Accuracy of the Wechsler Test of Adult Reading (WTAR) and National Adult Reading Test (NART) when estimating IQ in a healthy Australian sample

The Priority Goals and Underlying Impairments Contributing to Goal-Related Problems of People with Parkinson's Disease Receiving a Community-Based Rehabilitation Program

Background

Goal setting is a core rehabilitation practice in Parkinson's disease (PD). Targeting therapy towards specific goals leads to greater improvements in performance and psychosocial outcomes. Goal setting in PD is feasible, and although the nature of goals has been described in previous studies, the underlying impairments related to goals have not been described. Understanding the nature of goals ensures that interventions for people with PD are aligned with their needs and priorities. Understanding the underlying impairments highlights which symptoms have the biggest impact on daily life and is necessary for planning appropriate interventions to target them.

Aim

To describe the nature of the goals of people with PD; the underlying impairments related to goals; and to compare differences between high and low priority goals.

Method

Deductive content analysis was used to map goal statements to the international classification of function (ICF) activity and participation category and to map therapist field notes detailing the primary underlying impairment to the ICF Body Functions category. These results were then compared across goal priority rankings.

Results

88 goals of 22 people with PD were analysed. We found that people with PD set diverse goals across all chapters of the ICF Activity and Participation category, with "self-care" goals making up the highest proportion of goals. The primary underlying impairment related to the goals was predominantly related to impairments in "mental functions" under the Body Functions category. Regardless of goal priority, most goal-related underlying impairments were found to be in the "mental functions" category.

Conclusion

The goals of this sample of community-dwelling people with PD highlight their diverse needs and priorities. These findings indicate that nonmotor symptoms, namely, executive dysfunction and amotivation most commonly impact the performance of and participation in activities of greatest importance to people with PD. This trial is registered with ACTRN12621001483842.

The association between childhood trauma and emotion recognition is reduced or eliminated when controlling for alexithymia and psychopathy traits

Emotion recognition shows large inter-individual variability, and is substantially affected by childhood trauma as well as modality, emotion portrayed, and intensity. While research suggests childhood trauma influences emotion recognition, it is unclear whether this effect is consistent when controlling for interrelated individual differences. Further, the universality of the effects has not been explored, most studies have not examined differing modalities or intensities. This study examined childhood trauma's association with accuracy, when controlling for alexithymia and psychopathy traits, and if this varied across modality, emotion portrayed, and intensity. An adult sample (N = 122) completed childhood trauma, alexithymia, and psychopathy questionnaires and three emotion tasks: faces, voices, audio-visual. When investigating childhood trauma alone, there was a significant association with poorer accuracy when exploring modality, emotion portrayed, and intensity. When controlling for alexithymia and psychopathy, childhood trauma remained significant when exploring emotion portrayed, however, it was no longer significant when exploring modality and intensity. In fact, alexithymia was significant when exploring intensity. The effect sizes overall were small. Our findings suggest the importance of controlling for interrelated individual differences. Future research should explore more sensitive measures of emotion recognition, such as intensity ratings and sensitivity to intensity, to see if these follow accuracy findings.

Efficacy and Feasibility of the CO-OP Approach in Parkinson's Disease: RCT Study Protocol

Background. Parkinson's disease (PD) leads to cognitive dysfunction which limits participation and occupational performance. Cognitive Orientation to Daily Occupational Performance (CO-OP) approach is effective in other adult neurological populations and warrants investigation in PD. Purpose. To describe a study protocol evaluating the preliminary efficacy and feasibility of CO-OP approach in PD. Method. A randomised controlled trial (RCT) with adults with PD was assigned to either: CO-OP training-intensive (CO-OP-I, 20 sessions) or waitlist control (WLC) followed by CO-OP-standard (CO-OP-S, 10 sessions). Outcomes. Occupational performance and satisfaction of adults with PD in chosen goals. Measures will be obtained at baseline, post-intervention, and 3-month follow-up. Implications. As the first RCT focused on CO-OP in PD, this trial will provide evidence for the potential of this approach in PD and lay the groundwork for future large-scale trials. Trial Registration. Australian New Zealand Clinical Trials registry, ACTRN12621001483842. Registered November 1, 2021; retrospectively registered 3 months after commencement.

Intelligence decline across major depressive disorder, bipolar disorder, and schizophrenia

BACKGROUND

Major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SCZ) are associated with impaired intelligence that predicts poor functional outcomes. However, little is known regarding the extent and severity of intelligence decline, that is, decreased present intelligence quotient (IQ) relative to premorbid levels, across psychiatric disorders and which clinical characteristics affect the decline.

METHODS

Premorbid IQ, present IQ, and intelligence decline were compared across patients with MDD (n = 45), BD (n = 30), and SCZ (n = 139), and healthy controls (HCs; n = 135). Furthermore, we investigated which factors contribute to the intelligence decline in each diagnostic group.

