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Papers by Peter Arnett

Research paper thumbnail of Perceived Fatigue Impact and Cognitive Variability in Multiple Sclerosis

Journal of The International Neuropsychological Society, Mar 31, 2021

Objective: People with Multiple Sclerosis (PwMS) and healthy controls (HCs) were evaluated on cog... more Objective: People with Multiple Sclerosis (PwMS) and healthy controls (HCs) were evaluated on cognitive variability indices and we examined the relationship between fatigue and cognitive variability between these groups. Intraindividual variability (IIV) on a neuropsychological test battery was hypothesized to mediate the group differences expected in fatigue. Method: Fifty-nine PwMS and 51 HCs completed a psychosocial interview and battery of neuropsychological tests and questionnaires during a 1-day visit. Fatigue in this study was measured with the Fatigue Impact Scale (FIS), a self-report multidimensional measure of fatigue. IIV was operationalized using two different measures, a maximum discrepancy score (MDS) and intraindividual standard deviation (ISD), in two cognitive domains, memory and attention/processing speed. Two mediation analyses with group (PwMS or HCs) as the independent variable, variability composite (memory or attention/processing speed) measures as the mediators, total residual fatigue (after accounting for age) as the outcome, and depression as a covariate were conducted. The Baron and Kenny approach to testing mediation and the PROCESS macro for testing the strength of the indirect effect were used. Results: Results of a mediation analysis using 5000 bootstrap samples indicated that IIV in domains of both attention/ processing speed and memory significantly mediated the effect of patient status on total residual fatigue. Conclusion: IIV is an objective performance measure that is related to differences in fatigue impact between PwMS and HCs. PwMS experience more variability across tests of attention/processing speed and memory and this experience of variable performance may increase the impact of fatigue.

Research paper thumbnail of A-017 Lifestyle activity engagement and cognition: Findings in healthy controls across the lifespan

Archives of Clinical Neuropsychology, Aug 28, 2020

Objective: Engagement in physical and intellectual activity has been found to exert an impact on ... more Objective: Engagement in physical and intellectual activity has been found to exert an impact on processing speed and executive functioning. One critical issue that remains unclear is at what point in the lifespan self-reported lifestyle factors impact cognition. Method: A community sample of nondepressed adults aged 18-74 (N = 176) was administered measures assessing activity engagement (Cognitive Health Questionnaire), processing speed (SDMT), and executive functioning (PASAT, Oral Trails B). Very physically and intellectually active (over 3 instances/week of activity) participants were compared to those reporting less activity across three age ranges: young adults (YA; age 18-29), middle-aged adults (MA; age 30-55), and older adults (OA; age 56-74). Results: MA participants who frequently engaged in moderate or vigorous physical activity showed better SDMT performance than less active participants (p < .05). YA participants frequently engaging in mild physical activity showed a nonsignificant trend toward better PASAT and SDMT performance than those who were less active. YA and MA participants who reported high use of daily cognitive strategies showed stronger Oral Trails B (p < .05) and SDMT (p = .06) performance, respectively. Very intellectually active YA participants showed better PASAT performance than less active participants (p = .06). While OA participant group comparisons were not significant, small sample sizes for some analyses may have impacted results. Conclusions: We found that individuals with strong lifestyle activity engagement showed better processing speed and executive functioning than less active participants. These findings are consistent with previous research indicating that more robust activity engagement is associated with better cognition.

Research paper thumbnail of Integration of genetic factors with neuropsychological variables in predicting sports concussion outcome

American Psychological Association eBooks, 2019

Research paper thumbnail of Ask the Experts: Managing depression in multiple sclerosis: prevalence, pathology and progress

Neurodegenerative disease management, Dec 1, 2013

How frequently is depression seen in multiple sclerosis patients? Most studies show that approxim... more How frequently is depression seen in multiple sclerosis patients? Most studies show that approximately 50% of multiple sclerosis (MS) patients receive a diagnosis of depression during their lifetimes after their MS diagnoses [1,2]. This is much higher than the 10-15% lifetime prevalence seen in the general population [3]. Depression also appears to be more common in MS than in other chronic illnesses. A recent study by Holden and Isaac showed that, compared with participants with rheumatoid arthritis, individuals with MS had more than twice the risk for clinically significant depressive symptoms [4].

Research paper thumbnail of Speed of presentation influences story recall in multiple sclerosis patients

Archives of Clinical Neuropsychology, Nov 1, 1999

Research paper thumbnail of An etiological model of depressed mood in multiple sclerosis (MS)

Archives of Clinical Neuropsychology, Feb 1, 1998

Research paper thumbnail of Neuropsychology of sports-related concussion

American Psychological Association eBooks, 2019

Research paper thumbnail of Do traditional neuropsychological measures add value to computerized tests for concussion assessment in collegiate athletes?

