Neuropsychological Functioning In Adults Research Articles

Sex-differential patterns of neuropsychological functioning in adults with attention-deficit/hyperactivity disorder

BackgroundThe sex-differential prevalence of attention-deficit/hyperactivity disorder (ADHD) varies across the lifespan, but little is known about sex differences in executive functions in adults with ADHD. MethodsWe assessed 261 adults, aged 18–40 years, diagnosed with ADHD (170 males [assigned at birth], aged 25.81 ± 5.49; 91 females, aged 27.76 ± 5.42) and 308 neurotypical adults (176 males, aged 24.62 ± 5.14; 132 female, aged 25.37 ± 5.42) via psychiatric interviews to confirm ADHD and other psychiatric diagnoses. They were assessed by the Cambridge Neuropsychological Testing Automated Battery (CANTAB) on Reaction Time (arousal/processing speed), Rapid Visual Information Processing (sustained attention), Spatial Span (spatial memory), Spatial Working Memory, Intradimentional/Extradimensional Shift (set-shifting), and Stocking of Cambridge (spatial planning). The primary analyses were adjusted for age, full-scale IQ, and co-occurring psychiatric conditions. ResultsAdults with ADHD had various co-occurring psychiatric conditions without sex differences in ADHD-neurotypical differences. Both adult males and females with ADHD performed poorer in all CANTAB tasks than same-sex neurotypical adults. Significant sex-moderating effects were observed in neuropsychological performance, including greater ADHD-neurotypical differences in arousal for females than males and in location memory for spatial tasks in males than females. ConclusionThere were no sex-moderating effects in the presence of co-occurring psychiatric conditions in adult ADHD. However, there were sex-moderating effects on how ADHD related to neuropsychological functioning in adulthood. ADHD was associated with more challenges in arousal/processing speed in females and more challenges in strategy use or inhibition in spatial memory in males.

4 Neuropsychological Functioning in an Active Duty Service Member with Partial Agenesis of the Corpus Callosum and Bilateral Ventriculomegaly.

Objective:Partial agenesis of the corpus callosum (PACC) is a rare brain birth defect characterized by incomplete development of the corpus callosum, the primary white matter bundle that connects the right and left hemispheres. PACC can be associated with other congenital abnormalities, including malformation of the brain’s ventricular system, such as colpocephaly or ventriculomegaly, and it is typically considered a pediatric diagnosis. Clinically, this condition may present with a broad continuum of cognitive and socioemotional difficulties ranging from significant day-to-day impairment to relative independence. Newly diagnosed PACC with ventriculomegaly in adults is very rare (0.0200.025%) and little is known about neuropsychological functioning in adults with this condition. The aim of this case study is to add to the literature base for better PACC neuropsychological conceptualization.Participants and Methods:This case study involves neuropsychological evaluation of cognitive and behavioral health functioning of a 37-year-old active duty service member (ADSM) with recently identified PACC and ventriculomegaly (via incidental imaging finding). The ADSM reported a history of learning difficulty, though she was able to earn rank of sergeant first class in a low density military occupation specialty (i.e., Mortuary Affairs) over an 18.5 year active duty career.Results:Cognitive testing was notable for consistently low to exceptionally low attention and processing speed scores. Mild executive dysfunction was also noted in the areas of planning and inhibition. Emotionally, she endorsed mild somatic and depression symptoms. Interpersonally, she was shy and avoidant with longstanding characterological traits characterized by worry, insecurity, and general tendency to catastrophize.Conclusions:This case adds to the broad clinical presentation of PACC with ventriculomegaly, and highlights that even in the context of a significant congenital brain deformity and longstanding cognitive deficits, independent functioning can be achieved.

Association of Neighborhood Deprivation With Cognitive and Mood Outcomes in Adults With Pharmacoresistant Temporal Lobe Epilepsy.

