Deficits in executive and memory processes in delusional disorder: a case-control study

The characteristics of cognitive and daily living functions of neurocognitive disorders with delusions in elderly Alzheimer's disease

Background

Delusions in neurocognitive disorder due to Alzheimer's disease (AD) worsen patients' cognitive functions and activities of daily living (ADL), increasing caregiver burden and the risk of mortality. AD patients with delusions tend to experience a more rapid decline in cognition and have demonstrated poorer performance on various cognitive function tests. Considering the prognosis of delusion in AD patients, it tends to be more favorable with appropriate treatment. However, there is a lack of neuropsychological research, specifically examining the impact of delusions in AD, characterized by progressive deterioration of cognitive function. This study investigates the impact of delusions on cognitive function and ADL under conditions controlling for disease severity.

Methods

We compared cognitive function and ADL in AD patients aged 65 years or older according to the presence of delusions. To assess longitudinal change, we analyzed data from patients monitored for an average of 15 to 16 months. We assessed cognitive function and ADL using the Seoul Neuropsychological Screening Battery-Second Edition (SNSB-II) and delusions using the Neuropsychiatric Inventory (NPI). We used IBM SPSS Statistics version 25.0 for all statistical analyses. The analysis was not adjusted for multiple comparisons. We investigated how delusions impact cognitive function and ADL, controlling for age, educational level, and disease severity.

Results

The delusions group exhibited poorer immediate recall of verbal memory than the non-delusions group. In the follow-up evaluation, patients who developed delusions had lower baseline cognitive function than those who did not, and their language fluency declined over time. In addition, we found the presence of delusions associated with worse functional impairment in ADL as the disease progressed.

Conclusion

While controlling for the severity of AD, we found no significant negative impacts of delusions on most cognitive functions. Nevertheless, it is noteworthy that the immediate recall of verbal memory and the Controlled Oral Word Association Test (COWAT)_animal sensitively detected the negative impact of delusions. Furthermore, since delusions are associated with worsening ADL, we understand that delusion treatment is important for improving the quality of life for patients and caregivers.

Spurious Autobiographical Memory of Psychosis: A Mechanistic Hypothesis for the Resolution, Persistence, and Recurrence of Positive Symptoms in Psychotic Disorders

Psychotic disorders are complex disorders with multiple etiologies. While increased dopamine synthesis capacity has been proposed to underlie psychotic episodes, dopamine-independent processes are also involved (less responsive to dopamine receptor-blocking medications). The underlying mechanism(s) of the reduction in antipsychotic responsiveness over time, especially after repeated relapses, remain unclear. Despite the consistent evidence of dopamine overactivity and hippocampal volume loss in schizophrenia, few accounts have been provided based on the interactive effect of dopamine on hippocampal synapse plasticity mediating autobiographical memory processes. The present hypothesis builds upon previous works showing the potential effects of dopamine overactivity on hippocampal-mediated neuroplasticity underlying autobiographical memory, alongside known patterns of autobiographical memory dysfunction in psychosis. We propose that spurious autobiographical memory of psychosis (SAMP) produced during active psychosis may be a key mechanism mediating relapses and treatment non-responsiveness. In a hyperdopaminergic state, SAMP is expected to be generated at an increased rate during active psychosis. Similar to other memories, it will undergo assimilation, accommodation, and extinction processes. However, if SAMP fails to integrate with existing memory, a discontinuity in autobiographical memory may result. Inadequate exposure to normalizing experiences and hyposalience due to overmedication or negative symptoms may also impede the resolution of SAMP. Residual SAMP is hypothesized to increase the propensity for relapse and treatment non-responsiveness. Based on recent findings on the role of dopamine in facilitating hippocampal synapse plasticity and autobiographical memory formation, the SAMP hypothesis is consistent with clinical observations of DUP effects, including the repetition of contents in psychotic relapses as well as the emergence of treatment non-responsiveness after repeated relapses. Clinical implications of the hypothesis highlight the importance of minimizing active psychosis, integrating psychosis memory, avoiding over-medication, and fostering normalizing experiences.

