Premorbid Intellectual Ability Research Articles

Internalizing and somatic symptoms influence the discrepancy between subjective and objective cognitive difficulties in adults with ADHD who have valid and invalid test scores.

This study investigated the relationship between various intrapersonal factors and the discrepancy between subjective and objective cognitive difficulties in adults with attention-deficit hyperactivity disorder (ADHD). The first aim was to examine these associations in patients with valid cognitive symptom reporting. The next aim was to investigate the same associations in patients with invalid scores on tests of cognitive symptom overreporting. The sample comprised 154 adults who underwent a neuropsychological evaluation for ADHD. Patients were divided into groups based on whether they had valid cognitive symptom reporting and valid test performance (n = 117) or invalid cognitive symptom overreporting but valid test performance (n = 37). Scores from multiple symptom and performance validity tests were used to group patients. Using patients' scores from a cognitive concerns self-report measure and composite index of objective performance tests, we created a subjective-objective discrepancy index to quantify the extent of cognitive concerns that exceeded difficulties on objective testing. Various measures were used to assess intrapersonal factors thought to influence the subjective-objective cognitive discrepancy, including demographics, estimated premorbid intellectual ability, internalizing symptoms, somatic symptoms, and perceived social support. Patients reported greater cognitive difficulties on subjective measures than observed on objective testing. The discrepancy between subjective and objective scores was most strongly associated with internalizing and somatic symptoms. These associations were observed in both validity groups. Subjective cognitive concerns may be more indicative of the extent of internalizing and somatic symptoms than actual cognitive impairment in adults with ADHD, regardless if they have valid scores on cognitive symptom overreporting tests.

Free-listing and Semantic Knowledge: A Tool for Detecting Alzheimer Disease?

Impairment in semantic knowledge contributes to Alzheimer disease (AD)-related decline. However, the particulars of the impact AD has on specific domains of knowledge remain debatable. To investigate the impact of AD on specific semantic categories that are integral to daily functions-living things and man-made objects. We administered a free-listing task (written version) to 19 individuals with AD and 15 cognitively normal older adults and assessed the task's relationship with other cognitive and functional tests in clinical use. We compared the contents of the lists of salient concepts generated by the AD and control groups. Group membership (AD or control), after controlling for age, sex, formal education, and an estimate of premorbid intellectual ability, predicted the groups' performance on the free-listing task across two categories. Functional status was inversely related to performance on the free-listing task, holding demographic variables constant. Based on a comparison of the contents of the free lists that were generated by the two groups, it was possible to conclude that, in individuals with AD, conceptual knowledge central to the respective categories was well preserved, whereas the peripheral conceptual material showed evidence of degradation. The free-listing task, which is an easy-to-administer and cost-effective tool, could aid in the preliminary detection of semantic knowledge dysfunction, revealing concepts that are better preserved and, possibly, the characterization of AD. Cognitive assessment tools that can be applied across cultures are needed, and the free-listing task has the potential to address this gap.

Irregular word reading as a marker of semantic decline in Alzheimer’s disease: implications for premorbid intellectual ability measurement

BackgroundIrregular word reading has been used to estimate premorbid intelligence in Alzheimer’s disease (AD) dementia. However, reading models highlight the core influence of semantic abilities on irregular word reading, which shows early decline in AD. The primary objective of this study is to ascertain whether irregular word reading serves as an indicator of cognitive and semantic decline in AD, potentially discouraging its use as a marker for premorbid intellectual abilities.MethodSix hundred eighty-one healthy controls (HC), 104 subjective cognitive decline, 290 early and 589 late mild cognitive impairment (EMCI, LMCI) and 348 AD participants from the Alzheimer’s Disease Neuroimaging Initiative were included. Irregular word reading was assessed with the American National Adult Reading Test (AmNART). Multiple linear regressions were conducted predicting AmNART score using diagnostic category, general cognitive impairment and semantic tests. A generalized logistic mixed-effects model predicted correct reading using extracted psycholinguistic characteristics of each AmNART words. Deformation-based morphometry was used to assess the relationship between AmNART scores and voxel-wise brain volumes, as well as with the volume of a region of interest placed in the left anterior temporal lobe (ATL), a region implicated in semantic memory.ResultsEMCI, LMCI and AD patients made significantly more errors in reading irregular words compared to HC, and AD patients made more errors than all other groups. Across the AD continuum, as well as within each diagnostic group, irregular word reading was significantly correlated to measures of general cognitive impairment / dementia severity. Neuropsychological tests of lexicosemantics were moderately correlated to irregular word reading whilst executive functioning and episodic memory were respectively weakly and not correlated. Age of acquisition, a primarily semantic variable, had a strong effect on irregular word reading accuracy whilst none of the phonological variables significantly contributed. Neuroimaging analyses pointed to bilateral hippocampal and left ATL volume loss as the main contributors to decreased irregular word reading performances.ConclusionsWhile the AmNART may be appropriate to measure premorbid intellectual abilities in cognitively unimpaired individuals, our results suggest that it captures current semantic decline in MCI and AD patients and may therefore underestimate premorbid intelligence. On the other hand, irregular word reading tests might be clinically useful to detect semantic impairments in individuals on the AD continuum.