RESULTS

Significant differences were observed in premorbid IQ, present IQ, and intelligence decline across the diagnostic groups. Patients with each psychiatric disorder displayed lower premorbid and present IQ and more intelligence decline than HCs. Patients with SCZ displayed lower premorbid and present IQ and more intelligence decline than patients with MDD and BD, while there were no significant differences between patients with MDD and BD. When patients with BD were divided based on bipolar I disorder (BD-I) and bipolar II disorder (BD-II), degrees of intelligence decline were similar between MDD and BD-II and between BD-I and SCZ. Lower educational attainment was correlated with a greater degree of intelligence decline in patients with SCZ and BD but not MDD.

CONCLUSIONS

These findings confirm that although all psychiatric disorders display intelligence decline, the severity of intelligence decline differs across psychiatric disorders (SCZ, BD-I > BD-II, MDD > HCs). Higher educational attainment as cognitive reserve contributes to protection against intelligence decline in BD and SCZ.

Can IQ moderate the response to cognitive remediation in people with schizophrenia?

BACKGROUND

IQ and IQ decline are considered risk factors for poor prognosis in people with a diagnosis of schizophrenia. However, it is still not clear if, at least in part, IQ and IQ decline influence long-term outcomes via a negative effect on interventions.

AIM

To identify whether current IQ, estimated premorbid IQ, or IQ decline moderate the response to cognitive remediation (CR).

METHOD

Individual participant data from twelve randomised controlled trials of CR were considered. Hierarchical and k-means analyses were carried out to identify different IQ clusters. The moderating effect of estimated premorbid IQ, current IQ, and different IQ clusters (preserved, deteriorated and compromised trajectories) on cognitive outcomes at post-therapy and follow-up were evaluated using multiple linear regression.

RESULTS

Data from 984 participants (CR = 544, control = 440) with schizophrenia and schizoaffective disorders were considered. The sample had a mean current IQ of 84.16 (SD 15.61) and estimated premorbid IQ of 95.82 (SD 10.63). Current IQ moderated working memory outcomes: people with higher IQ had larger working memory gains after therapy compared to those with a lower IQ. Those with a preserved IQ had better cognitive outcomes compared to either the deteriorated or compromised IQ groups, and those with a deteriorated IQ had better outcomes compared to those in the compromised IQ group.

CONCLUSION

Current IQ is a significant moderator of cognitive gains after CR. These findings highlight the need to evaluate whether therapy adaptations (e.g. offering more sessions) can attenuate this effect so that those with lower IQ may derive benefit similar to those with higher IQ.

Testing the Cognitive Reserve Index Questionnaire in an Alzheimer's Disease Population

Background

Alzheimer's disease (AD) is the 6th leading cause of death in the United States and has no cure or progression prevention. The Cognitive Reserve (CR) theory poses that constant brain activity earlier in life later helps to deter pathological changes in the brain, delaying the onset of disease symptoms.

Objective

To determine the reliability and validity of the Cognitive Reserve Index questionnaire (CRIq) in AD patients.

Methods

Primary data collection was done using the CRIq to quantify CR in 90 participants. Correlations and multivariable linear regressions were used to assess reliability and validity.

Results

Reliability was tested in 34 participants. A Pearson correlation coefficient of 0.89 (p < 0.001) indicated a strong positive correlation. Validity was tested in 33 participants. A Pearson correlation coefficient of 0.30 (p = 0.10) indicated an insignificant weak positive correlation.

Conclusion

The CRIq was found reliable. Gaining a better understanding of how CR tools can be used in various cognitive populations will help with the establishment of a research tool that is universally accepted as a true CR measure.

Investigating the Test of Premorbid Functioning (TOPF) in predicting Wechsler Abbreviated Scale of Intelligence - Second edition (WASI-II) scores in an Australian sample

Accurate prediction of premorbid functioning is important in neuropsychological assessment. We aimed to investigate the predictive accuracy of the TOPF and examine this word list at an item level against WASI-II scores, using Australian pronunciations. The sample of 219 healthy Australians were aged 18-82 years. Multiple regression analyses were used to replicate the TOPF and simple demographic models based on the US TOPF standardization. Rasch analyses provided a comparison of Australian, US and UK word order from the proportion of words pronounced correctly. The variance explained in WASI-II index scores ranged from R²=.12 (PRI) to .33 (FSIQ-2), which was approximately half that reported in the US standardization study. The accuracy of predicted WASI-II scores was also slightly less in our sample. Thirty-two words were out of place by five places or more compared with the US word order and 30 compared with the UK. These results add to concerns about the application the TOPF with norms developed in the US and UK in the Australian context. Clinicians are advised not to apply the five error discontinue rule when using the TOPF in the local context. Development of a more accurate word reading task for use in Australia is warranted.