Temporal lobe epilepsy (TLE) is the most common adult form of epilepsy and is associated with a high risk of cognitive deficits and depressed mood. However, little is known about the role of environmental factors on cognition and mood in TLE. This cross-sectional study examined the relationship between neighborhood deprivation and neuropsychological function in adults with TLE. Neuropsychological data were obtained from a clinical registry of patients with TLE and included measures of intelligence, attention, processing speed, language, executive function, visuospatial skills, verbal/visual memory, depression, and anxiety. Home addresses were used to calculate the Area Deprivation Index (ADI) for each individual, which were separated into quintiles (i.e., quintile 1 = least disadvantaged and quintile 5 = most disadvantaged). Kruskal-Wallis tests compared quintile groups on cognitive domain scores and mood and anxiety scores. Multivariable regression models, with and without ADI, were estimated for overall cognitive phenotype and for mood and anxiety scores. A total of 800 patients (median age 38 years; 58% female) met all inclusion criteria. Effects of disadvantage (increasing ADI) were observed across nearly all measured cognitive domains and with significant increases in symptoms of depression and anxiety. Furthermore, patients in more disadvantaged ADI quintiles had increased odds of a worse cognitive phenotype (p = 0.013). Patients who self-identified as members of minoritized groups were overrepresented in the most disadvantaged ADI quintiles and were 2.91 (95% CI 1.87-4.54) times more likely to be in a severe cognitive phenotype than non-Hispanic White individuals (p < 0.001). However, accounting for ADI attenuated this relationship, suggesting neighborhood deprivation may account for some of the relationship between race/ethnicity and cognitive phenotype (ADI-adjusted proportional odds ratio 1.82, 95% CI 1.37-2.42). These findings highlight the importance of environmental factors and regional characteristics in neuropsychological studies of epilepsy. There are many potential mechanisms by which neighborhood disadvantage can adversely affect cognition (e.g., fewer educational opportunities, limited access to health care, food insecurity/poor nutrition, and greater medical comorbidities). Future research will seek to investigate these potential mechanisms and determine whether structural and functional alterations in the brain moderate the relationship between ADI and cognition.

Association between exposure to polycyclic aromatic hydrocarbons and brain cortical thinning: The Environmental Pollution-Induced Neurological EFfects (EPINEF) study

BackgroundAlthough some studies have suggested that exposure to polycyclic aromatic hydrocarbons (PAHs) induces neurodevelopmental disturbances in children and neurodegeneration in animals, the neurotoxic effect of PAH exposure is unclear in adults. The aim was to examine the associations of PAH exposure with brain structure and neuropsychological function in adults without known neurological diseases. MethodsThis study included 421 men and 528 women dwelling in four cities in the Republic of Korea. Urinary concentrations of four PAH metabolites (1-hydroxypyrene, 2-naphthol, 1-hydroxyphenanthrene, and 2-hydroxyfluorene) were obtained. Participants underwent brain 3 T magnetic resonance imaging and neuropsychological tests. Cortical thickness and volume were estimated using the region-of-interest method. Separate generalized linear models were constructed for each sex, adjusting for age, years of education, cohabitation status, income, tobacco use, alcohol consumption, and vascular risk factors. ResultsThe mean (standard deviation) age was 68.3 (6.6) years in men and 66.4 (6.1) years in women. In men, those in quartile 4 (versus quartile 1, the lowest) of urinary 2-naphthol concentration had cortical thinning in the global (β = −0.03, P = .02), parietal (β = −0.04, P = .01), temporal (β = −0.06, P < .001), and insular lobes (β = −0.05, P = .02). Higher quartiles of urinary 2-naphthol concentration were associated with cortical thinning in the global (P = .01), parietal (P = .004), temporal (P < .001), and insular lobes (P = .01). In women, those in quartile 4 (versus quartile 1) of urinary 1-hydroxypyrene concentration had cortical thinning in the frontal (β = −0.03, P = .006) and parietal lobes (β = −0.03, P = .003). Higher quartiles of urinary 1-hydroxypyrene concentration were associated with cortical thinning in the frontal (P = .006) and parietal lobes (P = .001). In both sexes, verbal learning and memory scores significantly declined with an increase in quartile of urinary 1-hydroxypyrene concentration. ConclusionsPAH exposure was associated with cortical thinning and decline in verbal learning and memory function in cognitively healthy adults. This suggests PAHs as an environmental risk factor for neurodegeneration.

