Correlation of Lifetime Symptom Dimensions with Cognitive Function and Other Clinical Characteristics in Schizophrenia Patients.

Cho, Youngah; Ryu, Seunghyong; Oh, Hyeji; Oh, Sohee; Park, Taesung; Yoon, Se Chang; Hong, Kyung Sue

doi:2014.17.2.72

Korean J Schizophr Res > Volume 17(2); 2014 > Article

Original Article

Korean Journal of Schizophrenia Research 2014;17(2):72-79.
DOI: https://doi.org/10.16946/kjsr.2014.17.2.72 Published online October 31, 2014.

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.

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