Obstetric complications and intelligence in patients on the schizophrenia-bipolar spectrum and healthy participants

BACKGROUND

Whether severe obstetric complications (OCs), which harm neural function in offspring, contribute to impaired cognition found in psychiatric disorders is currently unknown. Here, we sought to evaluate how a history of severe OCs is associated with cognitive functioning, indicated by Intelligence Quotient (IQ).

METHODS

We evaluated the associations of a history of OCs and IQ in 622 healthy controls (HC) and 870 patients on the schizophrenia (SCZ) - bipolar disorder (BIP) spectrum from the ongoing Thematically Organized Psychosis study cohort, Oslo, Norway. Participants underwent assessments using the NART (premorbid IQ) and the WASI (current IQ). Information about OCs was obtained from the Medical Birth Registry of Norway. Multiple linear regression models were used for analysis.

RESULTS

Severe OCs were equally common across groups. SCZ patients with OCs had lower performances on both premorbid and current IQ measures, compared to those without OCs. However, having experienced more than one co-occurring severe OC was associated with lower current IQ in all groups.

CONCLUSIONS

Severe OCs were associated with lower IQ in the SCZ group and in the BIP and HC groups, but only if they had experienced more than one severe OC. Low IQ might be a neurodevelopmental marker for SCZ; wherein, severe OCs influence cognitive abilities and increase the risk of developing SCZ. Considering OCs as a variable of neurodevelopmental risk for severe mental illness may promote the development of neuroprotective interventions, improve outcome in vulnerable newborns and advance our ability to make clinical prognoses.

Urate and Homocysteine: Predicting Motor and Cognitive Changes in Newly Diagnosed Parkinson's Disease

BACKGROUND

Urate and homocysteine are potential biomarkers for disease progression in Parkinson's disease (PD). Baseline serum urate concentration has been shown to predict motor but not cognitive decline. The relationship between serum homocysteine concentration and cognitive and motor impairment is unknown.

OBJECTIVES

The aim of this study was to examine the association between baseline serum urate and homocysteine, and prospective measures of disease progression and cognition over 54 months in early PD.

METHODS

154 newly diagnosed PD participants and 99 age-matched controls completed a schedule of assessments at baseline, 18, 36 and 54 months. The Movement Disorders Society Unified Parkinson's Disease Scale Part III (MDS-UPDRS III) was used to assess motor severity. The Montreal Cognitive Assessment (MoCA) was used to assess global cognition. Serum samples drawn at baseline were analysed for urate, homocysteine, red cell folate and vitamin B12 concentrations.

RESULTS

Baseline urate was 331.4±83.8 and 302.7±78.0μmol/L for control and PD participants, respectively (p = 0.015). Baseline homocysteine was 9.6±3.3 and 11.1±3.8μmol/L for controls and PD participants, respectively (p < 0.01). Linear mixed effects modelling showed that lower baseline urate (β= 0.02, p < 0.001) and higher homocysteine (β= 0.29, p < 0.05) predicted decline in motor function. Only higher homocysteine concentrations at baseline, however, predicted declining MoCA scores over 54 months (β= 0.11, p < 0.01).

CONCLUSIONS

Lower serum urate concentration is associated with worsening motor function; while higher homocysteine concentration is associated with change in motor function and cognitive decline. Therefore, urate and homocysteine may be suitable biomarkers for predicting motor and cognitive decline in early PD.

Intelligence decline between present and premorbid IQ in schizophrenia: Schizophrenia Non-Affected Relative Project (SNARP)

Schizophrenia patients (SCZ) display widespread cognitive deficits that are strongly associated with functional outcomes. Cognitive impairments occur along a genetic continuum among SCZ, their unaffected first-degree relatives (FRs) and healthy controls (HCs). Although SCZ impairs the premorbid intelligence quotient (IQ) and causes a subsequent intelligence decline (ID), a decrease in present IQ from the premorbid level, it remains unclear when during the illness course these impairments develop. Differences in premorbid and present IQ and ID were investigated among 125 SCZ, 61 FRs and 107 HCs, using analysis of covariance and a paired t-test. Furthermore, these subjects were classified into preserved and deteriorated IQ groups based on the degree of ID, and we investigated which factors contribute to this classification. We found significant differences in premorbid and present IQ among the diagnostic groups. Compared with HCs, SCZ and FRs displayed lower premorbid and present IQ. There was no significant difference in premorbid IQ between SCZ and FRs, but SCZ had a significantly lower present IQ than FRs. Only SCZ showed a significant ID. As most FRs and HCs did not display an ID, there were fewer subjects with deteriorated IQ among FRs and HCs than among SCZ. Subjects with preserved IQ showed higher educational attainment than those with deteriorated IQ among SCZ and FRs. These findings suggest that the impairment of premorbid IQ and the ID in SCZ become evident before and around the time of onset, respectively, and different pathophysiological mechanisms might be related to these impairments.