American Psychological Association eBooks, 2019

Research paper thumbnail of Multiple sclerosis and demyelinating disorders

American Psychological Association eBooks, Apr 21, 2014

Research paper thumbnail of Memory in multiple sclerosis: A reappraisal using the item specific deficit approach

Neuropsychology (journal), Feb 1, 2021

OBJECTIVE As many as 65% of people with multiple sclerosis (MS) have clinically significant memor... more OBJECTIVE As many as 65% of people with multiple sclerosis (MS) have clinically significant memory impairment, but the nature of this deficit is controversial. Some investigations suggest that an inability to retrieve newly learned information from memory is prominent, whereas others imply that compromised acquisition accounts for impairment. Prior research has not simultaneously evaluated acquisition and retrieval processes in MS, and fewer have attempted to account for initial acquisition when studying retrieval. The Item Specific Deficit Approach (ISDA) offers a method of quantifying acquisition, retrieval, and retention processes, with the latter two mechanisms being adjusted for initial acquisition. To simultaneously quantify acquisition and retrieval abilities, the ISDA was applied to list learning performance in two independent samples of people with MS and corresponding healthy comparison groups. PARTICIPANTS AND METHODS Study 1 included 85 people with MS and 47 healthy individuals. Study 2 involved a separate sample of 79 people with MS and 22 healthy people. They were administered neuropsychological batteries, and participants with MS were classified as globally impaired or unimpaired. The California Verbal Learning Test-II was administered to assess new-learning in both studies, and responses were scored using the ISDA. RESULTS Both studies revealed that cognitively impaired people with MS manifest weaknesses involving acquisition and retrieval. Nearly identical effect sizes emerged across samples, with cognitive impairment achieving a medium effect upon acquisition and a large effect upon retrieval. CONCLUSIONS These findings accord well with previous research showing diminished acquisition and retrieval among people with MS. The results may also reconcile contradictory findings in the extant literature by showing that memory impairment in MS is not exclusively attributable to either acquisition or retrieval. Rather, both processes may manifest across people with MS. The replication across samples with nearly identical effect sizes implies that these effects are reliable and possess external validity. These data hold implications for memory rehabilitation interventions involving people with MS, and suggest that acquisition and retrieval processes should be addressed in treatment. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Research paper thumbnail of Sleep Deprived or Concussed? The Acute Impact of Self-Reported Insufficient Sleep in College Athletes

Journal of The International Neuropsychological Society, Jul 9, 2020

Objective:Sleep deprivation is common among both college students and athletes and has been corre... more Objective:Sleep deprivation is common among both college students and athletes and has been correlated with negative health outcomes, including worse cognition. As such, the current study sought to examine the relationship between sleep difficulties and self-reported symptoms and objective neuropsychological performance at baseline and post-concussion in collegiate athletes.Method:Seven hundred seventy-two collegiate athletes completed a comprehensive neuropsychological test battery at baseline and/or post-concussion. Athletes were separated into two groups based on the amount of sleep the night prior to testing. The sleep duration cutoffs for these group were empirically determined by sample mean and standard deviation (M= 7.07,SD= 1.29).Results:Compared with athletes getting sufficient sleep, those getting insufficient sleep the night prior to baseline reported significantly more overall symptoms and more symptoms from each of the five symptom clusters of the Post-Concussion Symptom Scale. However, there were no significant differences on objective performance indices. Secondly, there were no significant differences on any of the outcome measures, except for sleep symptoms and headache, between athletes getting insufficient sleep at baseline and those getting sufficient sleep post-concussion.Conclusion:Overall, the effect of insufficient sleep at baseline can make an athlete appear similar to a concussed athlete with sufficient sleep. As such, athletes completing a baseline assessment following insufficient sleep could be underperforming cognitively and reporting elevated symptoms that would skew post-concussion comparisons. Therefore, there may need to be consideration of prior night’s sleep when determining whether a baseline can be used as a valid comparison.

Research paper thumbnail of Predictors of dyadic adjustment in multiple sclerosis

Multiple Sclerosis Journal, Dec 1, 2005

Because multiple sclerosis (MS) is usually diagnosed between the ages of 20 and 50, a time during... more Because multiple sclerosis (MS) is usually diagnosed between the ages of 20 and 50, a time during which most people begin serious relationships, dyadic adjustment for MS patients is a salient issue. However, little is known about factors that might contribute to dyadic adjustment problems in MS. In the present study, we predicted that MS patients showing evidence of three common sequelae of MS-depression symptoms, fatigue and cognitive dysfunction-would be most likely to display problems with dyadic adjustment. Sixty-four MS patients and 49 significant others were assessed. Patient-reported dyadic adjustment was significantly (P at least &lt;0.05) associated with depression (r=-0.48) and fatigue (r=-0.31), but not cognitive functioning. Significant other-reported dyadic adjustment was significantly associated with patients’ depression (r=-0.38), fatigue (r=-0.30) and executive functioning impairments (r=0.37). Stepwise regression analyses revealed that depression was the only significant predictor of dyadic adjustment, regardless of whether significant other (r2 change=0.16) or patient-reported (r2 change=0.22) dyadic adjustment was used as the criterion variable. If depression leads to dyadic problems in MS patients, treatment of depression may result in improved dyadic adjustment. Conversely, if dyadic problems contribute to depression in MS, then treatment of dyadic problems may lead to relief from depression in these patients.

