Paranoia and Grandiosity in the General Population: Differential Associations With Putative Causal Factors

Worry, negative self-beliefs, and sleep disturbance have been identified as contributory factors to the onset, maintenance, and severity of paranoia. We tested the specificity of these contributory factors to paranoia compared to grandiosity, a different type of delusional ideation. Data were used from 814 adults from the Nathan Kline Institute-Rockland (NKI-Rockland) study, a general population dataset. Paranoid and grandiose delusional ideation was assessed using the Peters Delusions Inventory (PDI-21) and correlated with self-reported worry (n = 228), negative self-beliefs (n = 485), and sleep quality (n = 655). Correlations were compared using Fisher's r-to-z transform to examine whether the magnitude of relationships differed by delusion type. Paranoia was significantly associated with worry, negative self-belief, and sleep quality. Grandiosity demonstrated significantly weaker relationships with worry and negative self-beliefs. Relationships with sleep quality were similar. We replicate previous reports that worry, negative self-beliefs and sleep quality are associated with paranoid ideation in the general population. We extend these findings by demonstrating that these contributory factors, particularly worry and negative self-beliefs, are associated with paranoid ideation to a greater extent than grandiosity. This suggests a degree of specificity of contributory factors to different types of delusional thinking, supporting the pursuit of specific psychological models and treatments for each delusion type.

Delusional Ideation and Data Quality

According to continuum models of psychosis, cognitive biases contribute to delusional ideation in the general population. In a large (N = 1002) pre-registered general population study, we examine key specific predictions of such models; in particular, the hypotheses that delusional ideation in the general population is predicted by the Jumping to Conclusions bias (JTC), Over-adjustment, the Bias Against Disconfirm-ing Evidence (BADE), and the Liberal Acceptance bias (LA). Crucially, we include explicit indices of data quality, and incorporate a new, animated Beads Task which overcomes known problems with this instrument. Our results initially appear to replicate several classic findings concerning the relationships between delusional ideation and the aforementioned cognitive biases: Delusional ideation predicted JTC, overadjustment, and BADE. Importantly, however, we demonstrate that many of these classic findings are either severely diminished — or disappear entirely — when inattentive participants are removed from the analyses. These findings highlight crucial issues that need to be addressed to rigorously test continuum models of psychosis.

The targets of all treachery: Delusional ideation, paranoia, and the need for uniqueness as mediators between two forms of narcissism and conspiracy beliefs

A number of recent studies have examined whether those high in grandiose narcissism are morelikely to believe in conspiracy theories. Few studies have, however, considered whether those high in vulnerable narcissism are also apt to believe in conspiracy theories, and none have attempted to identify the mechanisms that link these two forms of narcissism to conspiracy beliefs. The present study (N Participants = 397; N Informants = 460) investigated the relation of both grandiose narcissism and vulnerable narcissism with conspiracist ideation in the context of four theoretically-relevant mediators: (a) delusional ideation, (b) paranoia, (c) the need for uniqueness, and (d) the desire for control. Participants who were higher in grandiose narcissism and vulnerable narcissism were more likely to believe in conspiracy theories, seemingly because they were more likely to hold odd and unusual beliefs. There was, likewise, some evidence to suggest that those high in vulnerable narcissism believe in conspiracy theories because they suffer from paranoia, whereas those high in grandiose narcissism believe in conspiracy theories because of a desire to be unique. Together, these results suggest that the conspiracist ideation seen among those high in grandiose narcissism and vulnerable narcissism is a consequence of features that are shared between and unique to each of the two traits.

Evidence, and replication thereof, that molecular-genetic and environmental risks for psychosis impact through an affective pathway

