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Biomedical subjects

Jim van Os

Publications and source records attributed to Jim van Os.

At least 91 records · Page 5Linked to original sources
PubMed2003

Do urbanicity and familial liability coparticipate in causing psychosis?

OBJECTIVE: The urban environment and familial liability are risk factors for psychotic illness, but it is not known whether a biological synergism exists between these two proxy causes. METHOD: The amount of biological synergism between familial liability (defined as a family history of delusions and/or hallucinations necessitating psychiatric treatment) and a five-level rating of population density of place of residence was estimated from the additive statistical interaction in a general population risk set of 5,550 individuals. RESULTS: Both the level of urbanicity (adjusted summary odds ratio=1.57, 95% CI=1.30-1.89) and familial liability (adjusted odds ratio=4.59, 95% CI=2.41-8.74) increased the risk for psychotic disorder, independently of each other. However, the effect of urbanicity on the additive scale was much larger for individuals with evidence of familial liability (risk difference=2.58%) than in those without familial liability (risk difference=0.40%). An estimated 60%-70% of the individuals exposed to both urbanicity and familial liability had developed psychotic disorder because of the synergistic action of the two proxy causes. CONCLUSIONS: Given that familial clustering of psychosis is thought to reflect the effect of shared genes, the findings support a mechanism of gene-environment interaction in the causation of psychosis.

Adult↗
PubMed2002

Formation of delusional ideation in adolescents hearing voices: a prospective study.

Previous work suggests that auditory hallucinations in children and adolescents occur frequently in the absence of psychotic illness, although a number of such children go on to develop more severe psychotic symptomatology and need for care. We examined prospectively what factors are associated with formation of delusions in adolescents who are hearing voices. Eighty adolescents (mean age 12.9 years, SD = 3.1) who reported hearing voices were examined at baseline and followed-up three times over a period of 3 years. Fifty percent were receiving professional care, but 50% were not in need of care. Baseline measurement of voice appraisals, attributions, psychopathology, global functioning, dissociation, stressful life events, coping mechanisms, and receipt of professional care were used as predictors of delusion formation, measured as a score of 6 or greater on the extended BPRS items: "suspiciousness," "unusual thought content" and "grandiosity." Thirteen children (16%) displayed evidence of delusional ideation over at least one of the three follow-up periods, of which seven (9%) de novo. Adjusting for presence of baseline delusional ideation, delusion formation over the follow-up period was associated with baseline voice appraisals and attributions such as tone of the voice (hazard ratio voice "variably friendly and hostile" compared to "always friendly": HR = 6.8, 95% CI: 1.1, 41.0), perceived location of the voice (outside vs. inside head: HR = 2.9, 95% CI: 1.0, 8.7), and whether the voice resembled that of a parent (HR = 3.5, 95% CI: 1.0, 12.0); baseline BPRS anxiety/depression (HR = 6.4, 95% CI: 1.9, 21.4), baseline BPRS disorganization (HR = 5.0, 95% CI: 0.98, 26.1) and the baseline amount of reported recent stressful life events (HR continuous life events score: 1.8, 95% CI: 1.0, 3.3). In addition, in older children, the perceived influence of the voices on emotions and behavior was strongly associated with delusion formation (HR = 5.1, 95% CI: 1.0, 25.9). Delusion formation in children hearing voices may be responsive to triggering events and facilitated by feelings of anxiety/depression. The results also highlight the role of attributions associated with external sources, authority figures, perceived influence or "power" over the person, as well as emotional appraisal processes and cognitive disorganization.

Adolescent↗
PubMed2002

Social and clinical consequences of cognitive deficits in early psychosis: a two-year follow-up study of first-admitted patients.

OBJECTIVE: To explore whether baseline memory and executive deficits predicted poor social and clinical outcome over the 2 years following a first admission for psychosis, regardless of categorical diagnosis. METHOD: Cognitive functioning was assessed in first-admitted subjects with psychosis (n=35) with a neuropsychological battery of tests measuring executive, language and memory functions. Social and clinical outcome were assessed at 6-monthly intervals over a two-year follow-up using multiple sources of information. RESULTS: A dose-response relationship was found between visual and verbal memory performance at first admission and clinical outcome over the 2-year follow-up: the poorer the memory performance, the more likely the risk of presenting with psychotic symptoms and rehospitalization. Poor baseline performance on the WCST executive function predicted better medication adherence. No association was found between cognitive performance and occupational or residential outcome. CONCLUSION: Cognitive performance was a better predictor of clinical than social outcome in this sample of first-episode patients. The association between cognitive deficits and poor social outcome may be more marked in subjects with chronic psychosis than in first-episode subjects. The finding that cognitive deficits predict better medication adherence is in need of further exploration.

Activities of Daily Living↗
PubMed2002

Psychotic symptoms in non-clinical populations and the continuum of psychosis.

A growing body of evidence suggests that delusional or hallucinatory experiences are much more frequent in subjects from the general population than the prevalence of cases of psychotic disorders, thereby suggesting the existence of a symptomatic continuum between subjects from the general population and clinical cases of psychosis. Exploring the risk factors modulating the expression of psychosis-like signs in non-clinical populations may better contribute to elucidate the etiology of psychosis than research restricted to subjects at the endpoint of the distribution of the psychotic dimension. The aim of this paper is to briefly review research investigating the distribution of psychotic symptoms in non-clinical populations, the developmental aspects of psychosis proneness, and the outcome characteristics of psychosis-prone subjects.

Adolescent↗
PubMed2002

Does the urban environment independently increase the risk for both negative and positive features of psychosis?

BACKGROUND: Psychotic disorders are more common in urban environments. It is not known whether the increase in risk applies to both the positive and negative dimensions of psychosis. METHODS: In a random general population sample of 7076, measures of positive and negative symptoms of psychosis were constructed using Composite International Diagnostic Interview (CIDI) data. Three CIDI observed items of flat affect, retarded speech and retarded movement served as indicators of a negative symptom variable. RESULTS: Both negative and positive symptoms of psychosis were, independent of each other, associated with a five-level measure of population density of place of residence (adjusted OR negative symptoms: 1.42, 95 % CI: 1.18, 1.71; adjusted OR positive symptoms: 1.19, 95 % CI: 1.13, 1.24). These associations remained after exclusion of vulnerable individuals with any lifetime psychiatric disorder (n = 2910), any lifetime psychiatric treatment (n = 1352) and history of psychosis in the parents (n = 142). CONCLUSIONS: An environmental risk factor associated with urbanicity may act in early life to non-specifically influence risk for both negative and positive experience of psychosis, regardless of whether a formal psychiatric disorder is diagnosable.

Adolescent↗
PubMed2002

Determinants of occurrence and recovery from hallucinations in daily life.

BACKGROUND: Data related to the dynamics of hallucinatory experiences of patients suffering from schizophrenia are scarce. Detecting antecedent conditions and coping strategies may aid development of targeted psychological interventions. METHOD: We studied hallucinating and non-hallucinating patients suffering from schizophrenia spectrum disorder (n = 57), and non-schizophrenic severe mentally ill patients with depression (n = 37). Data were collected using the Experience Sampling Method (ESM) over a period of 1 week. Contingent on a randomly signalling beep, subjects filled in reports of ongoing hallucinations as well as thought, mood, current activity, social circumstances and places frequented. RESULTS: More subjects suffering from schizophrenia reported hallucinations, but for all hallucinating subjects the qualities of hallucination episodes were quite similar. More subjects reported visual hallucinations at least once. In contrast, the intensity of auditory hallucinations was higher. Anxiety was the most prominent emotion during hallucinations and reports of anxiety intensity exceeded baseline levels before the first report of auditory hallucinations. Context modified hallucination intensity over the course of an episode. Social withdrawal resulted in a decrease of hallucinatory intensity (AH > VH), while social engagement slightly raised intensity levels (VH > AH). Doing nothing (VH > AH) and work activities (AH > VH) led to decreases in intensity levels over time, while passive leisure activities (watching TV) resulted in increases in intensity levels of hallucinations (AH > VH). CONCLUSION: The results suggest that hallucinating experiences are subject to a host of contextual influences. Understanding variation offers useful insights for therapy.

Activities of Daily Living↗
PubMed2002

Neuroticism and low self-esteem as risk factors for psychosis.

