptom subgroup analyses. Severity was investigated by using the same task methodology as in autism research, to enable direct comparison with that disorder. Specificity was investigated using matched control tasks which were as difficult as the ToM tasks, but did not require ToM.

Results. Symptom subgroup analysis showed that schizophrenic patients with behavioural signs were impaired relative to controls on ToM, and that remitted patients and a single case with passivity symptoms performed as well as controls. Regression analysis showed that ratings of behavioural signs predicted impaired ToM in schizophrenia. There was weak evidence that a subgroup with paranoid symptoms had ToM impairments, although these were associated with low IQ. Schizophrenic patients only showed ToM deficits on the second-order task. No impairments appeared on the matched control tasks which did not require ToM.

Conclusions. There is a clear association between ToM impairment and behavioural signs in schizophrenia. Deficits in paranoid patients are harder to detect with current tasks and may be compensated for by IQ-dependent problem-solving skills. ToM impairments in schizophrenia are less severe than in autism, but are specific and not a reflection of general cognitive deficits.

Background. A number of studies have suggested that indirect semantic priming is enhanced in thought-disordered schizophrenics. However, research on direct semantic priming has produced conflicting results. The aim of the present study was to resolve some of the ambiguities of previous findings.

Methods. For the present study, 44 schizophrenic patients were split according to the presence of associative loosening into a positive thought-disordered (TD) and non-positive thought-disordered (NTD) group. Thirty healthy subjects and 36 psychiatric patients served as controls.

Results. Schizophrenics displayed increased indirect semantic priming compared with psychiatric controls. When subtyping the sample, TD-patients exhibited significantly enhanced indirect semantic priming compared with healthy and psychiatric controls as well as NTD-patients. Overall slowing was found to be independent of priming effects. Medication, age and chronicity of the schizophrenic illness did not modulate priming.

Conclusions. In line with Spitzer and Maher it is inferred that disinhibited semantic networks underlie formal thought disorder in schizophrenia. For future research, it would be appropriate to: employ indirect semantic priming rather than direct semantic priming conditions; and, pay more attention to potential moderators of the priming effect, most importantly, the prime display duration and the length of the stimulus onset asynchrony.

Background. Head injury has been reported to increase the likelihood of the development of schizophrenia-like psychosis (SLP), but its features and risk factors have been insufficiently investigated.

Method. Between 1987 and 1997, we examined 45 referred patients with SLP following brain trauma. These subjects were matched with 45 head-injured subjects without SLP on age (current and at injury) and gender, and their case records reviewed systematically. The groups were compared and logistic regression analyses performed.

Results.The psychoses had a mean age of onset of 26·3 years, a mean latency of 54·7 months after head injury, usually a gradual onset and a subacute or chronic course. Prodromal symptoms were common and depression often present at onset. Paranoid delusions and auditory hallucinations were the predominant features, with formal thought disorder, catatonic features and negative symptoms being uncommon. The SLP group had more widespread brain damage on neuroimaging, especially in the left temporal and right parietal regions, and were more impaired cognitively. Fewer (non-significantly) SLP subjects had epilepsy which was more likely to be well-controlled in this group. On regression analysis, a positive family history of psychosis and duration of loss of consciousness were the best predictors of SLP.

Conclusions. Head injury-related psychosis is usually paranoid-hallucinatory and subacute or chronic in its presentation. A genetic predisposition to schizophrenia and severity of injury with significant brain damage and cognitive impairment may be vulnerability factors.

Background. We used functional MRI to examine the functional anatomy of inner speech and different forms of auditory verbal imagery (imagining speech) in normal volunteers. We hypothesized that generating inner speech and auditory verbal imagery would be associated with left inferior frontal activation, and that generating auditory verbal imagery would involve additional activation in the lateral temporal cortices.

Methods. Subjects were scanned, while performing inner speech and auditory verbal imagery tasks, using a 1.5 Tesla magnet.

Results. The generation of inner speech was associated with activation in the left inferior frontal/insula region, the left temporo-parietal cortex, right cerebellum and the supplementary motor area. Auditory verbal imagery in general, as indexed by the three imagery tasks combined, was associated with activation in the areas engaged during the inner speech task, plus the left precentral and superior temporal gyri (STG), and the right homologues of all these areas.