Social Conformity in Autism

Humans are extremely susceptible to social influence. Here, we examine whether this susceptibility is altered in autism, a condition characterized by social difficulties. Autistic participants (N = 22) and neurotypical controls (N = 22) completed a memory test of previously seen words and were then exposed to answers supposedly given by four other individuals. Autistic individuals and controls were as likely to alter their judgements to align with inaccurate responses of group members. These changes reflected both temporary judgement changes (public conformity) and long-lasting memory changes (private conformity). Both groups were more susceptible to answers believed to be from other humans than from computer algorithms. Our results suggest that autistic individuals and controls are equally susceptible to social influence when reporting their memories.

Demographically Calibrated Norms for Two Premorbid Intelligence Measures: The Word Accentuation Test and Pseudo-Words Reading Subtest

The Word Accentuation Test (WAT, Spanish adaptation of the NART) and the Pseudo-Words (PW) Reading subtest from the Battery for Reading Processes Assessment-Revised (PROLEC-R) are measures to estimate premorbid IQ. This study aims to develop demographically calibrated norms for these premorbid measures in a representative sample of the adult Spanish population in terms of age, education, and sex. A sample of 700 healthy participants from 18 to 86 years old completed the WAT and the PW Reading subtest. The effect of age, years of formal education, and sex on WAT total score, PW total score, and time to complete the PW task (PW time) were analyzed. Percentiles and scalar scores were obtained for each raw score according to nine age ranges and individual education levels. The results indicated a significant effect of age and education on the premorbid performance assessed, with no significant effect of sex. Age and education explained from 1.9 to 33.2% of the variance in premorbid IQ variables. Older participants with fewer years of education obtained worse premorbid IQ estimates. This premorbid IQ estimation decline started in the 56-65 age range for WAT total score and PW time, whereas it started in the 71-75 age range for PW total score. This study reports the first demographic-calibrated norms for WAT and PW Reading subtest for Spanish-speaking population. Even though the influence of age and years of education on premorbid IQ measures was confirmed, the PW Reading subtest showed to be more resistant to decline in elderly population than the WAT.

The Effect of Housing First on Housing Stability for People with Mental Illness and Low Intellectual Functioning

OBJECTIVE

Housing First (HF) has been linked to increased tenure in housing for homeless people with mental illness, but the effect of HF on housing stability for people with borderline or lower intellectual functioning has not been examined. This study of homeless adults with mental illness in Toronto, Ontario assessed whether the association between housing stability and HF differed for adults with borderline or lower intellectual functioning, compared to adults with above borderline intellectual functioning.

METHOD

This study included 172 homeless adults with mental illness from the Toronto site of the At Home-Chez Soi randomized trial that compared receiving HF relative to treatment as usual. This sample was divided into two intellectual functioning groups: 1) adults with borderline or lower intellectual functioning (IQ < 85, 16%), and 2) adults with above borderline intellectual functioning (IQ ≥ 85, 84%). We compared these groups by modelling the percentage of days stably housed using a linear multivariable generalized estimating equation and included interaction between treatment and intellectual functioning. An interaction between treatment and time was also included.

RESULTS

There were no overall differences in housing stability for individuals with borderline or lower intellectual functioning compared to people with higher than borderline intellectual functioning in either the HF or the treatment as usual groups.

CONCLUSION

This study is the first to demonstrate that for homeless adults with mental illness, borderline or lower intellectual functioning did not significantly affect housing stability. This accentuates the need for more research and potentially wider consideration of their inclusion in housing interventions, such as HF.

A Brief Assessment of Intelligence Decline in Schizophrenia As Represented by the Difference between Current and Premorbid Intellectual Quotient

Patients with schizophrenia elicit several clinical features, such as psychotic symptoms, cognitive impairment, and subtle decline of intelligence. The latter two features become evident around the onset of the illness, although they may exist even before the disease onset in a substantial proportion of cases. Here, we review the literature concerning intelligence decline (ID) during the progression of schizophrenia. ID can be estimated by comparing premorbid and current intellectual quotient (IQ) by means of the Adult Reading Test and Wechsler Adult Intelligence Scale (WAIS), respectively. For the purpose of brief assessment, we have recently developed the WAIS-Short Form, which consists of Similarities and Symbol Search and well reflects functional outcomes. According to the degree of ID, patients were classified into three distinct subgroups; deteriorated, preserved, and compromised groups. Patients who show deteriorated IQ (deteriorated group) elicit ID from a premorbid level (≥10-point difference between current and premorbid IQ), while patients who show preserved or compromised IQ do not show such decline (<10-point difference). Furthermore, the latter patients were divided into patients with preserved and compromised IQ based on an estimated premorbid IQ score >90 or below 90, respectively. We have recently shown the distribution of ID in a large cohort of schizophrenia patients. Consistent with previous studies, approximately 30% of schizophrenia patients had a decline of less than 10 points, i.e., normal intellectual performance. In contrast, approximately 70% of patients showed deterioration of IQ. These results indicate that there is a subgroup of schizophrenia patients who have mild or minimal intellectual deficits, following the onset of the disorder. Therefore, a careful assessment of ID is important in identifying appropriate interventions, including medications, cognitive remediation, and social/community services.

