Current Cognitive Ability Research Articles

Treatment Options for Individuals with PTSD and Concurrent TBI: A Literature Review and Case Presentation.

Posttraumatic stress disorder (PTSD) is a well-studied mental health condition with existing guidelines and algorithms for treatment of PTSD. Those guidelines, while acknowledging an increased complexity, fail to provide clear PTSD treatment guidelines when an individual has a concurrent traumatic brain injury (TBI) diagnosis. Therefore, a literature review along with an accompanying case presentation is presented to demonstrate the minimum necessary considerations for approaching treatment of this complex population. Treatment approaches must be lead by providers that have the expertise and training necessary to consider all facets of the patient and their potential options. The provider must consider the pathophysiology of PTSD and TBI and be capable of leading a team to identify the patient's source(s) of dysfunction, current cognitive abilities, and potential indications for psychotropic medications and/or other types of therapeutic intervention.

Cognitive Dysfunction: Part and Parcel of the Diabetic Foot

The presence of a foot ulcer increases the self-treatment burden imposed on the individual with diabetes. Additionally, this condition increases the cognitive demands needed for adherence to medical recommendations. A potential gap could exist between medical recommendations and the individual's ability to implement them. Hence, the goal of this study was to examine whether the cognitive profile of people with diabetic foot ulcers differs from that of people with diabetes without this complication. This was a case-control study. Ninety-nine individuals with diabetic foot ulcers (case patients) and 95 individuals with type 2 diabetes (control subjects) (age range 45-75 years), who were matched for diabetes duration and sex, underwent extensive neuropsychological evaluation using a NeuroTrax computerized battery, digit symbol, and verbal fluency tests. A global cognitive score after standardization for age and education was computed as well as scores in the following six cognitive domains: memory, executive function, reaction time, attention, psychomotor abilities, and estimated premorbid cognition. Individuals with diabetic foot ulcers had significantly (P < 0.001) lower cognitive scores than individuals with diabetes without this complication, in all tested cognitive domains, excluding estimated premorbid cognition. Individuals with diabetic foot ulcers demonstrated a significant difference between precognitive and current cognitive abilities, as opposed to the nonsignificant difference among control subjects. The differences persisted in multivariable analysis after adjusting for depression and smoking. Individuals with diabetic foot ulcers were found to possess fewer cognitive resources than individuals with diabetes without this complication. Thus, they appear to face more self-treatment challenges, while possessing significantly fewer cognitive resources.

The Evolutionary Concept of "Preadaptation" Applied to Cognitive Neurosciences.

The Evolutionary Concept of "Preadaptation" Applied to Cognitive Neurosciences.

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.

Loneliness in psychotic disorders and its association with cognitive function and symptom profile

BackgroundLoneliness involves subjective, rather than objective, social isolation and has a range of negative effects on mental and physical functioning. The purpose of this study was to examine the prevalence of loneliness in psychotic disorders and its association with symptoms and cognitive performance. MethodData were drawn from the second Australian National Survey of Psychosis and comprised responses from 1642 participants with an International Classification of Diseases 10 diagnosis of psychotic disorder who had completed a semi-structured interview of symptoms and social functioning (including loneliness), along with standardized assessments of current (digit symbol coding; DSC) and premorbid (National Adult Reading Test) cognitive ability. We examined the prevalence of loneliness across the diagnostic categories of psychosis, and its association with psychotic and non-psychotic symptoms and digit symbol coding scores. ResultsThe prevalence of loneliness was high, ranging from 74.75% in participants with delusional disorders to 93.8% in depressive psychosis, and was significantly higher than in the general population. Loneliness was also significantly associated with anhedonia and subjective thought disorder. Participants feeling socially isolated/lonely for company had significantly lower DSC scores than those who only felt lonely occasionally. Unexpectedly, participants who reported not feeling lonely had the lowest DSC scores. ConclusionsLoneliness is common across all psychotic disorders, particularly in depressive psychosis. It is specifically associated with ongoing loss of pleasure and disordered thoughts as well as impairment in current cognitive functioning. However, poor cognitive functioning is not inevitably associated with loneliness. Implications for personalized treatment of psychosis are discussed.

