C. Christine Bow-Thomas

Do specific neurocognitive deficits predict specific domains of community function in schizophrenia

We examined whether specific neurocognitive deficits predicted specific domains of community outcome in 40 schizophrenic patients. Neuropsychological assessments were conducted before hospital discharge, and measures of functional outcome were obtained 1 to 3.5 years later. A priori hypotheses were generated based upon a recent review by Green (Green MF [1996] What are the functional consequences of neurocognitive deficits in schizophrenia? American Journal of Psychiatry, 153(3):321-330). As hypothesized, verbal memory predicted all measures of community outcome, vigilance predicted social outcomes, and executive functioning predicted work and activities of daily living (ADLs). However, in addition to the predicted relationships, many other associations were found between neuropsychological test scores and adaptive function. Furthermore, both cognitive and functional measures were intercorrelated. If deficits in adaptive functioning are neurocognitively multi-determined, utilizing compensatory strategies to bypass multiple areas of cognitive impairment may be more efficient than cognitive remediation in improving community outcomes.

Executive function in schizophrenia.

Many domains of executive function are impaired in patients with schizophrenia including forward planning, concept formation, initiation, self-monitoring, and the ability to direct attention and memory. These impairments are noticeable against a background of generalized cognitive deficits, and many affect 40% to 95% of individuals with this disorder. Specific executive deficits appear to be related to specific symptom clusters and are linked to structural and functional brain abnormalities. Executive impairment predicts multiple domains of functional outcome in schizophrenia patients. Atypical antipsychotic agents and cognitive rehabilitation may be promising new approaches for the treatment of cognitive and functional impairment in schizophrenia.

Predicting quality of life from symptomatology in schizophrenia at exacerbation and stabilization

There has been little research investigating how symptoms of schizophrenia and changes in symptomatology across the course of the illness relate to measures of quality of life in patients. We examined this issue in 45 patients assessed at hospital admission for illness exacerbation, at stabilization (prior to discharge) and at follow-up (5-9 months post-discharge). Symptom ratings at each time period consisted of the Brief Psychiatric Rating Scale (BPRS) and the Negative Symptom Assessment (NSA). The Heinrichs-Carpenter Quality of Life Scale (QLS) was administered upon admission to the hospital (assessing the 3 months prior to admission) and again at follow-up. Correlational analyses revealed relationships of both positive and negative symptoms with quality of life. These relationships are particularly strong at stabilization. Stepwise regression analyses revealed changes in the NSA motivation component to be most important in predicting quality of life for the patients at follow-up. BPRS psychosis and paranoia components are important predictors of quality of life at stabilization (but not during acute exacerbation). These results are important in terms of understanding the impact of changes in symptomatology on the quality of life for patients with schizophrenia as well as in targeting specific symptom clusters for treatment to maximize quality of life post-hospitalization.

A brief cognitive assessment for use with schizophrenia patients in community clinics

Cognitive impairment is a prominent feature of schizophrenia. The availability of very brief measures may increase the use of cognitive assessment in routine care settings. We examined the reliability and validity of the brief cognitive assessment (BCA), a battery that takes approximately 15 min to administer and score, and that was designed to be sensitive to changes in cognition with novel antipsychotics. The BCA was administered to 340 outpatients on two occasions, 3 months apart. A sub-sample of subjects received a full battery of cognitive tests (n=97) and additional measures of functional outcome. Results indicated that the BCA had very good test-retest reliability and inter-item consistency. Moreover, the BCA was strongly correlated with a comprehensive battery (r=0.72; p<0.0001) which took 8 to 10 times longer to administer. Finally, both cognitive batteries were correlated similarly with measures of community functioning. Changes over time for individual patients can be interpreted in the context of normative data available for each test in the BCA. The data provide preliminary evidence for the reliability and validity of the BCA. Further studies examining the utility of the BCA for tracking changes in cognitive functioning with treatment are encouraged.

Concurrent and predictive validity of the allen cognitive levels assessment

The present study examined the concurrent and predictive validity of the Allen Cognitive Levels (ACL) Assessment in a sample of 110 medicated patients with schizophrenia who received the ACL at discharge from a state psychiatric facility. Subsamples within this group of patients had received an Activities of Daily Living assessment (n = 64) and a comprehensive neuropsychological test battery (n = 48) at discharge, or a battery of community follow-up measures (n = 30) 1-3.5 years following discharge as part of other investigations. Positive correlations were found between the ACL and concurrent measures of adaptive and cognitive function. With respect to cognitive variables, stepwise multiple regression analysis revealed that the majority of the variance in ACL scores was predicted by neuropsychological test scores assessing higher level cognitive processes, such as visual organization, manipulation of information in working memory, and ability to inhibit a response to a prepotent stimulus. Finally, results revealed positive relationships between the ACL obtained at discharge and community functioning at follow-up. The results of this study provide some evidence for the concurrent and predictive validity of the ACL for patients with schizophrenia and suggest that further study of this assessment tool would be important to pursue in future investigations.

An investigation of instruments used to assess negative symptoms in patients with schizophrenia

Accurate assessment of changes in negative symptoms is necessary to evaluate new treatments for patients with schizophrenia. In an investigation of instrument sensitivity, Eckert et al., (1996) found the Negative Symptom Assessment (NSA) to be very effective in detecting negative symptom changes in patients with schizophrenia. The efficacy of the Positive and Negative Syndrome Scale (PANSS) was not examined. The current research replicates the finding that the NSA is sensitive to changes in negative symptomatology from initial assessment to ratings at discharge with 23 schizophrenic patients (effect size (ES) 1.2). PANSS and NSA ratings were available at the beginning and end of medication study. Some patients would ha ve been on standard medications, some on placebo and some on investigational medications. For this time period, the ES for the PANSS Negative factor was 0.51 while the NSA ES was very small ES (0.10) despite the fact that the NSA ES from the beginning of study to discharge was quite large ES (1.20) . This suggests that both the NSA and PANSS are sensitive to changes over time, however the Negative factor on the PANSS is assessing something different from the NSA. Further analyses indicated that some negative symptoms as measured by the NSA improved from initial assessment to the end of the medication study, while others worsened. Whereas, all negative symptoms assessed by the PANSS improved during the study period. Examining relationships between PANSS negative symptom items and NSA factors indicated that many PANSS negative items significantlycorrelate with multiple NSA factors. Attention was focused in particular on the 3 NSA factors that measure the negative symptoms listed as DSM IV diagnostic criteria. A potential explanation for this interesting finding is that the NSA items assess specific negative symptoms which can vary independently; while the PANSS negative symptom items measure a more general negative factor. Suggestionsare made for further examination to clarify the utility of the PANSS and NSA in detecting changes in negative symptoms.