Conclusions. These results are consistent with the use of the ‘articulatory loop' during both inner speech and auditory verbal imagery, and the greater engagement of verbal self-monitoring during auditory verbal imagery.

Background. Possible adverse health effects due to mercury released by amalgam fillings have been discussed in several studies of patients who attribute various symptoms to the effects of amalgam fillings. No systematic relation of specific symptoms to increased mercury levels could be established in any of these studies. Thus, a psychosomatic aetiology of the complaints should be considered and psychological factors contributing to their aetiology should be identified.

Methods. A screening questionnaire was used to identify subjects who were convinced that their health had already been affected seriously by their amalgam fillings (N = 40). These amalgam sensitive subjects were compared to amalgam non-sensitive subjects (N = 43). All participants were subjected to dental, general health, toxicological and psychological examinations.

Results. The two groups did not differ with respect to the number of amalgam fillings, amalgam surfaces or mercury levels assessed in blood, urine or saliva. However, amalgam sensitive subjects had significantly higher symptom scores both in a screening instrument for medically unexplained somatic symptoms (SOMS) and in the SCL-90-R Somatization scale. Additionally, more subjects from this group (50% versus 4·7%) had severe somatization syndromes. With respect to psychological risk factors, amalgam sensitive subjects had a self-concept of being weak and unable to tolerate stress, more cognitions of environmental threat, and increased habitual anxiety. These psychological factors were significantly correlated with the number and intensity of the reported somatic symptoms.

Conclusions. While our results do not support an organic explanation of the reported symptoms, they are well in accord with the notion of a psychological aetiology of the reported symptoms and complaints. The findings suggest that self-diagnosed ‘amalgam illness’ is a label for a general tendency toward somatization.

Background. Previous research suggests that children are a high risk group vulnerable to the effects of chronic noise exposure. However, questions remain about the nature of the noise effects and the underlying causal mechanisms. This study addresses the effects of aircraft noise exposure on children around London Heathrow airport, in terms of stress responses, mental health and cognitive performance. The research also focuses on the underlying causal mechanisms contributing to the cognitive effects and potential confounding factors.

Methods. The cognitive performance and health of 340 children aged 8–11 years attending four schools in high aircraft noise areas (16h outdoor Leq>66dBA) was compared with children attending four matched control schools exposed to lower levels of aircraft noise (16h outdoor Leq<57dBA). Mental health and cognitive tests were group administered to the children in the schools. Salivary cortisol was measured in a subsample of children.

Results. Chronic aircraft noise exposure was associated with higher levels of noise annoyance and poorer reading comprehension measured by standardized scales with adjustments for age, deprivation and main language spoken. Chronic aircraft noise was not associated with mental health problems and raised cortisol secretion. The association between aircraft noise exposure and reading comprehension could not be accounted for by the mediating role of annoyance, confounding by social class, deprivation, main language or acute noise exposure.

Conclusions.These results suggest that chronic aircraft noise exposure is associated with impaired reading comprehension and high levels of noise annoyance but not mental health problems in children.

Background. Many, but not all, studies have reported that job strain is related to cardiovascular morbidity and mortality. To date, this relationship has not been tested on an English full population sample. This study examines whether the demand–control model of job strain contributes to our understanding of the determinants of coronary heart disease.

Methods. The analysis uses data from 4350 working men aged 20–64 in the 1993 Health Survey for England. Job demand and control characteristics were determined by questionnaire. Several health outcomes were examined: self-rated health; psychiatric health; angina and possible myocardial infarction, measured by the Rose questionnaire; doctor-diagnosed heart disease; any heart disease. The relationship between job strain and the health outcomes was determined by logistic regression analyses after controlling for known confounders.

Results. Those in high strain jobs consistently reported poorer health on all measures than men with lower strain. Similarly, men reporting low job strain were least likely to report poor health in 5/6 health outcomes. Those with intermediate levels of strain tended to have intermediate prevalence rates for poor health. The pattern of association between job strain and the CHD was independent of coronary risk factors.

Conclusions. The analyses broadly support Karasek's demand–control model of job strain. Health selection into low strain jobs may account for the lack of an association between job strain and doctor diagnosed heart disease while independent associations between job strain and all CHD measures considered together indicate that job strain may have aetiological significance for heart disease.

Background. Marital status is a strong correlate of psychiatric morbidity in adulthood, but debate continues on how far this association reflects causal influences or selection effects based on prior psychological characteristics.