Reduced White Matter Integrity and Deficits in Neuropsychological Functioning in Adults With Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is currently viewed as a disorder of cortical systems connectivity, with a heavy emphasis being on the structural integrity of white matter tracts. However, the majority of the literature to date has focused on children with ASD. Understanding the integrity of white matter tracts in adults may help reveal the nature of ASD pathology in adulthood and the potential contributors to cognitive impairment. This study examined white matter water diffusion using diffusion tensor imaging in relation to neuropsychological measures of cognition in a sample of 45 adults with ASD compared to 20 age, gender, and full-scale-IQ-matched healthy volunteers. Tract-based spatial statistics were used to assess differences in diffusion along white matter tracts between groups using permutation testing. The following neuropsychological measures of cognition were assessed: processing speed, attention vigilance, working memory, verbal learning, visual learning, reasoning and problem solving, and social cognition. Results indicated that fractional anisotropy (FA) was significantly reduced in adults with ASD in the anterior thalamic radiation (P = 0.022) and the right cingulum (P = 0.008). All neuropsychological measures were worse in the ASD group, but none of the measures significantly correlated with reduced FA in either tract in the adults with ASD or in the healthy volunteers. Together, this indicates that the tracts that are the most impacted in autism may not be (at least directly) responsible for the behavioral deficits in ASD. Autism Res 2020, 13: 702-714. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: White matter tracts are the data cables in the brain that efficiently transfer information, and damage to these tracts could be the cause for the abnormal behaviors that are associated with autism. We found that two long-range tracts (the anterior thalamic radiation and the cingulum) were both impaired in autism but were not directly related to the impairments in behavior. This suggests that the abnormal tracts and behavior are the effects of another underlying mechanism.

The assessment of neuropsychological functioning in adults with autism spectrum disorders – tackling the challenge

Assessment of neuropsychological functioning in adults with ASD has been researched for a while now, yet there seems to be no consensus on what the actual profile of impairment in this group of patients is. Conflicting results of various studies may be connected to many factors: heterogeneity of the clinical group, changes in diagnostic criteria, applied tests and assessment methods, trouble with matching healthy controls because of individual differences in neuropsychological functioning. The aim of the following paper is to analyse the selected domains of cognitive functioning in adult ASD individuals. It seems that the most consistent findings in this group are connected to central coherence and cognitive flexibility which in turn affect social functions and repetitive behavioral patterns - two core issues of ASD patients. The implications of those findings for clinical practice and diagnostic approach to adult ASD patients are discussed. Especially in regards to high-functioning ASD individuals whose neuropsychological impairment may not show in a standard neuropsychological assessment.

Do Neuropsychological Deficits Predict Anger Dysregulation in Adults with ADHD?

Objective: To examine the relationship between anger and neuropsychological functioning in adults with ADHD.Method: Seventy adults with ADHD were assessed. Correlational and hierarchical multiple regression analyses were performed using neurocognitive tasks and subscales of the State Trait Anger Expression Inventory (STAXI)-trait anger, anger out, anger control, while controlling for anxiety and depression (HADS), and full-scale IQ (WASI). Selective, divided, and shifting attention were assessed using the Test of Everyday Attention (TEA) subscales. Sustained attention was measured using Continuous Performance Test (CPT) scores. Response inhibition was measured using scores from the CPT and Matching Familiar Figures test (MFFT).Results: Trait anger and anger out were both found to have a significant relationship to shifting attention (TEA - visual elevator task) and anxiety. Anger control was found to have a significant relationship to response inhibition (MFFT).Conclusion: Anger was significantly related to two measures of neuropsychological functioning, and anxiety. Shifting attention was more significantly associated with trait anger and anger out than response inhibition, which was significantly related to anger control. These findings have the potential to inform targeted interventions in forensic psychiatry and may have implications regarding which model of ADHD best accounts for anger dysregulation.

