Showing papers by "Robin M. Murray published in 2003"

Pre-morbid characteristics and co-morbidity of methamphetamine users with and without psychosis.

Abstract: Background The long-term use of methamphetamine (MAMP) can result in psychosis but it is not clear why some individuals develop psychotic symptoms, while others use MAMP regularly over long periods and remain unscathed. We set out to characterize MAMP users and to examine the relationship of pre-morbid personality, pre-morbid social function and other psychiatric disorders to MAMP psychosis. Method Four hundred and forty-five amphetamine users were recruited from a psychiatric hospital and a detention centre in Taipei, and were assessed with the Diagnostic Interview for Genetic Studies (DIGS). Their parents were interviewed with the Premorbid Schizoid and Schizotypal Traits (PSST) and the Premorbid Social Adjustment (PSA) schedules. Pre-morbid characteristics and psychiatric co-morbidity were compared between the MAMP users with a lifetime diagnosis of MAMP psychosis and those without. Results The MAMP users with psychosis presented a clinical picture which mimicked the positive symptoms of schizophrenia: 85% had auditory hallucinations; 71% persecutory delusions; 63% delusions of reference. Compared with their non-psychotic counterparts, these MAMP users were younger at first MAMP use, used larger amounts of MAMP, had a significantly higher mean PSST score, and higher rates of major depressive disorder, alcohol dependence and antisocial personality disorder. Conclusions Earlier and larger use of MAMP was associated with increased risk of psychosis. Our data are also compatible with the view that pre-morbid schizoid/schizotypal personality predisposes MAMP users to develop psychosis, and that the greater the personality vulnerability, the longer the psychosis will persist.

Prevalence of violent victimisation in severe mental illness.

Abstract: Background Since de-institutionalisation, much has been written about the risk posed to the community by those with severe mental illness. However, violent victimisation of people with mental illnesses has received little attention. Aims To establish the 1-year prevalence of violent victimisation in community-dwelling patients with psychosis and to identify the socio-demographic and clinical correlates of violent victimisation. Method A total of 691 subjects with established psychotic disorders were interviewed. The past-year prevalence of violent victimisation was estimated and compared with general population figures. Those who reported being violently victimised were compared with those who did not on a range of social and clinical characteristics. Results Sixteen per cent of patients reported being violently victimised. Victims of violence were significantly more likely to report severe psychopathological symptoms, homelessness, substance misuse and previous violent behaviour and were more likely to have a comorbid personality disorder. Conclusions Those with psychosis are at considerable risk of violent victimisation in the community. Victimisation experience should be recorded in the standard psychiatric interview.

Engagement of brain areas implicated in processing inner speech in people with auditory hallucinations.

Abstract: Background The neurocognitive basis of auditory hallucinations is unclear, but there is increasing evidence implicating abnormalities in processing inner speech. Previous studies have shown that people with schizophrenia who were prone to auditory hallucinations demonstrated attenuated activation of brain areas during the monitoring of inner speech. Aims To investigate whether the same pattern of functional abnormalities would be evident as the rate of inner speech production was varied. Method Eight people with schizophrenia who had a history of prominent auditory hallucinations and eight control participants were studied using functional magnetic resonance imaging while the rate of inner speech generation was varied experimentally. Results When the rate of inner speech generation was increased, the participants with schizophrenia showed a relatively attenuated response in the right temporal, parietal, parahippocampal and cerebellar cortex. Conclusions In people with schizophrenia who are prone to auditory hallucinations, increasing the demands on the processing of inner speech is associated with attenuated engagement of the brain areas implicated in verbal self-monitoring.

A quantitative genetic analysis of schizotypal personality traits.

Abstract: Background. Previous twin studies investigating the heritability of schizotypy have often had limited power and have failed to measure the disorganization/social anxiety component.Method. Seven hundred and thirty-three female twin pairs, drawn from the Institute of Psychiatry Volunteer Twin Register, completed the Oxford–Liverpool Inventory of Feelings and Experiences and the Peters et al. Delusions Inventory. Structural equation modelling was carried out on scores for MZ and DZ twin pairs.Results. The best fitting models for all scales comprised additive genetic and unique environmental effects. Heritability was estimated at approximately 50% for most scales, although it was lower at 37% for the PDI scale. Multivariate structural equation model fitting revealed a best-fitting model in which additive genetic and unique environmental influences act through a single common pathway for Cognitive Disorganization, Unusual Experiences and the PDI, and through a separate common pathway for Cognitive Disorganization and Introvertive Anhedonia.Conclusions. The various components of schizotypy are moderately heritable. Multivariate model fitting indicates that at least two latent factor structures are required to account for the covariation between the various components of schizotypy. The positive and negative components of schizotypy are relatively genetically independent, although each in turn may be related to Cognitive Disorganization.

