Age-associated differences in cognitive performance in older community dwelling schizophrenia patients: differential sensitivity of clinical neuropsychological and experimental information processing tests

Autobiographical memory in chronic schizophrenia: A follow-up study

Chronic schizophrenia is a very disabling disease and patient's social integration remains difficult. One important aspect is autobiographical memory (AM) as it is impaired in schizophrenia and highly correlated to patient's outcome, since its closely linked to self and identity. Reduced specificity and lack of details are characteristics of patients' AM, but its longitudinal course in schizophrenia remains unclear. We examined 21 patients who underwent our protocol twice with an interval of 7 years. AM was assessed using a semi-structured interview, covering four periods of life and addressing semantic knowledge and autobiographical episodes as well as their details. The results can be divided into three parts, separating semantic memories, specific autobiographical memories and details describing the latter. While a significant deterioration of semantic AM over time could be revealed, the specificity of the free recalled autobiographical episodes remained rather stable - albeit on a low level. In contrast, unique events were remembered with significantly less details at follow-up than at the first examination. While floor-effects given a relatively small number of unique events have to be considered, semantic AM and episodic details seem to be a valuable target for AM remediation given their further deterioration over time.

Self-report versus performance based executive functioning in people with psychotic disorders

Background

Although executive functioning is often measured using performance-based measures, these measures have their limits, and self-report measures may provide added value. Especially since these two types of measures often do not correlate with one another. It thus has been proposed they might measure different aspects of the same construct. To explore the differences between a performance-based measure of executive functioning and a self-report measure, we examined their associations in patients with a psychotic disorder with the following: other neurocognitive measures; psychotic symptoms; anxiety and depression symptoms, and daily-life outcome measures.

Method

This cross-sectional study consisted of baseline measures collected as part of a cohort study of people with a psychotic disorder (the UP'S study; n = 301). The Behavioral Rating Inventory of Executive Functioning Adult version (BRIEF-A) was used to assess self-rated executive functioning, and the Tower of London (TOL) to assess performance-based executive functioning. Generalized linear models (GLM) were used with the appropriate distribution and link function to study the associations between TOL and BRIEF-A, and the other variables, including the Brief Assessment of Cognition in Schizophrenia (BACS), the Positive and Negative Symptoms Scale-Remission (PANSS-R), the General Anxiety Disorder - 7 (GAD-7), the Patient Health Questionnaire - 9 (PHQ-9) and the WHO Disability Assessment Schedule 2.0 (WHODAS 2.0). Model selection was based on the Wald test.

Results

The TOL was associated with other neurocognitive measures, such as verbal list learning (β = 0.24), digit sequencing (β = 0.35); token motor task (β = 0.20); verbal fluency (β = 0.24); symbol coding (β = 0.43); and a screener for intelligence (β = 2.02). It was not associated with PANNS-R or WHO-DAS scores. In contrast, the BRIEF-A was associated not with other neurocognitive measures, but with the PANSS-R (β = 0.32); PHQ-9 (β = 0.52); and GAD-7 (β = 0.55); and with all the WHODAS domains: cognition domain (β = 0.54), mobility domain (β = 0.30) and selfcare domain (β = 0.22).

Conclusion

Performance-based and self-report measures of executive functioning measure different aspects of executive functioning. Both have different associations with neurocognition, symptomatology and daily functioning measures. The difference between the two instruments is probably due to differences in the underlying construct assessed.

Executive deficits in schizophrenia: mediation by processing speed and its relationships with aging

BACKGROUND

Executive deficits are a core characteristic of schizophrenia. Yet, the origin of these impairments remains unclear as they may be caused by processing slowing. This issue is of particular interest for aging insofar as cognitive aging is also associated with a decline in executive functioning and a slowing of processing speed. As schizophrenia patients' life expectancy increases, a better understanding of the origin of older patients' cognitive deficits becomes essential so that healthcare can be adapted to suit them. This study aims to determine whether processing speed mediates how schizophrenia affects executive functions and whether these relationships are moderated by age.

METHODS

Sixty-two schizophrenia patients (27 women) and 62 healthy comparison subjects matched for age (range: 18-76 years), gender and education performed neurocognitive tests to evaluate their executive functions (shifting, updating, inhibition and access) and processing speed.

RESULTS

Processing speed mediated the effect of schizophrenia on the four specific executive functions, and age moderated this mediation for shifting, updating and access, but in different ways. Age moderated the effect of processing speed on shifting, the direct effect of schizophrenia on access, and both the effect of processing speed and the direct effect of schizophrenia on updating.

CONCLUSIONS

This research highlights the need to evaluate processing speed routinely during therapeutic follow-up, as it is easy and simple to assess and appears to be at the heart of the cognitive deficits in schizophrenia. Finally, processing speed abilities yield information about the evolution of cognition with aging in schizophrenia.

Neurological soft signs and cognition in the late course of chronic schizophrenia: a longitudinal study

Neurological soft signs (NSS) are minor ('soft') neurological abnormalities in sensory and motor performances, which are frequently reported in patients with schizophrenia at any stage of their illness. It has been demonstrated that NSS vary in the clinical course of the disorder: longitudinally NSS decrease in parallel with remission of psychopathological symptoms, an effect which mainly applies to patients with a remitting course. These findings are primarily based on patients with a first episode of the disorder, while the course of NSS in patients with chronic schizophrenia and persisting symptoms is rather unknown. Therefore, we investigated NSS twice in 21 patients with chronic schizophrenia (initial mean duration of illness: 23 ± 11 years) with a mean follow-up interval of 7 years. NSS were evaluated by the Heidelberg Scale, established instruments were used to rate neuropsychological performance and psychopathological symptoms. NSS showed significant increases on the subscales "motor coordination" and "integrative functions", while positive and negative symptoms, including apathy, showed only minor, non-significant changes. Verbal memory, verbal fluency, and cognitive flexibility along with severity of global cognitive deficits demonstrated a significant deterioration. Regression analyses identified executive dysfunction (cognitive flexibility and verbal fluency) at baseline as significant predictors of NSS increase at follow-up. Our findings indicate that NSS deteriorate in the long-term course of chronic schizophrenia. This effect may be accounted for by a decrease of executive functions and logical memory, which can be attributed to premature brain aging.

