The relationship among insight, cognitive function of patients with schizophrenia and their relatives' perception

Numerosity comparison, cognitive strategies, and general cognitive functioning in older people

Introduction

Studies have shown age-related differences in numerical cognition, for example, in the level of numerosity comparison ability. Moreover, some studies point out individual differences in the cognitive strategies employed during the performance of numerosity comparison tasks and reveal that they are related to the aging process. One probable cause of these differences is the level of cognitive functioning. The aim of our study was to determine the relationships among numerosity comparison ability, the cognitive strategies utilized in the performance of numerosity comparison tasks and the general cognitive functioning in older people.

Methods

Forty-seven elderly people participated in the study. The participants were examined using overall cognitive functioning scales and computerized numerosity comparison task.

Results

The results showed many correlations between the participants' level of cognitive functioning and the percent of correct responses (PCR) and response time (RT) during numerosity comparison, as well as with the cognitive strategies applied by the participants. Task correctness was positively related to the level of performance in the attention and executive function tasks. In contrast, the long-term memory resources index and visuospatial skills level were negatively correlated with RT regarding numerosity comparison task performance. The level of long-term memory resources was also positively associated with the frequency of use of more complex cognitive strategies. Series of regression analyses showed that both the level of general cognitive functioning and the cognitive strategies employed by participants in numerosity comparison can explain 9-21 percent of the variance in the obtained results.

Discussion

In summary, these results showed significant relationships between the level of cognitive functioning and proficiency in numerosity comparison measured in older people. Moreover, it has been shown that cognitive resources level is related to the strategies utilized by older people, which indicates the potential application for cognitive strategy examinations in the development of new diagnostic tools.

Neurocognition, sleep, and PET findings in type 2 vs type 1 narcolepsy

OBJECTIVE

To analyze differences in functional brain images collected in patients with type 2 and type 1 narcolepsy compared to normal controls and the relationship among brain images, objective neuropsychologic tests, and sleep findings.

METHODS

Data collection included comprehensive clinical investigation, study of sleep/wake with actigraphy, polysomnography, Multiple Sleep Latency Test, human leukocyte antigen typing, ¹⁸F-fluorodeoxyglucose PET, and cognitive tests obtained from 29 patients with type 2 narcolepsy, 104 patients with type 1 narcolepsy, and 26 sex- and age-matched normal control individuals. Conners' Continuous Performance Test (CPT II) and Wisconsin Card-Sorting Task were performed simultaneously with the FDG-PET examination. After analyses of variance, data between patients with type 1 and type 2 narcolepsy were compared by post hoc analysis, and correlation between functional brain imaging findings and results of neurocognitive tests was obtained.

RESULTS

All patients with narcolepsy presented with at least 2 sleep-onset REM periods (SOREMP) and subjective sleepiness. Patients with type 2 narcolepsy compared to patients with type 1 narcolepsy had significantly less SOREMP, longer mean sleep latencies, and lower body mass indexes, apnea-hypopnea indexes, and frequency of human leukocyte antigen DQ-Beta1*0602. In patients with type 2 narcolepsy, FDG-PET studies showed significantly less hypermetabolism in the fusiform gyrus, striatum, hippocampus, thalamus, basal ganglia, and cerebellum than in patients with type 1 narcolepsy, and significantly less hypometabolism in the regions of frontal lobe, posterior cingulum, angular gyrus, and part of the parietal lobe; these changes were associated with fewer errors on the CPT.

CONCLUSION

Young patients with type 2 narcolepsy have fewer clinical impairments and less distinct brain functional abnormalities than patients with type 1 narcolepsy, who are significantly more affected.

Unraveling interrelationships among psychopathology symptoms, cognitive domains and insight dimensions in chronic schizophrenia

INTRODUCTION

Insight in schizophrenia is long known to have a complex relationship with psychopathology symptoms and cognition. However, very few studies have examined models that explain these interrelationships.

METHODS

In a large sample derived from the NIMH Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) schizophrenia trial (N=1391), we interrogated these interrelationships for potential causal pathways using structural equation modeling. Using the NIMH consensus model, latent variables were constructed for psychopathology symptom dimensions, including positive, negative, disorganized, excited and depressed from the Positive and Negative Syndrome Scale (PANSS) items. Neurocognitive variables were created from five predefined domains of working memory, verbal memory, reasoning, vigilance and processing speed. Illness insight and treatment insight were tested using latent variables constructed from the Illness and Treatment Attitude Questionnaire (ITAQ).