Intra- and inter-network functional alterations in Parkinson's disease with mild cognitive impairment

Mild cognitive impairment (MCI) is prevalent in 15%-40% of Parkinson's disease (PD) patients at diagnosis. In this investigation, we study brain intra- and inter-network alterations in resting state functional magnetic resonance imaging (rs-fMRI) in recently diagnosed PD patients and characterise them as either cognitive normal (PD-NC) or with MCI (PD-MCI). Patients were divided into two groups, PD-NC (N = 62) and PD-MCI (N = 37) and for comparison, healthy controls (HC, N = 30) were also included. Intra- and inter-network connectivity were investigated from participants' rs-fMRIs in 26 resting state networks (RSNs). Intra-network differences were found between both patient groups and HCs for networks associated with motor control (motor cortex), spatial attention and visual perception. When comparing both PD-NC and PD-MCI, intra-network alterations were found in RSNs related to attention, executive function and motor control (cerebellum). The inter-network analysis revealed a hyper-synchronisation between the basal ganglia network and the motor cortex in PD-NC compared with HCs. When both patient groups were compared, intra-network alterations in RSNs related to attention, motor control, visual perception and executive function were found. We also detected disease-driven negative synchronisations and synchronisation shifts from positive to negative and vice versa in both patient groups compared with HCs. The hyper-synchronisation between basal ganglia and motor cortical RSNs in PD and its synchronisation shift from negative to positive compared with HCs, suggest a compensatory response to basal dysfunction and altered basal-cortical motor control in the resting state brain of PD patients. Hum Brain Mapp 38:1702-1715, 2017. © 2016 Wiley Periodicals, Inc.

Anxiety is associated with cognitive impairment in newly-diagnosed Parkinson's disease

Introduction

Anxiety and mild cognitive impairment (MCI) are prevalent non-motor manifestations of Parkinson's disease (PD). While few studies have demonstrated a possible link between cognitive dysfunction and anxiety in PD, to our knowledge, no studies have directly examined the association between them. This study investigated the association between anxiety and cognitive deficits in newly diagnosed PD patients.

Methods

Patients with newly diagnosed PD (N = 185) were recruited from community and outpatient clinics. Anxiety was assessed using the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) clinician rated anxiety item, which has previously been validated against a standardized criteria for the diagnosis of anxiety disorders in PD. Participants scoring ≥2 were classified as anxious. A threshold of 1 SD below normative values (obtained from controls) was used to define cognitive impairment. Impairments in specific cognitive domains were identified as being >1 SD below controls in ≥1 test per domain.

Results

After controlling for age, education and motor severity, patients with anxiety were three times more likely to have cognitive impairment compared to those without anxiety (OR = 3.0, 95% CI = 1.2–7.3, p < 0.05). Patients with anxiety were more than twice as likely to be classified as having cognitive impairment due to impairment in the memory domain compared with PD without anxiety (OR = 2.3, 95% CI = 1.0–5.1, p < 0.05), whilst no associations were found between anxiety and performance on other cognitive domains.

Conclusion

This study shows an association between anxiety and cognitive impairment (specifically memory impairment). Examining the neural basis of this association warrants future research in this developing field.

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Anxiety was associated with mild cognitive impairment (MCI) in PD.

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Patients with anxiety were three times more likely to have cognitive impairment.

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Anxiety was specifically associated with impairments in the memory domain.

The National Adult Reading Test: restandardisation against the Wechsler Adult Intelligence Scale-Fourth edition

Since publication in 1982, the 50-item National Adult Reading Test (NART; Nelson, 1982; NART-R; Nelson & Willison, 1991) has remained a widely adopted method for estimating premorbid intelligence both for clinical and research purposes. However, the NART has not been standardised against the most recent revisions of the Wechsler Adult Intelligence Scale (WAIS-III; Wechsler, 1997, and WAIS-IV; Wechsler, 2008). Our objective, therefore, was to produce reliable standardised estimates of WAIS-IV IQ from the NART. Ninety-two neurologically healthy British adults were assessed and regression equations calculated to produce population estimates of WAIS-IV full-scale IQ (FSIQ) and constituent index scores. Results showed strong NART/WAIS-IV FSIQ correlations with more moderate correlations observed between NART error and constituent index scores. FSIQ estimates were closely similar to the published WAIS and WAIS-R estimates at the high end of the distribution, but at the lower end were approximately equidistant from the highly discrepant WAIS (low) and WAIS-R (high) values. We conclude that the NART is likely to remain an important tool for estimating the impact of neurological damage on general cognitive ability. We advise caution in the use of older published WAIS and/or WAIS-R estimates for estimating premorbid WAIS-IV FSIQ, particularly for those with low NART scores.

