Biomedical subjects

Peter A Arnett

Publications and source records attributed to Peter A Arnett.

13 recordsLinked to original sources

PubMed2006

The impact of motivation on neuropsychological performance in sports-related mild traumatic brain injury.

The current project examined the impact of differential motivation on baseline versus post-mild traumatic brain injury (MTBI) neuropsychological measures in athletes. Collegiate athletes were administered a neuropsychological battery prior to and post-MTBI. High Motivation at Baseline (HMB) and Suspect Motivation at Baseline (SMB) groups were established for each measure based on whether baseline performance fell +/- one or more standard deviations from the mean of the given measure. Greater improvement was expected in the SMB group than the HMB group given hypothesized differences in baseline motivation. In repeated measures analysis of covariance (ANCOVA) that removed achievement performance, the SMB groups demonstrated greater improvement than the HMB groups for the Trail Making Test A & B (TMT-A & B), Digit Span, and Stroop-Color Word (Stroop-CW) tests. Also, the percentage of participants who improved according to reliable change indices was greater for the SMB groups on the TMT-A & B, Stroop-CW, and the Vigil. These findings are likely due to lower motivation in the SMB group for each test. However, results also suggest that some tests may be relatively unaffected by motivation. These data may have clinical implications and point to the need for better methods of identifying athletes with suspect motivation at baseline.

Adult↗

PubMed2005

An examination of four models predicting fatigue in multiple sclerosis.

Fatigue is a common symptom of multiple sclerosis (MS) that is purported to cause significant distress and have detrimental effects on daily functioning, social and occupational obligations, and overall well-being. The prevalence of fatigue in MS is high, with 53-87% of patients reporting significant problems with fatigue across different studies reported in the literature. The cause of fatigue in MS is still poorly understood. Some researchers have suggested that fatigue is a direct consequence of the MS disease process, but several studies have failed to find a relationship between disease severity and MS fatigue. A number of investigations have reported that depression and sleep are significantly related to fatigue in MS, as well as to one another. The purpose of the present investigation was to examine the relationships among disease severity, depression, and sleep disturbance in MS, and their possible role in predicting fatigue. Four models were proposed to explore these relationships. The best fitting model showed that all three were significant independent contributors to fatigue in MS, accounting for 43% of the variance, with sleep disturbance reigning as the largest contributor. Furthermore, although disease severity predicted fatigue in our sample, both depression and sleep disturbance emerged as stronger predictors. These findings suggest that, beyond core physical/neurological MS symptomatology, there are other factors that contribute to fatigue in MS, namely, depression and sleep disturbance.

Adult↗

PubMed2005

Longitudinal consistency of the relationship between depression symptoms and cognitive functioning in multiple sclerosis.

BACKGROUND: Lifetime prevalence rates of cognitive dysfunction and depression in multiple sclerosis (MS) have typically been reported to be approximately 50 percent. However, an inconsistent relationship between these two common features of MS has been reported in the literature. Because neurovegetative depression symptoms overlap with MS symptoms, it may be that literature inconsistencies can partly be explained by the fact that only those depression symptom clusters unambiguously reflective of depression are associated with cognitive dysfunction. OBJECTIVE: To explore the relationship between different depression symptom clusters and a battery of tests measuring cognitive domains commonly impaired in MS and was examined at two time points 3 years apart. METHODS: The Chicago Multiscale Depression Inventory was employed to measure mood, negative evaluative, and neurovegetative symptom clusters in 53 MS patients who were also administered a battery of neuropsychological tests. RESULTS: At time point 1, Mood and Evaluative Chicago Multiscale Depression Inventory scales were significantly associated with tasks of complex speeded attention, planning, and working memory. At time point 2, the Evaluative scale was still significantly associated with these domains, in addition to spatial memory; however, all of the significant correlations with the Mood scale dropped out. CONCLUSION: These results show that negative evaluative depression symptoms are most consistently predictive of cognitive dysfunction in MS. It may be that negative evaluative depression symptoms use up available cognitive capacity, thus compromising performance on cognitive capacity demanding tasks in MS patients.

Cognition Disorders↗

PubMed2005

MS patients with depressive symptoms exhibit affective memory biases when verbal encoding strategies are suppressed.