Development of The Multicultural Neuropsychological Scale (MUNS): A New Tool for Neuropsychological Assessment of Culturally Diverse Populations

OBJECTIVES: The purpose of this study is to describe the development of the Multi-cultural Neuropsychological Scale (MUNS). METHODS: This is a short scale devised with universal stimuli which are easy to translate into different languages. It consists of 7 subtests evaluating five cognitive domains: attention, memory, executive functioning, constructional praxis and language and was applied to 72 adults of both sexes in an educational range between 1 and 20 years of education. RESULTS: Age correlated with memory subtests (range= -.28 to -.32); and education was correlated with memory (range= .37 to .49), constructional praxis (.44), language (.59) and attention (.25). There were no significant differences between males and females. CONCLUSIONS: The MUNS appears as a short, portable, and user-friendly tool to assess neuropsychological functioning in adults with low and high education. Future studies remain to be conducted in order to demonstrate its cross-cultural validity.

Low-level inorganic arsenic exposure and neuropsychological functioning in American Indian elders

BackgroundInorganic arsenic at high and prolonged doses is highly neurotoxic. Few studies have evaluated whether long-term, low-level arsenic exposure is associated with neuropsychological functioning in adults. ObjectivesTo investigate the association between long-term, low-level inorganic arsenic exposure and neuropsychological functioning among American Indians aged 64–95. MethodsWe assessed 928 participants in the Strong Heart Study by using data on arsenic species in urine samples collected at baseline (1989–1991) and results of standardized tests of global cognition, executive functioning, verbal learning and memory, fine motor functioning, and speed of mental processing administered during comprehensive follow-up evaluations in 2009–2013. We calculated the difference in neuropsychological functioning for a 10% increase in urinary arsenic with adjustment for sex, age, education, and study site. ResultsThe sum of inorganic and methylated arsenic species (∑As) in urine was associated with limited fine motor functioning and processing speed. A 10% increase in ∑As was associated with a .10 (95% CI −.20, −.01) decrease on the Finger Tapping Test for the dominant hand and a .13 decrease (95% CI −.21, −.04) for the non-dominant hand. Similarly, a 10% increase in ∑As was associated with a .15 (95% CI −.29, .00) decrease on the Wechsler Adult Intelligence Scale–Fourth Edition Coding Subtest. ∑As was not associated with other neuropsychological functions. ConclusionsFindings indicate an adverse association between increased urinary arsenic fine motor functioning and processing speed, but not with other neuropsychological functioning, among elderly American Indians.

The Impact of Single Session Intermittent Theta-Burst Stimulation over the Dorsolateral Prefrontal Cortex and Posterior Superior Temporal Sulcus on Adults with Autism Spectrum Disorder.

Intermittent theta burst stimulation (iTBS), a patterned repetitive transcranial magnetic stimulation, was applied over the posterior superior temporal sulcus (pSTS) or dorsolateral prefrontal cortex (DLPFC) to explore its impact in adults with autism spectrum disorder (ASD). Among 25 adults with ASD, 19 (mean age: 20.8 years) completed the randomized, sham-controlled, crossover trial. Every participant received iTBS over the bilateral DLPFC, bilateral pSTS and inion (as a sham control stimulation) in a randomized order with a 1-week interval. Neuropsychological functions were assessed using the Conners' Continuous Performance Test (CCPT) and the Wisconsin Card Sorting Test (WCST). Behavioral outcomes were measured using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Social Responsiveness Scale (SRS). In comparison to that in the sham stimulation, the reaction time in the CCPT significantly decreased following single DLPFC session (p = 0.04, effect size = 0.71) while there were no significant differences in the CCPT and WCST following single pSTS session. Besides, the results in behavioral outcomes were inconsistent and had discrepancy between reports of parents and patients. In conclusion, a single session of iTBS over the bilateral DLPFC may alter the neuropsychological function in adults with ASD. The impacts of multiple-sessions iTBS over the DLPFC or pSTS deserve further investigations.