Incidence of schizophrenia in south-east London between 1965 and 1997.

Abstract: Background There has been much debate about changes in the incidence of schizophrenia. Aims To identify any changes in incidence of schizophrenia in Camberwell, south-east London, between 1965 and 1997. Method Research Diagnostic Criteria and DSM—III—R diagnoses were generated for all first contacts by the OPCRIT computer program, and incidence rates of schizophrenia in seven time periods were measured. Indirect standardisation and Poisson models were used to measure the effect of time period and to examine interactions with age and gender. Results There was a continuous and statistically significant increase in the incidence of schizophrenia, which was greatest in people under 35 years of age and was not gender-specific. Conclusions The incidence of schizophrenia has doubled in south-east London over the past three decades.

Selectivity of verbal memory deficit in schizophrenic patients and their relatives.

Abstract: Some of the relatives of people with schizophrenia show impairments of memory and executive function. It is not known, however, whether within these domains there is a class of processes that is especially impaired. Seventy schizophrenic or schizoaffective patients, 115 of their relatives and 66 normal controls underwent a series of assessments evaluating modality specific recall/learning, and aspects of executive functioning, including, planning ability, spatial working memory, strategy formation and rapid mental flexibility. The pattern of performance across cognitive processes was assessed using z-scores that allow direct comparison between tests with different raw score metrics. Selectivity of deficit was evaluated by subtracting the z-score of each cognitive process from the mean of the z-scores of those remaining. Patients performed out worse than controls on most measures, with verbal immediate recall and visual memory/learning the most impaired. Their relatives showed lower scores than controls on verbal and visual memory/learning and strategy formation; verbal memory and strategy formation remained impaired after eliminating those relatives with a psychiatric diagnosis. Consistent with the findings in their schizophrenic kin, healthy relatives also showed disproportionate impairments in verbal immediate recall. Our finding of a selective deficit in verbal memory among relatives suggests that such impairment constitutes a familial, probably genetic, risk factor for schizophrenia.

Schizotypal Personality Traits in Nonpsychotic Relatives Are Associated With Positive Symptoms in Psychotic Probands

Abstract: There remains disagreement over whether increased risk of schizotypal personality disorder (SPD) is confined to the relatives of patients with a diagnosis of schizophrenia or whether it is a more general characteristic of the relatives of all psychotic patients. To examine the relationship between schizotypal dimensions in relatives and psychopathological syndromes in patients with functional psychoses, factor analysis was carried out on (1) ratings from Present State Examination (PSE) interviews with 172 consecutively admitted patients with psychosis (52% of them with schizophrenia), and (2) ratings on items from three schizotypal scales concerning 263 of their nonpsychotic first degree relatives. The factors derived from the patients' PSE interviews were correlated with the schizotypal factors and the nine DSM-IV criteria for SPD concerning the relatives and subjected to a canonical correlation analysis. In this study, no differences were observed concerning the distribution of schizotypal factors or DSM-IV schizotypal features in the relatives of patients with different psychotic diagnoses. However, a syndrome characterized by delusions, hallucinations, and thought interference (positive symptoms) in patients was correlated with high scores on the three schizotypy scales and with positive and negative schizotypal features in relatives.

Childhood origins of violent behaviour in adults with schizophreniform disorder.

Abstract: Background People with psychosis have an elevated risk of violence. Aims To examine whether violent behaviour in adults with psychosis can be accounted for by psychotic symptoms or physical aggression in childhood. Method We used data from a prospective longitudinal study of a complete birth cohort born in New Zealand. When cohort members were 26 years old, information was obtained on past-year psychiatric diagnosis of schizophreniform disorder and on violent behaviour. Childhood psychotic symptoms were measured at age 11 years using a diagnostic interview, and childhood physical aggression was assessed by teachers when cohort members were aged 7, 9 and 11 years. Results Participants with schizophreniform disorder were more likely to be violent than participants without, even after controlling for sociodemographic variables and concurrent substance dependence disorders. Childhood psychotic symptoms were a strong risk factor for violence in adults with schizophreniform disorder, as was childhood physical aggression, although to a lesser extent. Conclusions Violence by individuals with schizophreniform disorder could be prevented by monitoring early signs of psychotic symptoms and by controlling childhood physical aggression.

beta-1,3-Glucuronyltransferase-1 gene implicated as a candidate for a schizophrenia-like psychosis through molecular analysis of a balanced translocation.