What does it take to be rigid? Reflections on the notion of rigidity in autism

Characterizations of autism include multiple references to rigid or inflexible features, but the notion of rigidity itself has received little systematic discussion. In this paper we shed some light on the notion of rigidity in autism by identifying different facets of this phenomenon as discussed in the literature, such as fixed interests, insistence on sameness, inflexible adherence to routines, black-and-white mentality, intolerance of uncertainty, ritualized patterns of verbal and non-verbal behavior, literalism, and discomfort with change. Rigidity is typically approached in a disjointed fashion (i.e., facet by facet), although there are recent attempts at providing unifying explanations. Some of these attempts assume that the rigidity facets mainly relate to executive functioning: although such an approach is intuitively persuasive, we argue that there are equally plausible alternative explanations. We conclude by calling for more research on the different facets of rigidity and on how they cluster together in the autistic population, while suggesting some ways in which intervention could benefit from a finer-grained view of rigidity.

Aberrant memory and delusional ideation: A pernicious partnership?

Delusions can be conceptualized as beliefs that are both at odds with consensus reality and espoused with high conviction. While delusions represent a cardinal symptom of schizophrenia, delusion-like beliefs can be found in the general population. Do similar cognitive mechanisms support delusionality across this spectrum? If so, what are they? Here, we examine evidence for a mechanistic role of the (associative) memory system in the formation and maintenance of delusions and delusion-like beliefs. While general neurocognitive metrics do not tend to associate with delusionality, our scoping review of the clinical and subclinical literature reveals several subdomains of memory function that do. These include a propensity to commit errors of commission (i.e., false alarms and intrusions), source memory biases, and metamemory impairment. We discuss how several of these effects may stem from aberrant associative memory function and offer recommendations for future research. Further, we propose a state/trait interaction model in which underlying traits (i.e., impaired associative and metamemory function) may become coupled with delusionality during states of acute psychosis, when memory function is particularly challenged by aberrant salience attribution and noisy perceptual input. According to this model, delusions may arise as explanations to high-salience (but low-source) mnemonic content that is endorsed with high confidence.

Positive symptoms of schizophrenia and their relationship with cognitive and emotional executive functions

BACKGROUND

Positive symptoms of schizophrenia are associated with significant difficulties in daily functioning, and these difficulties have been associated with impaired executive functions (EEFF). However, specific cognitive and socio-emotional executive deficits have not been fully established.

OBJECTIVE

The present study has several objectives. First, we aimed to examine the specific deficits in cognitive and socio-emotional EEFF in a group of patients with schizophrenia with a predominance of positive symptoms, as well as to determine if these patients present clinically significant scores in any of the three fronto-subcortical behavioral syndromes: Dorsolateral, Orbitofrontal, or Anterior Cingulate.

METHOD

The sample consisted of 54 patients, 27 with a predominance of positive symptoms, and 27 healthy controls matched for gender, age, and education. The two groups completed four cognitive and three socio-emotional EEFF tasks. In the group of patients, positive symptoms were evaluated using the scale for the Evaluation of Positive Symptoms (SANS), while the behavioral alterations associated with the three fronto-subcortical syndromes were evaluated using the Frontal System Behavior Scale (FrSBe).

RESULTS

The patients, in comparison with a control group, presented specific deficits in cognitive and socio-emotional EEFF. In addition, a high percentage of patients presented clinically significant scores on the three fronto-subcortical syndromes.

CONCLUSION

The affectation that these patients present, in terms of both cognitive and emotional components, highlights the importance of developing a neuropsychological EEFF intervention that promotes the recovery of the affected cognitive capacities and improves the social and emotional functioning of the affected patients.

Delusional Disorder in Old Age: A Hypothesis-Driven Review of Recent Work Focusing on Epidemiology, Clinical Aspects, and Outcomes

The theme, strength, and duration of a delusion are considered important in distinguishing one psychosis of old age from another. Research results, however, are mostly based on studies conducted on one form of psychosis, namely schizophrenia. The aim of this hypothesis-driven narrative review is to gather clinically important information about the psychosis identified as delusional disorder (DD), as it affects persons of senior age. We hypothesized that DD becomes relatively prevalent in old age, especially in women; and that it is associated with demonstrable brain changes, which, in turn, are associated with cognitive defects and poor pharmacological response, thus increasing the risk of aggression and suicide. Computerized searches in PubMed and ClinicalTrials.gov were conducted using the following search terms: (delusional disorder) AND (elderly OR old OR aged OR psychogeriatrics). A total of 16 recent studies (including case reports) were reviewed. Our hypotheses could not be definitively confirmed because research evidence is lacking. In order to improve eventual outcomes, our literature search demonstrates the need for more targeted, well-designed studies.