Free‐listing and semantic knowledge: A diagnostic tool for detecting Alzheimer’s disease?

AbstractBackgroundA semantic memory impairment figures prominently among the manifestations of Alzheimer’s disease (AD). That impairment manifests itself relatively early in the disease trajectory with longitudinal studies showing evidence in patients with mild cognitive impairment and preclinical AD. We investigate the impact of AD on specific semantic categories integral to daily function: living kinds and artefacts.MethodWe relied on a “free‐listing task” as developed in cultural domain analysis, and assessed its relationship with other cognitive and functional tests in clinical use. We chose the written version for the elicitation of the free‐lists that we analyze here. A written format leads to the generation of longer lists than an oral elicitation. The participant pool was comprised of 19 AD patients and a control group, 15 cognitively normal age‐matched adults.ResultThe median number of items generated in each list for the patients was 12 for living things and 18 for man‐made objects, for the control group, 39 and 45, respectively. Controlling for age, education, estimate of premorbid intellectual ability, and sex, group membership (AD or control) predicts performance in the free‐listing in the two categories. Holding demographic variables constant, functional status is inversely related to the performance on free‐listing.ConclusionEven when provided the modality (written) to generate longer lists, individuals with AD still performed worse than controls. Our findings confirm previous observations identifying an impairment of semantic knowledge in AD. Free‐listing is effective at detecting this impairment. This easy‐to‐administer, cost‐effective tool could facilitate the fast preliminary characterization of AD in distinct cultural environments.

Supervised machine learning classification of psychosis biotypes based on brain structure: findings from the Bipolar-Schizophrenia network for intermediate phenotypes (B-SNIP)

Traditional diagnostic formulations of psychotic disorders have low correspondence with underlying disease neurobiology. This has led to a growing interest in using brain-based biomarkers to capture biologically-informed psychosis constructs. Building upon our prior work on the B-SNIP Psychosis Biotypes, we aimed to examine whether structural MRI (an independent biomarker not used in the Biotype development) can effectively classify the Biotypes. Whole brain voxel-wise grey matter density (GMD) maps from T1-weighted images were used to train and test (using repeated randomized train/test splits) binary L2-penalized logistic regression models to discriminate psychosis cases (n = 557) from healthy controls (CON, n = 251). A total of six models were evaluated across two psychosis categorization schemes: (i) three Biotypes (B1, B2, B3) and (ii) three DSM diagnoses (schizophrenia (SZ), schizoaffective (SAD) and bipolar (BD) disorders). Above-chance classification accuracies were observed in all Biotype (B1 = 0.70, B2 = 0.65, and B3 = 0.56) and diagnosis (SZ = 0.64, SAD = 0.64, and BD = 0.59) models. However, the only model that showed evidence of specificity was B1, i.e., the model was able to discriminate B1 vs. CON and did not misclassify other psychosis cases (B2 or B3) as B1 at rates above nominal chance. The GMD-based classifier evidence for B1 showed a negative association with an estimate of premorbid general intellectual ability, regardless of group membership, i.e. psychosis or CON. Our findings indicate that, complimentary to clinical diagnoses, the B-SNIP Psychosis Biotypes may offer a promising approach to capture specific aspects of psychosis neurobiology.

Lifespan normative data (18-89 years) for Raven's Advanced Progressive Matrices Set I.

Raven's Advanced Progressive Matrices (APM) Set I is a validated and brief test of fluid intelligence, ideal for use in busy clinical settings. However, there is a dearth of normative data allowing an accurate interpretation of APM scores. To address this, we present normative data from across the adult lifespan (18-89 years) for the APM Set I. Data are presented in five age cohorts (total N= 352), including two older adult cohorts (65-79 years and 80-89 years), which allows age-standardized assessment. We also present data from a validated measure of premorbid intellectual ability, which was absent from previous standardizations of longer forms of the APM. In line with previous findings, a striking age-related decline was noted, beginning relatively early in adulthood and most marked amongst lower-scoring individuals. Older adults did not demonstrate difficulty with specific test items or make an increased proportion of specific errors. Sex was not a significant predictor of performance. The data set is of particular use in the neuropsychological assessment of older adults, given the known susceptibility of fluid intelligence to both the effects of normal ageing and acquired brain injury in older age. The results are discussed in light of theories of neurological ageing.

