Os, J. van

Early trauma and familial risk in the development of the extended psychosis phenotype in adolescence (Article)

2012-10-01T00:00:00Z

Objective: Both genetic and environmental factors are thought to play a role in the development of psychotic outcomes; however, their respective contributions over time, including possible developmental interactions, remain largely unknown. Method: The contribution of parental general and psychotic psychopathology as proxies of genetic risk to the development of subthreshold psychosis and its hypothesized interaction with childhood trauma were studied in a general population sample of 2230 adolescents, followed from age 10-16years. Outcome measures were: i) level of psychotic experiences at age 16years and ii) persistence of such experiences over the total follow-up period. Results: General parental psychopathology was associated with CAPE score (OR=1.08; P<0.043 for highest quintile) and suggestively predicted psychosis persistence (OR, 1.16; P<0.072). Psychotic parental psychopathology was suggestively associated with CAPE score (OR, 2.25; P<0.063 for highest quintile), predicted membership of the Persistent group (OR, 3.72; P<0.039) and suggestively predicted membership of the Decreasing group (OR 2.04; P<0.051). Childhood trauma was associated with CAPE score and with all developmental trajectories of subclinical psychosis. No evidence was found for an interaction between trauma and parental psychopathology. Conclusion: The development and persistence of subthreshold psychotic symptoms may be conditional on non-interacting proxy genetic and environmental influences.

AKT1 Moderation of Cannabis-Induced Cognitive Alterations in Psychotic Disorder (Article)

2011-07-20T00:00:00Z

Genetic variation in AKT1 may be associated with sensitivity to the psychotomimetic effects of cannabis as well as with increased risk for psychotic disorder following cannabis use. Investigation of the effect of this interaction on relevant intermediate phenotypes for psychosis, such as cognition, may help to clarify the underlying mechanism. Thus, verbal memory (visually presented Word Learning Task), sustained attention (Continuous Performance Test, CPT), AKT1 rs2494732 genotype, and cannabis use were examined in a large cohort of patients with psychotic disorder. No evidence was found for AKT1 × cannabis interaction on verbal memory. Cannabis use preceding onset of psychotic disorder did interact significantly with AKT1 rs2494732 genotype to affect CPT reaction time (β=8.0, SE 3.9, p=0.037) and CPT accuracy (β=-1.2, SE 0.4, p=0.003). Cannabis-using patients with the a priori vulnerability C/C genotype were slower and less accurate on the CPT, whereas cannabis-using patients with the T/T genotype had similar or better performance than non-using patients with psychotic disorder. The interaction was also apparent in patients with psychotic disorder who had not used cannabis in the 12 months preceding assessment, but was absent in the unaffected siblings of these patients and in healthy controls. In conclusion, cannabis use before onset of psychosis may have long-lasting effects on measures of sustained attention, even in the absence of current use, contingent on AKT1 rs2494732 genotype. The results suggest that long-term changes in cognition may mediate the risk-increasing effect of the AKT1 × cannabis interaction on psychotic disorder.Neuropsychopharmacology advance online publication, 20 July 2011; doi:10.1038/npp.2011.141.

The structure of the extended psychosis phenotype in early adolescence - A cross-sample replication (Article)

2011-07-01T00:00:00Z

The extended psychosis phenotype, or the expression of nonclinical positive psychotic experiences, is already prevalent in adolescence and has a dose-response risk relationship with later psychotic disorder. In 2 large adolescent general population samples (n = 5422 and n = 2230), prevalence and structure of the extended psychosis phenotype was investigated. Positive psychotic experiences, broadly defined, were reported by the majority of adolescents. Exploratory analysis with Structural Equation Modelling (Exploratory Factor Analysis followed by Confirmatory Factor Analysis [CFA]) in sample 1 suggested that psychotic experiences were best represented by 5 underlying dimensions; CFA in sample 2 provided a replication of this model. Dimensions were labeled Hallucinations, Delusions, Paranoia, Grandiosity, and Paranormal beliefs. Prevalences differed strongly, Hallucinations having the lowest and Paranoia having the highest rates. Girls reported more experiences on all dimensions, except Grandiosity, and from age 12 to 16 years rates increased. Hallucinations, Delusions, and Paranoia, but not Grandiosity and Paranormal beliefs, were associated with distress and general measures of psychopathology. Thus, only some of the dimensions of the extended psychosis phenotype in young people may represent a continuum with more severe psychopathology and predict later psychiatric disorder.

Evidence for a persistent, environment-dependent and deteriorating subtype of subclinical psychotic experiences: a 6-year longitudinal general population study (Article)

2011-04-11T00:00:00Z

BACKGROUND: Research suggests that subclinical psychotic experiences during adolescence represent the behavioral expression of liability for psychosis. Little is known, however, about the longitudinal trajectory of liability in general population samples. METHOD: Growth mixture modeling was used to examine longitudinal trajectories of self-reported positive psychotic experiences in the Youth Self Report (YSR), completed three times over a period of 6 years by a general population cohort of adolescents aged 10-11 years at baseline (n=2230). RESULTS: Four groups with distinct developmental trajectories of low, decreasing, increasing and persistent levels of mild positive psychotic experiences were revealed. The persistent trajectory was associated strongly with cannabis use, childhood trauma, developmental problems and ethnic minority status, and consistently displayed strong associations with factors known to predict transition from subclinical psychotic experience to clinical psychotic disorder (severity of and secondary distress due to psychotic experiences, social and attentional problems and affective dysregulation) and also with high levels of parental-reported psychotic experiences and use of mental health care at the end of the follow-up period. Progressively weaker associations were found for the increasing, decreasing and low trajectories respectively. CONCLUSIONS: The results suggest that the outcome of early developmental deviation associated with later expression of psychotic experiences is contingent on the degree of later interaction with environmental risks inducing, first, persistence of psychotic experiences and, second, progression to onset of need for care and service use. Insight into the longitudinal dynamics of risk states in representative samples may contribute to the development of targeted early intervention in psychosis.

