Examining delusional ideation: Relationships with race and socioeconomic status

Race and socioeconomic status (SES) are commonly cited as risk factors for psychosis and psychotic-like experiences (PLEs). However, few studies have investigated the relationships between race and SES with specific domains of PLEs. Specifically, little work has examined the relationships between race and SES with delusional ideation, severity (preoccupation, conviction, distress), and delusional themes. Using cross-sectional, general population data (N = 727) from the Nathan Kline Institute-Rockland (NKI-Rockland) database, we investigated racial differences in delusional ideation and severity between Black and White participants, including differences in delusional themes. Then, we investigated SES's relationship with delusional thinking and the interaction between race and SES on delusional thinking. Black American participants endorsed higher delusional ideation with stronger severity than White Americans. A significant interaction between race and delusional theme revealed that Black Americans endorse significantly more delusional ideation in themes of grandiosity, religiosity, and referential-guilt. Black Americans endorse greater delusional severity in grandiose and religious ideations. Black Americans endorse stronger preoccupation and conviction - but not distress-in their referential-guilt ideation. SES was not significantly associated with delusional thinking, nor did SES moderate the significant relationships between race and delusional ideation. These results illuminate the clear racial disparity that exist in delusional ideation within a general population, which did not extend to SES in this dataset. Future work should investigate deeper into the contributory factors to these racial disparities, particularly whether they are based in psychological and/or cultural differences or are the result of assessment/measurement bias.

Associations between social engagement, internalizing symptoms, and delusional ideation in the general population

BACKGROUND

Delusions are a hallmark feature of psychotic disorders and lead to significant clinical and functional impairment. Internalizing symptoms-such as symptoms of depression, anxiety, and trauma exposure-are commonly cited to be related to delusions and delusional ideation and are often associated with deficits in social functioning. While emerging studies are investigating the impact of low social engagement on psychotic-like experiences, little work has examined the relationship between social engagement, internalizing symptoms, and delusional ideation, specifically.

METHODS

Using general population data from the Nathan Kline Institute-Rockland (NKI-Rockland) database (N = 526), we examined the relationships between self-reported delusional ideation, internalizing symptoms, and social engagement and tested four indirect effect models to understand how these factors interrelate.

RESULTS

Delusional ideation was significantly associated with both increased internalizing symptoms (r = 0.41, p < 0.001) and lower social engagement (r = - 0.14, p = 0.001). Within aspects of social engagement, perceived emotional support showed the strongest relationship with delusional ideation (r = - 0.17, p < 0.001). Lower social engagement was also significantly associated with increased internalizing symptoms (r = - 0.29, p < 0.001). Cross-sectional models suggest that internalizing symptoms have a significant indirect effect on the association between delusional ideation and social engagement.

CONCLUSIONS

These findings reveal that elevated delusional ideation in the general population is associated with lower social engagement. Elevated internalizing symptoms appear to play a critical role in reducing engagement, possibly exacerbating delusional thinking. Future work should examine the causal and temporal relationships between these factors.

Reasoning biases and delusional ideation in the general population: A longitudinal study

BACKGROUND

Reasoning biases have been suggested as risk factors for delusional ideation in both patients and non-clinical individuals. Still, it is unclear how these biases are longitudinally related to delusions in the general population. We hence aimed to investigate longitudinal associations between reasoning biases and delusional ideation in the general population.

METHODS

We conducted an online cohort study with 1184 adults from the German and Swiss general population. Participants completed measures on reasoning biases (jumping-to-conclusion bias [JTC], liberal acceptance bias [LA], bias against disconfirmatory evidence [BADE], possibility of being mistaken [PM]) and delusional ideation at baseline, and delusional ideation 7 to 8 months later.

RESULTS

A greater JTC bias was associated with a greater increase in delusional ideation over the following months. This association was better described by a positive quadratic relationship. Neither BADE, LA nor PM were associated with subsequent changes in delusional ideation.

CONCLUSIONS

This study suggests that jumping-to-conclusions predicts delusional ideation in the general population but that this association may follow a quadratic trajectory. While no other associations turned significant, future studies with shorter temporal distances may shed further light on the role of reasoning biases as risk factors for delusional ideation in non-clinical samples.

Dopamine D1 receptor availability is not associated with delusional ideation measures of psychosis proneness

The dopamine D1 receptor (D1R) is thought to play a role in psychosis and schizophrenia, however positron emission tomography studies comparing patients and controls have been inconsistent. To circumvent some of the limitations of clinical studies, such as antipsychotic exposure, an alternative approach is to examine subclinical psychotic symptoms within the general population, i.e. psychosis proneness traits. In this study, we investigated whether D1R availability is associated with delusional ideation in healthy controls, in four experiments, using [¹¹C]SCH23390 PET (n = 76) and psychometric questionnaires (n = 217). We performed exploratory analyses, direct self-replication, and confirmatory analyses using Bayesian statistical modelling. Collectively, we found strong evidence that there is little to no linear association between delusional ideation and D1R. If hypothesised changes in D1R in drug-naive psychosis patients can be confirmed, our results suggest that they may either occur at disease onset, or that they are associated with specific aspects of psychosis other than delusional ideation.