The effect of damage to the white matter network and premorbid intellectual ability on postoperative verbal short-term memory and functional outcome in patients with brain lesions.

Cognitive reserve is the capacity to cope with cognitive decline due to brain damage caused by neurological diseases. Premorbid IQ has been investigated as a proxy for cognitive reserve. To date, no study has focused on the effects of premorbid IQ in patients with brain tumors, considering the damage to white matter tracts. We investigated whether a higher premorbid IQ has a beneficial impact on postoperative verbal short-term memory and functional outcomes in patients with brain tumors. A total of 65 patients with brain tumors (35 right and 30 left hemisphere lesions) and 65 healthy subjects participated in the study. We used multiple regression analysis to examine whether white matter tract damage and premorbid IQ affect postoperative verbal short-term memory, and the interaction effects of premorbid IQ with damage to white matter tract on postoperative verbal short-term memory. Path analysis was used to investigate the relationship between damage to the white matter tract and premorbid IQ on postoperative functional ability. Our results showed that damage to the left arcuate fasciculus affected postoperative functional ability through verbal short-term memory, working memory, and global cognition in patients with left hemisphere lesions. In the right hemisphere lesion group, high premorbid IQ had a positive effect on functional ability by mediating verbal short-term memory, verbal working memory, and global cognition. We found that damage to the eloquent pathway affected postoperative verbal short-term memory regardless of the premorbid IQ level. However, a higher premorbid IQ was associated with better postoperative verbal short-term memory and functional outcomes when the brain lesions were not located in a crucial pathway. Our findings suggest that premorbid IQ and damage to the white matter tracts should be considered predictors of postoperative functional outcomes.

Premorbid intellectual ability in schizophrenia influence family appraisal related to cognitive impairments: a cross-sectional study on cognitive impairment and family assessments

BackgroundPatients with schizophrenia are unaware of their cognitive impairments. Misperception of cognitive impairment is an important factor associated with real-world functional outcomes in patients with schizophrenia. The patient’s family member plays a crucial role in detecting patients’ cognitive impairments when the patients are unaware of their own cognitive impairments. Previous studies have reported that not only the patient’s subjective rating, but also the patient’s family members’ rating of their cognitive impairment may not be precise. However, it is unclear why family ratings are inaccurate, and which factors impact family ratings. This study investigated whether family ratings differed significantly from the patients’ subjective ratings of the patients’ cognitive impairments and sought to determine the reason for the differences between the family ratings and the patients’ neurocognitive performances. We investigated the relationship between patients’ subjective ratings, family ratings for patients’ cognitive impairments, neuropsychological performance, and other aspects, including premorbid IQ and clinical symptoms.MethodWe evaluated 44 patients with schizophrenia for cognitive function using neuropsychological tests; in addition, both the patients and their families rated the patients’ cognitive impairments through questionnaires. We used the Mann–Whitney U test to examine whether the family ratings differed significantly from the patients’ self-reported ratings of their cognitive impairment. We conducted multiple regression analysis and structural equation modeling to determine why the patients’ subjective ratings and the family ratings were not definitively associated with the patients’ neurocognitive performances. We performed multiple regression analysis with a stepwise method with neurocognitive performance, premorbid IQ, positive symptoms, and negative symptoms as independent variables and family ratings of patients’ cognitive impairments as dependent variables.ResultsWe found that the family ratings differed significantly from the patients’ subjective self-reported ratings of their cognitive impairments. Our results showed that the premorbid IQ of patients is the strongest predictor of family ratings. Furthermore, among the neurocognitive domains, only the processing speed of patients was associated with family ratings.ConclusionsWe found that the family ratings were not consistent with the patients’ subjective self-reported ratings and the family ratings were most affected by the patients’ premorbid intellectual abilities. These results suggest that the families’ current assessments of the patients’ current cognitive impairments were affected by the patients’ premorbid intellectual ability rather than the patients’ current neurocognitive performance. Patients’ processing speed predicted family ratings; however, family members' ratings were not related to verbal learning/memory, executive function, and language of patients. Therefore, our findings highlight that patients’ family ratings may differ from patients’ subjective ratings, results of performance-based neuropsychological tests, and clinician ratings.