Executive functions in schizophrenia aging: Differential effects of age within specific executive functions

There are common cognitive and brain abnormalities in schizophrenia and healthy aging which may cumulate in schizophrenia aging. However, the course of executive deficits in late-life schizophrenia is still controversial as it remains unclear whether schizophrenia patients show accelerated aging. The use of specific models of executive functions might help to shed new lights on this issue. The aim of this study was then to determine how each of the four specific executive functions (shifting, updating, inhibition and access to long-term memory) is affected by aging in schizophrenia compared to healthy aging. 20 younger (age 18-34), 17 middle-aged (age 35-49) and 25 older (age 59-76) schizophrenia patients and 62 healthy comparison participants matched for gender, age and education performed a neurocognitive battery evaluating the four specific executive functions. Schizophrenia patients performed worse than comparison participants on shifting, updating and access, whereas inhibition appeared preserved. Age affected the four functions with increased degradation of shifting and access in schizophrenia patients, whereas updating and inhibition showed a normal decline with age. These results suggest a vulnerability of prefrontal and cingulate cortexes in schizophrenia aging. Moreover, as age affected the specific executive functions differently, remediation programs should be adapted to older patients. Models of specific executive functions are useful for understanding the complexity of cognition in schizophrenia and its course during later life so that healthcare can be adapted accordingly.

Guanfacine Augmentation of a Combined Intervention of Computerized Cognitive Remediation Therapy and Social Skills Training for Schizotypal Personality Disorder

OBJECTIVE

Impaired cognition is a hallmark of schizophrenia spectrum disorders, including schizotypal personality disorder, and it is the best predictor of functional outcome. Cognitive remediation therapy has demonstrated efficacy for improving cognition, augmenting other rehabilitation efforts in schizophrenia, and effecting gains in real-world functioning. Pharmacological augmentation of cognitive remediation has been attempted, but the effects of augmentation on combined therapies, such as cognitive remediation and social skills training, have not been studied.

METHODS

Twenty-eight participants with schizotypal personality disorder enrolled in an 8-week, randomized, double-blind, placebo-controlled trial of guanfacine plus cognitive remediation and social skills training (15 guanfacine, 13 placebo). Cognition was assessed with the MATRICS (Measurement and Treatment Research to Improve Cognition in Schizophrenia) Consensus Cognitive Battery (MCCB), social cognition with the Movie for the Assessment of Social Cognition (MASC), and functional capacity with the University of California San Diego Performance-Based Skills Assessment (UPSA).

RESULTS

A statistically significant pre- versus posttreatment effect was observed for MCCB speed of processing, verbal learning, and visual learning and UPSA total score. A significant time-by-medication (guanfacine, placebo) interaction was observed for MCCB reasoning and problem solving and UPSA total score; the time-by-treatment interaction approached significance for MASC hypomentalizing errors.

CONCLUSIONS

Both guanfacine and cognitive remediation plus social skills training were well tolerated, with no side effects or dropouts. Participants treated with cognitive remediation, social skills training, and guanfacine demonstrated statistically significant improvements in reasoning and problem solving, as well as in functional capacity and possibly social cognition, compared with those treated with cognitive remediation, social skills training, and placebo. Cognitive remediation plus social skills training may be an appropriate intervention for individuals with schizotypal personality disorder, and guanfacine appears to be a promising pharmaceutical augmentation to this psychosocial intervention.

Brain-derived neurotrophic factor is associated with cognitive impairments in first-episode and chronic schizophrenia

Brain-derived neurotrophic factor (BDNF) may be related to the pathophysiology of schizophrenia. This study aims to examine the relation between plasma BDNF levels and the cognition of patients with schizophrenia. We recruited 31 patients with chronic schizophrenia, 34 first-episode patients, and 35 healthy control subjects. We examined the MATRICS Consensus Cognitive Battery (MCCB) and the plasma BDNF levels in all groups. The schizophrenic symptoms were assessed using the positive and negative syndrome scale. The BDNF levels of schizophrenic patients were remarkably lower than those of the controls. The cognitive MCCB global composite scores and part index scores of schizophrenic patients were remarkably lower than those of the controls. Moreover, remarkable correlations were observed between BDNF levels and partial cognitive dimensions, such as visual learning, memory, and processing speed. Therefore, BDNF may be involved in the pathophysiology and cognitive impairment of schizophrenia.

Disorganization and real-world functioning in schizophrenia: Results from the multicenter study of the Italian Network for Research on Psychoses

BACKGROUND

A general consensus has not yet been reached regarding the role of disorganization symptoms in real-world functioning in schizophrenia.

METHODS

We used structural equations modeling (SEM) to analyze the direct and indirect associations between disorganization and real-world functioning assessed through the Specific Levels of Functioning Scale (SLOF) in 880 subjects with schizophrenia.

RESULTS

We found that: 1) conceptual disorganization was directly and strongly connected with SLOF daily activities; difficulty in abstract thinking was associated with moderate strength to all SLOF domains, and poor attention was connected with SLOF work skills; 2) grandiosity was only related with poor work skills, and delusions were associated with poor functioning in all SLOF domains; interpersonal relationships were weakly indirectly influenced by hallucinatory behavior, delusions and unusual thought contents through the mediation of social cognition (SC); 3) among the negative symptoms, avolition had only direct links with SLOF work skills and SLOF activities; anhedonia had direct links with SLOF work skills and SLOF interpersonal and indirect link with SLOF work skills through functional capacity (FC); asociality with SLOF interpersonal; blunted affect had direct links with SLOF activities and indirect links with SLOF interpersonal relationships mediated by SC. Lastly, alogia had only indirect links mediated by SC, FC, and neurocognition (NC).

