It is known that elevated serum
homocysteine, decreased
folate, and low
vitamin B12 serum levels are associated with poor cognitive function,
cognitive decline, and
dementia. Current literature shows that some
psychiatric disorders, mainly affective and psychotic ones, can be related to the levels of
vitamin B12,
folate, and
homocysteine. These results can be explained by the importance of
vitamin B12,
folate, and
homocysteine in
carbon transfer metabolism (methylation), which is required for the production of
serotonin as well as for other monoamine
neurotransmitters and
catecholamines. Earlier studies focused on the relationship between
folate deficiency,
hyperhomocysteinemia, and
depressive disorders. Although depressive and
anxiety disorders show a common comorbidity pattern, there are few studies addressing the effect of impaired one-
carbon metabolism in
anxiety disorders - especially in
obsessive-compulsive disorder (OCD). This study aimed to measure the levels of
vitamin B12,
folate, and
homocysteine specifically in order to see if eventual alterations have an etiopathogenetic significance on patients with OCD. Serum
vitamin B12,
folate, and
homocysteine concentrations were measured in 35 patients with OCD and 22 controls. In addition, the Structured Clinical Interview for the Diagnostic and Statistical Manual for
Mental Disorders, Fourth Edition, Text Revision, Yale-Brown Obsessive Compulsive Scale, Hamilton Rating Scale for Depression, and Hamilton Rating Scale for Anxiety were conducted for each patient. It was found that
vitamin B12 levels were decreased and
homocysteine levels were increased in some OCD patients.
Homocysteine levels were positively correlated with Yale-Brown compulsion and Yale-Brown total scores. In conclusion, findings of this study suggest that some OCD patients might have
vitamin B12 deficiency and higher
homocysteine levels.