A-8 Developmental Cognitive Phenotypes in First-Episode Psychosis and Longitudinal Cognitive Change Following Antipsychotic Treatment

Abstract Objective The present study applied a developmentally based subgrouping procedure previously examined in chronic psychosis patients to a sample of first-episode psychosis (FEP) and examined change in cognition following treatment with antipsychotic medication. Method Medication naïve FEP patients (n = 119; age = 27.96; 63.9% male; 62.2% White, 32.8% Black, 5.0% Other) recruited during initial hospitalization were categorized into groups based on 1) estimated premorbid intellectual ability and 2) the discrepancy between predicted (modeled on 151 healthy controls) and current cognitive ability. Consistent with findings from chronic psychosis samples, groups were characterized as Preserved (n = 46; average premorbid, no discrepancy), Deteriorated (n = 44; average premorbid, significant discrepancy), and Compromised (n = 29, low premorbid and current cognitive ability). A mixed analysis of variance was used to examine change in a composite cognitive score derived from a comprehensive neuropsychological battery at baseline, 6 weeks, and 12 months. Results There was a significant group by time interaction [Figure 1; F(5.4142.4) = 2.81, p = 0.02] in which the Preserved group performed similar to healthy controls across all time points, the Compromised group demonstrated stable deficits after treatment, and the Deteriorated group diverged from the Compromised group at 6 weeks and 12 months. Discussion There is considerable cognitive heterogeneity in FEP at baseline and after initiation of antipsychotic medication. Findings of cognitive improvement in the Deteriorated group after treatment initiation suggests a differential response to antipsychotic medications that was not found in the Compromised or Preserved groups. Future work may benefit from examining medication and symptom severity as potential factors contributing to the unique change observed in the Deteriorated group.

Diagnostic Precision in the Detection of Mild Cognitive Impairment: A Comparison of Two Approaches

OBJECTIVEThis study compared diagnostic rates and clinical predictors of discrepancies between diagnoses conferred via: 1) a comprehensive neuropsychological evaluation and National Institute on Aging–Alzheimer's Association (NIA-AA) criteria versus 2) a cognitive screener and Diagnostic Statistical Manual of Mental Disorders (DSM-5) criteria. DESIGNCross-sectional examination of baseline data from the Prevention of Alzheimer's dementia (AD) using Cognitive remediation and transcranial direct current stimulation in Mild Cognitive Impairment (MCI) and Depression (PACt-MD; ClinicalTrials.gov Identifier: NCT02386670) trial. SETTINGFive geriatric psychiatry and memory clinics located at academic hospitals affiliated with the Department of Psychiatry, University of Toronto. PARTICIPANTSOlder adults (N = 431) with a history of major depressive disorder (MDD) in remission, MCI, or both. MEASUREMENTSMain outcome was a comparison of NIA-AA diagnostic rates of MCI or dementia versus DSM-5 rates of mild or major neurocognitive disorder. Secondary analyses examined demographic, race, gender, premorbid intellectual ability, psychosocial, health-related, and genetic predictors of discrepancy between DSM-5 and NIA-AA diagnoses. RESULTSThere were 103 (23.8%) discrepant cases, with most (91; 88.3%) of these discrepant cases reflecting more impairment with the detailed neuropsychological testing and NIA-AA criteria. Discrepancies were more likely in individuals with a history of MDD or who had at least one ApoE4 allele. CONCLUSIONThe NIA-AA criteria, in conjunction with comprehensive neuropsychological testing, identified a greater prevalence of cognitive impairment than DSM-5 criteria, in conjunction with the Montreal Cognitive Assessment. Detailed neuropsychological evaluations are recommended for older adults who have a history of MDD or a genetic vulnerability to dementia.

Polygenic scores for schizophrenia and general cognitive ability: associations with six cognitive domains, premorbid intelligence, and cognitive composite score in individuals with a psychotic disorder and in healthy controls

Cognitive impairments are considered core features in schizophrenia and other psychotic disorders. Cognitive impairments are, to a lesser degree, also documented in healthy first-degree relatives. Although recent studies have shown (negative) genetic correlations between schizophrenia and general cognitive ability, the association between polygenic risk for schizophrenia and individual cognitive phenotypes remains unclear. We here investigated the association between a polygenic score for schizophrenia (SCZPGS) and six well-defined cognitive domains, in addition to a composite measure of cognitive ability and a measure of premorbid intellectual ability in 731 participants with a psychotic disorder and 851 healthy controls. We also investigated the association between a PGS for general cognitive ability (COGPGS) and the same cognitive domains in the same sample. We found no significant associations between the SCZPGS and any cognitive phenotypes, in either patients with a psychotic disorder or healthy controls. For COGPGS we observed stronger associations with cognitive phenotypes in healthy controls than in participants with psychotic disorders. In healthy controls, the association between COGPGS (at the p value threshold of ≥0.01) and working memory remained significant after Bonferroni correction (β = 0.12, p = 8.6 × 10−5). Altogether, the lack of associations between SCZPGS and COGPGS with cognitive performance in participants with psychotic disorders suggests that either environmental factors or unassessed genetic factors play a role in the development of cognitive impairments in psychotic disorders. Working memory should be further studied as an important cognitive phenotype.