CONCLUSIONS

Overall conceptual disorganization is the symptom that contributed more (both directly and indirectly) to the activities of community living in real-world. Thus, it should be considered as a treatment target in intervention programs for patients with schizophrenia.

Longitudinal analysis of statistical and clinically significant psychosocial change following mental health rehabilitation

Purpose: With appropriate mental health rehabilitation, schizophrenia is increasingly associated with reports of recovery and stability. However, there is little empirical evidence evaluating the efficacy of services delivering this care. This study evaluated the effectiveness of rehabilitation for improving psychosocial function in consumers with schizophrenia.Methods: An electronic database of standardized assessment instruments mandated and maintained by the health service was retrospectively reviewed to extract ratings of psychosocial function, daily living skills, and mood state from consecutive admissions to an inpatient rehabilitation service. Outcomes were compared at admission, discharge, and one-year follow-up to identify statistically significant change. Individual reliable and clinically significant change was also assessed by comparison with a normative group of clients functioning independently in the community.Results: From admission to discharge the rehabilitation group made statistically significant gains in psychosocial function and daily living skills. Improvements were reliable and clinically significant in one-quarter to one-third of individual consumers. Approximately half sustained their improvements at follow-up, although this represented only a small fraction of the overall cohort. Consumers not demonstrating gains exhibited psychometric floor effects at admission.Conclusions: Rehabilitation can produce statistically and clinically significant immediate improvement in psychosocial function for a sub-set of consumers with elevated scores at admission. The durability of any gains is less clear, and strategies promoting longer-term maintenance are encouraged. Furthermore, currently mandated outcome measures are confounded by issues of sensitivity and reporting compliance, and exploration of alternative instruments for assessing recovery is recommended.Implications for RehabilitationRoutinely collected standardized outcome measures can be used to investigate the effectiveness of mental health rehabilitationIn addition to statistical significance, the clinical significance of outcomes should be evaluated to identify change that is individually meaningfulCurrently mandated outcomes instruments do not adequately evaluate many individuals' recovery journeyMental health service evaluation and quality improvement processes would likely benefit from adoption of recovery-oriented measures.

Cognitive and functional deficits in people with schizophrenia: Evidence for accelerated or exaggerated aging?

Cognitive and functional deficits are commonly seen in people with schizophrenia. The profile of these impairments has a resemblance to the cognitive changes seen in healthy aging. In specific, many of the cognitive ability domains that change the most with aging in healthy people are the most salient of these deficits seen in people with schizophrenia, including prominent deficits in processing speed, working memory, and episodic memory. Functional deficits seen in schizophrenia are also similar to those seen in healthy aging. There is a relationship between multiple psychotic relapses and treatment resistance and longitudinal cognitive and functional changes in schizophrenia, with this relationship starting early in the course of illness. Cognitive performance in people with schizophrenia may be consistent with accelerated or premature aging. People with schizophrenia perform similarly to healthy people who are 3 or more decades older on indices of both cognition and their everyday functional skills. Some people with schizophrenia show exaggerated cognitive changes as well. Cognitive and functional performance worsens at the outset of the illness in schizophrenia compared to premorbid functioning, meaning that these deficits are not due to development disabilities. There are multiple medical and substance abuse comorbidities in schizophrenia and although these comorbidities affect cognitive functioning, they are not completely responsible for age-related changes.

Assessing the Relationship between Performance on the University of California Performance Skills Assessment (UPSA) and Outcomes in Schizophrenia: A Systematic Review and Evidence Synthesis

OBJECTIVE

To perform a systematic review of the published literature to evaluate how functional capacity, as measured by the University of California at San Diego (UCSD) Performance-based Skills Assessment (UPSA), relates to other functional measures and real-world outcomes among individuals with schizophrenia.

METHODS

The MEDLINE® and Embase® databases were searched to identify joint evaluations with UPSA and key functional outcomes (functional scale measures; generic or disease-specific, health-related quality of life [HRQoL]; or real-world outcomes [residential status; employment status]) in patients with schizophrenia. Pearson correlations were estimated between UPSA scores, HRQoL, other functional scale measures, and real-world outcomes, for outcomes described in at least six studies.

RESULTS

The synthesis included 76 studies that provided 73 unique data sets. Quantitative assessment between the Specific Level of Function (SLOF) (n=18) scores and UPSA scores demonstrated a moderate borderline-significant correlation (0.45, p=0.06). Quantitative analysis of the relationship between the Global Assessment of Functioning (GAF) (n=11) and the Multidimensional Scale of Independent Functioning (MSIF) (n=6) scales revealed moderate and small nonsignificant Pearson correlations of -0.34 (p=0.31) and 0.12 (p=0.83), respectively. There was a small borderline-significant correlation between UPSA score and residential status (n=36; 0.31; p=0.08), while no correlation was found between UPSA score and employment status (n=19; 0.04; p=0.88).

CONCLUSION

The SLOF was the most often used functional measure and had the strongest observed correlation with the UPSA. Although knowledge gaps remain, evidence from this review indicates that there is a quantitative relationship between functional capacity and real-world outcomes in individuals with schizophrenia.

The impact of chronic psychiatric disorders on cognitive decline

OBJECTIVES

Based on seemingly contradictory results in the existing literature, the objective of our study was to investigate whether older individuals suffering from chronic psychiatric disorders show a more rapid decline in cognitive performances than their non-psychiatric counterparts, or if the pattern of decline through older age is similar in both groups.