Delusional themes in Body Dysmorphic Disorder (BDD): Comparisons with psychotic disorders and non-clinical Controls

The prevailing nosological classification of body dysmorphic disorder (BDD) encompasses an optional specifier "with absent insight/delusional beliefs" for patients who hold high conviction of the veracity of their disorder-specific beliefs. Yet limited research has examined the explicit nature of delusional beliefs in BDD. The current study therefore aimed to compare themes of delusional ideation in BDD relative to schizophrenia (SCZ) and healthy controls (HCs). Participants had a primary diagnosis of BDD (n = 44) or SCZ (n = 55), or were HCs (n = 55) with no personal or immediate family history of a diagnosable mental health disorder. Assessment of multidimensional delusional ideation was based on the Peters Delusional Inventory (PDI). Results showed that BDD and SCZ groups endorsed significantly more items, and had significantly elevated preoccupation and conviction than the HC group. Only the SCZ group exhibited significantly elevated distress relative to HC participants. In addition, BDD (akin to SCZ) participants were more likely to endorse somatic (appearance-related), control and thought alienation themes than the HC group. These findings suggest that delusional beliefs in BDD may not be strictly appearance-related, but rather span broader themes. This conveys therapeutic implications in terms of designing and administering targeted treatments aimed at delusional thinking in BDD.

Functional brain networks underlying evidence integration and delusional ideation

Cognitive biases affecting evidence integration contribute to delusions and delusional ideation in the psychosis continuum. In previously published work we observed hyperactivity in a visual attention network (VsAN) during confirmatory evidence integration, and hypoactivity in a cognitive evaluation network (CEN) during disconfirmatory evidence integration in schizophrenia patients with delusions, suggesting that a task-specific imbalance of these networks may contribute to delusion maintenance. In the current study, we investigated whether patterns of aberrant functional connectivity observed in past work were associated with delusional ideation in 41 healthy individuals by examining associations between cognitive biases, subclinical schizotypal traits, and functional brain activity during evidence integration. Behaviourally, we replicated positive associations between schizotypal traits and cognitive biases and further showed that this association was driven by delusional ideation specifically. Constrained principal component analysis for fMRI (fMRI-CPCA) revealed recruitment of the brain networks observed in our previous clinical and non-clinical evidence integration studies: default-mode network (DMN); cognitive evaluation network (CEN); and visual attention (VsAN) network. Moreover, as with clinically-significant delusions, delusional ideation was associated with decreased CEN activity during the processing of disconfirmatory evidence and increased VsAN activity during the processing of confirmatory evidence. These findings suggest that this altered pattern of activation across networks during evidence integration may underlie delusional ideation and delusions in the psychosis continuum.

Resting-State Functional Connectivity and Psychotic-like Experiences in Childhood: Results From the Adolescent Brain Cognitive Development Study

BACKGROUND

Psychotic-like experiences (PLEs) during childhood are associated with greater risk of developing a psychotic disorder (and other mental disorders), highlighting the importance of identifying neural correlates of childhood PLEs. Three major cortical networks-the cingulo-opercular network (CON), default mode network (DMN), and frontoparietal network-are consistently implicated in psychosis and PLEs in adults. However, it is unclear whether variation in functional connectivity is associated with PLEs in school-aged children.

METHODS

Using hierarchical linear models, we examined the relationships between childhood PLEs and resting-state functional connectivity of the CON, DMN, and frontoparietal network, as well as the other networks, using an a priori network parcellation, using data from 9- to 11-year-olds (n = 3434) in the ABCD (Adolescent Brain Cognitive Development) study. We examined within-network, between-network, and subcortical connectivity.

RESULTS

Decreased CON and DMN connectivity, as well as cinguloparietal (CPAR) network connectivity, were associated with greater PLEs, even after accounting for family history of psychotic disorders, internalizing symptoms, and cognitive performance. Decreased DMN connectivity was more strongly associated with increased delusional ideation, whereas decreased CON connectivity was more strongly associated with increased perceptual distortions. Increased CON-cerebellar and decreased CPAR-cerebellar connectivity were also associated with increased PLEs, and CPAR-cerebellar connectivity was more strongly associated with increased perceptual distortions.

CONCLUSIONS

Consistent with hypotheses about the dimensionality of psychosis, our results provide novel evidence that neural correlates of PLEs, such as reduced functional connectivity of higher-order cognitive networks, are present even in school-aged children. The results provide further validation for continuity of PLEs across the life span.

Delusional ideation during the perinatal period in a community sample

BACKGROUND

Despite the prevalence of mental health problems during the perinatal period, little research has examined psychotic symptoms in a community sample across pregnancy and the postpartum. Exposure to environmental risk factors, and immigration in particular, are associated with increased risk for psychotic disorders. The current investigation examined whether psychosocial risk and immigrant status would predict levels of delusional ideation across the perinatal period when controlling for depression, anxiety, and demographic factors.

METHODS

A community sample of 316 pregnant women was assessed at 12-14 and 32-34weeks gestation during routine clinic visits, and at 7-9weeks postpartum during a home visit. Measures included self-report ratings of psychosocial risk (e.g., history of mental health problems or abuse, stressful life events, lack of social support), pregnancy-related anxiety, depressive symptomatology, and delusional ideation.

RESULTS

There was less delusional ideation during the postpartum period than during early pregnancy. Across all time points, levels of delusional ideation were lower than in the general population. Analyses using multilevel modeling indicated significant fixed-effects for the variables time, age, partnership, being religious and prenatal anxiety, but not depressive symptomatology, on delusional ideation. Immigrant status moderated the effect of psychosocial risk such that greater psychosocial risk predicted more symptoms of delusional ideation among immigrants, but not non-immigrants.

CONCLUSION

Psychosocial risk factors place immigrant women at an increased likelihood for experiencing delusional ideation during the perinatal period.