Cognitive decline and quality of life in incident Parkinson's disease: The role of attention

Introduction

Parkinson's disease dementia (PDD) is associated with poorer quality of life (QoL). Prior to the onset of PDD, many patients experience progressive cognitive impairment. There is a paucity of longitudinal studies investigating the effects of cognitive decline on QoL. This study aimed to determine the longitudinal impact of cognitive change on QoL in an incident PD cohort.

Methods

Recently diagnosed patients with PD (n = 212) completed a schedule of neuropsychological assessments and QoL measures; these were repeated after 18 (n = 190) and 36 months (n = 158). Mild cognitive impairment (PD-MCI) was classified with reference to the Movement Disorder Society criteria. Principal component analysis was used to reduce 10 neuropsychological tests to three cognitive factors: attention, memory/executive function, and global cognition.

Results

Baseline PD-MCI was a significant contributor to QoL (β = 0.2, p < 0.01). For those subjects (9%) who developed dementia, cognitive function had a much greater impact on QoL (β = 10.3, p < 0.05). Multivariate modelling showed attentional deficits had the strongest predictive power (β = −2.3, p < 0.01); brief global tests only modestly predicted decline in QoL (β = −0.4, p < 0.01).

Conclusions

PD-MCI was associated with poorer QoL over three years follow up. Cognitive impairment had a greater impact on QoL in individuals who developed dementia over follow-up. Impaired attention was a significant determinant of QoL in PD. Interventions which improve concentration and attention in those with PD could potentially improve QoL.

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Rate of QoL decline was three times faster in PD-MCI subjects compared those with normal cognition.

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Cognitive decline predicted worsening of QoL over 36 months.

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Decline in attention was the strongest cognitive predictor of declining QoL.

The impact of premorbid and current intellect in schizophrenia: cognitive, symptom, and functional outcomes

BACKGROUND

Cognitive heterogeneity among people with schizophrenia has been defined on the basis of premorbid and current intelligence quotient (IQ) estimates. In a relatively large, community cohort, we aimed to independently replicate and extend cognitive subtyping work by determining the extent of symptom severity and functional deficits in each group.

METHODS

A total of 635 healthy controls and 534 patients with a diagnosis of schizophrenia or schizoaffective disorder were recruited through the Australian Schizophrenia Research Bank. Patients were classified into cognitive subgroups on the basis of the Wechsler Test of Adult Reading (a premorbid IQ estimate) and current overall cognitive abilities into preserved, deteriorated, and compromised groups using both clinical and empirical (k-means clustering) methods. Additional cognitive, functional, and symptom outcomes were compared among the resulting groups.

RESULTS

A total of 157 patients (29%) classified as 'preserved' performed within one s.d. of control means in all cognitive domains. Patients classified as 'deteriorated' (n=239, 44%) performed more than one s.d. below control means in all cognitive domains except estimated premorbid IQ and current visuospatial abilities. A separate 138 patients (26%), classified as 'compromised,' performed more than one s.d. below control means in all cognitive domains and displayed greater impairment than other groups on symptom and functional measures.

CONCLUSIONS

In the present study, we independently replicated our previous cognitive classifications of people with schizophrenia. In addition, we extended previous work by demonstrating worse functional outcomes and symptom severity in the compromised group.

Anxiety in epilepsy: a neglected disorder

OBJECTIVE

Anxiety disorders and symptoms are highly prevalent and problematic comorbidities in people with epilepsy (PWE), yet they remain poorly understood and often go undetected. This research aimed to further our understanding about anxiety in PWE.

METHODS

Study 1 assessed the effectiveness of the commonly utilised yet unvalidated measure (Hospital Anxiety Depression Scale-Anxiety subscale; HADS-A) to identify DSM-IV anxiety disorders in 147 adult epilepsy outpatients.

RESULTS

This study found that although the HADS-A had reasonable specificity (75%), its poor sensitivity (61%) and inadequate area under the curve (.68) deemed it unreliable as a screener for anxiety disorders in this population.

METHODS

Study 2 aimed to further our understanding of the relationship between anxiety disorders, as defined by clinical interview, and psychosocial correlates in PWE. One hundred and twenty-two participants from Study 1 completed a battery of psychosocial measures.

RESULTS

Multivariate analysis revealed that the presence of an anxiety disorder was associated with unemployment, which was found to be the only independent predictor. That is, despite the fact that psychosocial factors together contributed to the variance in anxiety disorders none were revealed to be significant independent predictors.