A population-based cross-sectional study of cognitive deficits in paranoia

This study sought to investigate the association between paranoia and performance in a range of neurocognitive domains using a large community sample. We conducted a cross-sectional survey of 4507 individuals within the PISMA-ep Study. We used a large community sample selected after multistage sampling using standard stratification techniques. Socio-demographic variables such as age, gender, educational level, urbanicity, and geographical region were recorded. The Spanish version of the Green Paranoid Thought Scale (S-GPTS) was used to assess paranoid thoughts. The Screening for Cognitive Impairment in Psychiatry (SCIP) was used to assess neurocognitive performance both globally and by domains (i.e., immediate and delayed verbal learning, working memory, verbal fluency and processing speed). Individuals with high S-GPTS paranoia scores showed significantly lower performance on global cognitive function and also on immediate (but not delayed) verbal learning, working memory, verbal fluency and processing speed. These results held statistical significance even after controlling for the effects of education and estimated IQ. We propose that cognitive deficits may be mediators of paranoid thinking formation and need to be considered when assessing patients with high levels of paranoia.

Induced ideas of reference during social unrest and pandemic in Hong Kong

Ideas of reference (IOR) are often implicated in predicting psychosis onset. They have been conceptualized to present on a continuum, from oversensitive psychological reactions to delusional thoughts. It is however unknown to what extent IOR may be triggered by collective environmental stress. We obtained timely data from 9873 individuals to assess IOR in relation to trauma exposure in the 2019-2020 social unrest in Hong Kong. Two levels of IOR are distinguished: attenuated IOR (IOR-A), being the experience of feeling particularly referred to within a group; and exclusive IOR (IOR-E), the experience of feeling exclusively referred to while others are not. Logistic regressions showed that event-based rumination was a shared predictor for IOR-A (OR = 1.07, CI = 1.03-1.10) and IOR-E (OR = 1.09, CI = 1.02-1.17). For IOR-A, three categories of social unrest-related traumatic events (TEs) were significant predictors, including being attacked or having experienced sexual violence (OR = 4.14, CI = 1.93-8.85), being arrested (OR = 4.48, CI = 1.99-10.10), and being verbally abused (OR = 2.66, CI = 1.28-5.53). Being arrested was significant for IOR-E (OR = 3.87, CI = 1.03-14.52), though not when rumination was included. Education level also significantly predicted IOR-E (OR = 0.72, CI = 0.52-0.99). Further analysis revealed that rumination significantly mediated between TEs and IOR severity (β = 0.26, SE = 0.01, CI = 0.24-0.28). The findings are consistent with the hypothesis that IOR-A and IOR-E occur as levels on a continuum, but each has some distinctive correlates. Extrinsic events may play a more prominent role in IOR-A, while intrinsic factors, such as cognitive capacity, may play a more prominent role in IOR-E. The involvement of rumination across the IOR spectrum suggests an opportunity for intervention.

Sleep Disturbances in Patients with Persistent Delusions: Prevalence, Clinical Associations, and Therapeutic Strategies

Sleep disturbances accompany almost all mental illnesses, either because sound sleep and mental well-being share similar requisites, or because mental problems lead to sleep problems, or vice versa. The aim of this narrative review was to examine sleep in patients with delusions, particularly in those diagnosed with delusional disorder. We did this in sequence, first for psychiatric illness in general, then for psychotic illnesses where delusions are prevalent symptoms, and then for delusional disorder. The review also looked at the effect on sleep parameters of individual symptoms commonly seen in delusional disorder (paranoia, cognitive distortions, suicidal thoughts) and searched the evidence base for indications of antipsychotic drug effects on sleep. It subsequently evaluated the influence of sleep therapies on psychotic symptoms, particularly delusions. The review’s findings are clinically important. Delusional symptoms and sleep quality influence one another reciprocally. Effective treatment of sleep problems is of potential benefit to patients with persistent delusions, but may be difficult to implement in the absence of an established therapeutic relationship and an appropriate pharmacologic regimen. As one symptom can aggravate another, comorbidities in patients with serious mental illness all need to be treated, a task that requires close liaison among medical specialties.

