Stability and validity of memory-based subtypes of schizophrenia.

This study assessed whether verbal memory performance indexed by the California Verbal Learning Test (CVLT) can organize and reduce the heterogeneity of schizophrenia. The temporal stability, cognitive and clinical validity of: (a) a putatively cortical-subcortical-normative typology derived from dementia patients' scores on the CVLT and (b) a memory performance dichotomy based on a psychometric criterion and 1 CVLT summary score were evaluated. These memory subtypes were examined in 102 schizophrenia patients, 55 of whom were assessed again 3 years later. The results indicate that both methods yield potentially valuable illness distinctions on a cross-sectional basis, but fail to show truly trait-like properties. Furthermore, the evidence favors the validity of a parsimonious dichotomy over a more complex dementia-based typology.     

Neurocognitive and functional correlates of mobile phone use in middle-aged and older patients with schizophrenia

Objectives: Our objective was to examine the association of mobile phone use and ownership with psychopathology, cognitive functioning, and functional outcome in 196 outpatients aged 40 years and older who were diagnosed with schizophrenia.

Method: Participants reported their past and current mobile phone use on a standardized self-report scale and they were administered tests of global cognition, functional capacity, and informant-rated functional outcome.

Results: The great majority of subjects had used a mobile phone (78%) but few currently owned one (27%). After adjusting for age (mean age 51), any past mobile phone use was associated with less severe negative symptoms, and higher global cognitive performance, functional capacity, and functional outcome. A total of 60% of participants reported being comfortable with mobile phones, but comfort was not associated with any cognitive or functional outcomes.

Conclusion: Most of the older patients with schizophrenia have used mobile phones and lifetime mobile phone use is a positive indicator of cognitive and functional status.     

Depressed mood and its functional correlates in institutionalized schizophrenia patients

OBJECTIVE: To determine the frequency of depressed mood in institutionalized schizophrenia patients and its association with illness-related and functional variables. METHODS: Out of 657 institutionalized schizophrenia patients, patients with depressed mood were identified and compared to non-depressed patients, matching for potential confounders. RESULTS: Forty-eight (7.3%) patients had moderate to severe depressed mood. They were younger, more educated and had fewer years since their first hospitalization than non-depressed patients. After matching for these variables, depressed patients showed more positive symptoms and exhibited better social and cognitive functioning. When controlling for negative symptoms, the differences in social and cognitive functioning between the depressed and non-depressed patients disappeared, and depressed patients showed more positive symptoms and more impaired impulse control. CONCLUSIONS: Unlike the negative impact of depressed mood in other populations, this study shows that symptoms of depressed mood may identify a subgroup of institutionalized schizophrenia patients who show better functioning across a variety of indicators. Future studies should determine differential treatment responses and long-term outcomes of these patients.     

Neurocognition, symptomatology, and functional skills in older alcohol-abusing schizophrenia patients

Deficits in neurocognitive functioning are common to both schizophrenia and alcoholism. Recent studies suggest that neurocognitive functioning is the most significant predictor of social-adaptive functioning in schizophrenia. Cognitive impairment induced by alcoholism may result in more impaired functional outcome for comorbid patients. Past research examining alcohol-abusing schizophrenia patients has not examined correlates with functional outcome and has generally been limited to relatively younger patients. This study examined neurocognitive functioning and its correlates in alcohol-abusing schizophrenia patients between the ages of 40 and 80. Outpatients with schizophrenia (SZ; n = 17) or both schizophrenia and alcohol abuse or dependence (SZ + ETOH; n = 18) were tested on a neurocognitive battery, rated for symptomatology, and assessed for functional abilities. The results suggest that alcohol abuse in schizophrenia is associated with more impaired functioning across many domains, including memory impairment, negative and general psychopathology symptoms, and adaptive functions. The only significant predictor of impaired functional status in the overall sample and the SZ + ETOH group was neurocognitive functioning.     

The relationship of neuropsychological abilities to specific domains of functional capacity in older schizophrenia patients.

BACKGROUND: This study sought to determine the relative importance of cognitive measures in predicting various domains of everyday functional capacity in older outpatients with schizophrenia. METHODS: Ninety-three psychiatry outpatients with diagnoses of schizophrenia and schizoaffective disorders underwent a comprehensive neuropsychiatric evaluation, including neuropsychological testing and clinical ratings of psychopathology. Functional capacity was assessed with the Direct Assessment of Functional Status, a performance measure of basic and instrumental activities of daily living (ADLs/IADLs). RESULTS: Neuropsychological performance significantly predicted most ADLs/IADLs measured, except simple eating behaviors, time orientation, and grooming. Lower educational level and negative symptoms also were associated with worse functional capacity, whereas positive symptoms and depressed mood were not. Measures of cognitive functioning accounted for more variance in functional capacity than did psychiatric ratings of symptoms, and multiple regression analyses demonstrated that neuropsychological performance was predictive of functional capacity, over and above clinical symptoms. No specific cognitive domains were differentially predictive of specific domains of functional capacity. CONCLUSIONS: Neurocognitive abilities were more predictive of functional capacity than level of clinical symptoms; however, these abilities were not specific predictors of functioning. This is consistent with findings of relatively generalized, intercorrelated cognitive impairment in schizophrenia and multiply determined domains of everyday functioning.     

Psychopathological and functional correlates of behavioral activation and avoidance in schizophrenia

Behavioral activation and avoidance are well studied in depression, yet the relationship of these constructs to symptoms, cognitive ability and functioning in schizophrenia is poorly understood. In a sample of 73 middle-aged and older outpatients with schizophrenia (mean [SD] age, 50.3 [6.3] years), we examined the relationship of the Activation and Avoidance subscales of the Behavioral Activation for Depression Scale with measures of psychopathology (positive and negative symptoms, depression), global cognitive ability, and functioning (observer-rated, performance-based, and subjective functioning). Neither activation nor avoidance related to sociodemographic variables, age of onset, or antipsychotic dose. Although activation and avoidance were significantly intercorrelated, only behavioral activation was significantly associated with depression and subjective functioning, whereas only avoidance related to negative symptoms. Avoidance accounted for significant variation in observer-rated functioning after adjusting for cognitive ability. These results suggest that activation and avoidance may be important therapeutic targets in schizophrenia, with somewhat divergent pathways among psychopathological features to functional impairment.     

Neuropsychological and functional correlates of clock‐drawing test in elderly institutionalized patients with schizophrenia

Background: There has been a growing need for a cognitive assessment tool that can be used for older adults with schizophrenia in clinical settings. The clock‐drawing test (CDT) is a brief cognitive test that covers a wide range of cognitive function. Although it is widely used to assess patients with dementia, limited data are available on its usefulness in older patients with schizophrenia. Thus, we investigated the psychometric properties of the CDT and their relationship with life functions to examine the test's usefulness for assessing cognitive function in older adults with schizophrenia. Methods: Seventy‐three older adults with chronic schizophrenia who had been hospitalized for over 1 year participated in the study. We adopted the executive clock‐drawing task for administration and scoring of the CDT, which consists of free‐drawn and copy conditions. The Mini‐Mental State Examination and the Brief Assessment of Cognition in Schizophrenia were administered. Symptom severity and life functions were assessed with the Positive and Negative Syndrome Scale and the Life Skills Profile, respectively. Results: Both free‐drawn and copy scores significantly correlated with the Mini‐Mental State Examination score and the Brief Assessment of Cognition in Schizophrenia composite score. These scores also significantly correlated with symptom severity and length of current hospitalization. Stepwise regression analysis showed that only the copy score, together with symptom severity, predicted the Life Skills Profile score. Conclusions: The CDT can assess cognitive function in older adults with schizophrenia. Moreover, CDT performance is associated with life functions independent from other clinical variables. These results suggest that the CDT is a useful cognitive assessment tool for this population.     

Citalopram augmentation of antipsychotic treatment in older schizophrenia patients.

BACKGROUND: Depressive symptoms are common in older patients with schizophrenia; yet, few studies have examined the usefulness of antidepressants in this population. OBJECTIVE: We conducted a 10-week single-blind trial of citalopram (20-40 mg/day) vs no citalopram augmentation in 19 middle-aged and elderly patients with schizophrenia hospitalized for more than six of the last 12 months. At study-entry, the patients had been on stable doses of antipsychotics for at least two weeks, and had a 17-item Hamilton Depression Rating (HAM-D) scale score of 12 or greater. Nine patients were randomly assigned to citalopram augmentation, and 10 to no augmentation of antipsychotics. RESULTS: Patients in both groups improved on positive and negative symptoms, but the citalopram group had significantly greater improvement in HAM-D and Clinical Global Impression Scale scores than the control group. There were no major side effects. CONCLUSION: Larger double-blind studies are needed to follow up on these preliminary findings.     

Apathy in schizophrenia: clinical correlates and association with functional outcome

Apathy is considered one of the negative symptoms of schizophrenia, but its natural history and relationship to other clinical characteristics have not been systematically studied. The purpose of this cross-sectional study was to measure the level of apathy in schizophrenia and its relation to other symptoms and functional outcome. Twenty-eight patients with schizophrenia, and receiving antipsychotic treatment, were assessed with the Apathy Evaluation Scale (AES). The mean level of apathy of patients with schizophrenia, as rated by the AES, was significantly higher than that of matched healthy control subjects. In the patients, apathy was not significantly correlated with positive symptoms or depressive symptoms. It was significantly correlated with the item "emotional withdrawal" on the negative subscale of the Positive and Negative Syndrome Scale (PANSS), but was not correlated with the overall negative subscale score. Apathy was more highly associated with functional outcome than were other symptom measures, and it was independently associated with functional outcome above and beyond other negative symptoms. It was not associated with observed interest in playing a video game or performance on a simulated clerical task.     

Stability of cognitive performance in older patients with schizophrenia: an 8-week test-retest study

OBJECTIVE: It is important to understand the stability of cognitive performance in schizophrenia in order to understand 1) the potential improvements in performance associated with the beneficial effects of cognitive-enhancing medications and 2) the potential variation in performance on cognitive measures that are components of neuroimaging studies. There are several factors that could lead to spurious improvements in cognitive test scores, including practice effects and random test-retest errors. METHOD: Forty-five older patients with schizophrenia who were receiving conventional antipsychotic medications participated in the study. All subjects completed a comprehensive neuropsychological test battery at baseline and again at an 8-week follow-up evaluation. RESULTS: Performance on all of the cognitive measures was stable over time, as evidenced by significant test-retest correlations, and practice effects were generally absent or minimal. Tests administered with alternate forms were no more temporally stable than tests administered twice with the same form. Very few individual cases had substantial variation at retest across the 22 test scores. From these data, "norms for evaluating change" were developed and described using the reliable change index method. CONCLUSIONS: The data suggest that the findings of modest cognitive improvements seen in some prior studies of schizophrenia patients when treated with second-generation antipsychotic medications were probably not due to simple retesting artifacts. At the same time, because of the variance in some of these test-retest performances, relatively substantial changes in performance on the part of individual patients would be required to be clearly interpretable.     

Neuropsychological correlates of error negativity and positivity in schizophrenia patients

The purpose of the present paper was to determine error-monitoring ability and its relationship with executive function in patients with schizophrenia. In order to evaluate error-monitoring ability, the error negativity (Ne) and error positivity (Pe) were measured using the Stroop task. The correct-related negativity (CRN) and positivity (Pc) were also measured. In addition, neuropsychological tests were administered in order to evaluate executive function. The patients with schizophrenia had significantly reduced Ne and augmented CRN amplitudes, but the Pe and Pc amplitudes of the patients were comparable to those of the controls. In addition, the Ne amplitude, measured at Fcz was positively correlated with the Trail Making Test (TMT), part B response time, and the categories achieved on the Wisconsin Card Sorting Test (WCST) in patients with schizophrenia. No significant correlations were found between Ne amplitude and performance on the neuropsychological tests in the controls. And no associations were detected between CRN, Pe, Pc amplitudes and neuropsychological performance, in either the patients with schizophrenia or the controls. Reduced Ne amplitudes and augmented CRN amplitudes in patients with schizophrenia suggest the dysfunctional behavior-monitoring system in these patients. The functional significances of Ne and Pe are discussed.     

Symptomatic and functional correlates of regional brain physiology during working memory processing in patients with recent onset schizophrenia

Patients with schizophrenia show altered patterns of functional activation during working memory processing; specifically, high-performing patients appear to hyper-activate and low-performing patients appear to hypo-activate when compared with controls. It remains unclear how these individual differences in neurophysiological activation relate to the clinical presentation of the syndrome. In this functional magnetic resonance imaging (fMRI) study, the relationship is examined using partial least squares (PLS), a multivariate statistical technique that selects underlying latent variables based on the covariance between two sets of variables, in this case, clinical variables and regional fMRI activations during a verbal working memory task. The PLS analysis extracted two latent variables, and the significance of these associations was confirmed through permutation. Lower levels of activation during task performance across frontal and parietal regions of interest in the left hemisphere were found to covary with poorer role functioning and greater severity of negative and disorganized symptoms, while lower activation in right frontal and subcortical regions of interest was found to covary with better social functioning and fewer positive symptoms. These results suggest that appropriately lateralized patterns of functional activation during working memory processing are related to the severity of negative and disorganized symptoms and to the level of role and social functioning in schizophrenia.     

Neural correlates of semantic associations in patients with schizophrenia

Patients with schizophrenia have semantic processing disturbances leading to expressive language deficits (formal thought disorder). The underlying pathology has been related to alterations in the semantic network and its neural correlates. Moreover, crossmodal processing, an important aspect of communication, is impaired in schizophrenia. Here we investigated specific processing abnormalities in patients with schizophrenia with regard to modality and semantic distance in a semantic priming paradigm. Fourteen patients with schizophrenia and fourteen demographically matched controls made visual lexical decisions on successively presented word-pairs (SOA = 350 ms) with direct or indirect relations, unrelated word-pairs, and pseudoword-target stimuli during fMRI measurement. Stimuli were presented in a unimodal (visual) or crossmodal (auditory-visual) fashion. On the neural level, the effect of semantic relation indicated differences (patients > controls) within the right angular gyrus and precuneus. The effect of modality revealed differences (controls > patients) within the left superior frontal, middle temporal, inferior occipital, right angular gyri, and anterior cingulate cortex. Semantic distance (direct vs. indirect) induced distinct activations within the left middle temporal, fusiform gyrus, right precuneus, and thalamus with patients showing fewer differences between direct and indirect word-pairs. The results highlight aberrant priming-related brain responses in patients with schizophrenia. Enhanced activation for patients possibly reflects deficits in semantic processes that might be caused by a delayed and enhanced spread of activation within the semantic network. Modality-specific decreases of activation in patients might be related to impaired perceptual integration. Those deficits could induce and increase the prominent symptoms of schizophrenia like impaired speech processing.     

Neuropsychological and oculomotor correlates of spatial working memory performance in schizophrenia patients and controls.

Recent reports of spatial working memory deficits in schizophrenia provide evidence for dorsolateral prefrontal cortical (DLPFC) dysfunction. However, the question of how spatial working memory performance relates to other task impairments in schizophrenia considered reflective of frontal dysfunction, such as the Wisconsin Card Sorting Test (WCST) and smooth pursuit eye tracking, has been largely unexplored. Spatial working memory, as measured by a computerized visual-manual delayed response task (DRT), was evaluated in 42 schizophrenia patients and 54 normal controls. Subjects also completed a battery of neuropsychological and oculomotor tasks. Schizophrenia patients performed as accurately as controls on a no-delay, sensory-motor control condition, but showed a significant impairment in spatial accuracy with the addition of an 8-s delay and verbal distraction task. For the patients, working memory impairment was associated with fewer categories on the WCST, impaired eye tracking, fewer words learned on the Rey Auditory Verbal Learning Test, but not with measures of general cognitive and clinical functioning. Results suggest the presence of a sub-group of schizophrenia patients with common pathophysiology that accounts for the co-variance of several tasks implicating prefrontal dysfunction.     

Prevalence and correlates of agoraphobia in older adults.

OBJECTIVE: Agoraphobia has been previously found to be a relatively prevalent disorder in the older adult. However, little is known about the nature of this disorder in the elderly population. The purpose of this study was to identify risk factors, illness characteristics, and comorbidity of agoraphobia in the elderly. METHODS: This was a national community mental health survey that included 12,792 individuals > or = 55 years. Agoraphobia was assessed using the World Mental Health Composite International Diagnostic Interview. Social, demographic, psychiatric, and physical variables previously found to be associated with agoraphobia in the adult population were measured. Bivariate and logistic regression analyses were used to examine these associations. RESULTS: The prevalence of agoraphobia in adults over 55 was 0.61% (95% confidence interval [CI]: 0.40-0.82). In bivariate analysis, the condition was more common in the younger age groups, women, and those widowed or divorced. It was also more common in individuals with chronic health conditions and those with comorbid psychiatric disorders. However, in the multivariate model, chronic health conditions and panic disorder were no longer significant. Most cases of agoraphobia in the elderly were of early onset (age <55 years). The majority of patients with agoraphobia did not have concurrent panic disorder. CONCLUSION: Lower prevalence rates of agoraphobia in the elderly were found compared with previous studies. The degree to which this is a measurement issue is discussed. The low correlation between agoraphobia and panic disorder raises further questions about the nature and etiology of agoraphobia in the elderly. Implications for future research and clinical practice are discussed.     

Dementia in schizophrenia. Magnetic resonance and clinical correlates

Thirty-nine patients with a chronic schizophrenic disorder and 29 healthy control subjects were examined by means of multiplanar magnetic resonance imaging. Schizophrenics as a group showed increased ventricular brain ratio and reduced corpus callosum area. When patients were grouped according to their performance on the Luria-Nebraska Neuropsychological Battery (LNNB), a distinct subgroup of six patients emerged. These patients failed to perform neuropsychological testing, due to their inability to fulfill the instructions, despite often repeated full explanations of the test procedures; four of these patients had enlarged lateral ventricles and all met operational criteria for Kraepelin's dementia praecox. Two other patients subgroups were categorized as LNNB normal and abnormal. These two subgroups showed lesser brain abnormalities and lower negative symptom scores than the former.