As many as 50% of multiple sclerosis (MS) patients experience clinical or subclinical depression. A voluminous literature has documented affective memory biases (AMB) among depressed individuals. Despite this, little is known regarding how depressive symptoms may affect MS patients' ability to recall positive and negative material. The present study employed an affective list-learning task that increased cognitive load and inhibited the use of higher order encoding strategies. The purpose of the study was twofold: to determine whether MS patients exhibit AMB and to examine whether subvocal repetition and other higher order encoding strategies are essential to the formation of AMB among people experiencing depression. Results indicated a strong relationship between depression and AMB in MS. The results are discussed in relation to existing biological research that indicates limbic and/or other subcortical systems may play a role in the formation of AMB.

Affect↗

PubMed2005

Depression and fatigue in relapsing-remitting MS: the role of symptomatic variability.

Depression and fatigue are common psychosocial sequelae of MS. An infrequently examined issue in the MS literature is the effect of MS-related symptom variability on incidence of depression and fatigue. The current study was designed to examine the relationship of variability in physical, cognitive, and social/environmental functioning with depression and fatigue in MS. Forty-eight relapsing-remitting MS patients from a larger sample completed self-report measures of depression and fatigue. They were also administered a structured interview that assessed current, best, and worst levels of functioning since being diagnosed with MS. Higher levels of symptom variability since disease onset were associated with depression and fatigue, even after accounting for MS-related physical disability. Regression analyses indicated that variability in social and environmental functioning was particularly associated with depression, and variability in physical abilities was associated with fatigue. These findings suggest that a more variable course of MS symptoms is associated with increased depression and fatigue. Focused assessment of variability in symptoms may be useful in detecting and subsequently treating depression and fatigue in MS patients.

Adult↗

PubMed2005

Factors related to employment status changes in individuals with multiple sclerosis.

In a sample of 50 individuals with multiple sclerosis (MS), participants able to work full-time ('W'), those who reduced their hours ('CB') and those who were unemployed ('NW') were compared on demographic and disease variables and symptoms that the participants identified as being responsible for their work status change. The NW group had significantly greater physical disability than the other two groups and significantly more fatigue than the W group. The CB group had significantly more years of education and higher occupational prestige ratings than the NW group. The W group reported significantly greater mood disturbance compared with the NW group. Employment status was unrelated to age, gender, full scale IQ estimate, disease duration, diagnosis duration or cognitive functioning. Ninety per cent of the CB group reported that fatigue was a primary symptom responsible for their work status change, whereas 86% of the NW group reported that broad physical/neurological symptoms were responsible for their change in work status.

Adult↗

PubMed2005

Predictors of dyadic adjustment in multiple sclerosis.

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 <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.

Adaptation, Psychological↗

PubMed2004

Speed of presentation influences story recall in college students and persons with multiple sclerosis.

Story memory tests are commonly used in clinical neuropsychology. Surprisingly, no guidelines are provided for speed of presentation for two of the most commonly used story memory tests in clinical neuropsychology. The current investigation was designed to explore whether speed of presentation influences recall on the Story subtest from the Rivermead Behavioural Memory Test. Consistent with predictions, college students in Study 1 and multiple sclerosis participants in Study 2 recalled significantly more story elements at immediate recall when the story was presented slow versus fast. This effect, however, was limited to the conditions where the fast story was presented before the slow story. At delayed recall, participants in both studies recalled more story elements in the slow versus fast story independent of presentation conditions. Both studies also revealed that significantly more participants fell in the "impaired" range on immediate recall for the fast story in the condition where it was presented first. Data from these studies show that speed of presentation can substantially alter story recall in a wide range of individuals. It will be important to develop story tests for which speed of presentation is standardized to ensure that erroneous conclusions regarding memory are not drawn about individuals seen in clinical neuropsychological practice.

Adolescent↗

PubMed2004

Metamemory in multiple sclerosis: exploring affective and executive contributors.

Although previous reports have examined metamemory in various neurological groups, no study to date has examined various affective and cognitive contributors to metamemory collectively in a sample of multiple sclerosis (MS) patients. In the present study, 48 MS patients completed the Memory Functioning Questionnaire (MFQ) and were administered measures assessing depression, depressive attitudes, and executive functioning. Correlational analyses indicated that certain aspects of metamemory in MS were associated with both affective and executive variables. Structural equation modeling (SEM) analyses of three a priori models revealed the best fit with one model proposing that greater executive dysfunction and depression were associated with increased self-reported memory complaints, but via the mediating influence of depressive attitudes. Although our results suggest some objective basis for metamemory complaints in MS (i.e., executive dysfunction), they also suggest that these complaints may be exacerbated by the potentially reversible influences of depression and depressive attitudes. Treatment of depression and depressive attitudes in MS may result in MS patients having more accurate perceptions of their actual memory abilities that, in turn, may lead to improvements in their quality of life.