M62. PERIPHERAL INFLAMMATION MARKERS IDENTIFY SUBSET OF PATIENTS WITH SCHIZOPHRENIA AND RELATED PSYCHOSES WHO HAVE INTELLECTUAL DECLINE FROM PREMORBID LEVELS

BackgroundHigher inflammation has been identified in a substantial subset of both high-risk and chronically ill patients with schizophrenia and related psychoses and this may account for some of the heterogeneity of the schizophrenia. There is also much heterogeneity in cognitive deficits related to schizophrenia with some patients showing a marked decline from premorbid intellectual levels while others show little change from either normal or low intellect. However, the relationship between intellectual change with the illness onset and inflammation in schizophrenia has not been established.MethodsHere, we report the assessment of two common markers of inflammation from two independent samples of generally chronically ill patients with schizophrenia and related psychoses (one sample of 73 patients versus 70 healthy controls from Sydney, NSW, Australia and one sample of 297 patients from Syracuse, NY, USA). Peripheral venous blood samples were collected from all patients and blood markers of inflammation (C-Reactive Protein, CRP, and Neutrophil to Lymphocyte Ratio, NLR) were assayed using standard procedures. Assessment of premorbid and current intellectual abilities were obtained from the Sydney cohort of patients.ResultsGrouping the patients and controls from the Sydney sample into those with elevated (> 3 mg/L) versus normal (< 3 mg/L) CRP levels revealed 42% of the patients versus 20% of the healthy controls had elevated CRP (Chi Square = 9.16, p = .002) and further evidence of inflammation with an elevated mean NLR of 2.5. The frequency of peripheral inflammation was confirmed by the independent sample from Syracuse in which 39% of the patients (n= 115) had an elevated NLR above a cutoff score for normal of 2.2 which was consistent with the Sydney sample. Patients from the Sydney sample who had an elevated CRP also had a significant mean 15-point IQ decline from premorbid IQ levels, whereas the patients with CRP levels within normal limits did not show a statistically significant drop in IQ from premorbid levels (mean IQ decline 7.6 points). Healthy controls with normal CRP had no IQ change (0.0 points) and healthy controls with elevated CRP has a slight, non-significant IQ decline (mean 2.3 points).DiscussionThus, our study showed supportive evidence of elevated peripheral inflammation markers in subgroups of chronically ill patients with schizophrenia from two independent samples and a link between marked intellectual decline from premorbid levels and current peripheral inflammation in one chronically ill subgroup of patients with schizophrenia suggesting a role for inflammation in the cognitive impairment of a substantial proportion (40%) of patients with schizophrenia.