Research paper thumbnail of Impact of neurological impairment, depression, cognitive function and coping on quality of life of people with multiple sclerosis: A relative importance analysis

Multiple Sclerosis Journal, Dec 22, 2014

Determining the relative importance of factors that predict quality of life (QoL) in people with ... more Determining the relative importance of factors that predict quality of life (QoL) in people with multiple sclerosis (MS) must be addressed through multiple regression metrics, e.g. relative weights, which are designed to solve colinearity problems. We aimed to compare disease variables, Expanded Disability Status Scale (EDSS), depressive symptomatology (BDI-FS), cognitive performance and coping in predicting MS patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; QoL, using relative weights. We assessed 97 patients with MS, using the Functional Assessment of MS (FAMS) as the criterion. EDSS predicted global and physical QoL domains, whereas BDI-FS predicted general contentment and global QoL. EDSS and BDI-FS are relevant determinants of QoL in people with MS.

Research paper thumbnail of Pain and affective memory biases interact to predict depressive symptoms in multiple sclerosis

Multiple Sclerosis Journal, 2007

A large literature supports a direct relationship between pain and depressive symptoms among vari... more A large literature supports a direct relationship between pain and depressive symptoms among various patient populations. Patients with multiple sclerosis (MS) frequently experience both pain and depression. Despite this, no relationship between pain and depression has been found in MS. The present investigation explored the relationship between pain and depression in a sample of patients with MS. Consistent with cognitive theories of depression, results supported the hypothesis that pain would only contribute to depression when MS patients exhibited a concomitant cognitive vulnerability. Cognitive vulnerability to depression was measured using a performance based affective memory bias (AMB) task. Patients with high levels of pain and negative AMB reported more depressive symptoms compared to patients with pain and positive AMB. Implications for the identification and treatment of depression in MS are discussed.

Research paper thumbnail of Worsening of symptoms is associated with lower physical activity levels in individuals with multiple sclerosis

Multiple Sclerosis Journal, 2008

The present study examined the relationship between the worsening of symptoms across a 3-5-year p... more The present study examined the relationship between the worsening of symptoms across a 3-5-year period of time and self-reported physical activity in a sample of 51 individuals with multiple sclerosis (MS). Of the 51 participants, 35 reported a worsening of symptoms over the 3-5-year period of time. The worsening of symptoms was associated with significantly and moderately lower levels of selfreported physical activity independent of depression and EDSS scores and MS-disease course (P ϭ0.04). This study provides novel evidence that a worsening of symptoms is associated with lower levels of physical activity in individuals with MS.

Research paper thumbnail of Depressed mood in multiple sclerosis: Relationship to capacity-demanding memory and attentional functioning

Neuropsychology (journal), 1999

Because it is theorized that depression results in reduced available attentional capacity that, i... more Because it is theorized that depression results in reduced available attentional capacity that, in turn, can explain the impaired performance on capacity-demanding tasks in depressed individuals, the authors predicted that multiple sclerosis (MS) patients with depressed mood would have difficulty with these types of tasks. Twenty depressed mood MS participants were compared with 41 nondepressed mood MS participants and 8 nondepressed mood controls on 5 attentional capacity-demanding clinical memory and attentional tasks and 3 tasks with minimal capacity demands. Depressed mood MS patients performed significantly worse than both nondepressed mood groups on the 3 speeded capacity-demanding attentional measures but not on any of the tasks requiring few capacity demands, supporting the authors' predictions. The possibility that the impaired performance of depressed mood MS patients on speeded attentional tasks was mediated by reduced verbal working memory capacity, impaired deployment of executive strategies that access working memory capacity, or psychomotor slowing is explored. Many studies have demonstrated that the prevalence of depression in patients with multiple sclerosis (MS) is substantially greater than that found in the general population, normal control participants, patients with other neurological illnesses, and spinal cord injured patients (Minden & Schiffer, 1990). Studies that have used a range of methods for diagnosing depression in MS have reported lifetime prevalence rates between 37% and 54% (Minden & Schiffer, 1991). Similar to non-MS depressed patients (Cohen, Weingartner, Smallberg, Pickar, & Murphy, 1982; Hartlage, Alloy, Vazquez, & Dykman, 1993), MS patients show their greatest cognitive impairments on tasks that require atten