Utility of the cognitive difficulties scale and association with objective test performance.

Subjective memory complaints (SMCs) are commonly noted in memory disorder clinic patients. The present study sought to examine the presence of SMCs on the Cognitive Difficulties Scale (CDS) in older adults and to examine the relationship between CDS scores and current cognitive ability. Participants were 50 adults diagnosed with possible/probable Alzheimer's disease (AD), 100 with amnestic mild cognitive impairment (MCI) and 84 cognitively healthy controls (HCs). Participants completed a neuropsychological evaluation and the self- and informant-reported CDS. Results indicated that greater self-reported SMCs were noted in the group with MCI ; however, self-reported CDS scores were associated with cognition in HCs only. Informant-reported CDS scores were predictive of cognitive ability in the diagnosis of MCI but not AD, indicating the importance of obtaining caregiver report in the evaluation of memory disorders. As AD is a neurodegenerative disorder, SMCs lose value in determining degree of cognitive impairment as disease stage increases.

Psychosis prevalence and physical, metabolic and cognitive co-morbidity: data from the second Australian national survey of psychosis.

There are insufficient data from nationwide surveys on the prevalence of specific psychotic disorders and associated co-morbidities. The 2010 Australian national psychosis survey used a two-phase design to draw a representative sample of adults aged 18-64 years with psychotic disorders in contact with public treatment services from an estimated resident population of 1 464 923 adults. This paper is based on data from 1642 participants with an International Classification of Diseases (ICD)-10 psychotic disorder. Its aim is to present estimates of treated prevalence and lifetime morbid risk of psychosis, and to describe the cognitive, physical health and substance use profiles of participants. The 1-month treated prevalence of psychotic disorders was 3.10 cases per 1000 population aged 18-64 years, not accounting for people solely accessing primary care services; lifetime morbid risk was 3.45 per 1000. Mean premorbid intelligence quotient was approximately 0.5 s.d.s below the population mean; current cognitive ability (measured with a digit symbol coding task) was 1.6 s.d.s below the population mean. For both cognitive tests, higher scores were significantly associated with better independent functioning. The prevalence of the metabolic syndrome was high, affecting 60.8% of participants, and pervasive across diagnostic groups. Of the participants, two-thirds (65.9%) were current smokers, 47.4% were obese and 32.4% were sedentary. Of the participants, half (49.8%) had a lifetime history of alcohol abuse/dependence and 50.8% lifetime cannabis abuse/dependence. Our findings highlight the need for comprehensive, integrative models of recovery to maximize the potential for good health and quality of life for people with psychotic illness.

Cognitive and language skills in adults with autism: a 40‐year follow‐up

It is well established that very few individuals with autism spectrum disorders (ASD) and an IQ below 70 are able to live independently as adults. However, even amongst children with an IQ in the normal range, outcome is very variable. Childhood factors that predict later stability, improvement or decline in cognitive functioning remain uncertain and, in particular, very little is known about trajectories in later adulthood. Changes in cognitive and language ability from childhood to adulthood were assessed in 60 individuals with autism, all of whom had an IQ in the average range as children. Mean age in childhood = 6 years (range 2-13 years); mean age in adulthood = 44 years (range 29-64 years). Trajectories of change and factors related to current cognitive abilities were explored. For the majority of participants (N = 45, 75%), who were testable both as children and adults, IQ remained very stable and language also improved over time. However, 15 individuals could not be assessed on standard tests as adults and their developmental level could be estimated only on the Vineland Adaptive Behavior Scales. Almost all these adults (apart from one who had suffered a major stroke) showed severe aggressive or self-injurious behaviours; none had ever developed language above a 3-year level, and seven had developed epilepsy. For most individuals with autism who had an IQ in the average range (i.e. ≥ 70) as children, childhood IQ proved a reliable predictor of cognitive functioning well into mid- to- later adulthood. However, a significant minority was no longer testable on standard tests as adults. Their current very low levels of functional ability were generally associated with severe behavioural disturbance and persisting and severe language impairment; 50% of these individuals had also developed epilepsy, pointing to the role of organic brain dysfunction. Implications for early intervention are discussed.