RESULTS

Disorganized symptoms had the strongest effect on insight. Illness insight mediated the relationship of positive, depressed, and disorganized symptoms with treatment insight. Neurocognition mediated the relationship between disorganized and treatment insight and depressed symptoms and treatment insight. There was no effect of negative symptoms on either illness insight or treatment insight. Taken together, our results indicate overlapping and unique relational paths for illness and treatment insight dimensions, which could suggest differences in causal mechanisms and potential interventions to improve insight.

Insight in Psychiatry and Neurology: State of the Art, and Hypotheses

In spite of the increasing number of studies on insight in psychiatry and also in neurology and psychology, its nature is still elusive. It encompasses at least three fundamental characteristics: the awareness of suffering from an illness, an understanding of the cause and source of this suffering, and an acknowledgment of the need for treatment. As such, insight is fundamental for patients' management, prognosis, and treatment. Not surprisingly, the majority of available data, which have been gathered on schizophrenia, show a relationship between low insight and poorer outcomes. For mood disorders, however, insight is associated with less positive results. For other psychiatric disorders, insight has rarely been investigated. In neurology, the impaired ability to recognize the presence of sensory, perceptual, motor, affective, or cognitive functioning-referred to as anosognosia-has been related to damage of specific brain regions. This article provides a comprehensive review of insight in different psychiatric and neurological disorders, with a special focus on brain areas and neurotransmitters that serve as the substrate for this complex phenomenon.

Neurocognitive Profiles of Methamphetamine Users: Comparison of Those With or Without Concomitant Ketamine Use

OBJECTIVE

Methamphetamine (MAMP) and ketamine are neurotoxic drugs whose chronic use has been linked with a cognitive decline in some users. This paper aims to assess the possible effect of concomitant ketamine use on the neurocognitive performance of MAMP users.

METHODS

This study divides 42 MAMP users into MAMP users who use ketamine (MAMP+K, n = 16) and MAMP users who do not use ketamine (MAMP-K, n = 26). The performance of these two groups was compared using the Brief Assessment of Cognition in Schizophrenia (BACS), Conners' Continuous Performance Tests (CPT), the Wisconsin Card Sorting Test (WCST), the Iowa Gambling Task (IGT), and the Barratt Impulsiveness Scale (BIS).

RESULTS

In comparison to the MAMP-K group, the MAMP+K group showed worse performances in verbal fluency, executive function and composite score in BACS; worse performances in total errors, perseverative errors, nonperseverative errors and conceptual level response in WCST; and greater levels of total scores and novelty-seeking in BIS. Neither the attention function evaluated with CPT nor the decision-making behavior evaluated with IGT was associated with previous ketamine use.

CONCLUSION

This study detected worse executive function and higher impulsivity level among MAMP users with additional ketamine use versus their counterparts without ketamine use. Further studies with a longitudinal design and a large sample size are necessary to clarify the connection between cognitive deficits and concomitant use of MAMP and ketamine.

Neurocognitive effects of aripiprazole in adolescents and young adults with schizophrenia

BACKGROUND

The use of aripiprazole has been associated with a positive influence on mood and improved cognitive skills and social interactions; however, studies of its effects on young schizophrenic patients have been limited to active symptoms.

AIMS

This prospective, open-label study investigated the neurocognitive effects of aripiprazole in adolescents and young adults with first and repeated episodes of schizophrenia.

METHODS

Twenty-three of 42 schizophrenic outpatients aged 12-26 completed a trial of aripiprazole, and its efficacy was determined using the Brief Psychiatric Rating Scale (BPRS), Clinical Global Impressions Severity (CGI-S) and WHO Quality of Life (WHOQOL) scales. Cognitive function was measured with the Cognitive Performance Test (CPT) and Wisconsin Card Sorting Test (WCST) at 4, 12 and 24 weeks of treatment.

RESULTS

Results showed statistically significant improvements in BPRS, CGI-S and WHOQOL scores in certain (but not all) subcategories of cognitive measures including CPT detectability and total errors and perseverative errors on the WCST. There were few adverse side-effects.

CONCLUSIONS

Psychotic symptoms and cognitive skills improved during treatment with aripiprazole in adolescents and young adults with schizophrenia. Patients with first psychotic episodes did better than did those with repeat episodes.