Research paper thumbnail of Caregiver burden in multiple sclerosis

Journal of Neurology, Neurosurgery, and Psychiatry, Oct 1, 2007

Research paper thumbnail of B-59 * Comprehensive Examination of Factors Contributing to Employment Status in Multiple Sclerosis

Archives of Clinical Neuropsychology, Aug 28, 2014

Objective: Unemployment is common among individuals with Multiple Sclerosis (MS) and is associate... more Objective: Unemployment is common among individuals with Multiple Sclerosis (MS) and is associated with significant socioeconomic burden. Several MS-related factors have been found to associate with employment status including fatigue, depression, cognitive problems, and motor difficulties. However, few studies have examined these factors collectively in predicting employment. Method: Fifty-seven individuals with MS participating in a research study of cognitive, emotional, and social factors related to MS were examined. Composite scores were created using factor analysis that represented cognition, fatigue, depression, and motor function. These composite scores, along with disease duration and age, were explored as predictors of employment status (working, not working) via logistic regression. Models of mediation were also investigated. Results: A model including composites of motor function, cognition, depression, and fatigue significantly predicted employment status, x 2 (4) ¼ 10.16, p¼. 038, Nagelkerke R 2 ¼ .22. However, only the cognitive composite was found to be a significant predictor after controlling for all other variables in the model. Results of a mediation analysis using 1, 000 bootstrap samples indicated that the cognitive composite significantly mediated both the effect of age (indirect effect¼. 027, 95% CI [.0005, 1160]) and disease duration (indirect effect¼. 042, 95% CI [.0067, .1059]) on work status. Conclusion(s): Cognitive function predicts employment status above and beyond fatigue, depression, and motor function. Additionally, cognitive function partially mediates the effect of age and disease duration on employment status. Interventions targeting cognitive difficulties in MS may be effective in allowing individuals to maintain employment.

Research paper thumbnail of Loss of Consciousness is Associated with Elevated Cognitive Intra-Individual Variability Following Sports-Related Concussion

Journal of The International Neuropsychological Society, Aug 10, 2020

Objective:The purpose of this study was to evaluate whether loss of consciousness (LOC), retrogra... more Objective:The purpose of this study was to evaluate whether loss of consciousness (LOC), retrograde amnesia (RA), and anterograde amnesia (AA) independently influence a particular aspect of post-concussion cognitive functioning—across-test intra-individual variability (IIV), or cognitive dispersion.Method:Concussed athletes (N = 111) were evaluated, on average, 6.04 days post-injury (SD = 5.90; Mdn = 4 days; Range = 1–26 days) via clinical interview and neuropsychological assessment. Primary outcomes of interest included two measures of IIV—an intra-individual standard deviation (ISD) score and a maximum discrepancy (MD) score—computed from 18 norm-referenced variables.Results:Analyses of covariance (ANCOVAs) adjusting for time since injury and sex revealed a significant effect of LOC on the ISD (p = .018, ηp2 = .051) and MD (p = .034, ηp2 = .041) scores, such that athletes with LOC displayed significantly greater IIV than athletes without LOC. In contrast, measures of IIV did not significantly differ between athletes who did and did not experience RA or AA (all p &gt; .05).Conclusions:LOC, but not RA or AA, was associated with greater variability, or inconsistencies, in cognitive performance acutely following concussion. Though future studies are needed to verify the clinical significance of these findings, our results suggest that LOC may contribute to post-concussion cognitive dysfunction and may be a risk factor for less efficient cognitive functioning.

Research paper thumbnail of Examination of the Chicago Multiscale Depression Inventory and Initial Validation of a Positive Scale

Journal of The International Neuropsychological Society, Nov 9, 2015

The Chicago Multiscale Depression Inventory (CMDI) was developed to improve accuracy in measuring... more The Chicago Multiscale Depression Inventory (CMDI) was developed to improve accuracy in measuring depression symptoms in individuals with non-psychiatric medical illness. Earlier psychometric evaluation of the CMDI has emphasized properties of items that measure negative affect and experience. In this study, we provide an initial evaluation of an outcome scale of positive items that are also included within the CMDI but have previously been excluded from calculation of the total score. Psychometric data for the CMDI negative and positive item subscales were determined in healthy adults and patients with multiple sclerosis. Analysis included measurements of factor structure, reliability, and validity in comparison with other established measures of depression and affect. Study findings indicate that in healthy and patient samples, the CMDI Positive scale has very good reliability and validity. The Positive scale score also appears to predict depression symptoms beyond the negative item scale scores. The CMDI Positive scale could be a valuable clinical and research tool. Inclusion of the Positive scale in the CMDI total score appears to improve the measure by further capturing symptoms of affect and experience that are important to diagnosis of depression and are not covered by the negative scales alone.