DIAGNOSING COGNITIVE DECLINE: COMPARING NIA-AA TO DSM-5 APPROACHES

Introduction Both the DSM-5 and NIA-AA (Albert et al., 2011) stipulate methods for assessing and diagnosing cognitive decline but differ in their approach for estimating cognitive ability. The DSM suggests that evidence of cognitive decline is demonstrated either through culturally normed neuropsychological evaluation or through the use of “bedside” assessments such as the Mini Mental State Examination (MMSE) or Montreal Cognitive Assessment (MoCA). By contrast, the 2011 recommendations from the National Institute of Aging – Alzheimer Association (NIA–AA) emphasize the use of objective testing ideally via a neuropsychological evaluation of cognitive impairment in one or more cognitive domains. The current study compared differences in diagnostic rates between these two standards. Since the NIA-AA standards emphasize a more detailed cognitive assessment, we hypothesized that these criteria would identify a larger proportion of individuals with cognitive impairment than the DSM-5 criteria. We then examined possible clinical predictors of this discrepancy, including demographic, psychosocial, health-related, and genetic factors. Methods Data was drawn from 604 participants who were recruited into the Prevention of Alzheimer's Disease With Cognitive Remediation Plus tDCS in Mild Cognitive Impairment and Depression (PACt-MD; ClinicalTrials.gov Identifier: NCT02386670) trial. This is a randomized, controlled trial to evaluate brain stimulation and computerized brain training interventions for the prevention of cognitive decline in older adults. Participants either had a clinical history of mild cognitive impairment (MCI), major depressive disorder in remission, both, or were recruited as healthy controls without history of cognitive difficulty or mental disorder. All participants underwent a clinical and neuropsychological evaluation. Cognitive diagnoses were determined during biweekly consensus conferences. Both the DSM-5 and NIA-AA criteria were used during each consensus conference. The current analysis is based on the baseline data (i.e., prior to the intervention) of the 455 participants for whom a consensus conference was completed. We first compared diagnostic rates of MCI (NIA-AA) vs. mild neurocognitive disorder (DSM-5), as well as dementia (NIA-AA) vs. major neurocognitive disorder (DSM-5). We then used binary logistic regression models to examine demographic (age, education, race, sex, premorbid intellectual ability), psychosocial (English as a primary language, history of depression), health-related (severity of medical illness burden), and genetic (APOE e4 carrier status) predictors of diagnostic discrepancy between DSM-5 and NIA-AA criteria. Analyses were conducted separately for two groups of participants: (i) the group for which NIA-AA diagnoses reflected greater cognitive impairment than did the DSM-5 diagnoses (e.g., NIA-AA diagnosis of dementia but DSM-5 diagnosis of mild neurocognitive disorder); and (ii) the group for which DSM-5 diagnoses reflected greater cognitive impairment (e.g., DSM-5 diagnosis of major neurocognitive disorder but NIA-AA diagnosis of MCI. Results At baseline, there were 103 (22.6%) cases of discrepant diagnoses between the two classification systems: 50 cases had a NIA-AA diagnosis of MCI and no DSM-5 cognitive diagnosis (i.e., normal cognitive status); 41 cases had a NIA-AA diagnosis of dementia and a DSM-5 diagnosis of mild neurocognitive disorder; 12 cases had a DSM-5 diagnosis of mild neurocognitive disorder and no NIA-AA diagnosis. Compared to the 352 cases in agreement, the 91 cases with NIAA diagnoses reflecting greater cognitive impairment were more likely to have a history of major depressive disorder in remission (46% vs. 39%; B=-1.058, p=.003), be an APOE4 carrier (50% vs. 27%; B=-1.120, p=.001), and be older (72?vs. 71 years; B=.063, p=.02). APOE4 status, history of depression, and age were independent predictors. Compared to the 352 cases in agreement, the 12 cases with DSM-5 diagnosis reflecting greater cognitive impairment were less likely to have a history of depression (17% vs. 41%; B=2.414, p=.025). Conclusions While there was overall agreement with cognitive diagnoses when using NIA-AA or DSM-5 criteria, the two systems were discrepant in 22.6% of cases. Discrepancies were more likely to occur in participants with a history of depression, who were APOE4 carriers, or who were older. Overall, NIA-AA criteria yielded diagnoses reflecting greater cognitive impairment, especially in participants with a history of prior depression or those who were APOE4 carriers. These results suggest that more detailed neuropsychological evaluations may be indicated in older adults with a history of depression or who have a genetic vulnerability to dementia. This research was funded by: This project has been made possible by Brain Canada through the Canada Brain Research Fund, with the financial support of Health Canada and the Chagnon Family.

Comparing the North American Adult Reading Test (NAART) and the Test of Premorbid Functioning (TOPF) to estimate premorbid Wechsler Adult Intelligence Scale - 4th edition FSIQ in a clinical sample with epilepsy

Estimating premorbid general cognitive functioning is an essential component to the neuropsychological evaluation process. The North American Adult Reading Test (NAART) is a method to predict premorbid general cognitive functioning based on word reading skills developed using the Wechsler Adult Intelligence Scale-Revised (WAIS-R), which is currently in its fourth edition (WAIS-IV). The Test of Premorbid Function (TOPF) was developed using the WAIS-IV, based on the same method as the NAART, to estimate premorbid intellectual ability. There is a paucity of research comparing estimates of premorbid general intellectual ability between the NAART and TOPF. This study evaluated the clinical utility of premorbid estimates of FSIQ derived from the NAART and TOPF in a sample of 101 patients with temporal lobe epilepsy (TLE). Differences between NAART-derived premorbid FSIQs and TOPF simple demographic predicted FSIQs were significant (p < .001) with large effect sizes. NAART estimated premorbid FSIQ (M = 104.04, SD = 8.42) was significantly greater than TOPF premorbid estimates (M = 99.83, SD = 9.26). Results suggested NAART-derived estimates of premorbid FSIQ may be more accurate than TOPF-based estimates, which likely underestimated premorbid FSIQ in this sample of patients with epilepsy. Limitations and future directions are discussed.

