Correlation of Lifetime Symptom Dimensions with Cognitive Function and Other Clinical Characteristics in Schizophrenia Patients. |
Youngah Cho, Seunghyong Ryu, Hyeji Oh, Sohee Oh, Taesung Park, Se Chang Yoon, Kyung Sue Hong |
1Department of Psychiatry, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. hongks@skku.edu 2Center for Clinical Research, Samsung Biomedical Research Institute, Seoul, Korea. 3Department of Biostatistics, Boramae Medical Center, Seoul, Korea. 4Department of Statistics, Seoul National University, Seoul, Korea. |
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Abstract |
OBJECTIVES Considering large diversity of clinical presentation of schizophrenia, it is important to identify valid clinical subtypes or dimensions that might have homogeneous biological underpinning. The current study aimed to explore lifetime symptom-based dimensional phenotypes in patients with chronic schizophrenia, and to investigate their correlation with cognitive functions and other clinical characteristics. METHODS Lifetime-based symptoms and additional clinical variables were measured using the Diagnostic Interview for Genetic Studies and the Schedule for the Deficit Syndrome in 315 clinically stable patients with chronic schizophrenia. Through principal components factor analysis, eight dimensional phenotypes were obtained. Comprehensive neuropsychological tests were administered for 103 out of 315 patients, and domain scores were calculated for cognitive domains defined in the MATRICS consensus battery. RESULTS 'Non-paranoid delusion factor' including delusions of grandiose or religious nature, showed significant negative correlation with processing speed, working memory, attention/vigilance, and general cognitive ability, and positive correlation with intra-individual variability. 'Negative symptom factor' showed significant negative correlation only with general cognitive ability. Those two factors were also negatively correlated with function levels measured by Global Assessment Scale (GAS), and associated with poor treatment responses. CONCLUSION Symptom-based dimensional phenotypes of schizophrenia measured on a lifetime basis showed discriminative correlation with cognitive function domains, global functioning level, and overall treatment responses, indicating their possibility as valid phenotype axes of schizophrenia having homogeneous biologic basis. |
Key Words:
Schizophrenia · Symptom dimensions · Cognition |
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