The purpose of the present study was to identify the factor structure of neurocognitive tests used on schizophrenia patients by using the confirmative factor analysis, and to assess the factor score differences of schizophrenia patients and healthy controls. Comprehensive neurocognitive tests were administered to stabilized schizophrenia patients (N=114) and healthy controls (N=120). In the results of factor analyses on patients, the multifactorial-6-factor model, which included the speed of processing, working memory, verbal learning and memory, visual learning and memory, attention/vigilance, and reasoning/problem solving as suggested by the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS), showed the better goodness of fit than any of the other models tested. And assessing the group differences of factor scores, we found the patients performed worse than the controls in all factors, but the result showed meaningful variations of impairments across the cognitive factors. Our study identifies the six major domains with multifactorial structure of cognitive abilities in schizophrenia patients and confirms the distinctive impairment patterns of each cognitive domain. These results may have utility in better understanding the pathology of schizophrenia as well as in genetic studies.
Adolescent ; Adult ; Attention ; Cognition Disorders/etiology ; Factor Analysis, Statistical ; Female ; Humans ; Male ; Memory ; Middle Aged ; Models, Psychological ; Neuropsychological Tests ; Problem Solving ; Schizophrenia/*diagnosis/etiology ; Severity of Illness Index ; Verbal Behavior ; Verbal Learning

OBJECTIVES: Intra-individual variability of cognitive performance across different tests or domains has been reported as an important index of cognitive function. The aim of the current study is to examine the intra-individual variability across different cognitive domains and tests in patients with schizophrenia, their unaffected siblings, and normal controls. We also compared the variability among three patient sub-groups divided according to the duration of illness. METHODS: Comprehensive neurocognitive tests were administered in order to stabilize patients with schizophrenia (n=129), healthy siblings (n=38) of the patients, and normal controls (n=110). Intra-individual variability was computed from the variance of the scores of six cognitive domains of the Measurement and Treatment Research to Improve Cognition in Schizophrenia consensus battery. We examined intra-individual variability across six factor-based cognitive scores and individual test scores of each cognitive domain. RESULTS: Compared to the normal control and sibling groups, patients showed significantly increased intra-individual variability across six cognitive domains and individual cognitive tests of each domain. Compared to the normal control, siblings showed significantly increased intra-individual variability only across individual tests of the processing of speed domain. Among patient sub-groups, those with the longest duration of illness (> or =11 years) showed significantly higher intra- individual variability across six cognitive domains and across individual tests of the processing of speed domain compared to the other two groups. CONCLUSION: This study identified cognitive dissonances across six cognitive domain schizophrenia patients. These cognitive characteristics were not observed in the sibling groups and seemed to progress during the course of illness.
Cognition ; Cognitive Dissonance ; Consensus ; Humans ; Neuropsychological Tests* ; Schizophrenia* ; Siblings*

OBJECTIVES: Recurrence of mood episodes associated with a specific season has been described in various mood disorders. Seasonal change in mood and behavior as a lifetime trait is also observed in healthy individuals. This study aimed at comparing the lifetime trait of seasonal variations of mood and behavior between bipolar disorder patients and controls as well as investigating associated factors of seasonality. METHODS: Subjects were ninety-four clinically stable patients with bipolar disorder and 188 age- and sex-matched healthy controls. Seasonality of mood and behavior was assessed retrospectively on lifetime basis using Seasonal Pattern Assessment Questionnaire(SPAQ). RESULTS: The patient group showed a higher median global seasonality score(GSS) of SPAQ and a higher rate of seasonal affective disorder(SAD) compared to the control group(p < 0.0001). For subjects showing prominent seasonality, the seasonal symptom profile and seasonal pattern was similar in both patient and control groups. In addition to the diagnosis, female gender was shown to be a predictor of seasonality in the multiple linear regression analysis(p = 0.045). CONCLUSION: This study suggests that lifetime trait of seasonality may be related to the susceptibility of bipolar disorder.
Bipolar Disorder ; Female ; Humans ; Linear Models ; Mood Disorders ; Recurrence ; Retrospective Studies ; Seasons

PURPOSE: Lung Cancer Subcommittee of Korean Radiation Oncology Group (KROG) has recently launched a prospective clinical trial (KROG 17-06) of hippocampus-sparing whole brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) in treating multiple brain metastases from non-small cell lung cancer. In order to improve trial quality, dummy run studies among the participating institutions were designed. This work reported the results of two-step dummy run procedures of the KROG 17-06 study. MATERIALS AND METHODS: Two steps tested hippocampus contouring variability and radiation therapy planning compliance. In the first step, the variation of the hippocampus delineation was investigated for two representative cases using the Dice similarity coefficients. In the second step, the participating institutions were requested to generate a HS-WBRT with SIB treatment plan for another representative case. The compliance of the treatment plans to the planning protocol was evaluated. RESULTS: In the first step, the median Dice similarity coefficients of the hippocampus contours for two other dummy run cases changed from 0.669 (range, 0.073 to 0.712) to 0.690 (range, 0.522 to 0.750) and from 0.291 (range, 0.219 to 0.522) to 0.412 (range, 0.264 to 0.598) after providing the hippocampus contouring feedback. In the second step, with providing additional plan priority and extended dose constraints to the target volumes and normal structures, we observed the improved compliance of the treatment plans to the planning protocol. CONCLUSION: The dummy run studies demonstrated the notable inter-institutional variability in delineating the hippocampus and treatment plan generation, which could be decreased through feedback from the trial center.
Brain ; Carcinoma, Non-Small-Cell Lung ; Compliance ; Hippocampus ; Lung Neoplasms ; Neoplasm Metastasis ; Prospective Studies ; Radiation Oncology ; Radiotherapy