Relationship between serum homocysteine, folate and vitamin B12 levels and cognitive function in patients with first-treated obsessive-compulsive disorder

Abstract

Background The study aimed to investigate the correlation between HCY, vitamin B12, and folate levels and cognitive function in patients with obsessive-compulsive disorder (OCD). Methods Fifty patients with first-treated OCD and 50 matched healthy controls recruited during the same period were enrolled. Subjects were cognitively assessed using the Wisconsin Card Sorting test (WCST) and The MATRICS Consensus Cognitive Battery (MCCB) scales. Serum homocysteine was also measured by enzyme cycle assay, serum folate and vitamin B12 by ELISA. The Kruskal-Wallis test was then used to compare the differences in hematologic indices and cognitive functioning between the OCD and control groups, and Spearman correlation analyses were used to explore the relationship between hematologic indices and cognitive functioning. Mediating effects modeling was further introduced. Results Patients with first-treated OCD had extensive cognitive impairment compared with controls (P <0.05). Serum homocysteine, vitamin B12, and folate levels were significantly different compared to the control group (P < 0.05). Serum homocysteine levels were positively correlated with Yale Brown Obsessive-Compulsive Scale scores and length of time spent on the Trail Making Test, and negatively correlated with verbal learning ability and emotional management ability. Folate levels were negatively correlated with Yale Brown Obsessive-Compulsive Scale scores and length of time spent on the Trail Making Test, and positively correlated with verbal learning ability and emotional management ability. No significant correlation was found with serum vitamin B12 levels. SPSS mediation effect model analysis showed that homocysteine level partially mediated the relationship between the degree of obsessive-compulsive symptoms and verbal learning ability, with a mediation effect value of -0.43, 95% CI [-0.58~-0.28], and serum folate level partially mediated the relationship between the degree of obsessive-compulsive symptoms and the speed of information processing and verbal learning ability, with a mediation effect value of 1.78,95%CI[0.62 ~ 3.47];-0.11,95%CI[-0.21~-0.03]. Conclusions Serum homocysteine levels are positively correlated with the degree of symptoms and cognitive dysfunction in patients with first-treated obsessive-compulsive disorder, and serum folate levels may be protective against cognitive alterations in patients with first-treated OCD. Symptom severity of OCD and serum homocysteine and folate levels together influence cognitive function.