Experiences of depression and anxiety are common among patients with persecutory delusions. It has been theorized that emotional disturbances affect the formation and appraisal of persecutory delusions directly and possibly via increasing the sense of aberrant salience.

Using a time-lagged analysis of experience sampling data, this study modelled the role of momentary levels of negative emotions and aberrant salience in maintaining persecutory delusions in patients with active delusions.

Clinically acute participants with at least a mild level of persecutory delusions were assessed using experience sampling method (ESM; 7 entries per day for 14 days) and clinical rating scales. ESM data of participants who completed at least 30 ESM entries were analysed by using multilevel regression modelling.

The final sample consisted of 14 participants, with a total of 1161 momentary observations. Time-lagged analysis revealed that both negative emotions (B = 0.125, P = .009) and aberrant salience (B = 0.267, P< .001) predicted an increase in persecutory delusions in the next moment. Conversely, persecutory delusions did not predict change in negative emotions or change in aberrant salience in the next moment (ps> .05). Negative emotions also predicted an increase in aberrant salience in the next moment (B = 0.087, P = .009).

Our results supported the hypothesis that both negative emotions and aberrant salience exacerbate persecutory delusions, rather than being merely the sequelae of the symptoms. Our results suggested both direct and indirect (via aberrant salience) pathways from negative emotions to persecutory delusions.

The authors have not supplied their declaration of competing interest.

Belief inflexibility (BI) has been considered as a crucial factor for delusional conviction, but less is known about other dimensions of delusional beliefs. Question has been raised regarding the extent to which BI distinguishes delusions from strongly held (non-deluded) personally meaningful beliefs.

We examined the association between BI and major dimensions of delusional beliefs/non-clinical personally meaningful beliefs, and compared results from two BI measures (Maudsley assessment of delusions schedule [MADS] and bias against disconfirmatory evidence [BADE] task).

Idiosyncratic delusional beliefs from 40 outpatients with non-affective psychosis and personally meaningful beliefs from 30 healthy controls were assessed in an interview. Belief dimensions (conviction, preoccupation, and distress) and BI were measured.

Compared with controls, patients reported higher levels of distress and preoccupation but a comparable level of conviction (3.30/4 vs. 3.00/4, t(66.967) = 1.928. P = n.s.). Patients exhibited lower belief flexibility than controls on MADS but not on BADE. In patients, delusional conviction was associated with lower flexibility on a MADS item (“possibility of being mistaken”: t(38) = 4.808, P < 001) and the BADE evidence integration index (r = 0.463, P = 01). In healthy controls, belief conviction was associated with lower flexibility on a MADS item (“reaction to hypothetical contradiction”: t(27) = 3.345, P=.002). Two-way ANOVA revealed that the association between possibility of being mistaken and conviction was stronger in patients than controls (F(1) = 6.718, P = 012). In both groups, BI on either measure did not correlate with distress or preoccupation.

BI was specifically associated with belief conviction. The association was significant for both groups, and was stronger in patients than controls.

The authors have not supplied their declaration of competing interest.