Comparing psychotic experiences in low-and-middle-income-countries and high-income-countries with a focus on measurement invariance

BACKGROUND

The prevalence of psychotic experiences (PEs) is higher in low-and-middle-income-countries (LAMIC) than in high-income countries (HIC). Here, we examine whether this effect is explicable by measurement bias.

METHODS

A community sample from 13 countries (N = 7141) was used to examine the measurement invariance (MI) of a frequently used self-report measure of PEs, the Community Assessment of Psychic Experiences (CAPE), in LAMIC (n = 2472) and HIC (n = 4669). The CAPE measures positive (e.g. hallucinations), negative (e.g. avolition) and depressive symptoms. MI analyses were conducted with multiple-group confirmatory factor analyses.

RESULTS

MI analyses showed similarities in the structure and understanding of the CAPE factors between LAMIC and HIC. Partial scalar invariance was found, allowing for latent score comparisons. Residual invariance was not found, indicating that sum score comparisons are biased. A comparison of latent scores before and after MI adjustment showed both overestimation (e.g. avolition, d = 0.03 into d = -0.42) and underestimation (e.g. magical thinking, d = -0.03 into d = 0.33) of PE in LAMIC relative to HIC. After adjusting the CAPE for MI, participants from LAMIC reported significantly higher levels on most CAPE factors but a significantly lower level of avolition.

CONCLUSION

Previous studies using sum scores to compare differences across countries are likely to be biased. The direction of the bias involves both over- and underestimation of PEs in LAMIC compared to HIC. Nevertheless, the study confirms the basic finding that PEs are more frequent in LAMIC than in HIC.

Does social defeat cause negative symptoms? A prospective study in a multi-national community sample

Psychological models of the consequences of ostracism (i.e. being socially excluded and ignored) and negative symptoms in schizophrenia suggest that repeatedly experiencing ostracism can lead to elevated levels of amotivation, anhedonia, and asociality (i.e. negative symptoms). We tested this assumption in a prospective study, following up a large multi-national community sample from Germany, Indonesia, and the United States (N = 962) every four months over one year. At each of the four assessment points (T0 - T3), participants rated their recent ostracism experiences and negative symptoms. Using cross-lagged panel analyses we found a) that negative symptoms and experiences of ostracism were significantly associated in each of the four assessment points, b) that ostracism predicted negative symptoms over time (T2 to T3), and c) that negative symptoms increased ostracism (T0 to T1). The results are in line with the social defeat model of negative symptoms and suggest a bi-directional longitudinal relationship between ostracism and negative symptoms. Moving forward, it will therefore be important to gain an understanding of potential moderators involved in the mechanism.

The Community Assessment of Psychic Experiences: Optimal cut-off scores for detecting individuals with a psychotic disorder

OBJECTIVES

The need for a brief screening tool for psychosis is widely recognized. The Community Assessment of Psychic Experiences (CAPE) is a popular self-report measure of psychosis, but a cut-off score that can detect those most likely to fulfill diagnostic criteria for psychotic disorder is not established.

METHODS

A case-control sample from the Genetic Risk and Outcome of Psychosis Project study (N = 1375, healthy individuals, n = 507, and individuals with a psychotic disorder, n = 868), was used to examine cut-off scores of the CAPE with receiver operating curve analyses. We examined 27 possible cut-off scores computed from a combination of scores from the frequency and distress scales of the various factors of the CAPE.

RESULTS

The weighted severity positive symptom dimension was most optimal in detecting individuals with a psychotic disorder (>1.75 cut-off; area under the curve = 0.88; sensitivity, 75%; specificity, 88%), which correctly identified 80% of the sample as cases or controls with a diagnostic odds ratio of 22.69.

CONCLUSIONS

The CAPE can be used as a first screening tool to detect individuals who are likely to fulfill criteria for a psychotic disorder. The >1.75 cut-off of the weighted severity positive symptom dimension provides a better prediction than all alternatives tested so far.

How Universal Is a Construct of Loneliness? Measurement Invariance of the UCLA Loneliness Scale in Indonesia, Germany, and the United States

The UCLA Loneliness Scale (ULS-20) and its short version (ULS-8) are widely used to measure loneliness. However, the question remains whether or not previous studies using the scale to measure loneliness are measuring the construct equally across countries. The present study examined the measurement invariance (MI) of both scales in Germany, Indonesia, and the United States (N = 2350). The one-, two-, and three-factor structure of the ULS-20 did not meet the model fit cut-off criteria in the total sample. The ULS-8 met the model fit cut-off criteria and has configural, but not metric invariance because two items unrelated to social isolation were not MI. The final six items (ULS-6) exclusively related to social isolation had complete MI. Participants from the United States scored highest in the ULS-6, followed by participants from Germany and then Indonesia. We conclude that the ULS-6 is an appropriate measure for cross-cultural studies on loneliness.