Abstract: We have mapped and sequenced both chromosome breakpoints of a balanced t(6;11)(q14.2;q25) chromosome translocation that segregates with a schizophrenia-like psychosis. Bioinformatics analysis of the regions revealed a number of confirmed and predicted transcripts. No confirmed transcripts are disrupted by either breakpoint. The chromosome 6 breakpoint region is gene poor, the closest transcript being the serotonin receptor 1E (HTR1E) at 625 kb telomeric to the breakpoint. The chromosome 11 breakpoint is situated close to the telomere. The closest gene, beta-1,3-glucuronyltransferase (B3GAT1 or GlcAT-P), is 299 kb centromeric to the breakpoint. B3GAT1 is the key enzyme during the biosynthesis of the carbohydrate epitope HNK-1, which is present on a number of cell adhesion molecules important in neurodevelopment. Mice deleted for the B3GAT1 gene show defects in hippocampal long-term potentiation and in spatial memory formation. We propose that the translocation causes a positional effect on B3GAT1, affecting expression levels and making it a plausible candidate for the psychosis found in this family. More generally, regions close to telomeres are highly polymorphic in both sequence and length in the general population and several studies have implicated subtelomeric deletions as a common cause of idiopathic mental retardation. This leads us to the hypothesis that polymorphic or other variation of the 11q telomere may affect the activity of B3GAT1 and be a risk factor for schizophrenia and related psychoses in the general population.

Suicide and attempted suicide among people of Caribbean origin with psychosis living in the UK.

Abstract: BACKGROUND: A report from a 1980s cohort claimed that suicidal behaviour was four times less common in UK-resident people of Caribbean origin with psychosis than in British Whites. Since then, evidence has accumulated that the rate of suicide and suicidal ideation has been increasing. Aims To compare rates of suicidal behaviour in people of Caribbean and British White origin in a large multi-centre sample of patients with psychosis. METHOD: A secondary analysis of 708 patients with psychosis followed up for 2 years. Outcome measures of reported suicide and attempted suicide were adjusted for socio-economic and clinical differences between groups at baseline. RESULTS: People of Caribbean origin had a lower risk of suicidal behaviour than British Whites (odds ratio adjusted for age and gender 0.49, 95% CI 0.26-0.92). There was a strong negative interaction between ethnic group and age: suicidal acts were four times less likely in people of Caribbean origin aged over 35 years compared with British Whites, but there was no large or significant difference in those under 35. CONCLUSIONS: The previously reported lower relative risk of suicidal behaviour in people of Caribbean origin with psychosis is restricted to those over 35 years, suggesting that the protective effect of Caribbean origin is disappearing in younger generations. Language: en

The causes of schizophrenia: neurodevelopment and other risk factors.

Abstract: Understanding the etiology of schizophrenia has been a considerable challenge. The neurodevelopmental hypothesis has held sway in recent years, focusing our attention on biological causes acting in early life. Much evidence supports this hypothesis and risk factors operating in early life (e.g., obstetric complications) have been shown to be associated with the later development of schizophrenia. Indicators of abnormal neurodevelopment that characterize individuals vulnerable to later developing schizophrenia have also been identified. For example, as a group, children who will later develop schizophrenia subtly differ from their peers in terms of their motor, cognitive, and social functioning. However, there is much that cannot be explained in purely neurodevelopmental terms. There is growing evidence of associations between the risk of schizophrenia and factors such as drug misuse, ethnicity/migration, life events, and urbanicity. A multifactorial model of causation that encompasses biological, social, and psychological elements is arguably both a better representation of current research findings and a more appropriate model for clinical practice.

Does dopamine sensitization underlie the association between schizophrenia and drug abuse

Abstract: Drugs that release dopamine, such as amphetamines and cocaine, have long been known to be associated with schizophrenia. As Professor Stefanis pointed out many years ago, people with schizophrenia also commonly consume cannabis, which, like the psychostimulants, also enhances dopaminergic activity.

Prenatal underdevelopment and schizophrenia: a case report of monozygotic twins.

Abstract: A case is described herein of monozygotic twins discordant for schizophrenia that illustrates possible causal events of prenatal underdevelopment, morphological changes in the brain, poor premorbid functioning, and the development of schizophrenia. The affected twin was born with a birthweight of 1620 g, whereas the unaffected twin weighed 2300 g at birth. Marked differences in sociability and intelligence were observed between the twins from early childhood. Magnetic resonance imaging of the brain revealed high-intensity signals in the white matter and enlarged ventricles in the affected twin, while no such abnormality was detected in the well twin. This twin pair suggests a possibility that hypoxic brain damage associated with prenatal underdevelopment may be a causal factor for abnormalities in psychosocial development and subsequent schizophrenia.