CONCLUSION

These findings add to the literature indicating that the HADS may indicate distress, but does not adequately identify people with anxiety disorders and highlights the urgent need for the development of a reliable anxiety screening measure for PWE. Further, the results suggest that anxiety disorders in PWE are likely to be multiply determined with respect to psychosocial factors and require further investigation.

Intelligence and Psychopathy Do Not Influence Malingering

This study examined the influence of psychopathy and intelligence on malingering in a simulated malingering design. We hypothesized that participants high in both traits would be more adept at evading detection on performance validity tests (PVTs). College students (N = 92) were first administered the Wechsler Test of Adult Reading, a reading measure that estimates intelligence, and the Psychopathic Personality Inventory-Short Form under standard conditions. They were then asked to imagine as if they had suffered a concussion a year ago and were instructed to fake or exaggerate symptoms in a believable fashion to improve their settlement as part of a lawsuit. Participants were subsequently administered a brief neuropsychological battery that included the Word Memory Test, Rey 15-Item Test with Recognition, Finger-Tapping Test, and Digit Span from the Wechsler Adult Intelligence Scale-Fourth Edition. Moderated multiple regressions with hierarchical entry were conducted. Intelligence, psychopathy, and the interaction of intelligence and psychopathy were not related to performance on any of the PVTs. In other words, participants who scored higher on intelligence and psychopathy did not perform differently on these measures compared with other participants. Though a null finding, implications of this study are discussed in terms of the broader research and clinical literature on malingering.

Cognitive and Brain Reserve and the Risk of Postoperative Delirium in Older Patients

BACKGROUND

Cognitive and brain reserve theories suggest that aspects of neural architecture or cognitive processes modify the impact of neuropathological processes on cognitive outcomes. While frequently studied in the context of dementia, reserve in delirium is relatively understudied.

METHODS

We examined the association of three markers of brain reserve (head circumference, MRI-derived brain volume, and leisure time physical activity) and five markers of cognitive reserve (education, vocabulary, cognitive activities, cognitive demand of lifetime occupation, and interpersonal demand of lifetime occupation) and the risk of postoperative delirium in a prospective observational study of 566 older adults free of dementia undergoing scheduled surgery.

FINDINGS

Twenty four percent of patients (135/566) developed delirium during the postoperative hospitalization period. Of the reserve markers examined, only the Wechsler Test of Adult Reading (WTAR) was significantly associated with the risk of delirium. A one-half standard deviation better performance on the WTAR was associated with a 38% reduction in delirium risk (P = 0·01); adjusted relative risk of 0·62, 95% confidence interval 0·45-0·85.

INTERPRETATION

In this relatively large and well-designed study, most markers of reserve fail to predict delirium risk. The exception to this is the WTAR. Our findings suggest that the reserve markers that are important for delirium may be different from those considered to be important for dementia.

A low glycaemic load breakfast can attenuate cognitive impairments observed in middle aged obese females with impaired glucose tolerance

BACKGROUND AND AIMS

There has been no systematic investigation of the individual and combined effects of impaired glucose tolerance (IGT) and obesity on cognitive function in the absence of ageing. The aims were to examine the effects of IGT and increased waist circumference on cognitive function in ostensibly healthy adults, and to investigate whether a low glycaemic load (GL) breakfast can attenuate cognitive impairments in these populations.

METHODS AND RESULTS

Sixty five females aged 30-50 years were classified into one of four groups following waist circumference (WC) measurements and an oral glucose tolerance test: NGT/low WC (n = 25), NGT/high WC (n = 22), IGT/low WC (n = 9), IGT/high WC (n = 9). Memory, psychomotor and executive functions were examined 30 and 120 min after consuming low GL, high GL and water breakfasts according to a randomised, crossover, counterbalanced design. IGT was associated with impairment of verbal and spatial memory, and psychomotor function relative to females with NGT, independent of waist circumference. Increased waist circumference was associated with impairment of verbal memory and executive function relative to females with low WC, independent of IGT. Consumption of the LGL breakfast attenuated verbal memory impairment in the IGT/high WC group relative to the HGL breakfast and no energy control.

CONCLUSION

Increased central adiposity and abnormalities in glucose tolerance preceding type 2 diabetes can have demonstrable negative effects on cognitive function, even in ostensibly healthy, middle-aged females. The potential for GL manipulations to modulate glycaemic response and cognitive function in type 2 diabetes and obesity merits further investigation.

Severity of mild cognitive impairment in early Parkinson's disease contributes to poorer quality of life

Background

Poor quality of life (QoL) is a feature of people with Parkinson's disease (PD) who develop dementia. The relationship between mild cognitive impairment in PD (PD-MCI) and QoL is less clear. To address this, we studied the impact of varying severities of cognitive impairment on QoL in a cohort of non-demented patients with early PD.

Method

Patients with newly diagnosed PD (n = 219) and age and sex matched healthy controls (n = 99) completed a schedule of neuropsychological tests, in addition to scales assessing QoL (PDQ-39), depression, sleep, neuropsychiatric symptoms and a clinical examination. The Movement Disorder Society criteria were used to define and classify PD-MCI.

