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Biomedical subjects

Matthew M Kurtz

Publications and source records attributed to Matthew M Kurtz.

13 recordsLinked to original sources
PubMed2006

Computer-assisted cognitive remediation in schizophrenia: what is the active ingredient?

An emerging body of research has shown that computer-assisted cognitive remediation, consisting of training in attention, memory, language and/or problem-solving, produces improvement in neurocognitive function that generalizes to untrained neurocognitive tests and may also impact symptoms and work functioning in patients with schizophrenia. The active ingredient of these interventions, however, remains unknown as control groups in these studies have typically included few, if any, of the elements of these complex behavioral treatments. This study compared the effects of an extended (12-month), standardized, computer-assisted cognitive remediation intervention with those of a computer-skills training control condition that consisted of many of the elements of the experimental intervention, including hours spent on a computer, interaction with a clinician and non-specific cognitive stimulation. Forty-two patients with schizophrenia were randomly assigned to one of two conditions and were assessed with a comprehensive neuropsychological test battery before and after treatment. Results revealed that cognitive-remediation training produced a significant improvement in working memory, relative to the computers-skills training control condition, but that there was overall improvement in both groups on measures of working memory, reasoning/executive-function, verbal and spatial episodic memory, and processing speed. Taken together, these findings suggest that specific practice in neurocognitive exercises targeted at attention, memory and language, produce improvements in neurocognitive function that are not solely attributable to non-specific stimulation associated with working with a computer, interacting with a clinician or cognitive challenge, but that non-specific stimulation has a salutary effect on neurocognition as well.

Adult↗
PubMed2006

A virtual reality apartment as a measure of medication management skills in patients with schizophrenia: a pilot study.

Performance on a novel, virtual reality (VR) assessment of medication management skills, the Virtual Reality Apartment Medication Management Assessment (VRAMMA), was investigated in 25 patients with schizophrenia and 18 matched healthy controls. The VRAMMA is a virtual 4-room apartment consisting of a living room with an interactive clock and TV, a bedroom, a kitchen, and a bathroom with an interactive medicine cabinet. After an exploratory phase, participants were given a mock prescription regimen to be taken 15 minutes later from pill bottles located in the medicine cabinet in the bathroom of the virtual environment. The VRAMMA was administered with a validated measure of medication management skills, several neurocognitive tests, and a symptom scale. Results revealed that (1) schizophrenic patients made significantly more quantitative errors in the number of pills taken, were less accurate at taking the prescribed medications at the designated time, and checked the interactive clock less frequently than healthy controls; (2) in patients with schizophrenia, there was significant agreement in classification of adherence vs nonadherence between a validated measure of medication management skills and the VRAMMA; and (3) in patients with schizophrenia, years of education and a measure of verbal learning and memory were linked to quantitative errors on the VRAMMA, while positive symptoms, specifically delusional symptoms, were inversely linked to distance traveled within the VRAMMA. This is the first study, to our knowledge, to provide evidence for the utility of VR technology in the assessment of instrumental role functioning in patients with schizophrenia.

Adult↗
PubMed2006

Virtual reality assessment of medication compliance in patients with schizophrenia.

Medication compliance is essential to treating the symptoms of schizophrenia effectively. This study utilized a virtual reality (VR) apartment paradigm to assess medication compliance behaviors in 25 patients with schizophrenia and in 16 healthy control subjects. Participants were assigned a prescription consisting of three medications and were asked to self-administer this regimen in 15 min. Results demonstrate that patients had considerably more difficulty in complying with the medication regimen than did controls. They manifested significantly more quantitative errors, and were much less accurate in consuming the medications at the assigned time. Significant differences in performance between these groups were also evidenced by a variety of validated neuropsychological measures. Correlations between the data may suggest a convergent validity for this new VR task. Future research will investigate the validity of this task in predicting additional measures of psychosocial functioning.

Adult↗
PubMed2006

Symptoms versus neurocognitive skills as correlates of everyday functioning in severe mental illness.

A critical review of cross-sectional and longitudinal studies conducted from 2001-2005 investigating the relationship of symptoms and neurocognitive skills to everyday functioning in patients with severe mental illness was completed. Literature and bibliographic searches identified seven studies, which were grouped according to the methodology of measurement of everyday function selected: clinician-rated scales of psychosocial function based on patient and proxy report; performance-based measures of functional capacity; or competitive vocational success. Results of the review revealed that negative symptoms, such as social withdrawal, psychomotor slowing and blunted affect, and neurocognitive measures of attention, executive function, working memory, verbal memory and psychomotor speed, were most commonly linked to all three domains of everyday function. With the exception of one study, there was no evidence of a relationship between positive symptoms, such as delusions and hallucinations, and everyday function. The implications of these findings for guiding future research are discussed.

Activities of Daily Living↗
PubMed2005

Differences in performance and learning proficiency on the Wisconsin Card Sorting Test in schizophrenia: do they reflect distinct neurocognitive subtypes with distinct functional profiles?