Brain white matter damage in aging and cognitive ability in youth and older age

Cerebral white matter hyperintensities (WMH) reflect accumulating white matter damage with aging and impair cognition. The role of childhood intelligence is rarely considered in associations between cognitive impairment and WMH. We studied community-dwelling older people all born in 1936, in whom IQ had been assessed at age 11 years. We assessed medical histories, current cognitive ability and quantified WMH on MR imaging. Among 634 participants, mean age 72.7 (SD 0.7), age 11 IQ was the strongest predictor of late life cognitive ability. After accounting for age 11 IQ, greater WMH load was significantly associated with lower late life general cognitive ability (β = −0.14, p < 0.01) and processing speed (β = −0.19, p < 0.001). WMH were also associated independently with lower age 11 IQ (β = −0.08, p < 0.05) and hypertension. In conclusion, having more WMH is significantly associated with lower cognitive ability, after accounting for prior ability, age 11IQ. Early-life IQ also influenced WMH in later life. Determining how lower IQ in youth leads to increasing brain damage with aging is important for future successful cognitive aging.

Accuracy of recalled body weight-a study with 20-years of follow-up

ObjectiveWeight changes may be an important indicator of an ongoing pathological process. Retrospective self-report might be the only possibility to capture prior weight. The objective of the study was to evaluate the accuracy of retrospective recall of body weight in old age and factors that might predict accuracy.Design and MethodsIn 2007, 646 participants (mean age, 71.6 years) of the Swedish Adoption/Twin Study of Aging (SATSA) answered questions about their present weight and how much they weighed 20-years ago. Of these, 436 had self-reported their weight twenty years earlier and among these 134 had also had their weight assessed at this time point.ResultsTwenty year retrospectively recalled weight underestimated the prior assessed weight by −1.89 ± 5.9 kg and underestimated prior self-reported weight by −0.55 ± 5.2 kg. Moreover, 82.4% of the sample were accurate within 10%, and 45.8% were accurate within 5% of their prior assessed weights; similarly, 84.2% and 58.0 % were accurate within 10% and 5% respectively, for prior self-reported weight. Current higher body mass index and preferences of reporting weights ending with zero or five was associated with an underestimation of prior weight, while greater weight change over 20 year, and low Mini-Mental State Scores (MMSE) (<25) led to an overestimation of prior weight.ConclusionsRecalled weight comes close to the assessed population mean, but at the individual level there is a large variation. The accuracy is affected by current BMI, changes in weight, end-digit preferences, and current cognitive ability. Recalled weight should be used with caution.

Toward a layered model of context for health information searching: An analysis of consumer‐generated questions

Designing effective consumer health information systems requires deep understanding of the context in which the systems are being used. However, due to the elusive nature of the concept of context, few studies have made it a focus of examination. To fill this gap, we studied the context of consumer health information searching by analyzing questions posted on a social question and answer site: Yahoo! Answers. Based on the analysis, a model of context was developed. The model consists of 5 layers: demographic, cognitive, affective, situational, and social and environmental. The demographic layer contains demographic factors of the person of concern; the cognitive layer contains factors related to the current search task (specifically, topics of interest and information goals) and users' cognitive ability to articulate their needs. The affective layer contains different affective motivations and intentions behind the search. The situational layer contains users' perceptions of the current health condition and where the person is in the illness trajectory. The social and environmental layer contains users' social roles, social norms, and various information channels. Several novel system functions, including faceted search and layered presentation of results, are proposed based on the model to help contextualize and improve users' interactions with health information systems.