METHOD

A total of 820 older adults were selected from the Ageing Multidisciplinary Investigation (AMI) cohort study, which studies health-related issues of people over 65 years old living in rural areas. Among them, 30 suffer from chronic psychiatric disorders. Cognition was assessed with four neuropsychological tests: the Mini-Mental State Examination, the Digit Symbol Substitution Test, the Free and Cued Selective Reminding test and the Isaacs Set Test. Linear mixed models were used to compare the evolution of cognitive performances in the two groups between baseline and the four-year follow-up.

RESULTS

Despite lower performances at baseline, the pattern of cognitive decline of the psychiatric group is similar to that of the control group.

CONCLUSION

As suggested by this study conducted in rural communities, community-dwelling people suffering from chronic psychiatric disorders should not be considered at greater risk of age-related accelerated cognitive decline than the non-psychiatric older population.

Exploring functioning in schizophrenia: Predictors of functional capacity and real-world behaviour

Impairment in daily functioning still represents a major treatment issue in schizophrenia and a more in-depth knowledge of underlying constructs is crucial for interventions to translate into better outcomes. This study aims to model factors influencing both functional capacity and real-life behaviour in a sample of outpatients with chronic schizophrenia, through a comprehensive assessment including evaluations of psychopathology, cognitive and social cognitive abilities, premorbid adjustment, family environment and early childhood experiences. No significant correlation was observed between functional capacity and real-life behaviour. Functional capacity was significantly predicted by IQ, while real-life behaviour was significantly predicted by empathy, affect recognition and symptoms. Functional capacity seems mainly related to neurocognition, whereas real-life behaviour appears more complex, requiring the integration of different factors including symptoms, with a major role of empathy. Results thus support a divergence between the two constructs of functioning and their underlying components and highlight the need to target both dimensions through individualized sequential rehabilitation programs in order to optimize functional outcome.

Abnormal Trajectory of Intracortical Myelination in Schizophrenia Implicates White Matter in Disease Pathophysiology and the Therapeutic Mechanism of Action of Antipsychotics

BACKGROUND

Postmortem and imaging studies provide converging evidence that the frontal lobe myelination trajectory is dysregulated in schizophrenia (SZ) and suggest that early in treatment, antipsychotic medications increase intracortical myelin (ICM). We used magnetic resonance imaging to examine whether the ICM trajectory in SZ is dysregulated and altered by antipsychotic treatment.

METHODS

We examined 93 subjects with SZ (64 men and 29 women) taking second-generation oral antipsychotics with medication exposures of 0-333 months in conjunction with 80 healthy control subjects (52 men and 28 women). Frontal lobe ICM volume was estimated using a novel dual contrast magnetic resonance imaging method that combines two images that track different tissue components.

RESULTS

When plotted against oral antipsychotic exposure duration, ICM of subjects with SZ was higher as a function of medication exposure during the first year of treatment but declined thereafter. In the age range examined, ICM of subjects with SZ was lower with increased age, while ICM of healthy control subjects was not.

CONCLUSIONS

In adults with SZ, the relationship between length of exposure to oral second-generation antipsychotics and ICM was positive during the first year of treatment but was negative after this initial period, consistent with suboptimal later adherence after initial adherence. This ICM trajectory resembles clinically observed antipsychotic response trajectory with high rates of remission in the first year followed by progressively lower response rates. The results support postmortem evidence that SZ pathophysiology involves ICM deficits and suggest that correcting these deficits may be an important mechanism of action for antipsychotics.

Cognitive Performance in Patients with Chronic Schizophrenia Across the Lifespan

Abstract. Chronic schizophrenia involves neuropsychological deficits that primarily strike executive functions and episodic memory. Our study investigated these deficits throughout the lifespan in patients with chronic schizophrenia and in healthy controls. Important neuropsychological functions were tested in 94 patients and 66 healthy controls, who were assigned to three age groups. Compared with the healthy controls, patients performed significantly poorer on all tests applied. Significant age effects occurred on all tests except the digit span forward, with older subjects scoring well below the younger ones. With respect to cognitive flexibility, age effects were more pronounced in the patients. These findings underline the importance of cognitive deficits in chronic schizophrenia and indicate that diminished cognitive flexibility shows age-associated differences.

Treatment resistant schizophrenia: Course of brain structure and function

Approximately 30% of people with schizophrenia manifest a minimal response to conventional and atypical antipsychotic medications and manifest continuous symptoms of psychosis, with this condition referred to as "treatment resistant schizophrenia (TRS)". There are several neurobiological consequences of continuous psychosis, including regional cortical atrophy and ventricular enlargement. Pharmacological treatments are available for TRS, with at least 1/3 of patients responding to treatment with clozapine. In this paper we review the evidence regarding the course of treatment resistant schizophrenia, as well as changes in brain structure and function in psychosis and on the possible role of clozapine treatment in altering cortical deterioration in patients with TRS.

Does aging affect source monitoring and cognitive confidence in schizophrenia? Preliminary results

This study tested the influence of aging on source-monitoring and cognitive confidence deficits in schizophrenia. Younger (n=13) and older (n=10) schizophrenia patients were compared with younger (n=17) and older (n=10) healthy controls in the source-monitoring task. These preliminary results suggest that age negatively influences old/new item recognition, but not source monitoring, in both groups. Age has a negative impact on subjective confidence, but no interaction between group and age was found.

