Correlation of serum homocysteine with attention and executive functions in patients with type I stable bipolar affective disorder

Objectives: The current study aimed to examine the correlation of the level of homocysteine (Hcy) in the serum with attention and executive functions in patients suffering from type I stable bipolar affective disorder. Methods: The present cross-sectional study was conducted on 170 participants in Huzhou, Zhejiang province, China, within July 2016 to December 2017. The subjects were divided into patients with schizophrenia (n=100) as the study group and healthy volunteers (n=70) as the control group. The Hcy and folic acid levels of fasting ulnar vein serum were determined using the chemiluminescent microparticle immunoassay. Patient attention was evaluated by the Trail Making Test A (TMTA), and executive functions were assessed using the Trail Making Test B (TMTB) and Stroop Color and Word Test (SCWT). Results: The serum Hcy value was significantly higher in the study group than that reported for the control group (19.01±5.83 and 11.40±4.62; P<0.001). The results of several tests of attention (59.39±19.27 and 53.26±14.82; P=0.027) and executive functions (123.75±40.60 and 107.52±29.31; P=0.013) were poorer in the study group. The serum Hcy value positively correlated with the disturbance variables of the TMTA, TMTB, and Trail Making Test. However, the duration of the Stroop-C test (SCT) and SCWT negatively correlated with the correct number of the SCT and SCWT. Conclusions: The increase in the level of serum Hcy is closely correlated with the impairment of attention and executive functions in patients suffering from type I stable bipolar affective disorder.