Neuroimaging in Psychiatry

Abstract: Functional Neuroimaging: An Introduction to the Technology, Methodology, Interpretation, and Applications, T.A. Russell, F. Zelaya, R.A. Bressan, and P.A. Bandettini Update on Functional Neuroimaging in Child Psychiatry, M. Ernst, J. Rumsey, and S. Munson Neuroimaging and Aging, D.J. Wegesin and Y. Stern Neuroimaging Studies of Human Drug Addiction, N.S. Lawrence and E.A. Stein Neuroimaging Studies of Mood Disorders, C.H.Y. Fu, N.D. Walsh, and W.C. Drevets Neuroimaging and Eating Disorders, R. Uher and J. Treasure Neuroimaging and the Pathophysiology of Obsessive-Compulsive Disorder, S. Saxena Imaging Brain Structure and Function in Schizophrenia: New Techniques Encounter Old Problems, R.A.E. Honey, K.J. Friston, and P.C. Fletcher Function Imaging Studies of Psychopathy, Antisocial Personality Disorder, and Related Psychological Processes, N. Tunstall, T. Fahy, and P. McGuire

Pregnancy and birth complications in patients with schizophrenia in Trinidad and London.

Abstract: It has been shown that an excess of pregnancy and birth complications (PBCs) does not contribute to the excess rates of schizophrenia reported for the population of Caribbean origin in Britain compared with the native Caucasian British population. We therefore attempted to compare the rate of PBCs between a sample of schizophrenics in Britain with that of a sample from Trinidad where some of the Caribbean migrants to Britain originated. First contact patients with schizophrenia according to the CATEGO system diagnosis were identified in Trinidad and London. Their mothers, where available, were interviewed using the Lewis-Murray scale for pregnancy and birth complications. Data from Trinidad and Tobago concerning 56 patients were compared with those of the Caucasian (n = 61) and African-Caribbean (n = 50) patients in London. The rate of PBCs was similar for the Caucasian British patients (24.6%) and the patients in Trinidad and Tobago (21.7%). The rates were lowest in the African-Caribbean patients in London (14.0%), though this difference was not statistically significant. These findings suggest that pregnancy and birth complications are a risk factor for a substantial minority of patients with schizophrenia in Trinidad and London. It also confirms that the excess rates of schizophrenia reported for the Caribbean population in Britain are not due to these complications.

[Personality dimensions and neuropsychological performance in first-degree relatives of patients with schizophrenia and by affective psychosis].

Abstract: Plusieurs etudes ont montre qu'il existait, chez les apparentes de patients schizophrenes, une augmentation de la prevalence de certains troubles de la personnalite. D'autres etudes ont montre, chez ces memes apparentes, des modifications subtiles des performances neuropsychologiques. Cependant, la specificite des troubles de la personnalite a ete peu etudiee, de meme que la relation eventuelle entre les traits de personnalite et les deficits neuropsychologiques. Cent apparentes de patients schizophrenes (AS) et 88 apparentes de patients presentant des troubles schizoaffectifs et troubles bipolaires avec elements psychotiques (APA) ont complete le questionnaire de personnalite de Eysenck. Ce questionnaire mesure le degre d'extraversion, de neuroticisme et de psychoticisme des sujets. Les sujets ont aussi ete soumis a une evaluation de leur efficience intellectuelle, au test du Trail Making (TM) et a un test de fluence verbale. Les apparentes de sexe masculin du groupe AS ont obtenu des scores plus hauts sur l'echelle de psychoticisme que les apparentes de sexe masculin du groupe APA. Cette difference entre les deux groupes n'existe pas pour les apparentes de sexe feminin. Dans le groupe AS, une correlation negative significative a ete mise en evidence entre les performances au TM et les scores d'extraversion, et une correlation negative significative entre les scores d'efficience intellectuelle et les scores de psychoticisme. En conclusion, ces resultats indiquent qu'il existe une augmentation specifique du score de psychoticisme chez les apparentes masculins des patients schizophrenes. De plus, la relation entre les traits de personnalite et les performances neuropsychologiques pourraient indiquer que le psychoticisme augmente la vulnerabilite a la schizophrenie alors que l'extraversion la diminue.