Neck muscle cross-sectional area, brain volume and cognition in healthy older men; a cohort study

BackgroundTwo important consequences of the normal ageing process are sarcopenia (the age-related loss of muscle mass and function) and age-related cognitive decline. Existing data support positive relationships between muscle function, cognition and brain structure. However, studies investigating these relationships at older ages are lacking and rarely include a measure of muscle size. Here we test whether neck muscle size is positively associated with cognition and brain structure in older men.MethodsWe studied 51 healthy older men with mean age 73.8 (sd 1.5) years. Neck muscle cross-sectional area (CSA) was measured from T1-weighted MR-brain scans using a validated technique. We measured multiple cognitive domains including verbal and visuospatial memory, executive functioning and estimated prior cognitive ability. Whole brain, ventricular, hippocampal and cerebellar volumes were measured with MRI. General linear models (ANCOVA) were performed.ResultsLarger neck muscle CSA was associated with less whole brain atrophy (t = 2.86, p = 0.01, partial eta squared 17%). Neck muscle CSA was not associated with other neuroimaging variables or current cognitive ability. Smaller neck muscle CSA was unexpectedly associated with higher prior cognition (t = −2.12, p < 0.05, partial eta squared 10%).ConclusionsIn healthy older men, preservation of whole brain volume (i.e. less atrophy) is associated with larger muscle size. Longitudinal ageing studies are now required to investigate these relationships further.

Preserved cognitive function is associated with suicidal ideation and single suicide attempts in schizophrenia

ObjectiveSuicide is the leading cause of death in schizophrenia. An association between suicidal behavior and both higher and lower cognitive ability in schizophrenia has been reported. To clarify this relationship, we investigated whether the relationship between suicidality and neurocognition varied according to differences in suicidal ideation and behavior. MethodsThree hundred and ten patients with DSM-IV diagnoses of schizophrenia or schizoaffective disorder were categorized based on patient and staff interviews as either non-suicide attempters, non-attempters expressing suicidal ideation, single suicide attempters, or multiple suicide attempters. These groups were compared on a neuropsychological battery examining current general cognitive ability, episodic and working memory, and attentional control. ResultsNeuropsychological performance in those with a history of suicidal ideation (n=63), and those who had made one suicide attempt (n=48) was comparable. Together, these groups outperformed patients with no history of either suicidal behavior or ideation (n=172) on measures of IQ, episodic memory and working memory. Only differences in global cognition remained significant after controlling for between-group differences in depressive symptoms. Those who had either expressed suicidal ideation and/or made a single suicide attempt demonstrated trend level advantages in neuropsychological tests over those that had made multiple suicide attempts. DiscussionThese findings support earlier evidence of an association between suicidality and neurocognitive ability in schizophrenia. Specifically, these data suggest that patients who have contemplated suicide or made a single suicide attempt have better cognitive functioning than those who have not. Suicidality in multiple attempters, who do not perform better in neurocognitive tests than those who have neither contemplated nor attempted suicide, is likely to be influenced by factors other than neurocognitive ability.

Inter-individual Differences in fMRI Entropy Measurements in Old Age

We investigated the association between individual differences in cognitive performance in old age and the approximate entropy (ApEn) measured from functional magnetic resonance imaging (fMRI) data acquired from 40 participants of the Aberdeen Birth Cohort 1936 (ABC1936), while undergoing a visual information processing task: inspection time (IT). Participants took a version of the Moray House Test (MHT) No. 12 at age 11, a valid measure of childhood intelligence. The same individuals completed a test of non-verbal reasoning (Raven's Standard Progressive Matrices [RPM]) aged about 68 years. The IT, MHT and RPM scores were used as indicators of cognitive performance. Our results show that higher regional signal entropy is associated with better cognitive performance. This finding was independent of ability in childhood but not independent of current cognitive ability. ApEn is used for the first time to identify a potential source of individual differences in cognitive ability using fMRI data.

Trends in Substance Abuse Treatment 1998–2008: Increasing Older Adult First-Time Admissions for Illicit Drugs

To see whether the percentage of older adults entering substance abuse treatment for their first time was increasing and whether there were changes in the use patterns leading to the treatment episode, particularly an increase in illicit drugs. The Treatment Episode Data Sets publicly available from the Substance Abuse Mental Health Services Administration from 1998 to 2008. Young adults age 30-54 years as a comparison group (N = 3,547,733) and those age 55 years or older (N = 258,542) with a first-time admission for a publicly funded substance abuse treatment. Demographic and substance use history variables at admission. The proportion of older adults going for substance abuse treatment for the first time is increasing relative to younger adults. The pattern of drug use is also changing, with an increasing illicit drug involvement (cocaine and heroin) in older adult admissions. We know little of these long-time users, their current medical state, cognitive abilities, and psychiatric symptoms after such a long exposure time. Previous studies on heroin and cocaine exposure focused on individuals identified much earlier in life, and the aging long-term users might represent a relatively large but unknown population.