Relationship between cognition, clinical and cognitive insight in psychotic disorders: a review and meta-analysis

The neurocognitive theory of insight posits that poor insight in psychotic illnesses is related to cognitive deficits in cognitive self-appraisal mechanisms. In this paper we perform a comprehensive meta-analysis examining relationships between clinical insight and neurocognition in psychotic disorders. We have also completed a meta-analysis of studies examining 'cognitive insight', as measured by the Beck Cognitive Insight Scale (BCIS), and its relationship with neurocognitive function in patients with psychosis. The clinical insight analysis included data from 72 studies and a total population of 5429 patients. We found that insight in psychosis was significantly associated with total cognition (r=0.16, p<0.001), IQ (r=0.16, p<0.001), memory (r=0.13, p<0.001) and executive function (r=0.14, p<0.001). All of these correlations were stronger when examined in patients with schizophrenia only. In the BCIS analysis we included 7 studies and 466 patients in total. We found that no significant associations were found between the self-reflectiveness sub-component and neurocognition. By contrast there were significant correlations between the self-certainty subcomponent and memory (r=-0.23, p<0.001), IQ (r=-0.19, p<0.001) and total cognition (r=-0.14, p=0.01). We did not find evidence of significant publication bias in any analyses. Overall, our results indicate that there is a small but significant relationship between clinical insight, some aspects of cognitive insight and neurocognition. These findings reflect the complexity of the insight construct and indicate that while the neurocognitive model is important it is likely to be one of many which contribute to the understanding of this phenomenon.

Localized infusions of the partial alpha 7 nicotinic receptor agonist SSR180711 evoke rapid and transient increases in prefrontal glutamate release

The ability of local infusions of the alpha 7 nicotinic acetycholine receptor (α7 nAChR) partial agonist SSR180711 to evoke glutamate release in prefrontal cortex was determined in awake rats using a microelectrode array. Infusions of SSR180711 produced dose-dependent increases in glutamate levels. The lower dose (1.0μg in 0.4μL) evoked a rapid rise (∼1.0s) in glutamate (1.41±0.30μM above baseline). The higher dose (5.0μg) produced a similarly rapid, yet larger increase (3.51±0.36μM above baseline). After each dose, the glutamate signal was cleared to basal levels within 7-18s. SSR180711-evoked glutamate was mediated by the α7 nAChR as co-infusion of the selective α7 nAChR antagonist α-bungarotoxin (10.0μM)+SSR1808711 (5.0μg) reduced the effect of 5.0μg alone by 87% (2.62 vs. 0.35μM). Finally, the clearance of the SSR180711 (5.0μg)-evoked glutamate was bidirectionally affected by drugs that inhibited (threo-beta-benzyl-oxy-aspartate (TβOA), 100.0μM) or facilitated (ceftriaxalone, 200mg/kg, i.p.) excitatory amino acid transporters. TβOA slowed both the clearance (s) and rate of clearance (μM/s) by 10-fold, particularly at the mid-late stages of the return to baseline. Ceftriaxone reduced the magnitude of the SSR180711-evoked increase by 65%. These results demonstrate that pharmacological stimulation of α7 nAChRs within the prefrontal cortex is sufficient to evoke rapid yet transient increases in glutamate levels. Such increases may underlie the cognition-enhancing effects of the drug in animals; further justifying studies on the use of α7 nAChR-positive modulators in treating cognition-impairing disorders in humans.

Neurocognitive effects of aripiprazole in adolescents and young adults with bipolar disorder

BACKGROUND

Patients with bipolar disorder have neurocognitive impairments, which are associated with poor functional outcomes.

AIMS

This study evaluated the neurocognitive effects of aripiprazole in adolescents and young adults with bipolar disorder.

METHODS

This was a 24-week, observational, prospective study performed in Taiwan. Participants in the study were clinically diagnosed as having bipolar disorder according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). In total, 28 patients participated and were administered aripiprazole. Neurocognitive function was assessed as a change from baseline in the Continuous Performance Test (CPT) and the Wisconsin Card Sorting Test (WCST).

RESULTS

The 28 patients had a mean age of 18.5 ± 3.3 years. During the 24-week aripiprazole treatment, these patients had significant improvements in omission score (χ(2) = 7.83, P = 0.050) and detectability scores (χ(2) = 13.79, P = 0.003) in the CPT, and perseverative errors (χ(2) = 17.42, P = 0.001) in the WCST. The WCST perseverative errors scores were significantly associated with general symptom scores in Brief Psychiatric Rating Scale (BPRS) (β = - 1.34, P = 0.024). No significant differences were found between the neurocognitive functions of patients with manic, depressive and mixed episodes from baseline to week 24.

CONCLUSIONS

Adolescents and young adults with bipolar disorder experienced significant neurocognitive function improvements after treatment with aripiprazole. A randomized, controlled design is warranted to determine whether these improvements are associated with aripiprazole or the course of bipolar disorder.

