Recent research shows that psychotic symptoms, or psychotic-like experiences (PLEs), are reported not only by psychosis patients but also by healthy members of the general population. Healthy individuals who report these symptoms are considered to represent a non-clinical psychosis phenotype, and have been demonstrated to be at increased risk of schizophrenia-spectrum disorder. Converging research now shows that this non-clinical psychosis phenotype is familial, heritable and covaries with familial schizophrenia-spectrum disorder. A review of the research also shows that the non-clinical phenotype is associated extensively with schizophrenia-related risk factors, including social, environmental, substance use, obstetric, developmental, anatomical, motor, cognitive, linguistic, intellectual and psychopathological risk factors. The criterion and construct validity of the non-clinical psychosis phenotype with schizophrenia demonstrates that it is a valid population in which to study the aetiology of psychosis. Furthermore, it suggests shared genetic variation between the clinical and non-clinical phenotypes. Much remains to be learned about psychosis by broadening the scope of research to include the non-clinical psychosis phenotype.

This study confirms the validity of a Spanish version of the General Health Questionnaire in its scaled 28-item version. The screening instrument was tested on a sample of 100 patients attending an internal medicine out-patient clinic, who were examined independently by psychiatrists standardized in the use of the Clinical Interview Schedule (CIS). The questionnaire correctly identified 85% of “cases” with a cutting score of 6/7 (sensitivity 76·9%, specificity 90·2%), and 83% of cases with a cutting score of 5/6 (sensitivity 84·6%, specificity 82%), suggesting a discriminative power almost as good as the Spanish GHQ-60. It has the important advantage of being considerably shorter and, although the 4 subscales are by no means independent, its concurrent validity with CIS ratings suggests that they provide additional information concerning anxiety and depression.

The construction and development of an inventory of 69 questions dealing with the subjective assessment of obsessional traits and symptoms is described. A card-sorting procedure requiring supervision is used, which gives rise to information about feelings of resistance and interference with other activities, in addition to the straightforward answers to the questions. The resulting scores are shown to differentiate well between a group of selected obsessional patients and normals. The problem of to what extent replies to apparently specific questions in inventories and questionnaires can be interpreted as having only general significance is discussed.

The idea that some phenotypes bear a closer relationship to the biological processes that give rise to psychiatric illness than diagnostic categories has attracted considerable interest. Much effort has been devoted to finding such endophenotypes, partly because it is believed that the genetic basis of endophenotypes will be easier to analyse than that of psychiatric disease. This belief depends in part on the assumption that the effect sizes of genetic loci contributing to endophenotypes are larger than those contributing to disease susceptibility, hence increasing the chance that genetic linkage and association tests will detect them. We examine this assumption by applying meta-analytical techniques to genetic association studies of endophenotypes. We find that the genetic effect sizes of the loci examined to date are no larger than those reported for other phenotypes. A review of the genetic architecture of traits in model organisms also provides no support for the view that the effect sizes of loci contributing to phenotypes closer to the biological basis of disease is any larger than those contributing to disease itself. While endophenotype measures may afford greater reliability, it should not be assumed that they will also demonstrate simpler genetic architecture.

Background. To test the hypothesis that certain psychotic symptomatology is due to a defect in self- monitoring, we investigated the ability of groups of psychiatric patients to differentiate perceptually between self-produced and externally produced tactile stimuli.

Methods. Responses to tactile stimulation were assessed in three groups of subjects: schizophrenic patients; patients with bipolar affective disorder or depression; and normal control subjects. Within the psychiatric groups subjects were divided on the basis of the presence or absence of auditory hallucinations and/or passivity experiences. The subjects were asked to rate the perception of a tactile sensation on the palm of their left hand. The tactile stimulation was either self-produced by movement of the subject's right hand or externally produced by the experimenter.

Results. Normal control subjects and those psychiatric patients with neither auditory hallucinations nor passivity phenomena experienced self-produced stimuli as less intense, tickly and pleasant than identical, externally produced tactile stimuli. In contrast, psychiatric patients with these symptoms did not show a decrease in their perceptual ratings for tactile stimuli produced by themselves as compared with those produced by the experimenter. This failure to show a difference in perception between self-produced and externally produced stimuli appears to relate to the presence of auditory hallucinations and/or passivity experiences rather than to the diagnosis of schizophrenia.

Conclusions. We propose that auditory hallucinations and passivity experiences are associated with an abnormality in the self-monitoring mechanism that normally allows us to distinguish self-produced from externally produced sensations.

The mechanisms responsible for the production of major extrapyramidal side-effects (parkinsonism, akathisia, acute dystonic reactions, chronic tardive dyskinesias) are reviewed in the light of the complex effects of these drugs on cerebral dopamine systems.

Background. The concept of duration of untreated psychosis (DUP) has recently attracted much interest because of its possible relationship to treatment outcome and implications for preventive efforts with reference to psychotic disorders, especially schizophrenia. In this paper we review critically the literature concerning the concept and its importance.

Methods. Articles concerned with measuring DUP and those that have been suggested to provide indirect or direct evidence of the effect of DUP on treatment outcome are reviewed.

Results. Evidence thus far suggests that DUP may be related to ease of reducing psychotic symptoms once treatment begins for first episode patients, but there is no evidence of a relationship to likelihood of relapse. There has been little investigation of the relationship of DUP to other long-term outcomes such as negative symptoms and cognitive functioning neither have the possible confounds of DUP been widely investigated or controlled.

Conclusions. It is important that there should be more thorough investigations of DUP, its correlates, and the extent to which it does mediate any advantages of earlier intervention.