Cattell–Horn–Carroll cognitive‐achievement relations: What we have learned from the past 20 years of research

AbstractContemporary Cattell–Horn–Carroll (CHC) theory of cognitive abilities has evolved over the past 20 years and serves as the theoretical foundation for a number of current cognitive ability assessments. CHC theory provides a means by which we can better understand the relationships between cognitive abilities and academic achievement, an important component of learning disabilities identification and instructional planning. A research synthesis of the extant CHC cognitive‐achievement (COG‐ACH) research literature is reported. Systematic and operationally defined research synthesis procedures were employed to address limitations present in the only prior attempted synthesis. Nineteen studies met the criteria for inclusion, which yielded 134 analyses. The 134 analyses were organized by three age groups (6–8, 9–13, and 14–19) and by four achievement domains (basic reading skills, reading comprehension, basic math skills, and math reasoning). The results reveal a much more nuanced set of CHC COG‐ACH relations than was identified in the only prior review because of (a) breadth of cognitive abilities and measures (broad vs. narrow), (b) breadth of achievement domains (e.g., basic reading skills and reading comprehension vs. broad reading), and (c) developmental (age) status. The findings argue for selective, flexible, and referral‐focused intelligence testing, particularly in the context of emerging Response to Intervention (RTI) assessment models. The results suggest that narrow CHC abilities should be the primary focus of instructionally relevant intelligence testing. Furthermore, the finding that more than 90% of the available research is based on the Woodcock–Johnson Battery argues for significant caution in generalizing the findings to other batteries. CHC‐based COG‐ACH research with other intelligence batteries is recommended. © 2010 Wiley Periodicals, Inc.

Long-term impact of neonatal intensive care and surgery on somatosensory perception in children born extremely preterm

Alterations in neural activity due to pain and injury in early development may produce long-term effects on sensory processing and future responses to pain. To investigate persistent alterations in sensory perception, we performed quantitative sensory testing (QST) in extremely preterm (EP) children (n=43) recruited from the UK EPICure cohort (born less than 26 weeks gestation in 1995) and in age and sex matched term-born controls (TC; n=44). EP children had a generalized decreased sensitivity to all thermal modalities, but no difference in mechanical sensitivity at the thenar eminence. EP children who also required neonatal surgery had more marked thermal hypoalgesia, but did not differ from non-surgical EP children in the measures of neonatal brain injury or current cognitive ability. Adjacent to neonatal thoracotomy scars there was a localized decrease in both thermal and mechanical sensitivity that differed from EP children with scars relating to less invasive procedural interventions or from those without scars. No relationship was found between sensory perception thresholds and current pain experience or pain coping styles in EP or TC children. Neonatal care and surgery in EP children are associated with persistent modality-specific changes in sensory processing. Decreases in mechanical and thermal sensitivity adjacent to scars may be related to localized tissue injury, whereas generalized decreases in thermal sensitivity but not in mechanical sensitivity suggest centrally mediated alterations in the modulation of C-fibre nociceptor pathways, which may impact on responses to future pain or surgery.

Is there information contained within the sentence‐writing component of the mini mental state examination? A retrospective study of community dwelling older people

To investigate the relationship between features of the MMSE written sentence and cognitive function, depression and disability. MMSE sentences from 191 community dwelling individuals without dementia from the Lothian Birth Cohort 1921 (LBC1921) study were: (a) photocopied and (b) typed as written. Sentences were rated for objective criteria: word number and frequency, first person usage, time orientation, and letter case. Twenty healthy raters (50% male, age 20-26 years), blind to all other data, rated each handwritten and typed sentence for subjective criteria: legibility, 'emotional' tone (positive to negative), estimated age, health, and intelligence. As part of the LBC1921 volunteers had results available for cognitive ability tests (from which we extracted a general cognitive ability factor, g), Hospital Anxiety and Depression Score (HADS), and Townsend disability scores. 43.5% of subjects were male, mean age 78.6, SD 0.43 years. There was no significant association between the objective sentence criteria, legibility or tone and measured cognitive ability or physical disability. However, estimates of intelligence from the MMSE written sentence correlated significantly with current cognitive ability (r = 0.29, p < 0.001). There was a trend towards sentences with a negative tone being associated with a higher HADS-depression score (rho = -0.12, p = 0.09). In community dwelling people aged around 80 years, despite no association between objectively rated features of the MMSE sentence and intelligence or disability, raters were able to make better-than-chance estimates of subjects' intelligence test scores.

Should cognitive impairment be included in the diagnostic criteria for schizophrenia?

Neurocognitive impairment is considered a core component of schizophrenia, and is increasingly under investigation as a potential treatment target. On average, cognitive impairment is severe to moderately severe compared to healthy controls, and almost all patients with schizophrenia demonstrate cognitive decrements compared to their expected level if they had not developed the illness. Compared to patients with affective disorders, cognitive impairment in schizophrenia appears earlier, is more severe, and is more independent of clinical symptoms. Although the DSM-IV-TR and ICD-10 descriptions of schizophrenia include several references to cognitive impairment, neither the diagnostic criteria nor the subtypology of schizophrenia include a requirement of cognitive impairment. This paper forwards for consideration a proposal that the diagnostic criteria include a specific criterion of "a level of cognitive functioning suggesting a consistent severe impairment and/or a significant decline from premorbid levels considering the patient's educational, familial, and socioeconomic background". The inclusion of this criterion may increase the "point of rarity" with affective psychoses and may increase clinicians' awareness of cognitive impairment, potentially leading to more accurate prognosis, better treatment outcomes, and a clearer diagnostic signal for genetic and biological studies. Future research will need to address the validity of these possibilities. The reliable determination of cognitive impairment as part of a standard diagnostic evaluation will present challenges to diagnosticians with limited resources or insufficient expertise. Cognitive assessment methods for clinicians, including brief assessments and interview-based assessments, are discussed. Given the current emphasis on the development of cognitive treatments, the evaluation of cognition in schizophrenia is an essential component of mental health education.

Measuring premorbid IQ in traumatic brain injury: An examination of the validity of the Wechsler Test of Adult Reading (WTAR)

Estimation of premorbid IQ in traumatic brain injury (TBI) is clinically and scientifically valuable because it permits the quantification of the cognitive impact of injury. This is achieved by comparing performances on tests of current ability to estimates of premorbid IQ, thereby enabling current capacity to be interpreted in light of preinjury ability. However, the validity of premorbid IQ tests that are commonly used for TBI has been questioned. In the present study, we examined the psychometric properties of a recently developed test, the Wechsler Test of Adult Reading (WTAR), which has yet to be examined for TBI. The cognitive performance of a group of 24 patients recovering from TBI (with a mean Glasgow Coma Scale score in the severely impaired range) was measured at 2 and 5 months postinjury. On both occasions, patients were administered three tests that have been used to measure premorbid IQ (the WTAR and the Vocabulary and Matrix Reasoning subtests of the Wechsler Adult Intelligence Scale 3rd Edition, WAIS-III) and three tests of current ability (Symbol Digit Modalities Test–Oral and Similarities and Block Design subtests of the WAIS-III). We found that performance significantly improved on tests of current cognitive ability, confirming recovery. In contrast, stable performance was observed on the WTAR from Assessment 1 (M = 34.25/50) to Assessment 2 (M = 34.21/50; r = .970, p < .001). Mean improvement across assessments was negligible (t = −0.086, p = .47; Cohen's d = −0.005), and minimal individual participant change was observed (modal scaled score change = 0). WTAR scores were also highly similar to scores on a demographic estimate of premorbid IQ. Thus, converging evidence—high stability during recovery from TBI and similar IQ estimates to those of a demographic equation—suggests that the WTAR is a valid measure of premorbid IQ for TBI. Where word pronunciation tests are indicated (i.e., in patients for whom English is spoken and read fluently), these results endorse the use of the WTAR for patients with TBI.