Method. Prospective data from the National Child Development Study were used to examine effects of adolescent emotional and behavioural problems on transitions into and out of first partnerships, and their implications for psychiatric morbidity at age 33.

Results. Emotional and behavioural problems in adolescence showed systematic links with early partnership transitions (age at partnership formation, type of first partnership, and risks of first partnership breakdown). More detailed tests suggested that these effects only accounted for a modest proportion of the associations between partnership status and psychiatric morbidity at age 33.

Conclusions. In a non-referred community sample selection effects associated with adolescent emotional and behavioural problems appear to play only a modest role in links between partnership status and adult mental health.

Background. This study examined the relationship between potential childhood risk factors and social phobia in an epidemiological sample. Identifying risk factors such as childhood adversities can often uncover important clues as to the aetiology of a disorder. This information also enables health care providers to predict which individuals are most likely to develop the disorder.

Methods. Data came from the Mental Health Supplement to the Ontario Health Survey of a survey of 8116 Canadian respondents, aged 15–64. Social phobia was diagnosed using the Composite International Diagnostic Interview (CIDI). Childhood risk factors were assessed by a series of standardized questions.

Results. A positive relationship was observed between social phobia and lack of close relationship with an adult, not being first born (in males only), marital conflict in the family of origin, parental history of mental disorder, moving more than three times as a child, juvenile justice and child welfare involvement, running away from home, childhood physical and sexual abuse, failing a grade, requirement of special education before age 9 and dropping out of high school. Many of these variables remained significant after controlling for phobias, major depressive disorder and alcohol abuse. The data also suggest that some childhood risk factors may interact with gender to influence the development of social phobia.

Conclusions. Although an association was detected between social phobia and childhood risk factors, naturalistic prospective studies are needed to clarify the aetiological importance of these and other potential risk factors for the disorder.

Background. The aim of this pilot study was to examine which unique factors (genetic and environmental) increase the risk for developing anorexia nervosa by using a case–control design of discordant sister pairs.

Methods. Forty-five sister-pairs, one of whom had anorexia nervosa and the other did not, were recruited. Both sisters completed the Oxford Risk Factor Interview for Eating Disorders and measures for eating disorder traits, and sib-pair differences. Blood or cheek cell samples were taken for genetic analysis. Statistical power of the genetic analysis of discordant same-sex siblings was calculated using a specially written program, DISCORD.

Results. The sisters with anorexia nervosa differed from their healthy sisters in terms of personal vulnerability traits and exposure to high parental expectations and sexual abuse. Factors within the dieting risk domain did not differ. However, there was evidence of poor feeding in childhood. No difference in the distribution of genotypes or alleles of the DRD4, COMT, the 5HT2A and 5HT2C receptor genes was detected. These results are preliminary because our calculations indicate that there is insufficient power to detect the expected effect on risk with this sample size.

Conclusions. A combination of intrinsic and extrinsic factors increases the risk of developing anorexia nervosa. It would, therefore, be informative to undertake a larger study to examine in more detail the unique genetic and environmental factors that are associated with various forms of eating disorders.

Background. Dutch (ex-)servicemen were deployed in the 1992–3-peace operation UNTAC in Cambodia. Since their return, they have voiced concerns about the health consequences of their service and they have reported symptoms such as fatigue and cognitive problems. The natural course of symptoms in Dutch Cambodia veterans was evaluated in a prospective study.

Methods. At 18-months follow-up, a questionnaire was sent to 354 veterans who met a set case definition for symptoms in Cambodia veterans or who had sub-threshold scores. Initial measurement of fatigue severity, psychological well-being, depression, post-traumatic stress disorder, trait-anxiety, self-efficacy and causal attributions, was used to evaluate predictors for self-reported improvement and low levels of fatigue at follow-up.

Results. At follow-up, 19% of the respondents reported complete recovery, 20% felt much better, 57% had the same complaints and 4% had become worse compared with their initial assessment. Self-reported improvement and less severe fatigue at follow-up were predicted by less severe fatigue at initial assessment and more perceived control over symptoms.

Conclusions. Self-reported improvement was reported in a considerable percentage of Cambodia veterans, whereas another substantial percentage of Cambodia veterans continued to suffer with severe levels of fatigue and related symptoms. Predictors of improvement in Cambodia veterans and patients with chronic fatigue syndrome show similarities and also seem to bear importance for Gulf War veterans.