Adult↗

PubMed2004

Self-reported everyday memory and depression in patients with multiple sclerosis.

Depression and memory difficulties are among the most common complaints voiced by patients with multiple sclerosis (MS). Nevertheless, little is known about how depression might affect patients' perceptions of their memory difficulties. The present investigation was designed to explore this issue. Results supported a model that integrates aspects of Beck's theory of depression and the concept of depressive realism. Consistent with the depressive realism literature, nondepressed MS patients significantly overestimated their everyday memory compared with their actual performance on verbal memory and attention/concentration indices, whereas moderately depressed patients' everyday memory ratings mirrored their actual neuropsychological performance. Supporting Beck's negative cognitive schema notion, mildly depressed patients significantly overestimated their memory difficulties. Implications for the treatment of memory problems among MS patients are discussed.

Adult↗

PubMed2002

Relationship between coping, cognitive dysfunction and depression in multiple sclerosis.

Given its relatively high prevalence, one possible source of stress for patients with multiple sclerosis (MS) is cognitive dysfunction. The authors' study was guided by a new theoretical model suggesting that cognitive dysfunction in MS may be most likely to lead to depression when patients use high levels of avoidance coping and/or low levels of active coping. To test this model, 55 patients with definite MS were administered a neuropsychological battery and measures of depression and coping. Consistent with predictions, regression analyses showed that coping significantly moderated the relationship between cognitive dysfunction and depression. Specifically, cognitive dysfunction was most likely to be associated with depression when patients used either high levels of avoidance or low levels of active coping. Implications of these data for clinical applications and for our theoretical conceptualization are discussed and limitations of the model explored.

Adaptation, Psychological↗

PubMed2002

Minimal neuropsychological assessment of MS patients: a consensus approach.

Cognitive impairment is common in multiple sclerosis (MS), yet patients seen in MS clinics and neurologic practices are not routinely assessed neuropsychologically. In part, poor utilization of NP services may be attributed to a lack of consensus among neuropsychologists regarding the optimal approach for evaluating MS patients. An expert panel composed of neuropsychologists and psychologists from the United States, Canada, United Kingdom, and Australia was convened by the Consortium of MS Centers (CMSC) in April, 2001. Our objectives were to: (a) propose a minimal neuropsychological (NP) examination for clinical monitoring of MS patients and research, and (b) identify strategies for improving NP assessment of MS patients in the future. The panel reviewed pertinent literature on MS-related cognitive dysfunction, considered psychometric factors relevant to NP assessment, defined the purpose and optimal characteristics of a minimal NP examination in MS, and rated the psychometric and practical properties of 36 candidate NP measures based on available literature. A 90-minute NP battery, the Minimal Assessment of Cognitive Function in MS (MACFIMS), emerged from this discussion. The MACFIMS is composed of seven neuropsychological tests, covering five cognitive domains commonly impaired in MS (processing speed/working memory, learning and memory, executive function, visual-spatial processing, and word retrieval). It is supplemented by a measure of estimated premorbid cognitive ability. Recommendations for assessing other factors that may potentially confound interpretation of NP data (e.g., visual/sensory/motor impairment, fatigue, and depression) are offered, as well as strategies for improving NP assessment of MS patients in the future.

Cognition Disorders↗

PubMed2002

Contributing factors to depressed mood in Multiple Sclerosis.

By applying the behavioral theory of Lewinsohn et al. [1985. An integrative theory of depression. In: S. Reiss, & R. R. Bootzin (Eds.), Theoretical issues in behavior therapy (pp. 331-359). San Diego, CA: Academic Press.] to multiple sclerosis (MS), it was hypothesized that physical disability, fatigue, and psychosocial dysfunction would be significantly predictive of depressed mood in MS patients. Seventy-six MS patients completed the following measures: the Sickness Impact Profile (SIP), the Fatigue Impact Scale (FIS), and the mood subscale from the Chicago Multiscale Depression Inventory (CMDI). Structural equation modeling revealed that physical disability and fatigue were indirectly predictive of depressed mood via their effects on recreational functioning. Fatigue also had a direct effect on mood. If reductions in recreational activities actually cause decrements in mood, depressed mood in MS may be treatable by helping patients identify recreational activities that they can enjoy regardless of physical or fatigue-related difficulties.

Journal Article↗