The Role of Inner Speech in Executive Functioning Tasks: Schizophrenia With Auditory Verbal Hallucinations and Autistic Spectrum Conditions as Case Studies

Several theories propose that one of the core functions of inner speech (IS) is to support subjects in the completion of cognitively effortful tasks, especially those involving executive functions (EF). In this paper we focus on two populations who notoriously encounter difficulties in performing EF tasks, namely, people diagnosed with schizophrenia who experience auditory verbal hallucinations (Sz-AVH) and people with autism spectrum conditions (ASC). We focus on these two populations because they represent two different ways in which IS can fail to help in EF tasks, which can be illustrative for other mental conditions. First, we review the main components of EF (see section "Executive Functions"). Then we explain the functions that IS is taken to perform in the domain of EF (see section "Inner Speech and Executive Functions") and review the evidence concerning problems about EF in the two populations of our study: Sz-AVH (see section "Executive Functions and Inner Speech in Sz-AVH") and ASC (see section "Executive Function and Inner Speech in ASC"). After this we further detail our account about what a properly functioning IS can do for both populations and how different IS profiles may impact EF performance: in the case of Sz-AVH, the uncontrolled and intrusive character of IS negatively affects EF performance, whereas in ASC, EF is not sufficiently supported by IS, given the tendency in this population to present a diminished use of IS (see section "IS in ASC and Sz-AVH: How It Relates to EF"). We finally briefly discuss Attention Deficit/Hyperactivity Disorder (ADHD) and Developmental Language Disorders (DLD) (see section "Further Considerations").

An Australian study of delusional disorder in late life

OBJECTIVES

There is a paucity of available research to guide clinical practice in delusional disorder (DD), particularly in late life. This study aimed to evaluate antipsychotic use and treatment outcomes in patients with DD aged 65 years and older. Secondarily, we sought to examine associated clinical features and socio-demographic variables.

DESIGN AND SETTING

This descriptive study reviewed all consecutive cases of DD referred to an Australian old age psychiatry service over a 12-year period. Fifty-five patients were assessed in the inpatient and/or community setting, with data verified from a review of all individual medical records.

MEASUREMENTS

Data were collected with respect to antipsychotic use, outcomes, and clinical features. Socio-demographic variables of DD cases were compared to a non-matched comparison group (n=278) and an age and gender matched comparison group with a 1:1 ratio (n=55).

RESULTS

The predominant type of DD was persecutory (87%). Non-prominent hallucinations were experienced by 18%, and depressive symptoms occurred in 22%. There was a statistically significant association between having DD and social isolation (χ2= 11.04 (DF=1) p<0.001; McNemar's test p<0.001). Atypical antipsychotic medication was prescribed in 32 cases, with follow-up permitted in 51 of the 55 cases (mean duration 36.6 months). Sustained recovery occurred in 20%, and improvement in an additional 35% of the study sample. Four patients subsequently developed dementia, and two developed mild cognitive impairment.

CONCLUSIONS

Clinical improvement, including sustained recovery, occurred in more than half of those with late life DD. The majority of those who improved (96%) received atypical antipsychotics.

Functionality and Neurocognition in Patients With Bipolar Disorder After a Physical-Exercise Program (FINEXT-BD Study): Protocol of a Randomized Interventionist Program

Introduction: Recent studies have shown that symptoms of psychiatric illness, functionality, and cognitive function improve with exercise. The aim of this study will be to investigate whether the implementation of an individualized exercise program will improve the functional status of patients with bipolar disorder (BD). Methods: This longitudinal, interventional, randomized, controlled, simple-blind clinical trial will include 80 patients aged 18-65 years, all of them with BD diagnosis. Patients will be randomly assigned to a physical exercise intervention + Treatment-As-Usual (TAU) group and a non-intervention + TAU group. Patients will be assessed by an extensive battery of clinical tests, physical parameters (e.g., brain structure changes measured by optical coherence tomography, cardiorespiratory fitness) and biological parameters (inflammation, oxidative stress and neurotrophic factors) at baseline, after a 4-month intervention period, and 6-month follow-up. Discussion: This is an innovative study aimed at gaining a deeper understanding of the physiopathology of BD and determining whether the prognosis and evolution of the disease can be improved through modifiable areas of the patient's lifestyle. Clinical Trial Registration: NCT04400630. NCT clinicaltrials.gov. Date of registration in primary registry 22 May 2020. clinicaltrials.gov.