Insight in schizophrenia: from conceptualization to neuroscience

Lack of insight into illness is a prevalent and distinguishing feature of schizophrenia, which has a complex history and has been given a variety of definitions. Currently, insight is measured and treated as a multidimensional phenomenon, because it is believed to result from psychological, neuropsychological and organic factors. Thus, schizophrenia patients may display dramatic disorders including demoralization, depression and a higher risk of suicide, all of which are directly or indirectly related to a lack of insight into their illness, and make the treatment difficult. To improve the treatment of people with schizophrenia, it is thus crucial to advance research on insight into their illness. Insight is studied in a variety of ways. Studies may focus on the relationship between insight and psychopathology, may view behavioral outcomes or look discretely at the cognitive dysfunction versus anatomy level of insight. All have merit but they are dispersed across a wide body of literature and rarely are the findings integrated and synthesized in a meaningful way. The aim of this study was to synthesize findings across the large body of literature dealing with insight, to highlight its multidimensional nature, measurement, neuropsychology and social impact in schizophrenia. The extensive literature on the cognitive consequences of lack of insight and the contribution of neuroimaging techniques to elucidating neurological etiology of insight deficits, is also reviewed.

Clinical symptoms and performance on the Continuous Performance Test in children with attention deficit hyperactivity disorder between subtypes: a natural follow-up study for 6 months

BACKGROUND

The aims of this study were to determine the time course of improvements in attention deficit hyperactivity disorder (ADHD) clinical symptoms and neurocognitive function in a realistic clinical setting, and the differences in ADHD symptom improvement using different classifications of ADHD subtypes.

METHODS

The Child Behavior Checklist (CBCL) was completed by parents of ADHD children at the initial visit. The computerized Continuous Performance Test (CPT), Swanson, Nolan, and Pelham, and Version IV Scale for ADHD (SNAP-IV), and ADHD Rating Scale (ADHD-RS) were performed at baseline, one month, three months, and six months later, respectively. Patient care including drug therapy was performed at the discretion of the psychiatrist. The ADHD patients were divided into DSM-IV subtypes (Inattentive, Hyperactive-impulsive and Combined type), and were additionally categorized into aggressive and non-aggressive subtypes by aggression scale in CBCL for comparisons.

RESULTS

There were 50 ADHD patients with a mean age of 7.84 ± 1.64 years; 15 of them were inattentive type, 11 were hyperactive-impulsive type, and 24 were combined type. In addition, 28 of the ADHD patients were grouped into aggressive and 22 into non-aggressive subtypes. There were significant improvements in clinical symptoms of hyperactivity and inattention, and impulsivity performance in CPT during the 6-month treatment. The clinical hyperactive symptoms were significantly different between ADHD patients sub-grouping both by DSM-IV and aggression. Non-aggressive patients had significantly greater changes in distraction and impulsivity performances in CPT from baseline to month 6 than aggressive patients.

CONCLUSIONS

We found that ADHD symptoms, which included impulsive performances in CPT and clinical inattention and hyperactivity dimensions, had improved significantly over 6 months under pragmatic treatments. The non-aggressive ADHD patients might have a higher potential for improving in CPT performance than aggressive ones. However, it warrant further investigation whether the different classifications of ADHD patients could be valid for predicting the improvements in ADHD patients' clinical symptoms and neurocognitive performance.

Correlates and long-term consequences of poor insight in patients with schizophrenia. A systematic review

Between 50 and 80% of the patients diagnosed with schizophrenia have been shown to be partially or totally lacking insight into the presence of their mental disorder. Although a causal chain connecting poor insight with poor treatment adherence and thus with poorer outcome and functioning is straight forward, numerous studies investigating correlates and long-term impact of insight have provided differing results. In addition, higher levels of insight in schizophrenia have been associated with depression and hopelessness, but the causal direction of the relationship is unclear and the data are inconclusive. The current study provides a critical review of 88 studies on the assessment of insight and its impact on symptoms and functioning. Studies published by June 2006 were selected using a keyword search for English peer-reviewed articles in the databases PsycINFO and MEDLINE. The majority of studies support the assumption that insight is associated with adherence during treatment phase, but the association with long-term adherence remains unclear. Insight correlates with better long-term functioning, but this might be explained by its association with symptoms. There is a positive cross-sectional and longitudinal relationship between insight and depression, but the underlying processes need further clarification. In the concluding discussion, the problems relating to definition and study designs are considered responsible for many of the inconclusive findings. Suggestions for further research are derived.