The aim of this study was two-fold: 1) to determine whether a priori subtyping of patients with schizophrenia based on both overall performance on a measure of executive-function, the Wisconsin Card Sorting Test (WCST), and ability to learn the task with expanded instruction, could be confirmed with other, independent measures of executive-function and learning, and, if so, 2) to determine whether these groups have different neurocognitive profiles and show differences in functional capacity. Fifty-four outpatients with schizophrenia were divided by WCST performance into three groups: intact executive-function (n=28), "good learner" (n=13), and "poor learner" (n=13) groups. These groups were then assessed with a comprehensive neurocognitive test battery and a performance-based measure of functional status, the UCSD Performance-based Skills Assessment (UPSA). The WCST-intact subgroup performed significantly better than other groups on a second measure of executive-function and in working memory, and speeded motor sequencing. Impaired WCST patients who benefited from expanded WCST instruction ("good learners") also showed better performance than patients who did not benefit from instruction ("poor-learners") on a second measure of learning, as well as on a measure of auditory divided attention. The intact WCST subgroup had greater functional capacity than either "strong" or "poor" learners. These subtypes may have implications for response to behavioral treatment interventions.

Activities of Daily Living↗
PubMed2005

Neurocognitive impairment across the lifespan in schizophrenia: an update.

A literature review and power analysis of longitudinal studies published since 1997 investigating the trajectory of neurocognitive deficits across time in patients with schizophrenia was conducted. Ten studies were identified, evaluating a total of 834 patients with mean ages of 24.0-77.8 years at study entry. Power estimates for the 10 studies ranged widely from 0.26 to 0.99 for a medium effect size of 0.4. Despite wide inter-study differences in cognitive measures selected, sample size and phase of illness studied, several consistent themes emerged. Studies of primarily community-dwelling outpatients with schizophrenia revealed that overall measures of IQ and gross cognitive status do not show deterioration greater than that associated with benign aging. Furthermore, performance on specific measures of neurocognition was remarkably consistent across ages studied. Indeed, there is some evidence that IQ, as well as other neurocognitive measures, may show improvement over a 5-year test-retest interval. Findings were consistent whether patients were in their first episode of illness or chronic. These results support a static "encephalopathy" model of cognitive deficits in schizophrenia. In contrast, studies of middle-aged and elderly institutionalized patients with schizophrenia have revealed markedly different findings. There is evidence in this population of a decline in gross measures of cognitive status even over a brief 2.5-year test-retest interval in patients 65 or older that may, in some cases, be linked to the emergence of orofacial dyskinesia. Taken together, these studies suggest two distinct neurocognitive trajectories during the lifespan in patients with schizophrenia that may represent manifestations of distinct pathophysiological mechanisms of the illness during different phases of the disease.

Adult↗
PubMed2005

Symptoms versus neurocognitive test performance as predictors of psychosocial status in schizophrenia: a 1- and 4-year prospective study.

In recent years, a growing body of literature has highlighted the significance of neurocognitive deficits as markers for subsequent psychosocial deficits in patients with schizophrenia. Relatively few studies, however, have directly compared symptoms and neurocognitive test performance as predictors of psychosocial status in a prospective design. In two studies with schizophrenia patients, we investigated the relationship between symptom dimensions (psychomotor poverty, disorganization, reality distortion) and neurocognitive measures (problem solving, attention, verbal learning and memory) obtained at study entry, and psychosocial status measured at a 1- and 4-year followup. Results from the 1-year followup (n = 70) revealed that psychomotor poverty, symptoms of disorganization, and performance on measures of card-sorting and visual vigilance were related to psychosocial status. Results from the 4-year followup (n = 26) revealed a similar pattern of findings with the exception of verbal learning, which emerged as a predictor of psychosocial status only at the 4-year followup. Stepwise regression revealed that performance on measures of visual vigilance and psychomotor poverty symptoms explained the largest amount of variance in psychosocial status at both followup intervals. The significance of these findings for the development and assessment of novel treatment interventions for schizophrenia is discussed.

Adult↗
PubMed2005

Neurocognitive function in schizophrenia at a 10-year follow-up: a preliminary investigation.

INTRODUCTION: A wealth of evidence indicates that neurocognitive deficits are evident in patients with schizophrenia at both illness onset and after many years of treatment. Little is known regarding if or how these deficits change during the lifespan. The goal of the study was to evaluate changes in full-scale intelligence quotient and neurocognitive test performance over a 10-year interval in patients with schizophrenia. METHODS: Twelve patients were administered the Wechsler Adult Intelligence Scale-Revised as a measure of intellectual function and a neuropsychological test battery including measures of attention, verbal and non-verbal memory, language, visuospatial function, problem-solving, and motor function at entry to the study and at a 10-year follow-up. RESULTS: With the exception of performance on a measure of speeded motor sequencing, there was no significant decline in any of the measures at 10-year follow-up. Results from a measure of sustained auditory attention showed improvement at follow-up. DISCUSSION: These data support a neurodevelopmental model of schizophrenia for young adult to middle-age patients by suggesting that neurocognitive deficits that emerge either before disease onset or early in the course of the illness remain stable as the patient ages. CONCLUSION: Overall, measures of intelligence quotient, as well as specific neurocognitive skills, do not decline over a 10-year period in at least a subgroup of patients with schizophrenia.

