I.C.M. Janssen

Childhood abuse as a risk factor for psychotic experiences.

Objective: To examine the hypothesis that individuals from the general population who report childhood abuse are at increased risk of developing positive psychotic symptoms.

Alterations in theory of mind in patients with schizophrenia and non-psychotic relatives

Objective: It has been proposed that alterations in theory of mind underlie specific symptoms of psychosis. The present study examined whether alterations in theory of mind reflect a trait that can be detected in non‐psychotic relatives of patients with schizophrenia.

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.

Social cognition and neurocognition as independent domains in psychosis

Patients with psychosis display alterations in social cognition as well as in the realm of neurocognition. It is unclear, however, to what degree these cognitive domains represent two separate dimensions of liability or the pleiotropic expression of a single deficit. The purpose of the present study was to investigate (i) to what extent alterations in social cognition represent an independent area of vulnerability to psychosis, separate from neurocognitive deficits and (ii) whether social cognition is one construct or can be divided into several subcomponents. Five social cognition and three neurocognitive tasks were completed by 186 participants with different levels of vulnerability for psychosis: 44 patients with psychotic disorder; 47 subjects at familial risk; 41 subjects at psychometric risk and 54 control subjects. The social cognition tasks covered important basic subcomponents of social cognition, i.e. mentalisation (or theory of mind), data gathering bias (jumping to conclusions), source monitoring and attribution style. Neurocognitive tasks assessed speed of information processing, inhibition, cognitive shifting and strategy-driven retrieval from semantic memory. The results of factor analysis suggested that neurocognition and social cognition are two separate areas of vulnerability in psychosis. Furthermore, the social cognition measures lacked significant overlap, suggesting a multidimensional construct. Cognitive liabilities to psychosis are manifold, and include key processes underlying basic person-environment interactions in daily life, independent of cognition quantified by neuropsychological tests.

Early trauma may increase the risk for psychotic experiences by impacting on emotional response and perception of control

Objective:  Exposure to early trauma may increase the risk of dysfunctional responses to anomalous psychotic experiences resulting in psychotic symptom formation.

Attribution style and psychosis: evidence for an externalizing bias in patients but not in individuals at high risk.

BACKGROUND The aims of the study were to investigate whether (i) patients with lifetime presence of non-affective psychosis show an external-personal attribution bias for negative events, (ii) this attribution style can also be detected in first-degree relatives of patients with psychosis and subjects with subclinical psychotic experiences, and (iii) this attribution style is related to the presence of psychotic symptoms, in particular delusions. METHOD Participants were 23 patients with lifetime presence of non-affective psychosis, a high- risk group of 36 first-degree relatives of patients with non-affective psychosis, a high-risk group of 31 subjects with subclinical psychotic experiences and 46 normal controls. Attribution style was measured by the Internal, Personal and Situational Attribution Questionnaire. Positive symptoms were assessed with the Present State Examination (PSE) and the Scale for the Assessment of Positive Symptoms (SAPS). RESULTS Relative to the controls, an externalizing bias was apparent in the patient group (beta = 0.20, p = 0.03) but not in the two high-risk groups. There was a dose-response association between externalizing bias and the delusions subscale of the PSE (relative to lowest level: highest level of delusions: beta = 0.53, p = 0.04; intermediate levels of delusions: beta = 0.23, p = 0.35). No significant differences were found in personalizing bias between the four groups. CONCLUSIONS Patients with psychosis tend to use an externalizing bias in their explanations of negative social events, and this bias is associated with the presence of positive psychotic symptoms, in particular delusions. A deviant attribution style is not part of the vulnerability to psychosis.

Are apparent associations between parental representations and psychosis risk mediated by early trauma

Objective:  It was investigated whether the reported association between representations of parental rearing style and psychosis does not represent a main effect, but instead is a proxy indicator of the true underlying risk factor of early trauma.

Cognitive alterations in groups at risk for psychosis: neutral markers of genetic risk or indicators of social disability?

Objective:  To investigate whether cognitive alterations associated with vulnerability to psychosis, are associated with expression of psychopathology and functional outcome in groups at different levels of risk for psychotic illness.

Childhood abuse as a risk factor for psychotic experiences

OBJECTIVE To examine the hypothesis that individuals from the general population who report childhood abuse are at increased risk of developing positive psychotic symptoms. METHOD Data were derived from a general population sample of 4045 subjects aged 18-64 years. First ever onset of positive psychotic symptoms at 2-year follow-up were assessed using the Composite International Diagnostic Interview and additional clinical interviews if necessary. Childhood abuse was assessed at baseline. RESULTS Baseline reported childhood abuse predicted development of positive psychotic symptoms associated with need for care [odds ratio (OR) = 11.5, 95% CI 2.6-51.6]. This association remained after adjustment for demographic variables, reported risk factors and presence of any lifetime psychiatric diagnosis at baseline (OR = 7.3, 95% CI 1.1-49.0). CONCLUSION The results suggest that early childhood trauma increases the risk for positive psychotic symptoms. This finding fits well with recent models that suggest that early adversities may lead to psychological and biological changes that increase psychosis vulnerability.

When does experience of psychosis result in a need for care? (NEMESIS)

Not all individuals with experience of psychosis develop need for care. 7076 general population individuals were studied for 3 years. 47 individuals experienced psychosis with no previous diagnosis of psychotic disorder. They were interviewed by telephone. Need for care was associated with severity of psychotic experiences rather than distress or total level of coping used. Also, individuals with need for care more often resorted to symptomatic coping style (giving in to symptoms; OR=6.07, 95% CI: 1.94, 18.95), which was associated with less perceived control (OR=0.79, 95% CI: 0.63, 0.98). Any type of coping was associated with level of distress, severity of hallucinations and presence of suspiciousness in both groups, but suspiciousness was larger in those in need for care (OR=2.27, 95% CI: 1.33, 3.87). A symptomatic coping style predicts decreased experience of control and results in need for care. Attribution of locus ofcontrol and a more submissive style vis à vis the psychotic experience may contribute to becoming a mental health patient.