Background There is evidence that environmental and genetic risk factors for schizophrenia spectrum disorders are transdiagnostic and mediated in part through a generic pathway of affective dysregulation. Methods We analysed to what degree the impact of schizophrenia polygenic risk (PRS-SZ) and childhood adversity (CA) on psychosis outcomes was contingent on co-presence of affective dysregulation, defined as significant depressive symptoms, in (i) NEMESIS-2 (n = 6646), a representative general population sample, interviewed four times over nine years and (ii) EUGEI (n = 4068) a sample of patients with schizophrenia spectrum disorder, the siblings of these patients and controls. Results The impact of PRS-SZ on psychosis showed significant dependence on co-presence of affective dysregulation in NEMESIS-2 [relative excess risk due to interaction (RERI): 1.01, p = 0.037] and in EUGEI (RERI = 3.39, p = 0.048). This was particularly evident for delusional ideation (NEMESIS-2: RERI = 1.74, p = 0.003; EUGEI: RERI = 4.16, p = 0.019) and not for hallucinatory experiences (NEMESIS-2: RERI = 0.65, p = 0.284; EUGEI: −0.37, p = 0.547). A similar and stronger pattern of results was evident for CA (RERI delusions and hallucinations: NEMESIS-2: 3.02, p < 0.001; EUGEI: 6.44, p < 0.001; RERI delusional ideation: NEMESIS-2: 3.79, p < 0.001; EUGEI: 5.43, p = 0.001; RERI hallucinatory experiences: NEMESIS-2: 2.46, p < 0.001; EUGEI: 0.54, p = 0.465). Conclusions The results, and internal replication, suggest that the effects of known genetic and non-genetic risk factors for psychosis are mediated in part through an affective pathway, from which early states of delusional meaning may arise.

A replication study of JTC bias, genetic liability for psychosis and delusional ideation

Background This study attempted to replicate whether a bias in probabilistic reasoning, or ‘jumping to conclusions’(JTC) bias is associated with being a sibling of a patient with schizophrenia spectrum disorder; and if so, whether this association is contingent on subthreshold delusional ideation. Methods Data were derived from the EUGEI project, a 25-centre, 15-country effort to study psychosis spectrum disorder. The current analyses included 1261 patients with schizophrenia spectrum disorder, 1282 siblings of patients and 1525 healthy comparison subjects, recruited in Spain (five centres), Turkey (three centres) and Serbia (one centre). The beads task was used to assess JTC bias. Lifetime experience of delusional ideation and hallucinatory experiences was assessed using the Community Assessment of Psychic Experiences. General cognitive abilities were taken into account in the analyses. Results JTC bias was positively associated not only with patient status but also with sibling status [adjusted relative risk (aRR) ratio : 4.23 CI 95% 3.46–5.17 for siblings and aRR: 5.07 CI 95% 4.13–6.23 for patients]. The association between JTC bias and sibling status was stronger in those with higher levels of delusional ideation (aRR interaction in siblings: 3.77 CI 95% 1.67–8.51, and in patients: 2.15 CI 95% 0.94–4.92). The association between JTC bias and sibling status was not stronger in those with higher levels of hallucinatory experiences. Conclusions These findings replicate earlier findings that JTC bias is associated with familial liability for psychosis and that this is contingent on the degree of delusional ideation but not hallucinations.

Evidence for an interrelated cluster of Hallucinatory experiences in the general population: an incidence study

Background Although hallucinations have been studied in terms of prevalence and its associations with psychopathology and functional impairment, very little is known about sensory modalities other than auditory (i.e. haptic, visual and olfactory), as well the incidence of hallucinations, factors predicting incidence and subsequent course. Methods We examined the incidence, course and risk factors of hallucinatory experiences across different modalities in two unique prospective general population cohorts in the same country using similar methodology and with three interview waves, one over the period 1996–1999 (NEMESIS) and one over the period 2007–2015 (NEMESIS-2). Results In NEMESIS-2, the yearly incidence of self-reported visual hallucinations was highest (0.33%), followed by haptic hallucinations (0.31%), auditory hallucinations (0.26%) and olfactory hallucinations (0.23%). Rates in NEMESIS-1 were similar (respectively: 0.35%, 0.26%, 0.23%, 0.22%). The incidence of clinician-confirmed hallucinations was approximately 60% of the self-reported rate. The persistence rate of incident hallucinations was around 20–30%, increasing to 40–50% for prevalent hallucinations. Incident hallucinations in one modality were very strongly associated with occurrence in another modality (median OR = 59) and all modalities were strongly associated with delusional ideation (median OR = 21). Modalities were approximately equally strongly associated with the presence of any mental disorder (median OR = 4), functioning, indicators of help-seeking and established environmental risk factors for psychotic disorder. Conclusions Hallucinations across different modalities are a clinically relevant feature of non-psychotic disorders and need to be studied in relation to each other and in relation to delusional ideation, as all appear to have a common underlying mechanism.