The impact of obesity on neuropsychological functioning in adults with and without major depressive disorder.

BackgroundEvidence suggests obesity exerts a negative impact on cognition. Major Depressive Disorder (MDD) is also linked to problems in cognitive functioning. Obesity is highly prevalent in individuals with MDD and is linked to a failure to return to a full level of functioning. The study’s objective was to investigate the effect of obesity on cognitive impairment in participants with MDD.MethodsThis study compared cognitive performance in obese individuals with MDD and two control populations (obese individuals without a psychiatric illness and non-obese controls). A standardized battery of neuropsychological tests specifically designed to assess performance in declarative memory, executive functioning, processing speed and attention was administered. Mood ratings, physical measurements, nutritional and health questionnaires were also completed.ResultsWe observed a consistent pattern across measures of memory, executive functioning, attention and processing speed. Whereas healthy controls performed better than both bariatric groups across the majority of measures administered, bariatric controls tended to outperform bariatric MDD patients.LimitationsThe overall sample size of our study was small and thus largely explorative in nature. However, it provides compelling results (while controlling for extraneous variables such as medication load, nutritional status and common metabolic comordidities) that strongly urges for further investigation and study replication with larger sample sizes.ConclusionsWe found obesity has a subtle impact on cognition in obese individuals, and when obesity is present in individuals with MDD, this impact may be significant. It is important to minimize all modifiable variables that can add to cognitive burden in this population.

Neuropsychological Functioning in Adults With ADHD and Adults With Other Psychiatric Disorders

Objective: The aim was to investigate how well neuropsychological measures can discriminate between adults with ADHD and those with other psychiatric disorders. Method: Adults with ADHD and a clinical control group (n = 110) were included. Neuropsychological functioning was investigated using measures of inhibition, working memory, set shifting, planning, fluency, reaction-time variability, and delay aversion. Results: Adults with ADHD performed more poorly compared with clinical controls with regard to all constructs. The effects of verbal memory, inhibition, set shifting, fluency, and delay aversion remained significant when controlling for IQ. However, when controlling for basic cognitive functions, only the effects of inhibition, fluency, and delay aversion were significant. Sensitivity ranged between 64% and 75%, and specificity between 66% and 81%. Conclusion: Neuropsychological tests have a relatively poor ability to discriminate between adults with ADHD and clinical controls, but they may be used to identify individuals at particularly high risk for poor daily functioning.

Cognitive Deficits in Adults With ADHD Go Beyond Comorbidity Effects

Objective: This study addresses if deficits in cognitive, attention, and inhibitory control performance in adults with ADHD are better explained by the disorder itself or by comorbid conditions. Method Adult patients with ADHD (n = 352) and controls (n = 94) were evaluated in the ADHD program of a tertiary hospital. The diagnostic process for ADHD and comorbidities was based on Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria. Stepwise regression analyses evaluated the effect of ADHD, demographics, and comorbidities on the scores from Wechsler Adult Intelligence Scale–Revised, Continuous Performance Test, and Stroop Color and Word Test. Results: Patients with ADHD of both genders had worse performance on neuropsychological domains, even after adjustment for comorbidities. The presence of comorbid bipolar disorder and specific phobia are associated with more Stroop errors, whereas patients with generalized anxiety disorder present a longer execution time in Stroop. Conclusion: Neuropsychological deficits in adults with ADHD go beyond comorbidity. Specific comorbid disorders may influence the neuropsychological functioning in adults with ADHD.