Cannabis use and genetic predisposition for schizophrenia: A case-control study (Article)

2008-09-01T00:00:00Z

Background. Cannabis use may be a risk factor for schizophrenia. Part of this association may be explained by genotype-environment interaction, and part of it by genotype-environment correlation. The latter issue has not been explored. We investigated whether cannabis use is associated with schizophrenia, and whether gene-environment correlation contributes to this association, by examining the prevalence of cannabis use in groups with different levels of genetic predisposition for schizophrenia. Method. Case-control study of first-episode schizophrenia. Cases included all non-Western immigrants who made first contact with a physician for schizophrenia in The Hague, The Netherlands, between October 2000 and July 2005 (n=100; highest genetic predisposition). Two matched control groups were recruited, one among siblings of the cases (n=63; intermediate genetic predisposition) and one among immigrants who made contact with non-psychiatric secondary health-care services (n=100; lowest genetic predisposition). Conditional logistic regression analyses were used to predict schizophrenia as a function of cannabis use, and cannabis use as a function of genetic predisposition for schizophrenia. Results. Cases had used cannabis significantly more often than their siblings and general hospital controls (59, 21 and 21% respectively). Cannabis use predicted schizophrenia [adjusted odds ratio (OR) cases compared to general hospital controls 7.8, 95% confidence interval (CI) 2.7-22.6; adjusted OR cases compared to siblings 15.9 (95% CI 1.5-167.1)], but genetic predisposition for schizophrenia did not predict cannabis use [adjusted OR intermediate predisposition compared to lowest predisposition 1.2 (95% CI 0.4-3.8)]. Conclusions. Cannabis use was associated with schizophrenia but there was no evidence for genotype-environment correlation.

Case registers in psychiatry: Do they still have a role for research and service monitoring? (Article)

2008-07-01T00:00:00Z

PURPOSE OF REVIEW: To follow up on reviews of case register research. Literature searches over a 2-year period were conducted to determine whether psychiatric case registers still have a role for research and service monitoring. RECENT FINDINGS: Case register research covers a wide range of topics, and is most often found in Denmark where national databases support all kinds of record linkage studies. Typically, case registers are used in studies of treated prevalence and incidence of psychiatric disorders, in research on patterns of care, as sampling frames in epidemiological studies, and in studies on risk factors and treatment outcome. SUMMARY: Despite a wide range of research based on administrative data, stakeholders in most countries are probably not well served by current priorities. Few studies investigate longitudinal patterns of service use to evaluate healthcare policies. There is a lack of comparative record linkage studies to inform local authorities on the cooperation between mental healthcare and public services. Implementing standard tools and procedures for routine outcome assessment seems still to be in an early phase in most register areas. When case register staff can capitalize on new opportunities, old and new case registers will continue to be important for research and service monitoring.

Langdurig zorgafhankelijke patiënten in de ggz: samenhang met verstedelijking (Article)

2008-01-01T00:00:00Z

Uitgaande van de verhoogde psychiatrische morbiditeit in stedelijke gebieden kan men een samenhang verwachten tussen de omvang van het zorggebruik en verstedelijking. De vraag is of dat in het bijzonder geldt voor langdurig zorgafhankelijke patiënten in de ggz (lza-patiënten). doel Onderzoeken of er een samenhang bestaat tussen het vóórkomen van lza-patiënten en de mate van verstedelijking en of er in dit opzicht verschillen zijn tussen typen lza-patiënten onderling en ten opzichte van de overige patiënten in de ggz. methode Onderzocht werden gegevens die waren verkregen uit drie psychiatrische casusregisters en van het cbs. Er werden daarbij drie typen lza-patiënten onderscheiden: 'longstay', 'verblijf en ambulant' en 'ambulant'. De onderzoekspopulatie werd verdeeld in vijf stedelijkheidscategorieën. In de toegepaste poisson-regressieanalyse werd gecorrigeerd voor verschillen in leeftijd, geslacht en burgerlijke staat en in omvang van het zorgaanbod. resultaten De 'incidence rate ratio's' (irr's) waren voor de categorieën 'verblijf en ambulant', 'ambulant' en voor de overige patiënten bij elke stedelijkheidscategorie significant hoger dan die voor de niet-stedelijke gemeenten. Er was eveneens een significant positief lineair verband. Voor de longstaypatiënten werd geen significant verband met de mate van verstedelijking gevonden. De ratio's voor de hele groep lza-patiënten waren hoger dan die voor de overige, niet-lza- patiënten. De ratio's voor 'verblijf en ambulant' waren hoger dan die voor 'ambulant'. conclusie De prevalentie van langdurig zorgafhankelijke patiënten in de ggz neemt toe met de mate van verstedelijking, en deze toename is sterker dan die van overige patiënten. Verder is het verband met verstedelijking voor de categorie 'verblijf en ambulant' sterker dan voor de ambulante lza-patiënten.