Results

Participants with PD-MCI were significantly older than those with normal cognition, had more severe motor symptoms, scored higher for depression and had poorer quality of life. Logistic regression showed that mild cognitive impairment, independent of other factors, was an indicator of poorer QoL. Using cognitive performance 2.0 standard deviations (SD) below normative data as a cut-off to define PD-MCI, there was a significant difference in QoL scores between patients with PD-MCI and those classified as having normal cognition. Subjects with less severe mild cognitive impairment did not exhibit significant differences in QoL.

Conclusions

PD-MCI is a significant, independent factor contributing to poorer QoL in patients with newly diagnosed PD. Those classified with greatest impairment (2.0 SD below normal values) have lower QoL. This has implications for clinical practice and future interventions targeting cognitive impairments.

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Quality of life declines with increased severity of cognitive impairment in PD.

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Mild cognitive impairment in PD (PD-MCI) independently contributes to poorer QoL.

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PD-MCI at 2 standard deviations below controls had the greatest impact on QoL.

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The optimal operational cut-off for PD-MCI may be 2 standard deviations.

Estimated verbal IQ and the odds of problem gambling: a population-based study

BACKGROUND

The neurocognitive deficits and other correlates of problem gambling are also observable in individuals with lower cognitive abilities, suggesting that a low IQ may be a determinant of problem gambling. There has been very little research into this possibility. This study aimed to investigate the characteristics associated with problem gambling in a large population-based study in England, with a particular focus on IQ.

METHOD

The Adult Psychiatric Morbidity Survey (APMS) 2007 comprised detailed interviews with 7403 individuals living in private households in England. Problem gambling was ascertained using a questionnaire based on DSM-IV criteria. Verbal IQ was estimated using the National Adult Reading Test (NART). Confounders included socio-economic and demographic factors, common mental disorders, impulsivity, smoking, and hazardous drug and alcohol use.

RESULTS

More than two-thirds of the population reported engaging in some form of gambling in the previous year, but problem gambling was rare [prevalence 0.7%, 95% confidence interval (CI) 0.5-1.0]. The odds of problem gambling doubled with each standard deviation drop in estimated verbal IQ [adjusted odds ratio (OR) 2.1, 95% CI 1.3-3.4, p = 0.003], after adjusting for other characteristics associated with problem gambling including age, sex, socio-economic factors, drug and alcohol dependence, smoking, impulsivity and common mental disorders. There was no strong relationship observed between IQ and non-problem gambling.

CONCLUSIONS

People with lower IQs may be at a higher risk of problem gambling. Further work is required to replicate and study the mechanisms behind these findings, and may aid the understanding of problem gambling and inform preventative measures and interventions.

Cognitive reserve protects against apathy in individuals with human immunodeficiency virus

Apathy is associated with impaired neuropsychological functioning in individuals with HIV. While cognitive reserve (CR) delays neurocognitive decline, CR's relationship with apathy has never been studied. We examined CR's association with apathy in 116 HIV-positive individuals recruited from an urban AIDS center and assessed whether this relationship is moderated by age and/or disease severity. Participants completed the Wechsler Test of Adult Reading and Apathy Evaluation Scale. A CR-composite, combining years of education and word-reading ability, significantly predicted apathy (t = -2.37, p = .02). CR's relationship with apathy was not moderated by age, but participants with nadir CD4 levels ≤ 200 demonstrated a stronger association (t = -3.25, p = .002) than those with nadir CD4 levels > 200 (t = -0.61, p = .55). These findings suggest a protective effect of CR against apathy in HIV-infected individuals across the age span, particularly after a certain threshold of disease severity.

Schizotypal traits are associated with poorer identification of emotions from dynamic stimuli

Recent research suggests that the emotion recognition difficulties seen in schizophrenia may also be present to a lesser degree in non-clinical individuals who report attenuated expressions of schizophrenia-like symptoms (schizotypy). However, evidence in non-clinical samples primarily comes from studies employing static facial emotion tasks, and it is not clear whether poorer emotion recognition in schizotypy persists when people have access to a broader range of emotional cues more representative of typical face-to-face social interactions. A community sample of 151 adults completed measures of schizotypal traits, IQ, and a task that assessed emotion recognition using dynamic video-based stimuli. Global schizotypy and positive schizotypal traits were each associated with poorer emotion recognition. Negative schizotypy was not associated with emotion recognition overall, but was associated with errors in recognising positive emotions. It appears that poorer emotion recognition in schizotypy is not limited to single-channel stimuli, but can be seen even when multiple emotional cues are available. Thus, individuals with high levels of schizotypal traits, and positive features in particular, may have greater difficulty when it comes to 'reading' the emotions of others in everyday social interactions.