It is generally recognized that social relationships occupy a central position in psychiatry. To examine the role of social relationships in the onset of minor psychiatric morbidity it is necessary to construct an instrument which will meet the need for a valid, reliable and comprehensive index of social relationships. Such an instrument has now been developed and used in a sample of the general population.

The Interview Schedule for Social Interaction arose from a research need, and was constructed to assess the availability and perceived adequacy for any individual of a number of facets of social relationships. These consist both of persons and of the provisions obtained through them. Data from a general population sample suggest this instrument to be sufficiently valid and reliable, and also sensitive to predictable variations between sociodemographic groups, to justify its use in clinical and epidemiological studies, both in psychiatry and general medicine.

Background. Psychiatric history, familial history of suicide attempts, and certain traumatic life events are important predictors of suicidal thoughts and behaviour. We examined the epidemiology and genetics of suicidality (i.e. reporting persistent suicidal thoughts or a plan or suicide attempt) in a large community-based sample of MZ and DZ twin pairs.

Method. Diagnostic telephone interviews were conducted in 1992–3 with twins from an Australian twin panel first surveyed in 1980–82 (N=5995 respondents). Data were analysed using logistic regression models, taking into account twin pair zygosity and the history of suicidality in the respondent's co-twin.

Results. Lifetime prevalence of suicidal thoughts and attempts was remarkably constant across birth cohorts 1930–1964, and across gender. Major psychiatric correlates were history of major depression, panic disorder, social phobia in women, alcohol dependence and childhood conduct problems. Traumatic events involving assault (childhood sexual abuse, rape or physical assault) or status-loss (job loss, loss of property or home, divorce), and the personality trait neuroticism, were also significantly associated with suicide measures. Prevalence of serious suicide attempts varied as a function of religious affiliation. After controlling for these variables, however, history of suicide attempts or persistent thoughts in the respondent's co-twin remained a powerful predictor in MZ pairs (odds ratio=3·9), but was not consistently predictive in DZ pairs. Overall, genetic factors accounted for approximately 45% of the variance in suicidal thoughts and behaviour (95% confidence interval 33–51%).

Conclusions. Risk of persistent suicidal thoughts and suicide attempts is determined by a complex interplay of psychiatric history, neuroticism, traumatic life experiences, genetic vulnerability specific for suicidal behaviour and sociocultural risk or protective factors.

Background. Follow-up studies of childhood ADHD have shown persistence of the disorder into adulthood, but no epidemiological data are yet available.

Method. ADHD DSM-IV symptoms were obtained by self-report in an adult population-based sample of 1813 adults (aged 18–75 years), that was drawn from an automated general practitioner system used in Nijmegen, The Netherlands. The structure of ADHD symptoms was analysed by means of confirmatory factor analyses. Other data used in this report are the General Health Questionnaire (GHQ-28), information about the presence of three core symptoms of ADHD in childhood, and about current psychosocial impairment.

Results. The three-factor model that allowed for cross-loadings provided the best fit in the entire sample. This result was replicated across gender and age subsamples. Inattentive and hyperactivity symptom scores were significantly associated with measures of impairment, even after controlling for the GHQ-28. Subjects with four or more inattentive or hyperactive–impulsive symptoms were significantly more impaired than subjects with two, one and no symptoms. The prevalence of ADHD in adults was 1·0% (95% CI 0·6–1·6) and 2·5% (1·9–3·4) using a cutoff of six and four current symptoms respectively, and requiring the presence of all three core symptoms in childhood.

Conclusions. These results support the internal and external validity of ADHD in adults between 18 and 75 years. ADHD is not merely a child psychiatric disorder that persists into young adulthood, but an important and unique manifestation of psychopathology across the lifespan.

Background. Traditional instruments that measure self-esteem may not relate directly to the schema construct as outlined in recent cognitive models. The Brief Core Schema Scales (BCSS) aim to provide a theoretically coherent self-report assessment of schemata concerning self and others in psychosis. The scales assess four dimensions of self and other evaluation: negative-self, positive-self, negative-other, positive-other.

Method. We analysed the psychometric properties of the BCSS using a sample of 754 students recruited by email and 252 people with psychosis recruited as part of a trial of cognitive therapy. We report the internal consistency, stability and the factor structure of the scale, and the association of the BCSS with measures of self-esteem and with symptoms of paranoia and grandiosity.

Results. The BCSS have good psychometric properties and have more independence from mood than the Rosenberg Self-Esteem Schedule. People with chronic psychosis reported extreme negative evaluations of both self and others on these scales, but their levels of self-esteem and positive evaluations of self and others were similar to the student sample.

Conclusions. Extreme negative evaluations of self and others appear to be characteristic of the appraisals of people with chronic psychosis, and are associated with symptoms of grandiosity and paranoia in the non-clinical population. The BCSS may provide a more useful measure of schemata about self and others than traditional measures of self-esteem.

Bulimia nervosa is a relatively common eating disorder which has a significant physical and psychological morbidity and a poor prognosis. A behavioural approach to its treatment is described. This focuses on increasing control over eating, eliminating food avoidance and changing maladaptive attitudes. Preliminary findings are promising, with improvement appearing to be maintained. Components of the treatment may benefit patients who simply complain of overeating.

A new diagnostic instrument, The Diagnostic Interview Schedule, was evaluated for use by lay interviewers by comparing its DSM-III diagnoses when given by lay interviewers with results obtained through an independent interview by a psychiatrist using the same schedule, his clinical judgement after the interview, his clinical judgement after both the interview and a free question period, and with diagnoses on the medical chart.