Instrumental Activities of Daily Living, Neuropsychiatric Symptoms, and Neuropsychological Impairment in Mild Cognitive Impairment.

Neuropsychological deficits, neuropsychiatric symptoms, and problems with instrumental activities of daily living are common in participants with mild cognitive impairment (MCI). To assess how subtle to mildly impaired instrumental activities of daily living (IADLs) might be related to neuropsychological abilities (including executive control and episodic memory) and neuropsychiatric symptoms (including apathy and depression) among participants with a diagnosis of MCI. Participants were evaluated for MCI and possible dementia at an outpatient memory clinic on the basis of a comprehensive neuropsychological evaluation, a geriatric psychiatry evaluation, a magnetic resonance image of the brain, and serum studies to evaluate for a possible reversible cause of cognitive decline. A series of stepwise regression analyses were conducted whereby IADL ability was the dependent variable and neuropsychological abilities, such as executive control and episodic memory, or neuropsychiatric symptoms, including apathy and depression, were the independent or predictor variables. The presence and severity of neuropsychiatric symptoms was assessed using a modified version of the Neuropsychiatric Inventory (mNPI). Participants were grouped by MCI diagnosis status (amnestic MCI, combined dysexecutive/mixed MCI, and no MCI). Twenty-six participants were in the amnestic MCI group, 19 in the combined dysexecutive/mixed MCI group, and 36 participants did not meet criteria for MCI (non-MCI group). Groups did not differ in age, education, Mini-Mental State Examination performance, IADL abilities, estimated premorbid general intellectual abilities, or mNPI ratings for apathy and depression. Stepwise regression analyses found a robust relationship between mild IADL impairment and greater apathy (R=0.497, r21,69=0.247, P<.001; β=-0.497, P<.001). Depression did not enter the final model. A weaker-but statistically significant-relationship was found between mild IADL impairment and worse executive control test performance (R=0.271, r21,68=0.073, P<.023; β=0.271, P<.23). Episodic memory did not enter the final model. When both apathy and executive control were assessed as related to IADL impairment, only apathy entered the final model (R=0.497, R21,69=0.247, P<.001; β=-0.497, P<.001). Mildly impaired IADL functioning can negatively affect quality of life. Moreover, apathy may be amenable to treatment. In a primary geriatric care setting, neuropsychiatric symptoms and neuropsychological abilities should be routinely assessed.

Neuropsychological functioning in early and chronic stages of schizophrenia and psychotic bipolar disorder

BackgroundNeuropsychological impairment is common in schizophrenia and psychotic bipolar disorder. It has been hypothesized that the pathways leading to impairment differ between disorders. Cognitive impairment in schizophrenia is believed to result largely from atypical neurodevelopment, whereas bipolar disorder is increasingly conceptualized as a neuroprogressive disorder. The current investigation tested several key predictions of this hypothesis. MethodsCurrent neuropsychological functioning and estimated premorbid intellectual ability were assessed in healthy individuals (n = 260) and a large, cross-sectional sample of individuals in the early and chronic stages of psychosis (n = 410). We tested the following hypotheses: 1) cognitive impairment is more severe in schizophrenia in the early stage of psychosis; and 2) cognitive decline between early and chronic stages is relatively greater in psychotic bipolar disorder. Additionally, individuals with psychosis were classified as neuropsychologically normal, deteriorated, and compromised (i.e. below average intellectual functioning) to determine if the frequencies of neuropsychologically compromised and deteriorated patients were higher in schizophrenia and psychotic bipolar disorder, respectively. ResultsNeuropsychological impairment in the early stage of psychosis was more severe in schizophrenia. Psychotic bipolar disorder was not associated with relatively greater cognitive decline between illness stages. The frequency of neuropsychologically compromised patients was higher in schizophrenia; however, substantial portions of both schizophrenia and psychotic bipolar disorder patients were classified as neuropsychologically compromised and deteriorated. ConclusionsWhile schizophrenia is associated with relatively greater neurodevelopmental involvement, psychotic bipolar disorder and schizophrenia cannot be strictly dichotomized into purely neuroprogressive and neurodevelopmental illness trajectories; there is evidence of both processes in each disorder.

