Manon Hanssen

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.

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.

Validity and reliability of the CAPE: a self-report instrument for the measurement of psychotic experiences in the general population

Objective:  General population longitudinal cohort studies have demonstrated the prognostic validity of self‐reported psychotic experiences, but data on reliability and cross‐validation with interview‐based measures of these experiences are sparse. This study tested the reliability and validity of the Community Assessment of Psychic Experiences (CAPE42).

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.

How psychotic are individuals with non-psychotic disorders?

Abstract.Background: The objective of this study was to compare, using a self-report questionnaire, the dimensions of psychosis across different patient groups in a community mental health service (CMHS) and in non-patients in the general population. Methods: The Community Assessment of Psychic Experiences (CAPE) is a 40-item self-report instrument with positive, negative and depressive symptom dimensions. Seven hundred and sixty-two patients and 647 subjects in the general population filled in the CAPE. In 555 of the 762 patients, a DSM-IV diagnosis was made. The following DSM-IV categories were used in the analyses: 1. Schizophrenia and Other Psychotic Disorders (n = 72), 2. Mood Disorders (n = 214), 3. Anxiety Disorders (n = 129). The patient and non-patient groups were compared on the three dimensions of the CAPE using multivariate regression analysis. Results: The patient groups scored significantly higher on the positive, negative and depressive dimensions than the non-patients. Patients with psychotic disorders had the greatest difference in positive psychosis items compared to non-patients (β = 0.94, 95 % CI: 0.7–1.18), whereas patients with mood and anxiety disorders had the highest depressive symptom scores, and positive symptom scores that were intermediate to that of non-patients and patients with psychotic disorders (mood disorders: β = 0.53, 95 % CI: 0.39–0.68; anxiety disorders: β = 0.22, 95 % CI: 0.04–0.39). The CAPE distress score adjusted for the corresponding frequency score was not significantly different between the patient groups, but compared to the general population, patient status did contribute significantly to the level of distress. Discussion: Patients with anxiety and mood disorders had elevated scores on positive psychosis items, indicating that expression of psychosis in non-psychotic disorders is common. The finding of elevated scores of the patient groups on all three dimensions compared to non-patients suggests that the psychopathology associated with psychotic disorders varies quantitatively across DSM-IV categories.

Self‐reported psychotic experiences in the general population: a valid screening tool for DSM‐III‐R psychotic disorders?

Objective:   To examine the diagnostic value of self‐reported psychotic‐like experiences for DSM‐III‐R psychotic disorders.

Evidence for instrument and family-specific variation of subclinical psychosis dimensions in the general population

It is unknown to what degree dimensions of schizotypy (subclinical psychosis) show independent, family-specific variation in the general population. Psychologists administered the Community Assessment of Psychic Experiences, the Structured Interview for Schizotypy-Revised (SIS-R), and the Brief Psychiatric Rating Scale to 257 subjects pertaining to 82 general population families. All 3 instruments showed family-specific variation for positive and negative subclinical psychosis dimensions with between-families proportions of total variance between 10% and 40%. However, only the SIS-R showed family-specific variation of the negative dimension independent of its correlation with the positive dimension. The positive dimension of subclinical psychosis shows familial-specific variation in samples unselected for psychiatric disorder, suggesting dimensional liability in the population. The SIS-R additionally captures family-specific variation in the negative domain.

Hallucinatory experiences and onset of psychotic disorder: evidence that the risk is mediated by delusion formation

Objective:  To examine the hypothesis that the risk for onset of psychotic disorder in individuals with self‐reported hallucinatory experiences (HE) would be higher in those who developed delusional ideation (DE) than in those who did not.

Familial covariation of the subclinical psychosis phenotype and verbal fluency in the general population

OBJECTIVE Cognitive impairments may be markers of familial transmission of liability to psychosis. This study examined to what degree the subclinical psychosis phenotype in the general population shows similar familial continuity with cognition, measured with a verbal fluency test, and whether this was similar for men and women. METHODS Measures of the subclinical psychosis phenotype and verbal fluency were administered to a general population sample of genetically related individuals (n=425). RESULTS In men but not women, higher levels of the subclinical psychosis phenotype were associated with worse verbal fluency performance both within and across relatives. CONCLUSION Psychosis and verbal fluency may be more strongly linked in men than in women, and this difference is also expressed at the subclinical level of the phenotype.

How false are "false" positive psychotic symptoms?

Recent population-based studies showed that self-reported positive symptoms of psychosis strongly predict the development of psychotic disorder in both the short and the long term (Hanssen et al., 2002 and Poulton, R., Caspi, A., Moffitt, T.E., Cannon, M., Murray, R. and Harrington, H., 2000. Childrens self-reported psychotic symptoms and adult schizophreniform disorder: a 15-year longitudinal study. Arch. Gen. Psychiatry 57, pp. 1053–1058. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (201)Poulton et al., 2000). Such findings seemingly contradict the conventional wisdom that the use of diagnostic assessment scales that essentially rely on self-report (Eaton et al., 2000) is problematic because they generate “false” positives (Andrews, 2000; Brugha et al., 2001 and Cooper et al., 1998). We compared the epidemiological value of false versus true positive self-reports of psychosis in a 3-year follow-up of a large general population sample.