Cognition and functionality in delusional disorder

Background:

Even if neurocognition is known to affect functional outcomes in schizophrenia, no previous study has explored the impact of cognition on functionality in delusional disorder (DD). We aimed to assess the effect of clinical characteristics, symptom dimensions and neuropsychological performance on psychosocial functioning and self-perceived functional impairment in DD.

Methods:

Seventy-five patients with a SCID-I confirmed diagnosis of DD underwent neurocognitive testing using a neuropsychological battery examining verbal memory, attention, working memory and executive functions. We assessed psychotic symptoms with the Positive and Negative Syndrome Scale, and calculated factor scores for four clinical dimensions: Paranoid, Cognitive, Affective and Schizoid. We conducted hierarchical linear regression models to identify predictors of psychosocial functioning, as measured with the Global Assessment of Functioning scale, and self-perceived functional impairment, as measured with the Sheehan’s Disability Inventory.

Results:

In the final linear regression models, higher scores in the Paranoid (β= 0.471, p <.001, r2 = 0.273) and Cognitive (β = 0.325, p <.001, r2 = 0.180) symptomatic dimensions and lower scores in verbal memory (β = −0.273, p <.05, r2 = 0.075) were significantly associated with poorer psychosocial functioning in patients with DD. Lower scores in verbal memory (β= −0.337, p <.01, r2 = 0.158) and executive functions (β= −0.323, p <.01, r2 = 0.094) were significantly associated with higher self-perceived disability.

Conclusions:

Impaired verbal memory and cognitive symptoms seem to affect functionality in DD, above and beyond the severity of the paranoid idea. This suggests a potential role for cognitive interventions in the management of DD.

A Psychopathological Comparison between Delusional Disorder and Schizophrenia

OBJECTIVE

To contribute to a better differential clinical categorisation of delusional disorder (DD) versus schizophrenia (SZ) and to add and complete evidence from previous clinical studies of DD compared to schizophrenia.

METHODS

A cross-sectional study using a clinical sample of 275 patients (132 patients with DD) was studied. Patients were consecutively attending public clinics located in urban and rural areas in both Andalusia and Catalonia (Spain). All participants met DSM-IV diagnostic criteria for either DD or SZ. Data were gathered on sociodemographics, illness duration, Barona-Index estimation of intelligence quotient (IQ), and global functioning, along with a thorough psychopathological assessment using the Positive and Negative Syndrome Scale (PANSS). Comparisons between both groups were calculated using χ², Student t, and multivariate analysis of covariance tests.

RESULTS

Patients with DD were older (mean [SD], 50.3 [14.6] years vs. 36.6 [11.1] years; t = 8.597; P ≤ 0.0001), were more frequently married (45.4% vs. 10.8%; χ² = 38.569; P ≤ 0.0001), and had a higher mean estimated premorbid IQ (111.4 vs. 105.4; t = 2.609; P ≤ 0.01). On the other hand, SZ patients were predominantly male (71.4% vs. 48.9%; χ² = 14.433; P ≤ 0.0001) and had greater work-related disability than DD patients (20.5% vs. 50.3%; χ² = 19.564; P ≤ 0.001). Overall, the DD group showed a less severe PANSS psychopathology than SZ group. Thus, total mean (SD) PANSS scores for schizophrenia and delusional disorder, respectively, were 76.2 (22.4) versus 54.1 (18.4) ( t = -8.762; P ≤ 0.0001). Moreover, patients with DD showed a better global functioning than those with SZ (62.7 [13.2] vs. 51.9 [16.9]; F = 44.114; P ≤ 0.0001).

CONCLUSIONS

DD is a milder and distinct disorder compared to SZ in terms of psychopathology and global functionality.