Research paper thumbnail of Perceived Fatigue Impact and Cognitive Variability in Multiple Sclerosis

Journal of The International Neuropsychological Society, Mar 31, 2021

Objective: People with Multiple Sclerosis (PwMS) and healthy controls (HCs) were evaluated on cog... more Objective: People with Multiple Sclerosis (PwMS) and healthy controls (HCs) were evaluated on cognitive variability indices and we examined the relationship between fatigue and cognitive variability between these groups. Intraindividual variability (IIV) on a neuropsychological test battery was hypothesized to mediate the group differences expected in fatigue. Method: Fifty-nine PwMS and 51 HCs completed a psychosocial interview and battery of neuropsychological tests and questionnaires during a 1-day visit. Fatigue in this study was measured with the Fatigue Impact Scale (FIS), a self-report multidimensional measure of fatigue. IIV was operationalized using two different measures, a maximum discrepancy score (MDS) and intraindividual standard deviation (ISD), in two cognitive domains, memory and attention/processing speed. Two mediation analyses with group (PwMS or HCs) as the independent variable, variability composite (memory or attention/processing speed) measures as the mediators, total residual fatigue (after accounting for age) as the outcome, and depression as a covariate were conducted. The Baron and Kenny approach to testing mediation and the PROCESS macro for testing the strength of the indirect effect were used. Results: Results of a mediation analysis using 5000 bootstrap samples indicated that IIV in domains of both attention/ processing speed and memory significantly mediated the effect of patient status on total residual fatigue. Conclusion: IIV is an objective performance measure that is related to differences in fatigue impact between PwMS and HCs. PwMS experience more variability across tests of attention/processing speed and memory and this experience of variable performance may increase the impact of fatigue.

Research paper thumbnail of A-017 Lifestyle activity engagement and cognition: Findings in healthy controls across the lifespan

Archives of Clinical Neuropsychology, Aug 28, 2020

Objective: Engagement in physical and intellectual activity has been found to exert an impact on ... more Objective: Engagement in physical and intellectual activity has been found to exert an impact on processing speed and executive functioning. One critical issue that remains unclear is at what point in the lifespan self-reported lifestyle factors impact cognition. Method: A community sample of nondepressed adults aged 18-74 (N = 176) was administered measures assessing activity engagement (Cognitive Health Questionnaire), processing speed (SDMT), and executive functioning (PASAT, Oral Trails B). Very physically and intellectually active (over 3 instances/week of activity) participants were compared to those reporting less activity across three age ranges: young adults (YA; age 18-29), middle-aged adults (MA; age 30-55), and older adults (OA; age 56-74). Results: MA participants who frequently engaged in moderate or vigorous physical activity showed better SDMT performance than less active participants (p < .05). YA participants frequently engaging in mild physical activity showed a nonsignificant trend toward better PASAT and SDMT performance than those who were less active. YA and MA participants who reported high use of daily cognitive strategies showed stronger Oral Trails B (p < .05) and SDMT (p = .06) performance, respectively. Very intellectually active YA participants showed better PASAT performance than less active participants (p = .06). While OA participant group comparisons were not significant, small sample sizes for some analyses may have impacted results. Conclusions: We found that individuals with strong lifestyle activity engagement showed better processing speed and executive functioning than less active participants. These findings are consistent with previous research indicating that more robust activity engagement is associated with better cognition.

Research paper thumbnail of Integration of genetic factors with neuropsychological variables in predicting sports concussion outcome

American Psychological Association eBooks, 2019

Research paper thumbnail of Ask the Experts: Managing depression in multiple sclerosis: prevalence, pathology and progress

Neurodegenerative disease management, Dec 1, 2013

How frequently is depression seen in multiple sclerosis patients? Most studies show that approxim... more How frequently is depression seen in multiple sclerosis patients? Most studies show that approximately 50% of multiple sclerosis (MS) patients receive a diagnosis of depression during their lifetimes after their MS diagnoses [1,2]. This is much higher than the 10-15% lifetime prevalence seen in the general population [3]. Depression also appears to be more common in MS than in other chronic illnesses. A recent study by Holden and Isaac showed that, compared with participants with rheumatoid arthritis, individuals with MS had more than twice the risk for clinically significant depressive symptoms [4].

Research paper thumbnail of Speed of presentation influences story recall in multiple sclerosis patients

Archives of Clinical Neuropsychology, Nov 1, 1999

Research paper thumbnail of An etiological model of depressed mood in multiple sclerosis (MS)

Archives of Clinical Neuropsychology, Feb 1, 1998

Research paper thumbnail of Neuropsychology of sports-related concussion

American Psychological Association eBooks, 2019

Research paper thumbnail of Do traditional neuropsychological measures add value to computerized tests for concussion assessment in collegiate athletes?