Psychotic Experiences and Related Distress: A Cross-national Comparison and Network Analysis Based on 7141 Participants From 13 Countries

Psychotic experiences (PEs) are common in the general population but do not necessarily reflect a risk status if they occur in relative isolation or are not distressing. Emerging evidence suggests that PEs might be experienced as more benign for individuals from collectivistic low- and middle-income countries (LAMIC) compared with individualistic high-income countries (HIC). The aim of this study was to determine whether: (1) self-reported PEs are less distressing in community samples from LAMIC than from HIC; (2) the network of PEs is significantly less connected in a sample from LAMIC than from HIC. Adults from 8 HIC (n = 4669) and 5 LAMIC (n = 2472) were compared. The lifetime frequency of PEs and related distress were assessed with the Community Assessment of Psychic Experiences. We analyzed the associations of PEs with distress and country type. The interconnection of PEs was visualized by a network analysis and tested for differences in global connection strengths. The average endorsement rates of PEs were significantly higher in LAMIC than in HIC (χ2 = 1772.87, P < .01, Φcramer = 0.50). There was a universal positive correlation between higher frequency of PEs and more distress, but the distress levels controlled for frequency were significantly higher in HIC (R2 = 0.11; b = 0.26; SE = 0.01; T = 17.68; P < .001). Moreover, the network of PEs was significantly less connected in LAMIC (S = 0.40, P < .05). The findings indicate that PEs are of less clinical relevance in LAMIC compared with HIC. The universal use of current high-risk criteria might thus not be adequate without consideration of associated distress and cultural values.

A longitudinal mediation analysis of the effect of negative-self-schemas on positive symptoms via negative affect

BACKGROUND

Cognitive models postulate that negative-self-schemas (NSS) cause and maintain positive symptoms and that negative affect mediates this link. However, only few studies have tested the temporal mediation claim systematically using an appropriate design.

METHODS

A longitudinal cohort design in an online community sample (N = 962) from Germany, Indonesia, and the USA was used. NSS, negative affect and positive symptoms were measured at four time-points (T0-T3) over a 1-year period. Cross-lagged panel and longitudinal mediation analyses with structural equation modeling were used to test the temporal mediation.

RESULTS

Independent cross-lagged panel models showed a significant unidirectional longitudinal path from NSS to positive symptoms (T2-T3, β = 0.18, p < 0.01) and bidirectional longitudinal associations from NSS to negative affect (T0-T1, γ = 0.14, p < 0.01) and vice versa (T0-T1, γ = 0.19, p < 0.01). There was also a significant indirect pathway from NSS at baseline via negative affect at T1 and T2 to positive symptoms at T3 (unstandardized indirect effect coefficient = 0.020, p < 0.05, BCa CI 0.004-0.035), indicating mediation.

CONCLUSIONS

Our findings support the postulated affective pathway from NSS to positive symptoms via negative affect. Specifically, our data indicate that NSS and negative affect influence each other and build up over the course of several months before leading on to positive symptoms. We conclude that interrupting this process by targeting NSS and negative affect early in the process could be a promising strategy to prevent the exacerbation of positive symptoms.

Targeting the link between loneliness and paranoia via an interventionist-causal model framework

Targeting the antecedents of paranoia may be one potential method to reduce or prevent paranoia. For instance, targeting a potential antecedent of paranoia - loneliness - may reduce paranoia. Our first research question was whether loneliness heightens subclinical paranoia and whether negative affect may mediate this effect. Second, we wondered whether this potential effect could be targeted via two interventionist pathways in line with an interventionist-causal model approach: (1) decreasing loneliness, and (2) intervening on the potential mediator - negative affect. In Study 1 (N = 222), recollecting an experience of companionship reduced paranoia in participants high in pre-manipulation paranoia but not in participants low in pre-manipulation paranoia. Participants recollecting an experience of loneliness, on the other hand, exhibited increased paranoia, and this effect was mediated by negative affect. In Study 2 (N = 196), participants who utilized an emotion-regulation strategy, cognitive reappraisal, to regulate the negative affect associated with loneliness successfully attenuated the effect of loneliness on paranoia. Targeting the effect of loneliness on paranoia by identifying interventionist pathways may be one promising route for reducing and preventing subclinical paranoia.