The Clinical Features of Paranoia in the 20th Century and Their Representation in Diagnostic Criteria From DSM-III Through DSM-5

This review traces, through psychiatric textbooks, the history of the Kraepelinian concept of paranoia in the 20th century and then relates the common reported symptoms and signs to the diagnostic criteria for paranoia/delusional disorder in DSM-III through DSM-5. Clinical descriptions of paranoia appearing in 10 textbooks, published 1899 to 1970, revealed 11 prominent symptoms and signs reported by 5 or more authors. Three symptoms (systematized delusions, minimal hallucinations, and prominent ideas of reference) and 2 signs (chronic course and minimal affective deterioration) were reported by 8 or 9 of the authors. Four textbook authors rejected the Kraepelinian concept of paranoia. A weak relationship was seen between the frequency with which the clinical features were reported and the likelihood of their inclusion in modern DSM manuals. Indeed, the diagnostic criteria for paranoia/delusional disorder shifted substantially from DSM-III to DSM-5. The modern operationalized criteria for paranoia/delusional disorder do not well reflect the symptoms and signs frequently reported by historical experts. In contrast to results of similar reviews for depression, schizophrenia and mania, the clinical construct of paranoia/delusional disorder has been somewhat unstable in Western Psychiatry since the turn of the 20th century as reflected in both textbooks and the DSM editions.

When emotion and cognition do (not) work together: Delusions as emotional and executive dysfunctions

In this commentary, I argue that the cognitive-emotional framework put forward by Pessoa (2013) can be successfully applied to psychopathology and, in particular, to the reasoning of delusional subjects. More specifically, I show that the notion of executive competition (Ch. 7) offers a significant contribution to the idea that delusions may involve both executive and emotional dysfunctions.

A dimensional comparison between delusional disorder, schizophrenia and schizoaffective disorder

INTRODUCTION

Since the early description of paranoia, the nosology of delusional disorder has always been controversial. The old idea of unitary psychosis has now gained some renewed value from the dimensional continuum model of psychotic symptoms.

AIMS

1. To study the psychopathological dimensions of the psychosis spectrum; 2. to explore the association between psychotic dimensions and categorical diagnoses; 3. to compare the different psychotic disorders from a psychopathological and functional point of view.

MATERIAL AND METHODS

This is an observational study utilizing a sample of some 550 patients with a psychotic disorder. 373 participants had a diagnosis of schizophrenia, 137 had delusional disorder and 40 with a diagnosis of schizoaffective disorder. The PANSS was used to elicit psychopathology and global functioning was ascertained using the GAF measure. Both exploratory and confirmatory factor analyses of the PANSS items were performed to extract psychopathological dimensions. Associations between diagnostic categories and dimensions were subsequently studied using ANOVA tests.

RESULTS

5 dimensions - manic, negative symptoms, depression, positive symptoms and cognitive - emerged. The model explained 57.27% of the total variance. The dimensional model was useful to explained differences and similarities between all three psychosis spectrum categories. The potential clinical usefulness of this dimensional model within and between clinical psychosis spectrum categories is discussed.

Working memory dysfunction in delusional disorders: an fMRI investigation

BACKGROUND

Delusional disorder (DD) is a rare and understudied psychiatric disorder. There is limited number of studies concerning cognitive characteristics in DD. Using an established working memory paradigm with variable levels of memory load, we investigated alterations in functional magnetic resonance imaging (fMRI) of brain regions in patients with DD.

METHODS

This case control study included 9 patients with DD and 9 healthy control subjects matched for age, sex, and education level. Diagnosis of DD was confirmed using the Structured Clinical Interview for DSM-IV Axis I. The severity of the symptoms was evaluated using the Positive and Negative Syndrome Scale. All patients were asked to perform 0-back and 2-back tasks during fMRI experiments. Functional imaging was performed using the 3.0 T Philips whole-body scanner using an 8-channel head coil.

RESULTS

Participants with DD had less neural activation of the left dorsolateral prefrontal cortex in fMRI scans obtained during performance tasks. On the other hand, neural activation of the left and right superior temporal gyrus, left middle and inferior temporal gyrus, right and left posterior cingulate gyrus, right amygdala, left and right fusiform gyrus was more prominent in patients with DD in comparison with the control group.

DISCUSSION

Patients with DD had dysfunction in the prefrontal, temporal and limbic regions of the brain in particular, during performance tasks of working memory. Our findings were in line with the findings of the early reports on deficient functioning in temporal or limbic regions of the brain. Further, patients with DD displayed prefrontal dysfunction as seen in patients with schizophrenia.