American Psychological Association eBooks, 2019

Research paper thumbnail of Multiple sclerosis and demyelinating disorders

American Psychological Association eBooks, Apr 21, 2014

Research paper thumbnail of Memory in multiple sclerosis: A reappraisal using the item specific deficit approach

Neuropsychology (journal), Feb 1, 2021

OBJECTIVE As many as 65% of people with multiple sclerosis (MS) have clinically significant memor... more OBJECTIVE As many as 65% of people with multiple sclerosis (MS) have clinically significant memory impairment, but the nature of this deficit is controversial. Some investigations suggest that an inability to retrieve newly learned information from memory is prominent, whereas others imply that compromised acquisition accounts for impairment. Prior research has not simultaneously evaluated acquisition and retrieval processes in MS, and fewer have attempted to account for initial acquisition when studying retrieval. The Item Specific Deficit Approach (ISDA) offers a method of quantifying acquisition, retrieval, and retention processes, with the latter two mechanisms being adjusted for initial acquisition. To simultaneously quantify acquisition and retrieval abilities, the ISDA was applied to list learning performance in two independent samples of people with MS and corresponding healthy comparison groups. PARTICIPANTS AND METHODS Study 1 included 85 people with MS and 47 healthy individuals. Study 2 involved a separate sample of 79 people with MS and 22 healthy people. They were administered neuropsychological batteries, and participants with MS were classified as globally impaired or unimpaired. The California Verbal Learning Test-II was administered to assess new-learning in both studies, and responses were scored using the ISDA. RESULTS Both studies revealed that cognitively impaired people with MS manifest weaknesses involving acquisition and retrieval. Nearly identical effect sizes emerged across samples, with cognitive impairment achieving a medium effect upon acquisition and a large effect upon retrieval. CONCLUSIONS These findings accord well with previous research showing diminished acquisition and retrieval among people with MS. The results may also reconcile contradictory findings in the extant literature by showing that memory impairment in MS is not exclusively attributable to either acquisition or retrieval. Rather, both processes may manifest across people with MS. The replication across samples with nearly identical effect sizes implies that these effects are reliable and possess external validity. These data hold implications for memory rehabilitation interventions involving people with MS, and suggest that acquisition and retrieval processes should be addressed in treatment. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Research paper thumbnail of Sleep Deprived or Concussed? The Acute Impact of Self-Reported Insufficient Sleep in College Athletes

Journal of The International Neuropsychological Society, Jul 9, 2020

Objective:Sleep deprivation is common among both college students and athletes and has been corre... more Objective:Sleep deprivation is common among both college students and athletes and has been correlated with negative health outcomes, including worse cognition. As such, the current study sought to examine the relationship between sleep difficulties and self-reported symptoms and objective neuropsychological performance at baseline and post-concussion in collegiate athletes.Method:Seven hundred seventy-two collegiate athletes completed a comprehensive neuropsychological test battery at baseline and/or post-concussion. Athletes were separated into two groups based on the amount of sleep the night prior to testing. The sleep duration cutoffs for these group were empirically determined by sample mean and standard deviation (M= 7.07,SD= 1.29).Results:Compared with athletes getting sufficient sleep, those getting insufficient sleep the night prior to baseline reported significantly more overall symptoms and more symptoms from each of the five symptom clusters of the Post-Concussion Symptom Scale. However, there were no significant differences on objective performance indices. Secondly, there were no significant differences on any of the outcome measures, except for sleep symptoms and headache, between athletes getting insufficient sleep at baseline and those getting sufficient sleep post-concussion.Conclusion:Overall, the effect of insufficient sleep at baseline can make an athlete appear similar to a concussed athlete with sufficient sleep. As such, athletes completing a baseline assessment following insufficient sleep could be underperforming cognitively and reporting elevated symptoms that would skew post-concussion comparisons. Therefore, there may need to be consideration of prior night’s sleep when determining whether a baseline can be used as a valid comparison.

Research paper thumbnail of Predictors of dyadic adjustment in multiple sclerosis

Multiple Sclerosis Journal, Dec 1, 2005

Because multiple sclerosis (MS) is usually diagnosed between the ages of 20 and 50, a time during... more Because multiple sclerosis (MS) is usually diagnosed between the ages of 20 and 50, a time during which most people begin serious relationships, dyadic adjustment for MS patients is a salient issue. However, little is known about factors that might contribute to dyadic adjustment problems in MS. In the present study, we predicted that MS patients showing evidence of three common sequelae of MS-depression symptoms, fatigue and cognitive dysfunction-would be most likely to display problems with dyadic adjustment. Sixty-four MS patients and 49 significant others were assessed. Patient-reported dyadic adjustment was significantly (P at least &lt;0.05) associated with depression (r=-0.48) and fatigue (r=-0.31), but not cognitive functioning. Significant other-reported dyadic adjustment was significantly associated with patients’ depression (r=-0.38), fatigue (r=-0.30) and executive functioning impairments (r=0.37). Stepwise regression analyses revealed that depression was the only significant predictor of dyadic adjustment, regardless of whether significant other (r2 change=0.16) or patient-reported (r2 change=0.22) dyadic adjustment was used as the criterion variable. If depression leads to dyadic problems in MS patients, treatment of depression may result in improved dyadic adjustment. Conversely, if dyadic problems contribute to depression in MS, then treatment of dyadic problems may lead to relief from depression in these patients.

