| 1 | Behav Neurol 2000 -1 12: 209-220 |
|---|---|
| PMID | 11568433 |
| Title | Dysexecutive syndrome in schizophrenia: A cross-cultural comparison between Japanese and British patients. |
| Abstract | This study tested the hypothesis that the dysexecutive syndrome of schizophrenia is impervious to cultural differences. 18 Japanese and 22 British patients and 14 Japanese and 19 British control subjects were compared on the BADS (Behavioural Assessment of Dysexecutive Syndrome), a comprehensive neuropsychological assessment battery, designed for 'ecological validity', and other measures of frontal executive functions (EFS). Both cultural groups of schizophrenic patients showed equally severe impairment in most executive tests including the BADS (verbal fluency and intelligence were less impaired). Irrespective of cultural origin, similar neuropsychological deficits were found in patients with minimal intellectual deterioration. Our study suggests that socio-cultural background does not affect the dysexecutive profile of schizophrenia very much, and that neuropsychological assessment may possibly provide added clinical information relevant to the management and rehabilitation of schizophrenic patients across different cultures. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 2 | Behav Neurol 2000 -1 12: 209-220 |
| PMID | 11568433 |
| Title | Dysexecutive syndrome in schizophrenia: A cross-cultural comparison between Japanese and British patients. |
| Abstract | This study tested the hypothesis that the dysexecutive syndrome of schizophrenia is impervious to cultural differences. 18 Japanese and 22 British patients and 14 Japanese and 19 British control subjects were compared on the BADS (Behavioural Assessment of Dysexecutive Syndrome), a comprehensive neuropsychological assessment battery, designed for 'ecological validity', and other measures of frontal executive functions (EFS). Both cultural groups of schizophrenic patients showed equally severe impairment in most executive tests including the BADS (verbal fluency and intelligence were less impaired). Irrespective of cultural origin, similar neuropsychological deficits were found in patients with minimal intellectual deterioration. Our study suggests that socio-cultural background does not affect the dysexecutive profile of schizophrenia very much, and that neuropsychological assessment may possibly provide added clinical information relevant to the management and rehabilitation of schizophrenic patients across different cultures. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 3 | Front Psychiatry 2013 -1 4: 35 |
| PMID | 23805107 |
| Title | Executive functioning in schizophrenia. |
| Abstract | The executive function (EF) is a set of abilities, which allows us to invoke voluntary control of our behavioral responses. These functions enable human beings to develop and carry out plans, make up analogies, obey social rules, solve problems, adapt to unexpected circumstances, do many tasks simultaneously, and locate episodes in time and place. EF includes divided attention and sustained attention, working memory (WM), set-shifting, flexibility, planning, and the regulation of goal directed behavior and can be defined as a brain function underlying the human faculty to act or think not only in reaction to external events but also in relation with internal goals and states. EF is mostly associated with dorsolateral prefrontal cortex (PFC). Besides EF, PFC is involved in self-regulation of behavior, i.e., the ability to regulate behavior according to internal goals and constraints, particularly in less structured situations. Self-regulation of behavior is subtended by ventral medial/orbital PFC. Impairment of EF is one of the most commonly observed deficits in schizophrenia through the various disease stages. Impairment in tasks measuring conceptualization, planning, cognitive flexibility, verbal fluency, ability to solve complex problems, and WM occur in schizophrenia. Disorders detected by executive tests are consistent with evidence from functional neuroimaging, which have shown PFC dysfunction in patients while performing these kinds of tasks. schizophrenics also exhibit deficit in odor identifying, decision-making, and self-regulation of behavior suggesting dysfunction of the orbital PFC. However, impairment in executive tests is explained by dysfunction of prefronto-striato-thalamic, prefronto-parietal, and prefronto-temporal neural networks mainly. Disorders in EFS may be considered central facts with respect to schizophrenia and it has been suggested that negative symptoms may be explained by that executive dysfunction. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 4 | Front Psychiatry 2013 -1 4: 35 |
| PMID | 23805107 |
| Title | Executive functioning in schizophrenia. |
| Abstract | The executive function (EF) is a set of abilities, which allows us to invoke voluntary control of our behavioral responses. These functions enable human beings to develop and carry out plans, make up analogies, obey social rules, solve problems, adapt to unexpected circumstances, do many tasks simultaneously, and locate episodes in time and place. EF includes divided attention and sustained attention, working memory (WM), set-shifting, flexibility, planning, and the regulation of goal directed behavior and can be defined as a brain function underlying the human faculty to act or think not only in reaction to external events but also in relation with internal goals and states. EF is mostly associated with dorsolateral prefrontal cortex (PFC). Besides EF, PFC is involved in self-regulation of behavior, i.e., the ability to regulate behavior according to internal goals and constraints, particularly in less structured situations. Self-regulation of behavior is subtended by ventral medial/orbital PFC. Impairment of EF is one of the most commonly observed deficits in schizophrenia through the various disease stages. Impairment in tasks measuring conceptualization, planning, cognitive flexibility, verbal fluency, ability to solve complex problems, and WM occur in schizophrenia. Disorders detected by executive tests are consistent with evidence from functional neuroimaging, which have shown PFC dysfunction in patients while performing these kinds of tasks. schizophrenics also exhibit deficit in odor identifying, decision-making, and self-regulation of behavior suggesting dysfunction of the orbital PFC. However, impairment in executive tests is explained by dysfunction of prefronto-striato-thalamic, prefronto-parietal, and prefronto-temporal neural networks mainly. Disorders in EFS may be considered central facts with respect to schizophrenia and it has been suggested that negative symptoms may be explained by that executive dysfunction. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 5 | Compr Psychiatry 2014 Aug 55: 1350-7 |