Similar verbal memory impairments in schizophrenia and healthy aging. Implications for understanding of neural mechanisms

Memory is impaired in schizophrenia patients but it is not clear whether this is specific to the illness and whether different types of memory (verbal and nonverbal) or memories in different cognitive domains (executive, object recognition) are similarly affected. To study relationships between memory impairments and schizophrenia we compared memory functions in 77 schizophrenia patients, 58 elderly healthy individuals and 41 young healthy individuals. Tests included verbal associative and logical memory and memory in executive and object recognition domains. We compared relationships of memory functions to each other and to other cognitive functions including psychomotor speed and verbal and spatial working memory. Compared to the young healthy group, schizophrenia patients and elderly healthy individuals showed similar severe impairment in logical memory and in the ability to learn new associations (NAL), and similar but less severe impairment in spatial working memory and executive and object memory. Verbal working memory was significantly more impaired in schizophrenia patients than in the healthy elderly. Verbal episodic memory impairment in schizophrenia may share common mechanisms with similar impairment in healthy aging. Impairment in verbal working memory in contrast may reflect mechanisms specific to schizophrenia. Study of verbal explicit memory impairment tapped by the NAL index may advance understanding of abnormal hippocampus dependent mechanisms common to schizophrenia and aging.

Neurocognition, functional competence and self-reported functional impairment in psychometrically defined schizotypy

INTRODUCTION

Schizotypy is phenologically and genetically related to schizophrenia-spectrum illness. Previous studies find cognitive function to be mildly impaired, but specific impairments and their relationship to functioning are not well understood. In this study, we sought to examine how cognitive load affects performance in schizotypy and to examine whether impairments might manifest in functional capacity and quality of life.

METHODS

Undergraduate students were screened for abnormally high levels of schizotypy (N = 72) and compared to those without psychopathology (N = 80) on a standard battery of neuropsychological tests, cognitive tests with varying cognitive load, functional capacity measures and quality of life.

RESULTS

The high schizotypy group did not differ from controls on traditional measures of neuropsychological functioning, but an interaction of group by cognitive load was observed, where those with schizotypy manifested a greater decline in performance as information processing load was parametrically increased. Differences in functioning were observed and cognitive impairment was associated with impaired functioning.

CONCLUSIONS

Cognitive and functional impairment can be observed in those with high schizotypal traits who are non-treatment seeking. The sensitivity of cognitive tests to impairment in this population might be a function of their ability to parametrically increase cognitive load.

Age or age at onset? Which of them really matters for neuro and social cognition in schizophrenia?

In schizophrenia patients, both an older age and earlier age at onset of the disease are related to worse cognitive functioning. As patients with later schizophrenia onset are also older, analysing the two effects separately can be misleading, as they can either be spurious or cancel one another out. The purpose of the present study was to elucidate the effects of age and onset-age on cognition in schizophrenia patients. Individuals with schizophrenia (N=151), aged 18-59 years, were examined with a MATRICS Consensus Cognitive Battery (MCCB) to get a full picture of their cognitive performance. Results showed age and age at onset indeed interrelated. Regression analyses revealed later onset of schizophrenia related to better social cognition. Patients׳ older age was related to a slower performance in symbol coding task, less effective executive functions, worse visual learning, lower attention, and lower total score in the MCCB. In the above regression analyses we controlled doses of antipsychotic medications. The results suggest that a previously found relationship between older age and social cognition might be spurious, and strengthen observations that it is specifically later onset-age which fosters better social cognition in schizophrenia patients.

Cognitive impairments in psychotic disorders: common mechanisms and measurement

Decades of research have provided robust evidence of cognitive impairments in psychotic disorders. Individuals with schizophrenia appear to be impaired on the majority of neuropsychological tasks, leading some researchers to argue for a "generalized deficit", in which the multitude of cognitive impairments are the result of a common neurobiological source. One such common mechanism may be an inability to actively represent goal information in working memory as a means to guide behavior, with the associated neurobiological impairment being a disturbance in the function of the dorsolateral prefrontal cortex. Here, we provide a discussion of the evidence for such impairment in schizophrenia, and how it manifests in domains typically referred to as cognitive control, working memory and episodic memory. We also briefly discuss cognitive impairment in affective psychoses, reporting that the degree of impairment is worse in schizophrenia than in bipolar disorder and psychotic major depression, but the profile of impairment is similar, possibly reflecting common mechanisms at the neural level. Given the recent release of the DSM-5, we end with a brief discussion on assessing cognition in the context of diagnosis and treatment planning in psychotic disorders.

Generalized and specific neurocognitive deficits in psychotic disorders: utility for evaluating pharmacological treatment effects and as intermediate phenotypes for gene discovery

A growing body of research suggests that schizophrenia and bipolar disorder share overlapping clinical, neurobiological, and genetic features, raising important questions about the boundaries and distinctiveness of these 2 major psychiatric disorders. A generalized cognitive impairment has long been understood to be a core feature of schizophrenia. More recently, it has become apparent that cognitive impairment also occurs in bipolar disorder, particularly in those patients with a history of psychotic symptoms. Whether a generalized deficit exists across a spectrum of psychotic disorders is less clearly established. Additionally, in the context of a broad impairment, it remains a significant challenge to identify deficits in specific cognitive processes that may have distinct neurochemical or regional brain substrates and linkages to particular risk-associated genetic factors. In this article, we review the findings from neuropsychological studies across a spectrum that includes schizophrenia, schizoaffective and bipolar disorders, and conclude the available evidence strongly supports that a generalized deficit is present across psychotic disorders that differs in severity more so than form. We then consider the implications of generalized and specific deficits in psychosis for 2 areas of research--the evaluation of pharmacological treatments targeting cognitive deficits, and the investigation of cognitive intermediate phenotypes in family genetic studies. Examples from the literature that touch on the relevance of the generalized deficit in these contexts are provided, as well as consideration for the continued need to identify specific impairments that are separable from the generalized deficit in order to advance drug and gene discovery.

Hospitalization and psychosis: influences on the course of cognition and everyday functioning in people with schizophrenia

Long term institutional stay has decreased markedly in people with schizophrenia, although there are still many individuals with a history of long-term institutional stay residing in the community. In addition, although the average duration of acute admissions for schizophrenia is also decreasing, there are indications that psychotic episodes leading to acute admissions are associated with risk for cognitive and functional declines and changes in brain structure. In this paper we review the literature on cognitive changes with aging and institutionalization in schizophrenia, reaching to the conclusion that the reasons for current chronic institutionalization largely include severe psychosis and aggressive behavior. Thus, these factors may be the operative factor in the age-related declines in cognition and functioning reported in this population. We also present evidence to suggest that these changes may be similar to those seen in younger patients who experience repeated psychotic episodes leading to hospitalization. Our conclusion is that there is minimal evidence that hospitalization, long or short, leads to cognitive and functional changes, but rather that the reason for these hospitalizations may underlie cognitive and functional declines. Prevention of relapse and discovering treatments to assist patients with resistant symptoms may reduce the risk of cognitive and functional declines across the lifespan in people with schizophrenia.

Functional outcomes, functional capacity, and cognitive impairment in schizotypal personality disorder

BACKGROUND

Individuals with schizotypal personality disorder (SPD) exhibit impaired cognitive functioning in a pattern similar to that found in schizophrenia; less clear is the extent to which these individuals also share schizophrenia patients' impairments in functional capacity and real-world functioning.

METHOD

We evaluated 46 SPD patients, as well as 38 individuals with avoidant personality disorder (AvPD) and 55 healthy controls (HC) on: cognitive functioning, real-world functioning (employment and residential status), and functional capacity (indexed by the UPSA, a performance-based skills assessment).

RESULTS

We found that individuals with SPD exhibited worse performance on both the cognitive battery and the UPSA than the other groups; they were also less likely to be employed and to be living independently. Additionally, cognitive and UPSA performance in the SPD group was intercorrelated to a degree comparable to what has been found in schizophrenia, and this relationship was not present in the AvPD group. Finally, real-world functioning was related to UPSA performance for both patient groups.

CONCLUSIONS

SPD patients exhibit impaired real-world functioning suggesting that these deficits extend across the schizophrenia spectrum. In addition, there is supportive evidence for the validity and importance of performance-based measures such as the UPSA to predict everyday outcomes across the schizophrenia spectrum.

Integrated psychological therapy: effectiveness in schizophrenia inpatient settings related to patients' age

OBJECTIVE

Elderly people with schizophrenia often suffer from cognitive impairments, which affect their social functioning. Today, only a few therapy approaches for middle-aged and older patients are available. The Integrated Psychological Therapy (IPT) combines neurocognitive and social cognitive interventions with social skills approaches. The aim of this study was to evaluate (1) whether IPT is effective in younger patients (age < 40 years) and middle-aged patients (age ≥ 40 years) and (2) whether control conditions (treatment as usual or unspecific group activities) reveal some change in outcome depending on age.

METHOD

A total of 15 controlled IPT studies with 632 inpatients with schizophrenia were evaluated in a standard meta-analytic procedure. Studies were categorized into two age categories.

RESULTS

Significant medium to large effect sizes (ES) were evident for IPT independent of age on the global cognitive score (mean score of all cognitive variables), on neurocognition, social cognition, social functioning, psychopathology, and the global therapy effect (mean of all variables). The IPT effects in middle-aged patients were significantly larger on the global cognitive score, on neurocognition, and on social cognition compared with younger patients. Opposite results could be observed in control conditions. Only younger patients participating in the control conditions showed small but significant ES on these variables, but almost middle-aged control patients did not. However, none of the differences in the control conditions were significant between the two age categories. A moderator analysis obtained no evidence for a strong impact of IPT variations, therapy setting, patient characteristics, and methodologic rigor of the research design.

CONCLUSIONS

These results support evidence for the efficacy of IPT independent of age. Results further indicate the need of goal-oriented specific psychological interventions for middle-aged and older patients with schizophrenia.

Cognitive performance of individuals with schizophrenia across seven decades: a study using the MATRICS consensus cognitive battery

OBJECTIVES

The objectives of this study were to determine the effect of aging, schizophrenia, and their interaction on cognitive function.

DESIGN

Cross-sectional controlled study.

SETTING

Community living.

PARTICIPANTS

A total of 235 subjects with schizophrenia age 19-79 and 333 comparison subjects age 20-81.

MEASUREMENTS

The Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB).

RESULTS

Older age was associated with poorer performance on 9 of 10 MCCB tests in both subjects with schizophrenia and comparison subjects. Subjects with schizophrenia were impaired relative to comparison subjects on each of the 10 tests. However, there was no interaction between aging and schizophrenia on any test. Essentially the same results were observed when analyzing performance on the seven MCCB cognitive domains and MCCB global composite score.

CONCLUSIONS

Consistent with other reports, schizophrenia appears to be a disorder marked by generalized cognitive dysfunction. However, the rate of cognitive decline appears to be similar to that observed in healthy comparison subjects. They do not experience acceleration in cognitive aging, which supports the hypothesis that schizophrenia is a syndrome of premature aging. Longitudinal studies including very old patients are needed to confirm and extend these findings.

Neurocognitive function in long-term treated schizophrenia: a five-year follow-up study

Neurocognitive deficits are a core feature of schizophrenia. Deficits covering a wide range of functions have been well documented. However there is still a lack of longitudinal studies regarding the development of neurocognitive impairment. The current study examined the effect of time in long-term treated patients with schizophrenia and healthy controls on cognitive functions. A neurocognitive test-battery was administered to 36 patients and 46 controls on two occasions with approximately 4.5 years interval. Patients performed significantly worse on all measures on both occasions. The only significant decline over time was the ability to shift mental set between different rules or categories (measured by Trail Making Test B). This decline was present in both patients and controls. Improvement on attention (tested by Continuous Performance Test) was found in patients only and improvement on verbal learning (tested by Rey Auditory Verbal Learning Test) was found only in controls. Education was significantly related to outcome in patients and age was related to outcome in controls. We conclude that neurocognitive function is relatively stable over 4.5 years in patients with long-term treated schizophrenia, in line with previous scientific research. The authors discuss the impact of age and education and limitations of the study.

Effects of novel, high affinity glycine transport inhibitors on frontostriatal dopamine release in a rodent model of schizophrenia

Dopaminergic hyperactivity within frontostriatal brain systems is a key feature of schizophrenia, and an objective neural correlate of positive schizophrenia symptoms. N-methyl-d-aspartate (NMDA) receptors are known to play a prominent role in regulation of frontostriatal dopamine release. Furthermore, disturbances in glutamatergic function are increasingly being linked to pathophysiology of both positive and negative symptoms of schizophrenia. Prior studies have demonstrated that subchronic continuous administration of the NMDA antagonist phencyclidine (PCP) induces schizophrenia-like hyper-reactivity of frontostriatal dopamine release to amphetamine (AMPH) in rodents, and that effects were reversed by glycine and the prototypic glycine transport inhibitor (GTI) NFPS. The present study investigates effectiveness of the novel, high affinity and well tolerated GTIs, R231857, R231860 and Org29335, to reverse schizophrenia-like enhancement of AMPH-induced DA release, along with effects of the partial glycine-site agonist d-cycloserine. As previously, PCP had no significant effect on basal DA levels, but significantly enhanced AMPH-induced DA release in prefrontal cortex. All GTIs tested, as well as d-cycloserine, significantly reduced PCP-induced enhancement of DA release in prefrontal cortex. Neither PCP nor GTIs significantly affected striatal DA release. Overall, these findings suggest that treatments which target the glycine modulatory site of the NMDA receptor may significantly reverse NMDA receptor antagonist-induced dysregulation of frontal DA systems, consistent with potential beneficial effects on positive-, in addition to negative-, symptoms of schizophrenia.

Age-associated differences in cognitive performance in older patients with schizophrenia: a comparison with healthy older adults

BACKGROUND

There are varying results regarding the conjoint influence of aging and schizophrenia on cognitive abilities. Previous studies have been limited by restricted age ranges among schizophrenia and psychiatrically healthy control samples as well as small numbers of control participants.

OBJECTIVE

To quantify the association between age and cognitive performance in patients with schizophrenia and psychiatrically healthy older adult controls and to determine if age-associated changes in cognitive performance were different in the two groups.

METHODS

People with schizophrenia (n = 226) and psychiatrically healthy individuals (n = 834) ranging in age from 40 to older than 80 years were compared on a battery of neuropsychological tests. To directly compare the impact of age on cognitive performance, age was also regressed on performance in the two samples.

RESULTS

The performance of psychiatrically healthy adults age 70 and older was superior to the performance of the youngest patients with schizophrenia (age 40-49) years on measures of working and episodic memory, executive function, and psychomotor speed. Regression analyses indicated that age effects on cognition were significantly greater for schizophrenia patients on measures of verbal learning and speed of processing. Within both the schizophrenia group, and psychiatrically healthy adults, the greatest age-related differences in performance seemed to occur for individuals aged more than 70 years.

CONCLUSION

In this cross-sectional study, the present findings underscore the fact that schizophrenia is associated with cognitive impairment across all ages and that older schizophrenia patients experience relatively greater age associated differences in cognitive functioning than healthy individuals. These findings have wide-ranging implications regarding the ability of older patients with schizophrenia to function independently and for the development of treatment strategies.

Neuropsychological performance in older patients with schizophrenia: a meta-analysis of cross-sectional and longitudinal studies

OBJECTIVE

Cognitive deficits are among the most reliable predictors of functional impairment in schizophrenia and a particular concern for older individuals with schizophrenia. Previous reviews have focused on the nature and course of cognitive impairments in younger cohorts, but a quantitative meta-analysis in older patients is pending.

METHOD

A previously used search strategy identified studies assessing performance on tests of global cognition and specific neuropsychological domains in older patients with schizophrenia and age-matched comparison groups. Both cross-sectional and longitudinal studies were included. Potential methodological, demographic, and clinical moderators were analyzed.

RESULTS

Twenty-nine cross-sectional (2110 patients, 1738 comparison subjects) and 14 longitudinal (954 patients) studies met inclusion criteria. Patients were approximately 65 years old, with 11 years of education, 53% male and 79% Caucasian. Longitudinal analysis (range 1-6 years) revealed homogeneity with small effect sizes (d = -0.097) being observed. Cross-sectional analyses revealed large and heterogeneous deficits in global cognition (d = -1.19) and on specific neuropsychological tests (d = -0.7 to -1.14). Moderator analysis revealed a significant role for demographic (age, sex, education, race) and clinical factors (diagnosis, inpatient status, age of onset, duration of illness, positive and negative symptomology). Medication status (medicated vs nonmedicated) and chlorpromazine equivalents were inconsequential, albeit underrepresented.

CONCLUSIONS

Large and generalized cognitive deficits in older individuals with schizophrenia represent a robust finding paralleling impairments across the life span, but these deficits do not decline over a 1-6 year period. The importance of considering demographic and clinical moderators in cross-sectional analyses is highlighted.

Effectiveness of integrated psychological therapy (IPT) for schizophrenia patients: a research update

Standardized recovery criteria go beyond symptom remission and put special emphasis on personal and social functioning in residence, work, and leisure. Against this background, evidence-based integrated approaches combining cognitive remediation with social skills therapy show promise for improving functional recovery of schizophrenia patients. Over the past 30 years, research groups in 12 countries have evaluated integrated psychological therapy (IPT) in 36 independent studies. IPT is a group therapy program for schizophrenia patients. It combines neurocognitive and social cognitive interventions with social skills and problem-solving approaches. The aim of the present study was to update and integrate the growing amount of research data on the effectiveness of IPT. We quantitatively reviewed the results of these 36 studies, including 1601 schizophrenia patients, by means of a meta-analytic procedure. Patients undergoing IPT showed significantly greater improvement in all outcome variables (neurocognition, social cognition, psychosocial functioning, and negative symptoms) than those in the control groups (placebo-attention conditions and standard care). IPT patients maintained their mean positive effects during an average follow-up period of 8.1 months. They showed better effects on distal outcome measures when all 5 subprograms were integrated. This analysis summarizes the broad empirical evidence indicating that IPT is an effective rehabilitation approach for schizophrenia patients and is robust across a wide range of sample characteristics as well as treatment conditions. Moreover, the cognitive and social subprograms of IPT may work in a synergistic manner, thereby enhancing the transfer of therapy effects over time and improving functional recovery.

Psychometric properties of performance-based measurements of functional capacity: test-retest reliability, practice effects, and potential sensitivity to change

Performance-based measures of the ability to perform social and everyday living skills are being more widely used to assess functional capacity in people with serious mental illnesses such as schizophrenia and bipolar disorder. Since they are also being used as outcome measures in pharmacological and cognitive remediation studies aimed at cognitive impairments in schizophrenia, understanding their measurement properties and potential sensitivity to change is important. In this study, the test-retest reliability, practice effects, and reliable change indices of two different performance-based functional capacity measures, the UCSD Performance-Based Skills Assessment (UPSA) and Social Skills Performance Assessment (SSPA) were examined over several different retest intervals in two different samples of people with schizophrenia (n's=238 and 116) and a healthy comparison sample (n=109). These psychometric properties were compared to those of a neuropsychological assessment battery. Test-retest reliabilities of the long form of the UPSA ranged from r=63 to r=80 over follow-up periods up to 36 months in people with schizophrenia, while brief UPSA reliabilities ranged from r=66 to r=81. Test-retest reliability of the NP performance scores ranged from r=77 to r=79. Test-retest reliabilities of the UPSA were lower in healthy controls, while NP performance was slightly more reliable. SSPA test-retest reliability was lower. Practice effect sizes ranged from .05 to .16 for the UPSA and .07 to .19 for the NP assessment in patients, with HC having more practice effects. Reliable change intervals were consistent across NP and both FC measures, indicating equal potential for detection of change. These performance-based measures of functional capacity appear to have similar potential to be sensitive to change compared to NP performance in people with schizophrenia.

The course of neuropsychological performance and functional capacity in older patients with schizophrenia: influences of previous history of long-term institutional stay

BACKGROUND

Chronically institutionalized patients with schizophrenia have been reported to manifest cognitive and functional decline. Previous studies were limited by the fact that current environment could not be separated from lifetime illness course. The present study examined older outpatients who varied in their lifetime history of long-term psychiatric inpatient stay.

METHODS

Community-dwelling patients with schizophrenia (n = 111) and healthy comparison subjects (n = 76) were followed up to 45 months and examined two or more times with a neuropsychological battery and performance-based measures of everyday living skills (University of California San Diego Performance-Based Skills Assessment Battery [UPSA]) and social competence. A mixed-effects model repeated-measures method was used to examine changes.

RESULTS

There was a significant effect of institutional stay on the course of the UPSA. When the schizophrenia patients who completed all three assessments were divided on the basis of length of institutional stay and compared with healthy comparison subjects, patients with longer stays worsened on the UPSA and social competence, while patients with shorter stays improved. For neuropsychological performance, both patient samples worsened slightly, while the healthy comparison group manifested a practice effect. Reliable change index analyses showed that worsening on the UPSA for longer stay patients was definitely nonrandom.

CONCLUSIONS

Lifetime history of institutional stay was associated with worsening on measures of social and everyday living skills. Neuropsychological performance in schizophrenia did not evidence the practice effect seen in the healthy comparison sample. These data suggest that schizophrenia patients with a history of long institutional stay may worsen even if they are no longer institutionalized.

Cognitive deficits in recent-onset and chronic schizophrenia

Although cognitive dysfunction is a primary characteristic of schizophrenia, only recently have investigations begun to pinpoint when the dysfunction develops in the individual afflicted by the disorder. Research to date provides evidence for significant cognitive impairments prior to disorder onset. Less is known about the course of cognitive dysfunction from onset to the chronic phase of schizophrenia. Although longitudinal studies are optimal for assessing stability of cognitive deficits, practice effects often confound assessments, and large and representative subject samples have not been followed over long periods of time. We report results of a cross-sectional study of cognitive deficits early and late in the course of schizophrenia carried out at four different geographic locations to increase sample size and generalizability of findings. We examined a broad set of cognitive functions in 41 recent-onset schizophrenia patients and 106 chronic schizophrenia patients. The study included separate groups of 43 matched controls for the recent-onset sample and 105 matched controls for the chronic schizophrenia sample in order to evaluate the effects of cohort (i.e., age) and diagnosis (i.e., schizophrenia) on cognitive functions. All measures of cognitive function showed effects of diagnosis; however, select time-based measures of problem solving and fine motor dexterity exhibited interactions of diagnosis and cohort indicating that these deficits may progress beyond what is expected with normal aging. Also, worse recall of material in episodic memory was associated with greater length of illness. Nevertheless, findings indicate that nearly all cognitive deficits are comparably impaired across recent-onset and chronic schizophrenia.