Impact of Dementia on Mindful Attention: a Cross-Sectional Comparison of People with Dementia and Those Without

Mindfulness-based interventions have been suggested as ways of improving mood and cognition in people with dementia. Existing findings suggest possible benefit from a mindfulness-based group intervention. However, it is unclear whether any structured group activity (rather than mindfulness practice per se) would produce the same benefits, particularly since dementia may impact mindful attention ability. Consequently, we investigated the potential impact of having dementia on mindful attention. We compared the performance of 34 people with dementia recruited from memory services with 55 community-recruited older people on measures of mindful attention, cognitive flexibility, and cognition, as well as putative nuisance variates of depression, anxiety and premorbid intellectual ability. The groups differed significantly on a range of demographic characteristics and some neuropsychological and mood measures. However, neither the primary prediction (that there would be a large effect size difference between groups, with people with dementia performing significantly more poorly on a measure of mindful attention to the breath), nor the secondary prediction (that performance on this measure would positively correlate with measures of executive function and overall cognition) was supported. We concluded that a diagnosis of dementia may not have a large effect on mindful attention, with consequent implications for future research.

Deviation from expected cognitive ability across psychotic disorders

Patients with schizophrenia show a deficit in cognitive ability compared to estimated premorbid and familial intellectual abilities. However, the degree to which this pattern holds across psychotic disorders and is familial is unclear. The present study examined deviation from expected cognitive level in schizophrenia, schizoaffective disorder, and psychotic bipolar disorder probands and their first-degree relatives. Using a norm-based regression approach, parental education and WRAT-IV Reading scores (both significant predictors of cognitive level in the healthy control group) were used to predict global neuropsychological function as measured by the composite score from the Brief Assessment of Cognition in Schizophrenia (BACS) test in probands and relatives. When compared to healthy control group, psychotic probands showed a significant gap between observed and predicted BACS composite scores and a greater likelihood of robust cognitive decline. This effect was not seen in unaffected relatives. While BACS and WRAT-IV Reading scores were themselves highly familial, the decline in cognitive function from expectation had lower estimates of familiality. Thus, illness-related factors such as epigenetic, treatment, or pathophysiological factors may be important causes of illness related decline in cognitive abilities across psychotic disorders. This is consistent with the markedly greater level of cognitive impairment seen in affected individuals compared to their unaffected family members.

The Wechsler Test of Adult Reading as a Measure of Premorbid Intelligence Following Traumatic Brain Injury

The current study sought to determine whether the Wechsler Test of Adult Reading (WTAR) provides a stable estimate of premorbid intellectual ability in acutely injured patients recovering from traumatic brain injury (TBI). A total of 135 participants (43 mild TBI [mTBI], 40 moderate/severe TBI [msevTBI], 52 healthy controls) were administered the WTAR at 1 and 12 months post-injury. Despite similar demographic profiles, participants with msevTBI performed significantly worse than controls on the WTAR at both time points. Moreover, the msevTBI group had a significant improvement in WTAR performance over the 1-year period. In contrast, those participants with mTBI did not significantly differ from healthy controls and both the mTBI and control groups demonstrated stability on the WTAR over time. Results indicate that word-reading tests may underestimate premorbid intelligence during the immediate recovery period for patients with msevTBI. Clinicians should consider alternative estimation measures in this TBI subpopulation.

Estimates of premorbid ability in a neurodegenerative disease clinic population: comparing the Test of Premorbid Functioning and the Wide Range Achievement Test, 4th Edition

Objective: Two frequently used measures to assess premorbid intellectual ability include the Wide Range Achievement Test, 4th Edition Reading Subtest (WRAT-4 READ) and the Test of Premorbid Functioning (TOPF). The present study compared estimates obtained from these measures in a neurodegenerative disease population. Method: Records from 85 referrals seen for neuropsychological evaluation in a neurodegenerative disorders clinic were reviewed. Evaluations included TOPF, WRAT-4 READ, and measures of memory, reasoning, language, and executive functioning. Pairwise correlations and concordance correlation coefficients (CCC) were calculated between raw scores and predicted intelligence estimates. Discrepancy scores were calculated between estimates and data were divided into three groups based on size of standardized discrepancy score: Equal, WRAT-4 READ > TOPF, and TOPF > WRAT-4 READ. analysis of variances compared groups on demographic characteristics and cognitive performance. Results: Despite strong Pearson correlation, CCC between predicted IQ estimates showed poor agreement between measures, with evidence of both fixed and proportional bias. Discrepancies ranged from −24.0 to 22.0 (M = 1.78, SD = 6.65), with TOPF generating higher estimates on average. Individuals performing better on WRAT-4 READ were significantly older (M age = 76.26, SD = 7.53) than those performing similarly on both measures and those performing better on TOPF (F (2, 82) = 7.31, p < .001). All other comparisons between groups on demographic variables and cognitive measures were non-significant. Conclusions: Estimates of premorbid intelligence obtained from the TOPF and WRAT-4 READ have a strong linear relationship, but systematically generate inconsistent estimates in a neurodegenerative disease clinical sample and should not be used interchangeably.