| PMID | 24850068 |
| Title | Ecological assessment of executive functions in adolescents genetically at high risk for schizophrenia. |
| Abstract | This study sought to examine specific executive deficits in the real-life environment among adolescents genetically at high risk for schizophrenia and understand the role of the genetic risk, victimization and family functioning, and their interaction on the deficits. The study included 96 non-affected adolescent offspring and siblings of patients with schizophrenia in the high-risk group (HR) and 193 healthy adolescents in the healthy control group (HC), all aged between 9 and 20 years. All participants completed assessments of executive functions (EFS), victimization, and family functioning. The multivariate analysis revealed that the HR group reported more difficulties on the Shift, Plan/Organize, and Task Completion scale than the HC group. Significant main effects were also detected for victimization level on all domains of EFS and for adaptability level on Inhibit, Working Memory, Plan, and Task Completion scales. Besides, the group×victimization level interactions were significant for Working Memory and Task Completion scales. Hierarchical regression analysis revealed that the genetic risk and victimization were predictors of executive deficits. The HR group showed impaired EFS in the everyday environment. And, the genetic risk for schizophrenia and victimization may be related to executive dysfunction. Our results may provide clues about explaining the mechanisms of executive impairments in the HR group and help to identify new targets for early interventions. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 6 | Eur. Psychiatry 2015 Nov 30: 894-9 |
| PMID | 26647863 |
| Title | Dynamic occupation assessment of executive function in adolescents with schizophrenia spectrum disorders: An initial report. |
| Abstract | This study presents an initial evaluation of the psychometric properties of the Dynamic Occupation Assessment of Executive Function (DOAEF), a new tool designed to assess adolescents' executive function (EF) in daily situations and offering two levels of mediation through the administration process. In the preliminary study, we tested 22 healthy adolescents. In the advanced stage, the instrument was administered to 105 healthy adolescents and to another 92 adolescents diagnosed with schizophrenia spectrum disorders. Information regarding EF was assessed by the DOAEF and Wisconsin Card Sorting Computer Version Test (WCST-CV-64). Inter-rater, test-retest and internal consistency indices were found to be satisfactory. Correlation between the DOAEF and the WCST-CV-64 scores supports the DOAEF's convergent validity. Significant differences were found between the healthy participants and the adolescents diagnosed with schizophrenia spectrum disorders, thus supporting the DOAEF's criterion validity. The DOAEF may be useful in assessing the level of mediation, which patients need for the comprehension of daily situations in which EFS are required. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 7 | J Child Psychol Psychiatry 2016 Apr 57: 462-71 |
| PMID | 26411927 |
| Title | Extending the 'cross-disorder' relevance of executive functions to dimensional neuropsychiatric traits in youth. |
| Abstract | Evidence that different neuropsychiatric conditions share genetic liability has increased interest in phenotypes with 'cross-disorder' relevance, as they may contribute to revised models of psychopathology. Cognition is a promising construct for study; yet, evidence that the same cognitive functions are impaired across different forms of psychopathology comes primarily from separate studies of individual categorical diagnoses versus controls. Given growing support for dimensional models that cut across traditional diagnostic boundaries, we aimed to determine, within a single cohort, whether performance on measures of executive functions (EFS) predicted dimensions of different psychopathological conditions known to share genetic liability. Data are from 393 participants, ages 8-17, consecutively enrolled in the Longitudinal Study of Genetic Influences on Cognition (LOGIC). This project is conducting deep phenotyping and genomic analyses in youth referred for neuropsychiatric evaluation. Using structural equation modeling, we examined whether EFS predicted variation in core dimensions of the autism spectrum disorder, bipolar illness, and schizophrenia (including social responsiveness, mania/emotion regulation, and positive symptoms of psychosis, respectively). We modeled three cognitive factors (working memory, shifting, and executive processing speed) that loaded on a second-order EF factor. The EF factor predicted variation in our three target traits, but not in a negative control (somatization). Moreover, this EF factor was primarily associated with the overlapping (rather than unique) variance across the three outcome measures, suggesting that it related to a general increase in psychopathology symptoms across those dimensions. Findings extend support for the relevance of cognition to neuropsychiatric conditions that share underlying genetic risk. They suggest that higher-order cognition, including EFS, relates to the dimensional spectrum of each of these disorders and not just the clinical diagnoses. Moreover, results have implications for bottom-up models linking genes, cognition, and a general psychopathology liability. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |