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Biomedical subjects

Jim van Os

Publications and source records attributed to Jim van Os.

At least 55 records · Page 3Linked to original sources
PubMed2005

Affective processes in the onset and persistence of psychosis.

OBJECTIVES: Cognitive models suggest that beliefs and appraisal processes are crucially important in the onset and persistence of psychosis. This study investigated whether (i) neuroticism increases the risk for development of psychotic symptoms, and (ii) a delusional interpretation and/or a depressed response to hallucinatory experiences predicts the onset of psychotic disorder. METHOD: A general population sample with no lifetime evidence of any psychotic disorder was interviewed with the Composite International Diagnostic Interview Schedule (CIDI) at baseline and 1 and 3 years later. At year 3, individuals with CIDI evidence of psychotic symptoms were interviewed by clinicians to identify onset of psychotic disorder. RESULTS: Baseline level of neuroticism increases the risk for incident psychotic symptoms. Given the presence of hallucinatory experiences at baseline, the increase in risk of having the psychosis outcome was much higher in the group with delusional ideation or depressed mood at year 1 than in those without delusional ideation or depressed mood. CONCLUSION: A cognitive style characterised by a tendency to worry increases the risk for newly developed psychotic symptoms. Individuals who report hallucinatory experiences and react to these with a delusional interpretation and/or negative emotional states have an increased risk for developing clinical psychosis.

Adolescent↗
PubMed2005

Size of burden of schizophrenia and psychotic disorders.

Schizophrenia is a severe mental disorder characterised by fundamental disturbances in thinking, perception and emotions. More than 100 years of research have not been able to fully resolve the puzzle that schizophrenia represents. Even if schizophrenia is not a very frequent disease, it is among the most burdensome and costly illnesses worldwide. It usually starts in young adulthood. Life expectancy is reduced by approximately 10 years, mostly as a consequence of suicide. Even if the course of the illness today is considered more favourable than it was originally described, it is still only a minority of those affected, who fully recover. The cumulative lifetime risk for men and women is similar, although it is higher for men in the age group younger than 40 years. According to the Global Burden of Disease Study, schizophrenia causes a high degree of disability, which accounts for 1.1% of the total DALYs (disability-adjusted life years) and 2.8% of YLDs (years lived with disability). In the World Health Report [The WHO World Health Report: new understanding, new hope, 2001. Geneva], schizophrenia is listed as the 8th leading cause of DALYs worldwide in the age group 15-44 years. In addition to the direct burden, there is considerable burden on the relatives who care for the sufferers. The treatment goals for the moment are to identify the illness as early as possible, treat the symptoms, provide skills to patients and their families, maintain the improvement over a period of time, prevent relapses and reintegrate the ill persons into the community so that they can lead as normal a life as possible.

Cost of Illness↗
PubMed2005

Residential instability in socioeconomically deprived neighbourhoods, good or bad?

Previously, both positive and negative effects of residential instability on various health outcomes have been described. The present study tests these effects in a European context, using two different data-sources (1) neighbourhood level data on socioeconomic deprivation and residential instability, and (2) individual-level community survey data to assess quality of life. Multilevel regression analyses showed that socioeconomic deprivation was negatively associated with several dimensions of quality of life, in stable neighbourhoods, while no such effect was observed in average or unstable neighbourhoods. Thus, when accounting for interaction effects, residential instability appeared to protect against negative effects of neighbourhood poverty and, therefore, may be beneficial for residents' quality of life.

Adult↗
PubMed2005

Explaining transitions over the hypothesized psychosis continuum.

OBJECTIVES: It is crucial to understand the psychological mechanisms that mediate transition from having one or two psychotic symptoms to becoming a patient with a psychotic disorder. This study investigated whether: (i) a delusional interpretation and/or a depressed response to hallucinatory experiences predicts the later onset of clinical psychotic disorder; and (ii) the presence of need for care in relation to psychotic disorder was associated with the use of particular coping strategies. METHOD: A general population sample of 4672 individuals with no lifetime evidence of any psychotic disorder were interviewed with the Composite International Diagnostic Interview Schedule (CIDI) at baseline and 1 and 3 years later. At year 3, individuals with CIDI evidence of psychotic symptoms were interviewed by clinicians to identify onset of psychotic disorder with need for care. Coping, subjective distress with and perceived control over the psychotic experience were assessed using the Maastricht Assessment of Coping Strategies (MACS). RESULTS: Given the presence of hallucinatory experiences at baseline, the increase in risk on the additive scale of having the psychosis outcome at T2 was higher in the group with delusional ideation at T1 than in those without delusional ideation at T1. Similarly, presence of depressed mood at T1 increased the risk of having the psychosis outcome at T2, but this effect overlapped partly with the risk-increasing effect of delusional ideation. Individuals with a need for care were much more likely to display symptomatic coping, whereas the presence of the other coping types was not different across the groups with and without need for care. CONCLUSION: Transitions over the psychosis continuum are, at least in part, driven by the emotional, cognitive and behavioural responses to the initial psychotic or psychosis-like experiences. Individuals who react with a delusional interpretation, negative emotional states and/or a symptomatic coping style have an increased risk for developing clinical psychosis.

Adaptation, Psychological↗
PubMed2005

The schizophrenia envirome.

PURPOSE OF REVIEW: To show which aspects of the environment increase the risk for schizophrenia and how they interact with pre-existing liability for psychosis. RECENT FINDINGS: Not only does cannabis survive as a risk factor for psychosis, but the evidence is showing concrete synergistic effects between cannabis and pre-existing liability to psychosis. The urban environment is, in terms of attributable risk, the most important proxy environmental risk factor. There is evidence that it interacts with genetic risk and it has been hypothesized that the mechanism involves the cumulative effects of altered social interactions at the individual level and possibly also at the level of the wider social environment, such as the neighbourhood. Early trauma is another aspect of the environment that has recently been linked prospectively to psychosis, and meta-analytic work demonstrates conclusively that minority status is a risk factor, part of which may be mediated by chronic exposure to discrimination. Prenatal environmental effects may involve folate or vitamin D deficiency, viral infections or adverse effects associated with low or high birth weight. The mechanism by which the environment is likely to impact on risk is through cognitive and emotional pathways on the one hand, and biological pathways, possibly involving dopamine sensitization, on the other. SUMMARY: Several synergistic mechanisms involving proxy measures of genes and proxy measures of the environment, such as gene-cannabis, gene-urbanicity and gene-stress interactions, offer concrete avenues to pursue research that stands a good chance of elucidating at least some of the causes of schizophrenia.

Journal Article↗
PubMed2005

First cannabis use: does onset shift to younger ages? Findings from 1988 to 2003 from the Dutch National School Survey on Substance Use.

AIMS: To investigate the hypothesis that changes in cannabis prevalence among Dutch secondary school students (aged 12-17 years) were paralleled by shifts in the age of first cannabis use. DESIGN AND PARTICIPANTS: Data were derived from five waves (1988, 1992, 1996, 1999 and 2003) of the Dutch National School Survey on Substance Use, a nationally representative cross-sectional study, with a total of 32,777 respondents. MEASUREMENTS: Written questionnaires on cannabis, tobacco, alcohol, other drug use and socio-demographic and behavioural variables were administered in classroom settings. FINDINGS: Survival analysis showed a strong increase in cumulative incidences by age of first cannabis use from 1988 to 1992, a further increase in 1996 and stabilization in 1999, continuing into 2003. From 1992 to 1996, age of onset shifted towards younger ages. Onset peaked at age 15 in 1992 and age 14 in 1996. The proportion of life-time cannabis users starting at age 13 or younger increased from 26% in 1992 to 41% in 1996. The overall trend was similar for boys and girls. CONCLUSIONS: The study largely confirmed the expectation that the increase in cannabis use from 1988 to 1996 was paralleled by a decrease in the age of first cannabis use. From 1996 to 2003 age of first cannabis use and prevalence stabilized, possibly occasioned by a change in cannabis policy in the mid-1990s.

Adolescent↗
PubMed2005

The impact of maternal stress on pregnancy outcome in a well-educated Caucasian population.

The aim of the study was to examine the association between stress and pregnancy outcome after adjustment for possible confounding and mediating variables. A prospective cohort study of 5511 pregnancies was conducted in 2001-03 in the Netherlands. A standardised questionnaire collecting demographics and mental health data was administered at 14 and 30 weeks of pregnancy. Medical data on the pregnancy and delivery were obtained from obstetricians and midwives. The results showed that a high level of perceived stress at 14 weeks of pregnancy increased the risk for delivery of an infant that was small-for-gestational-age (OR = 1.26 [95% CI 1.01, 1.56]), but the association was reduced after adjustment for the possible confounding effects of demographic variables (OR = 1.16 [95% CI 0.92, 1.47]). The results do not support a direct relationship between perceived stress and adverse pregnancy outcome. Demographic variables may explain the association between psychosocial stress and pregnancy outcome to a significant degree.

Adult↗
PubMed2005

Gender differences in incidence and age at onset of mania and bipolar disorder over a 35-year period in Camberwell, England.

OBJECTIVE: Despite clear gender differences in the symptoms and course of bipolar affective disorder, studies investigating age at onset by gender have yielded inconsistent results. The authors investigated gender differences in age at onset and incidence of first-episode mania and bipolar disorder in an epidemiological catchment area in southeast London over a 35-year period. METHOD: All adult cases of first-episode psychosis, mania, or hypomania presenting to services in Camberwell, southeast London (1965-1999), were identified. Computerized diagnoses for these cases were generated by using the Operational Checklist for Psychotic Disorders program. Incidence rates and rate ratios of DSM-IV bipolar I disorder, first manic episode, by gender and age (10-year age-at-onset categories) were calculated. Differences in age at onset of first-episode mania and bipolar disorder by gender were examined by using univariate and multivariate analyses. RESULTS: Men had a significantly earlier onset of first-episode mania and bipolar disorder, with childhood antisocial behavior also being significantly associated, after multivariate analysis. Women had higher incidence rates of bipolar I disorder throughout adult life, except for early life (ages 16-25 years), although gender differences in individual age bands did not reach statistical significance. CONCLUSIONS: Men appear to have an earlier onset of mania and bipolar disorder than women. The association of male gender and childhood antisocial behavior with early-onset bipolar disorder raised the possibility of the existence of an early-onset subgroup.

Adolescent↗
PubMed2005

Effect of COMT Val158Met polymorphism on the Continuous Performance Test, Identical Pairs Version: tuning rather than improving performance.

OBJECTIVE: It has been suggested that variation in catechol O-methyltransferase (COMT) activity associated with variation in COMT Val158Met genotypes may result in enhanced or reduced cognitive performance, depending on whether the phenotype requires cognitive stability or cognitive flexibility. The authors' goal was to determine whether, in confirmation of this prediction, performance on a measure of cognitive stability would be associated with Met loading. METHOD: COMT genotyping was investigated in relation to a measure of reaction time variability on the Continuous Performance Test, Identical Pairs Version, in a large and representative sample of 527 young men (mean age=21 years). RESULTS: Met loading was associated with reduced reaction time variability. CONCLUSIONS: Met genotype loading may confer enhanced "tuning" or greater stability in performance, possibly by stabilizing active neural representations in the prefrontal cortex during tasks involving working memory.

Adult↗
PubMed2005

Time for a shift in focus in schizophrenia: from narrow phenotypes to broad endophenotypes.

Many manifestations of mental illness, risk factors, course and even response to treatment are shared by several diagnostic groups. For example, cognitive and social impairments are present to some degree in most DSM and ICD diagnostic groups. The idea that diagnostic boundaries of mental illness, including schizophrenia, have to be redefined is reinforced by recent findings indicating that on the one hand multiple genetic factors, each exerting a small effect, come together to manifest as schizophrenia, and on the other hand, depending on interaction with the environment, the same genetic variations can present as diverse clinical phenotypes. Rather than attempting to find a unitary biological explanation for a DSM construct of schizophrenia, it would be reasonable to deconstruct it into the most basic manifestations, some of which are common with other DSM constructs, such as cognitive or social impairment, and then investigate the biological substrate of these manifestations.

Cognition Disorders↗
PubMed2005

Role of distress in delusion formation.

BACKGROUND: Contemporary cognitive psychological theories suggest that distress plays a mediating role in delusion formation. AIMS: To study the amplifying role of distress from early perceptual intrusions to delusion formation. METHOD: A general population sample of 7076 individuals was interviewed with the Composite International Diagnostic Interview (CIDI) in 1996 (baseline), 1997 (T1) and 1999 (T2). At T2, clinicians also scored the Brief Psychiatric Rating Scale (BPRS) item "unusual thought content". Analyses compared hallucinatory experiences with and without subjective distress at baseline for risk of delusion formation at follow-up. RESULTS: Individuals experiencing hallucinations with distress, compared with those without distress had a fourfold increased risk of subsequent delusion formation. CONCLUSIONS: This finding corroborates the hypothesis that distress associated with early perceptual intrusions serves as a catalyst in the development of delusions.

Adolescent↗
PubMed2005

Development of depressed mood predicts onset of psychotic disorder in individuals who report hallucinatory experiences.

OBJECTIVES: Current psychological theories state that the clinical outcome of hallucinatory experiences is dependent on the degree of associated distress, anxiety, and depression. This study examined the hypothesis that the risk for onset of psychotic disorder in individuals with self-reported hallucinatory experiences would be higher in those who subsequently developed depressed mood than in those who did not. DESIGN: A prospective cohort study of a general population sample. METHODS: A sample of 4,670 individuals with no lifetime evidence of any psychotic disorder were interviewed with the Composite International Diagnostic Interview Schedule (CIDI) at baseline and 1 and 3 years later. At Year 3, individuals with CIDI evidence of psychotic symptoms were interviewed by clinicians to identify potential onset of psychotic disorder. Psychotic disorder was specified at three levels; two involving severity of positive symptoms of psychosis, and one using additional clinical judgment of need for care. RESULTS: Given the presence of hallucinatory experiences at baseline, the increase in risk of having the psychosis outcome at Year 3 was higher in the group with depressed mood at Year 1 than in the group without depressed mood at Year 1 (any level of psychotic symptoms: risk difference 17.0%, 95% CI - 1.7, 35.7; severe level of psychotic symptoms: risk difference 21.7%, 95% CI 3.2, 40.2; needs-based diagnosis of psychotic disorder: risk difference 16.8%, 95% CI 0.4, 33.3). CONCLUSION: The results are in line with current psychological models of psychosis that emphasize the role of secondary appraisals of psychotic experiences in the onset of clinical disorder.