BACKGROUND: Low self-esteem and high neuroticism are common features in psychosis, but in the absence of longitudinal studies it is unclear whether they represent consequences of the illness or risk factors acting before illness onset. METHODS: A population sample of 3,929 individuals with no lifetime evidence of psychosis were interviewed with the Composite International Diagnostic Interview and were administered the Groningen Neuroticism Scale and the Rosenberg Self-Esteem Scale at baseline and 1 and 3 years later. At year 3, individuals with CIDI evidence of psychotic symptoms were interviewed by clinicians to identify incident psychotic or psychosis-like symptoms. RESULTS: Baseline neuroticism and self-esteem predicted first-ever onset of psychotic symptoms at year 3 (neuroticism, OR 1.16, 95% CI 1.09, 1.23; self-esteem, OR 1.09, 95% CI 1.01, 1.18).When adjusted for each other and for level of anxiety and depression, neuroticism was the strongest independent predictor for onset of psychotic symptoms (OR 1.16, 95% CI 1.07, 1.26). CONCLUSIONS: Neuroticism increases the risk for development of psychotic symptoms. Mechanisms of risk may involve certain cognitive styles associated with neuroticism, such as beliefs about the uncontrollability of certain events and experiences. The association between low self-esteem and psychosis may involve the area of overlap between self-esteem and neuroticism.

Adult↗
PubMed2002

Further evidence that congenital dermatoglyphic abnormalities are associated with psychosis: a twin study.

The presence of abnormal palmar flexion creases (APFC) and dermatoglyphic ridge dissociation (RD) may constitute enduring evidence of a prenatal insult that occurred before the third trimester of intrauterine life. We examined these dermatoglyphic abnormalities in a twin study of psychotic disorders. RD and APFC were analyzed in a monozygotic (MZ) twin sample from the Maudsley Hospital in London (11 normal control pairs, 16 pairs concordant for psychosis, 9 pairs discordant for psychosis, 1 concordant triplet, and 1 triplet with one affected member). The risk of either RD or APFC was 44 percent in affected twins and 20 percent in nonaffected twins (odds ratio = 3.25, 95% confidence interval: 1.03-10.31; one-sided p = 0.023). In the group of MZ twins discordant for psychosis, discordance for RD or APFC always paralleled discordance for psychosis (one-sided p = 0.078), suggesting the operation of nongenetic factors. The results confirm previous work suggesting the possibility that nongenetic factors early in pregnancy contribute to the liability to develop psychosis in later life.

Adult↗
PubMed2002

Are cognitive impairments associated with sensitivity to stress in schizophrenia? An experience sampling study.

OBJECTIVE: Patients with a diagnosis of schizophrenia display cognitive impairments and abnormal sensitivity to stress. However, little is known about the relationship between these two endophenotypes. METHOD: Neuropsychological tests were administered to 42 patients with schizophrenia or other psychosis to assess cognitive functioning, and the experience sampling method (a structured diary technique assessing current context and mood in daily life) was used to assess 1) appraised subjective stress related to daily events and activities and 2) emotional reaction to these daily life stressors. RESULTS: Multilevel random regression analyses showed that in some instances, cognitive functioning did not alter emotional reaction to stress. In other instances, an inverse relationship was found, indicating that a better performance on neuropsychological tests was related to greater emotional reaction to stress. CONCLUSIONS: The results indicate that emotional reaction to stress in the daily lives of patients with schizophrenia may not be a consequence of cognitive impairments and that the two mechanisms may act through different pathways. Such pathways may be related to the extremes of clinical outcome that have been observed in schizophrenia: an episodic, reactive, good outcome and a more chronic form characterized by high levels of negative symptoms and cognitive impairments.

Adult↗
PubMed2002

Patients' perceptions of intensive case management.

OBJECTIVE: The authors examined patients' perceptions of their case management care and the factors that influenced those perceptions. METHODS: A nine-item patients' perceptions questionnaire was administered to 225 patients with severe psychosis who were enrolled in a randomized controlled trial evaluating the efficacy of intensive versus standard case management. RESULTS: Factor analysis of the responses to the perceptions questionnaire revealed two principal components: quality of care received (including relationship and contact with the case manager) and overall perception of case management. Patients had a better overall perception of intensive case management compared with standard case management, but no significant differences were noted in perceived quality of care. Patients with female case managers had more positive perceptions of the quality of the care they received than those with male case managers. Several clinical and social variables were strongly associated with perceived quality of care but less so with overall perception of case management. CONCLUSIONS: Patients' general perceptions of intensive case management seemed more favorable than patients' general perceptions of standard case management, but no difference was noted in their perceptions of quality of care.

Adult↗
PubMedDate not supplied

Do different psychotic experiences differentially predict need for care in the general population?

INTRODUCTION: The pathway from subclinical psychotic experiences to need for care may depend on type of psychotic experience, level of associated distress, and previous experience of psychosis. METHOD: In a general population sample with no previous Diagnostic and Statistical Manual of Mental Disorders , Revised Third Edition , psychotic disorder (n = 4722), 83 subjects displayed at least one psychotic experience. Within the group of 83, subjects with (n = 24) and without need for care (n = 59) were compared. Presence of psychotic experiences at younger ages had been assessed at earlier interviews. RESULTS: Of 7 different psychotic experiences, only hearing voices, nonverbal hallucinations, and passivity phenomena were significantly associated with need for care. These associations were largely explained by the distress associated with the psychotic experience, but whether individuals had had psychotic experiences at earlier ages did not matter. CONCLUSIONS: Different psychotic experiences differ in the associated level of need for care and the mediating role of distress. Longer prior exposure to psychosis may not influence the pathway from subclinical to clinical.

Adolescent↗
PubMedDate not supplied

Does urbanicity shift the population expression of psychosis?

Growing up in an urban area has been shown to be associated with an increased risk of psychotic disorder in later life. While it is commonly held that a only a tiny fraction of exposed individuals will develop schizophrenia, recent evidence suggests that expression of psychosis in exposed individuals may be much more common, albeit at attenuated levels. Findings are based on a population sample of 2548 adolescents and young adults aged originally 14-24 years, and followed up over almost 5 years up to ages 17-28 years. Trained psychologists assessed all these subjects with the core psychosis sections on delusions and hallucinations of the Munich-Composite International Diagnostic Interview. Growing up in an urban area was associated with an increased risk of expression of psychosis in the adolescents and young adults (adjusted OR 1.31, 95% CI 1.03-1.66). The proxy environmental risk factor that urbanicity represents may shift a relatively large section of the adolescent population along a continuum of expression of psychosis. Other causal influences may be required to make the transition to schizophrenia in adult life.

Adolescent↗
PubMedDate not supplied

Nonreplication of the association between ab-ridge count and cerebral structural measures in schizophrenia.

The origins of cerebral abnormalities in psychotic patients remain unknown. Dermatoglyphics are suitable markers of prenatal injury due to their fetal ontogenesis and their susceptibility to some of the factors that also affect cerebral development. In a previous study, positive associations between brain volumetric measures and a dermatoglyphic marker, the ab-ridge count, were reported. The present study is an attempt to replicate that finding in an independent sample. Magnetic resonance imaging (MRI) scans and dermatoglyphic measures were available for 29 schizophrenia patients (Research Diagnostic Criteria [RDC] criteria) and 26 unrelated healthy controls. The images were processed using an automated procedure, yielding volumes of total grey matter, white matter, cerebrospinal fluid (CSF), and total brain volume. The ab-ridge count was not positively associated with brain volumes in either patients or controls. The present findings do not support the hypothesis that the changes in brain volume seen in patients with schizophrenia are of prenatal origin.

Adolescent↗
PubMedDate not supplied

Is there a continuum of psychotic experiences in the general population?

AIMS: Schizophrenia is a severe mental illness that affects 1% of the population. The diagnosis is made according to current diagnostic systems of DSM-IV (American Psychiatric Association, 1994) and ICD-10 (World Health Organisation, 1992), on the basis of characteristic 'positive' and 'negative' symptoms. The traditional model assumes a categorical view of the schizophrenia syndrome and its core symptoms, in which differences between psychotic symptoms and their normal counterparts are considered to be qualitative. An alternative, dimensional approach assumes that schizophrenia is not a discrete illness entity, but that psychotic symptoms differ in quantitative ways from normal experiences and behaviours. This paper reviews evidence for the continuity of psychotic symptoms with normal experiences, focusing on the symptoms of hallucinations and delusions. METHODS: A qualitative review of the relevant literature. RESULTS: The literature suggests that although current epidemiological approaches yield substantial evidence for a continuum view, it is rarely interpreted as such. CONCLUSIONS: The traditional concept of schizophrenia as a homogeneous disease entity has become outdated and is in dire need of a more valid and clinically useful successor.

Humans↗