Adolescent↗
PubMed2004

The Penn Conditional Exclusion Test (PCET): relationship to the Wisconsin Card Sorting Test and work function in patients with schizophrenia.

Performance on the Penn Conditional Exclusion Test (PCET), a new computerized measure of executive function with alternate forms, was compared with performance on the Wisconsin Card Sorting Test (WCST) in a sample of 32 patients with schizophrenia. In Analysis 1, the PCET and WCST were administered with several other standard neuropsychological measures to assess convergent and divergent validity. Results revealed that categories achieved and total errors on the PCET were closely related to analogous measures from the WCST. Divergent validity was supported through nonsignificant correlations between the PCET and measures of speeded visual sequencing, verbal learning and psychomotor speed. In Analysis 2, the relationship between the PCET, WCST and a detailed measure of vocational function, the Work Behavior Inventory (WBI), was compared. Results revealed that both executive-function measures were related to specific dimensions of work function as measured in a vocational setting. More specifically, categories achieved and total errors on both the WCST and PCET were related to measures of cooperativeness on the job. Errors on the PCET were also related to measurements of work quality and general impressions of work. These results provide the first evidence of criterion-related validity for the PCET and are part of a growing literature suggesting a relationship between performance on measures of executive function and work skills.

Adult↗
PubMed2004

The Penn Conditional Exclusion Test: a new measure of executive-function with alternate forms of repeat administration.

Studies of change in neuropsychological function over time in both healthy and diseased populations have been hindered by the absence of alternate forms of most commonly used neuropsychological tests. The Penn Conditional Exclusion Test (PCET) was developed as a new cognitive instrument to assess "executive" functioning with four alternate forms. In Study 1, the PCET was administered in counterbalanced order to 80 healthy young adults to establish equivalent test difficulty. Results revealed that the four versions were related on categories achieved, total number of errors and total number of trials. In Study 2, the PCET was administered to 25 healthy adults of a wide age range with a battery of computerized neuropsychological tests to assess construct validity. Convergent validity was confirmed by positive correlations between the PCET and a measure of abstraction. Divergent validity was established through low, nonsignificant correlations between the PCET and measures of facial emotion recognition, word and face memory, visuospatial function, and verbal reasoning.

Adolescent↗
PubMed2003

Neurocognitive rehabilitation for schizophrenia.

A critical review of randomized, controlled trials of extended programs of neurocognitive rehabilitation for the cognitive deficits characteristic of schizophrenia conducted between the years 2000 to 2002 was completed. Over the past several years, two models of cognitive rehabilitation have emerged. In one model, labeled "cognitive remediation," cognitive deficits are treated directly through repeated practice and acquisition of compensatory strategies on cognitive exercises designed to engage underfunctioning brain systems. In a second model, labeled "cognitive adaptation," neurocognitive deficits are addressed through modification of the patients' environment to allow patients to bypass their deficits. Results revealed that a range of cognitive remediation strategies varying widely along dimensions of duration, intensity, method, target of behavioral intervention, and clinical status of participants produced improvements on measures of working memory, emotion perception, and executive function distinct from those trained during remediation. No effects were evident in secondary verbal or nonverbal memory. Results of two pilot studies using functional magnetic resonance imaging to assess changes in task-evoked brain activation have revealed that these interventions may produce changes in several functionally relevant neural systems in a subset of patients. Results from studies of standardized cognitive adaptation interventions have indicated that these treatments can produce improvements in symptoms, psychosocial status, and relapse rates. A variety of approaches for future research are also discussed.

Cognition Disorders↗
PubMed2002

Development of an abbreviated schizophrenia quality of life scale using a new method.

The goal of the study was to develop and apply a predictive model approach to reduce the number of items collected for scales that yield a total summary score. A parsimonious subset of items from the 21-item Quality of Life Scale (QLS) that can accurately predict the total scale score was sought and evaluated in 198 patients with schizophrenia, using a statistical modeling approach. Two additional data sets were used for model validation: the subset of 101 patients used in the model construction who had the QLS administered approximately 1 year later and a new sample of 37 patients. Using only seven QLS items as predictors, the correlation was 0.9831 between the predicted and true QLS totals. Applying the model based for these seven QLS items, the correlations from the first and second validation data sets were 0.9791 and 0.9637, respectively. The study demonstrates that a small subset of items of the QLS predicts the entire 21-item scale with high accuracy. Two validation samples have confirmed the finding. This reduces the effort associated with scale administration and is likely to increase the assessment of an important functional domain. Such models can guide efforts for item reduction in other rating instruments.

Adolescent↗