Cognitive Complaints and Neuropsychological Functioning in Adults With and Without Attention-Deficit Hyperactivity Disorder Referred for Multidisciplinary Assessment

The present study aims to gain insight into the clinical presentation (viz., self-reported complaints and neuropsychological functioning) of adults referred for an attention-deficit hyperactivity disorder (ADHD) diagnosis. The investigation evaluated group differences between an ADHD and a non-ADHD sample (n = 30 and n = 42, respectively), all of which had been clinically referred for multidisciplinary assessment of ADHD. Forty-two percent of all referred patients were diagnosed with adult ADHD. Adults with ADHD made significantly more errors on a verbal learning task than the non-ADHD control group, which could indicate an impairment of the self-monitoring function in adult ADHD. The ADHD group reported more problems than the control group in the domains of executive functioning but not in the domains of attention and hyperactivity. More attention should be paid to executive complaints and functioning (present and past) when referring adults suspected of ADHD for multidisciplinary assessment. Also, characteristics that are thought to be striking symptoms of adult ADHD, such as problems with concentration and hyperactive behavior, are in fact not distinctive symptoms of ADHD at all.

Living with spina bifida: neurological and neuropsychological functioning in adults with severely impaired psychosocial adaptation

Background Spina Bifida (SB) is a birth defect caused by incomplete neural tube development, affecting physical, cognitive, and adaptive function. Findings from our previous study indicated that the visual-spatial and executive functions were especially important for psychosocial adaptation in young males. The aim of this study was to describe and examine a group of patients with severely impaired psychosocial adaptation, and to find out if there were gender specific differences with regard to clinical history, neurological and neuropsychological functioning.

Neuropsychological functioning in adults with Asperger syndrome

There is some consensus in the literature regarding the cognitive profile of people with Asperger syndrome (AS). Findings to date suggest that a proportion of people with AS have higher verbal than performance IQ, a non-verbal learning disability (NVLD) and impairments in some aspects of executive function (EF). However, there are few published studies on adults with AS and many have compared the AS group to an autistic control group alone. We compared cognitive functioning in 27 AS adults without a history of language delay and 20 normal controls who did not differ significantly in age, gender and IQ. People with AS had significant impairments on a test of visual memory and on EF tasks measuring flexibility and generativity, but not inhibition. There was no significant difference between verbal and performance IQ. Our results suggest that impairments on tests requiring flexibility of thought and generation occur at all ages and across a range of autistic disorders including AS.

Mobility Impairment in Type 2 Diabetes

The increasing prevalence of type 2 diabetes is a major health concern. Reducing the vascular complications of diabetes has been a primary focus of treatment. However, the less-recognized complications of physical disability, cognitive impairment, and depression that impact on quality of life (QOL) are also important primary care considerations in older patients with diabetes. Diabetes has been associated with a greater risk of decline in function and increased prospect of severe disability (1,2). Studies have sought to identify relationships or causal pathways between the syndromes of mobility, disability, and neuropsychological function in adults with type 2 diabetes (1,3). Few have simultaneously examined these factors potentially modifiable by physical activity (4) across multiple domains or at more than one point in time. The dose of aerobic and resistance exercise necessary to achieve metabolic benefits in clinical trials has sometimes led to poor compliance (5). Older adults with diabetes, often characterized by long-term sedentariness, overweight/obesity, and multiple comorbidities, may demonstrate better adherence to a low-intensity, low-impact exercise, such as Tai Chi. Although Tai Chi has demonstrated improved balance, gait speed, muscle strength, cardiorespiratory fitness, and QOL in older adults (6–13), it has never been tested specifically in a diabetic cohort for benefits across multiple domains. If Tai Chi was shown to be effective for mobility and other health outcomes relevant to this cohort, it may present a viable alternative exercise modality. The aim of this study was to examine the physiologic impairments associated …

Are Intellectual Processes Important in the Diagnosis and Treatment of ADHD?