Adult↗
PubMed2005

The incidence and outcome of subclinical psychotic experiences in the general population.

OBJECTIVES: To examine the incidence and 2-year stability and outcome of subclinical psychotic experiences in the general population. DESIGN: The Netherlands Mental Health Survey and Incidence Study (NEMESIS), a longitudinal general population study. METHODS: A representative population sample of 7,076 participants was interviewed with the composite international diagnostic interview at baseline, 1 year later at T(1) and again 2 years later at T(2). A sample of individuals was identified who had onset of a new, broadly defined psychotic experience between baseline and T(1) (N = 79; incidence = 2%). Stability and outcome of these incident positive psychotic experiences was reassessed by interview at T(2), at which 25 individuals had a CIDI rating of broadly defined psychotic experience (subclinical outcome) and 11 individuals had psychotic experiences with functional impairment and need for care (clinical outcome). RESULTS: The majority of individuals with an incident psychotic experience did not display persistence of the experience. Only 8% of individuals with a T1 incident psychotic experience had evidence of a T2 subclinical outcome, and only 8% had evidence of a T2 clinical outcome. The emotional context and the number of the T1 incident psychotic experiences were strong modifiers of predictive power for the clinical outcome, but not (or to a much lesser extent) for the subclinical outcome. CONCLUSIONS: The incidence of positive psychotic experiences in the general population is around 100 times greater than traditional estimates of incidence of psychotic disorder such as schizophrenia. The far most likely outcome for these experiences is discontinuity. For the small proportion who display continuity, there is an equally large likelihood of subclinical and clinical 2-year outcomes. Emotional appraisal and degree of intrusiveness of psychotic experiences are important modifiers not for continuity per se but for clinical outcome specifically.

Adolescent↗
PubMed2005

Effects of antipsychotic treatment on tardive dyskinesia: a 6-month evaluation of patients from the European Schizophrenia Outpatient Health Outcomes (SOHO) Study.

OBJECTIVE: To compare the incidence and persistence of tardive dyskinesia between patients diagnosed with schizophrenia (ICD-10 and/or DSM-IV) who were treated with second-generation antipsychotics and first-generation antipsychotics in routine clinical practice. METHOD: The European Schizophrenia Outpatient Health Outcomes (SOHO) study is a 3-year, prospective, observational study. Each country had a start date for patient enrollment before October 2000. All enrollment was completed by June 30, 2001. A simple, global measure of tardive dyskinesia was rated by participating clinicians. For the current analysis, data at baseline, 3 months, and 6 months were analyzed using a generalized estimating equation model. RESULTS: Second-generation antipsychotics conferred a lower risk for tardive dyskinesia at 6 months than first-generation antipsychotics (0.9% vs. 3.8%, odds ratio [OR] = 0.29, 95% confidence interval [CI] = 0.18 to 0.46). In addition, patients with tardive dyskinesia at baseline who were receiving second-generation antipsychotics were less likely than patients receiving first-generation antipsychotics to have tardive dyskinesia symptoms at 6 months (43.6% vs. 60.8%, OR = 0.50, 95% CI = 0.30 to 0.85). A sensitivity analysis suggested no bias related to pharmaceutical industry financial support. CONCLUSION: The results suggest that the relative advantage of second-generation antipsychotics in terms of lower rates of incidence and persistence of tardive dyskinesia, observed in technical randomized controlled trials, generalizes to routine clinical care.

Adult↗
PubMed2004

Hearing impairment and psychosis revisited.

The previously reported but still poorly investigated link between deafness or hearing impairment (DHI) and the onset of positive psychotic experiences was investigated prospectively in a general population sample. Of the 109 DHI subjects at baseline, 11 (10.1%) displayed psychotic experiences at T(2) versus 137 (2.9%) of the non-DHI subjects (OR=3.8, 95% CI: 2.0, 7.2). This effect size was only slightly attenuated after adjustment for baseline psychotic experiences (OR=3.2, 95% CI: 1.6, 6.5) and after adjustment for T(0) psychotic experiences and a range of other confounders (OR=3.0, 95% CI: 1.4, 6.2) These results confirm previous findings of an association between hearing impairments and psychosis and show that this association can also be found prospectively in a nonclinical population.

Adaptation, Psychological↗