Research paper thumbnail of Impact of neurological impairment, depression, cognitive function and coping on quality of life of people with multiple sclerosis: A relative importance analysis

Multiple Sclerosis Journal, Dec 22, 2014

Determining the relative importance of factors that predict quality of life (QoL) in people with ... more Determining the relative importance of factors that predict quality of life (QoL) in people with multiple sclerosis (MS) must be addressed through multiple regression metrics, e.g. relative weights, which are designed to solve colinearity problems. We aimed to compare disease variables, Expanded Disability Status Scale (EDSS), depressive symptomatology (BDI-FS), cognitive performance and coping in predicting MS patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; QoL, using relative weights. We assessed 97 patients with MS, using the Functional Assessment of MS (FAMS) as the criterion. EDSS predicted global and physical QoL domains, whereas BDI-FS predicted general contentment and global QoL. EDSS and BDI-FS are relevant determinants of QoL in people with MS.

Research paper thumbnail of Pain and affective memory biases interact to predict depressive symptoms in multiple sclerosis

Multiple Sclerosis Journal, 2007

A large literature supports a direct relationship between pain and depressive symptoms among vari... more A large literature supports a direct relationship between pain and depressive symptoms among various patient populations. Patients with multiple sclerosis (MS) frequently experience both pain and depression. Despite this, no relationship between pain and depression has been found in MS. The present investigation explored the relationship between pain and depression in a sample of patients with MS. Consistent with cognitive theories of depression, results supported the hypothesis that pain would only contribute to depression when MS patients exhibited a concomitant cognitive vulnerability. Cognitive vulnerability to depression was measured using a performance based affective memory bias (AMB) task. Patients with high levels of pain and negative AMB reported more depressive symptoms compared to patients with pain and positive AMB. Implications for the identification and treatment of depression in MS are discussed.

Research paper thumbnail of Worsening of symptoms is associated with lower physical activity levels in individuals with multiple sclerosis

Multiple Sclerosis Journal, 2008

The present study examined the relationship between the worsening of symptoms across a 3-5-year p... more The present study examined the relationship between the worsening of symptoms across a 3-5-year period of time and self-reported physical activity in a sample of 51 individuals with multiple sclerosis (MS). Of the 51 participants, 35 reported a worsening of symptoms over the 3-5-year period of time. The worsening of symptoms was associated with significantly and moderately lower levels of selfreported physical activity independent of depression and EDSS scores and MS-disease course (P ϭ0.04). This study provides novel evidence that a worsening of symptoms is associated with lower levels of physical activity in individuals with MS.

Research paper thumbnail of Depressed mood in multiple sclerosis: Relationship to capacity-demanding memory and attentional functioning

Neuropsychology (journal), 1999

Because it is theorized that depression results in reduced available attentional capacity that, i... more Because it is theorized that depression results in reduced available attentional capacity that, in turn, can explain the impaired performance on capacity-demanding tasks in depressed individuals, the authors predicted that multiple sclerosis (MS) patients with depressed mood would have difficulty with these types of tasks. Twenty depressed mood MS participants were compared with 41 nondepressed mood MS participants and 8 nondepressed mood controls on 5 attentional capacity-demanding clinical memory and attentional tasks and 3 tasks with minimal capacity demands. Depressed mood MS patients performed significantly worse than both nondepressed mood groups on the 3 speeded capacity-demanding attentional measures but not on any of the tasks requiring few capacity demands, supporting the authors' predictions. The possibility that the impaired performance of depressed mood MS patients on speeded attentional tasks was mediated by reduced verbal working memory capacity, impaired deployment of executive strategies that access working memory capacity, or psychomotor slowing is explored. Many studies have demonstrated that the prevalence of depression in patients with multiple sclerosis (MS) is substantially greater than that found in the general population, normal control participants, patients with other neurological illnesses, and spinal cord injured patients (Minden & Schiffer, 1990). Studies that have used a range of methods for diagnosing depression in MS have reported lifetime prevalence rates between 37% and 54% (Minden & Schiffer, 1991). Similar to non-MS depressed patients (Cohen, Weingartner, Smallberg, Pickar, & Murphy, 1982; Hartlage, Alloy, Vazquez, & Dykman, 1993), MS patients show their greatest cognitive impairments on tasks that require atten