It is widely accepted that there are two sets of behaviors associated with the diagnosis of attention deficit described as ADHD Hyperactive–Impulsive (ADHD–H) and ADHD Inattentive (ADHD–I) types along with a combined type that includes both dimensions. In this article we suggest that these types of ADHD should be assessed using a variety of measures and procedures but that psychometrically sound measures of basic psychological processes must be included. Assessment of the basic psychological processes addresses issues such as the role of “executive functions” in ADHD–H, the selective attention problems of those with ADHD–I, differential diagnosis of children with ADHD–H and ADHD–I as well as those with learning disabilities, and educational and behavioral treatment planning. This discussion will include references to previously published research papers but should also serve as a stimulus for needed research. Essentially, we suggest that ADHD–H can be viewed as a failure of what we (see Naglieri & Das, 2005) call Planning processing and ADHD–I is a failure of Attention processing. This discussion will begin with an examination of the connections between conceptualizations of these types of attention deficit and a theory of intelligence based on cognitive processing.

Low level methylmercury exposure affects neuropsychological function in adults.

BackgroundThe neurotoxic effects of methylmercury (MeHg) have been demonstrated in both human and animal studies. Both adult and fetal brains are susceptible to the effects of MeHg toxicity. However, the specific effects of adult exposures have been less well-documented than those of children with prenatal exposures. This is largely because few studies of MeHg exposures in adults have used sensitive neurological endpoints. The present study reports on the results of neuropsychological testing and hair mercury concentrations in adults (>17 yrs) living in fishing communities of Baixada Cuiabana (Mato Grosso) in the Pantanal region of Brazil.MethodsA cross-sectional study was conducted in six villages on the Cuiaba River. Participants included 129 men and women older than 17 years of age. They were randomly selected in proportion to the age range and number of inhabitants in each village. Questionnaire information was collected on demographic variables, including education, occupation, and residence history. Mercury exposure was determined by analysis of hair using flameless atomic absorption spectrophotometry. The neurocognitive screening battery included tests from the Wechsler Memory Scale and the Wechsler Adult Intelligence Scale, Concentrated Attention Test of the Toulouse-Pierron Factorial Battery, the Manual Ability Subtests of the Tests of Mechanical Ability, and the Profile of Mood States.ResultsMercury exposures in this population were associated with fish consumption. The hair mercury concentration in the 129 subjects ranged from 0.56 to 13.6 μg/g; the mean concentration was 4.2 ± 2.4 micrograms/g and the median was 3.7 μg/g. Hair mercury levels were associated with detectable alterations in performance on tests of fine motor speed and dexterity, and concentration. Some aspects of verbal learning and memory were also disrupted by mercury exposure. The magnitude of the effects increased with hair mercury concentration, consistent with a dose-dependent effect.ConclusionsThis study suggests that adults exposed to MeHg may be at risk for deficits in neurocognitive function. The functions disrupted in adults, namely attention, fine-motor function and verbal memory, are similar to some of those previously reported in children with prenatal exposures.

Are there cognitive subtypes in adult attention deficit/hyperactivity disorder?

There has been increasing knowledge of the treatment, diagnosis, and demographics of adults with residual attention deficit/hyperactivity disorder (ADHD). However, less is known about the neuropsychological functioning in adults with residual ADHD. In comparing the clinical neuropsychological test performance of a group of adult clinic patients with residual ADHD (N = 30) with that of normal controls (N = 10), we found the patients performed worse on the Trail Making Test, a visual continuous performance test, and the "Brown-Peterson" Auditory Consonant Trigrams Test, but not on any other neuropsychological measures. This pattern indicated a deficit in the area of executive control type functioning, a functional deficit that could be linked to dysregulation of frontal lobe brain systems. Of equal interest was that patients diagnosed with ADHD/hyperactive impulsive type (ADHD+) and patients diagnosed with ADHD/inattentive type (ADHD-) had different types of executive system deficits. ADHD+ was associated with relative deficiency on the Wisconsin Card Sorting Test. ADHD- was associated with relative deficiency on the "Brown-Peterson" Auditory Consonant Trigrams Test, a measure of working memory, as well as less olfactory identification on a smell identification test. The data are discussed in terms of recent localization theories of frontal lobe function. The preliminary data suggest that the different cognitive weaknesses of ADD subtypes may be linked to dysregulation of separate frontal brain regions and/or neurotransmitter systems.