Bullying Mediates Between Attention-Deficit/Hyperactivity Disorder in Childhood and Psychotic Experiences in Early Adolescence

Although a childhood diagnosis of attention-deficit/hyperactivity disorder (ADHD) is known to be linked to psychotic experiences and psychotic disorders in later life, the developmental trajectories that could explain this association are unknown. Using a sample from the prospective population-based Avon Longitudinal Study of Parents and Children (ALSPAC) (N = 8247), we hypothesized that the previously reported association of ADHD combined subtype in childhood and psychotic experiences in early adolescence is mediated by traumatic events and by involvement in bullying. Moreover, we expected this mediation to be specific to ADHD and tested this by comparison with specific phobia. Children with ADHD combined subtype at age 7 were more often involved in bullying at age 10 (OR 3.635, 95% CI 1.973-6.697) and had more psychotic experiences at age 12 (OR 3.362, 95% CI 1.781-6.348). Moreover, children who were involved in bullying had more psychotic experiences (2.005, 95% CI 1.684-2.388). Bullying was a significant mediator between ADHD and psychotic experiences accounting for 41%-50% of the effect. Traumatic events from birth to age 11 were also significantly associated with ADHD combined subtype and psychotic experiences; however, there was no evidence of mediation. Specific phobia was significantly associated with psychotic experiences, but not with bullying. To conclude, bullying is a relevant translating mechanism from ADHD in childhood to psychotic experiences in early adolescence. Interventions that eliminate bullying in children with ADHD could potentially reduce the risk of having psychotic experiences in later life by up to 50%. Clinicians should thus screen for bullying in routine assessments of children with ADHD.

Social Adversity and Psychosis: The Mediating Role of Cognitive Vulnerability

BACKGROUND

Social adversity is a risk factor for psychosis, but the translating mechanisms are not well understood. This study tests whether the relationship between social adversity and psychosis is mediated by cognitive vulnerability in the form of low perceived social rank, negative schemas related to self and other, and loneliness and whether the putative mediations are specific to psychosis or are largely explained by depression.

METHODS

The study was a survey in a community sample (N = 2350) from Germany (n = 786), Indonesia (n = 844), and the United States (n = 720). Mediation path analysis with structural equation modeling was used to test for the specificity of the hypothesized paths to psychosis controlling for depression.

RESULTS

Social adversity had a significant medium to large effect on positive (R2 = .20) and negative symptoms (R2 = .38). Social rank, negative schemas, and loneliness significantly mediated the relationship between social adversity and negative symptoms and the models explained a large amount of the variance (R2 = .43-.44). For positive symptoms, only negative schemas were a significant mediator (R2 = .27).

DISCUSSION

The results emphasize the role of social adversity in psychosis and support the assumption that cognitive vulnerability is a relevant translating mechanism as postulated by the social defeat hypothesis and cognitive models of psychosis. This underlines the relevance of the clinical practice of targeting beliefs in cognitive interventions for psychosis. It also indicates that targeting cognitive vulnerability in people experiencing social adversity could be a promising approach to prevention.

Associations of attention-deficit/hyperactivity and other childhood disorders with psychotic experiences and disorders in adolescence

Prodromal symptoms of psychosis are associated with an increased risk of transition, functional impairment, poor mental health, and unfavorable developmental prospects. Existing interventions targeting the prodrome are non-satisfactory. It may thus be more promising to attempt to identify risk factors in the premorbid phase preceding the prodrome to increase the chances of successful preventive approaches. Here, we investigate whether childhood mental disorders in general and attention-deficit/hyperactivity disorder (ADHD) specifically indicate a risk for subsequent psychotic experiences and disorders. We used a sample from the prospective Avon Longitudinal Study of Parents and Children (N = 5528). When the participants were 7 years old, mental disorders were assigned according to the DSM-IV. In standardized interviews, psychotic experiences were assessed at age 12 and psychotic disorders at age 18. We examined the associations of each of the childhood mental disorders alone and in combination with psychotic experiences at age 12 and psychotic disorders at age 18 using logistic regression. Compared to participants without a disorder, participants with a mental disorder had a higher risk of psychotic experiences at age 12 (OR 1.70, 95 % CI 1.28-2.27) and of psychotic disorders at age 18 (OR 2.31, 95 % CI 1.03-5.15). Particularly, the ADHD combined subtype at age 7 was strongly associated with psychotic experiences at age 12 (OR 3.26, 95 % CI 1.74-6.10). As expected, childhood mental disorders are risk indicators of psychotic experiences and disorders. To improve prevention, health care professionals need to screen for psychotic experiences in children with non-psychotic disorders.

Social adversities and psychotic symptoms: A test of predictions derived from the social defeat hypothesis

Based on the social defeat (SD) hypothesis, this study examines the postulate that various social adversities converge into one common factor, and whether this factor has an effect on psychotic symptoms while controlling for its effect on depression and anxiety. Competing hypotheses arguing for the reverse effect were also tested. The study was a cross-sectional survey in a community sample (N =2350) from Germany (n=786), Indonesia (n=844), and the United States (n=720). Confirmatory factor analysis (CFA) and path analysis with structural equation modeling were used to test the hypotheses. In the CFA two factors reflecting current and past experiences of SD could be identified with acceptable fit. Path analysis indicated acceptable fit for both SD and reverse models, and both the path from current SD to psychotic symptoms and the reverse one were significant, although the former was stronger than the latter. Interestingly, the current but not the past SD factor was significantly associated with psychotic symptoms. Overall, the results indicate that postulates derived from the SD hypothesis fit the data. However, longitudinal research is needed to further confirm the postulated directionality of the associations.