Research paper thumbnail of Caregiver burden in multiple sclerosis

Journal of Neurology, Neurosurgery, and Psychiatry, Oct 1, 2007

Research paper thumbnail of B-59 * Comprehensive Examination of Factors Contributing to Employment Status in Multiple Sclerosis

Archives of Clinical Neuropsychology, Aug 28, 2014

Objective: Unemployment is common among individuals with Multiple Sclerosis (MS) and is associate... more Objective: Unemployment is common among individuals with Multiple Sclerosis (MS) and is associated with significant socioeconomic burden. Several MS-related factors have been found to associate with employment status including fatigue, depression, cognitive problems, and motor difficulties. However, few studies have examined these factors collectively in predicting employment. Method: Fifty-seven individuals with MS participating in a research study of cognitive, emotional, and social factors related to MS were examined. Composite scores were created using factor analysis that represented cognition, fatigue, depression, and motor function. These composite scores, along with disease duration and age, were explored as predictors of employment status (working, not working) via logistic regression. Models of mediation were also investigated. Results: A model including composites of motor function, cognition, depression, and fatigue significantly predicted employment status, x 2 (4) ¼ 10.16, p¼. 038, Nagelkerke R 2 ¼ .22. However, only the cognitive composite was found to be a significant predictor after controlling for all other variables in the model. Results of a mediation analysis using 1, 000 bootstrap samples indicated that the cognitive composite significantly mediated both the effect of age (indirect effect¼. 027, 95% CI [.0005, 1160]) and disease duration (indirect effect¼. 042, 95% CI [.0067, .1059]) on work status. Conclusion(s): Cognitive function predicts employment status above and beyond fatigue, depression, and motor function. Additionally, cognitive function partially mediates the effect of age and disease duration on employment status. Interventions targeting cognitive difficulties in MS may be effective in allowing individuals to maintain employment.

Research paper thumbnail of Loss of Consciousness is Associated with Elevated Cognitive Intra-Individual Variability Following Sports-Related Concussion

Journal of The International Neuropsychological Society, Aug 10, 2020

Objective:The purpose of this study was to evaluate whether loss of consciousness (LOC), retrogra... more Objective:The purpose of this study was to evaluate whether loss of consciousness (LOC), retrograde amnesia (RA), and anterograde amnesia (AA) independently influence a particular aspect of post-concussion cognitive functioning—across-test intra-individual variability (IIV), or cognitive dispersion.Method:Concussed athletes (N = 111) were evaluated, on average, 6.04 days post-injury (SD = 5.90; Mdn = 4 days; Range = 1–26 days) via clinical interview and neuropsychological assessment. Primary outcomes of interest included two measures of IIV—an intra-individual standard deviation (ISD) score and a maximum discrepancy (MD) score—computed from 18 norm-referenced variables.Results:Analyses of covariance (ANCOVAs) adjusting for time since injury and sex revealed a significant effect of LOC on the ISD (p = .018, ηp2 = .051) and MD (p = .034, ηp2 = .041) scores, such that athletes with LOC displayed significantly greater IIV than athletes without LOC. In contrast, measures of IIV did not significantly differ between athletes who did and did not experience RA or AA (all p &gt; .05).Conclusions:LOC, but not RA or AA, was associated with greater variability, or inconsistencies, in cognitive performance acutely following concussion. Though future studies are needed to verify the clinical significance of these findings, our results suggest that LOC may contribute to post-concussion cognitive dysfunction and may be a risk factor for less efficient cognitive functioning.

Research paper thumbnail of Examination of the Chicago Multiscale Depression Inventory and Initial Validation of a Positive Scale

Journal of The International Neuropsychological Society, Nov 9, 2015

The Chicago Multiscale Depression Inventory (CMDI) was developed to improve accuracy in measuring... more The Chicago Multiscale Depression Inventory (CMDI) was developed to improve accuracy in measuring depression symptoms in individuals with non-psychiatric medical illness. Earlier psychometric evaluation of the CMDI has emphasized properties of items that measure negative affect and experience. In this study, we provide an initial evaluation of an outcome scale of positive items that are also included within the CMDI but have previously been excluded from calculation of the total score. Psychometric data for the CMDI negative and positive item subscales were determined in healthy adults and patients with multiple sclerosis. Analysis included measurements of factor structure, reliability, and validity in comparison with other established measures of depression and affect. Study findings indicate that in healthy and patient samples, the CMDI Positive scale has very good reliability and validity. The Positive scale score also appears to predict depression symptoms beyond the negative item scale scores. The CMDI Positive scale could be a valuable clinical and research tool. Inclusion of the Positive scale in the CMDI total score appears to improve the measure by further capturing symptoms of affect and experience that are important to diagnosis of depression and are not covered by the negative scales alone.