Background. Mental disorders often begin during the formative years of education. They may disrupt education and lead to social underachievement.

Methods. We examined the impact of mental disorders treated in hospital (ages 16–29) on educational attainment up to 31 years in the Northern Finland 1966 Birth Cohort (N = 10581). People discharged due to mental illness were grouped by DSM-III-R diagnoses (of schizophrenia, other psychoses and non-psychotic disorders) and were compared with those having no such hospital treatment. Associations between diagnoses and educational outcome (completion of basic level, upper secondary or tertiary education) were analysed stratified by age at onset (early onset < 22 years v. later), and adjusted for confounding by perinatal risk, early motor development, maternal education, family structure, parental social class, and school achievement using prospective data from earlier assessments and logistic regression analysis.

Results. Twelve per cent of the comparison group completed basic level education, 62% upper secondary, and 26% tertiary education. People with early onset disorder tended to stagnate in the basic level. Early onset schizophrenia and all non-psychotic cases had 3- to 6-fold adjusted odds for this outcome. Many with early onset schizophrenia completed secondary education, but none completed the tertiary level. Hospitalization for non-psychotic disorder increased the risk of underachievement in tertiary education for those with early onset.

Conclusions. Mental disorder treated in hospital truncates education. Failure to complete higher education may contribute to the ‘social exclusion’ of the mentally ill through reduced opportunities in later occupational life and failure to accumulate social capital.

Background. There is as yet little evidence available regarding the long-term outcomes of people with severe and enduring mental illness who have been cared for primarily in the community.

Methods. A 12-year follow-up was carried out of the clinical and social problems and needs for care of a group of long-term mentally ill patients (N=81) who were heavy users of psychiatric services when originally assessed in the Camberwell High Contact Survey between 1983 and 1985. The MRC Needs for Care Assessment Schedule used in the original baseline study was repeated at follow-up.

Results. The clinical and social functioning of the group had remained relatively stable, with high levels of problems and needs at both time points and little evidence of significant improvement or deterioration. The majority had remained in contact with services. There was some increase in levels of unmet as well as met needs, and a decrease in ratings of unmeetable needs, which may have been due to changes in clinical practice.

Conclusion. The challenge for current service providers is not only to keep clients stable, but also to help improve the clinical and social functioning of people who may no longer be the highest priority of current community mental health services. This could be approached by identifying the continuing needs of this group, and persistently delivering active treatments.

Background. Twin studies have concluded that there is a substantial genetic contribution to the aetiology of eating disorders. The aim of the present study was to estimate the genetic contribution to the aetiology of self-reported eating disorders in a sample of representative twins.

Method. A population cohort of 34142 young Danish twins was screened for eating disorders by a mailed questionnaire.

Results. Concordance rates differed significantly across monozygotic and dizygotic twin pairs for broadly defined self-reported anorexia nervosa and bulimia nervosa. Heritability estimates of 0·48, 0·52 and 0·61 respectively were estimated for narrow and broad definitions of self-reported anorexia nervosa and for self-reported bulimia nervosa.

Conclusions. There is a genetic contribution to the aetiology of self-reported eating disorders in the general population. The relationship between self-reported and clinical eating disorder remains to be examined.

Background. Much of the interest in hopelessness stems from the key role it plays in the prediction of suicidal behaviour. To measure hopelessness, Beck et al.(1974)developed a 20-item scale (BHS), applied exploratory factor analysis and argued that the scale measures three specific components (affective, motivational and cognitive). Subsequent exploratory factor analyses identified two, three or more factors underlying the scale.

Method. Several confirmatory factor analyses (LISREL) were run on data on 324 suicide attempters in Sweden in order to test the hypothesized factorial structures and to investigate the psychometric properties of the individual items.

Results. Neither three- nor two-factor models fitted the data. A simpler structure was sufficient to account for the observed correlations between most of the items. This led to the development of several variants of a one-factor model, each a combination of affective, motivational and cognitive items. The number of items varied between four and 15.

Conclusions. Our findings suggest that most of the items (15) of Beck's Hopelessness Scale measure one factor. They further suggest that the number of items could considerably be reduced. A four-item scale produced an excellent fit. It includes positive and negative items describing the perception of the future in terms of success, darkness, lack of opportunity and faith. It might even be possible to replace the total scale with one item only, ‘my future seems dark to me’.