Serum Claudin-5, but not Zonulin, May Be Associated with Obsessive-Compulsive Disorder

The aim of this research was to assess serum zonulin and claudin-5 concentrations to show whether or not their eventual changes in patients with obsessive-compulsive disorder (OCD) could have etiopathogenetic importance. There was no research in the literature assessing serum zonulin and claudin-5 levels in OCD to the best of our understanding.

In this study, we assumed that there may be a deterioration in serum zonulin and claudin-5 levels in OCD patients and this may affect the severity of the disease. Thirty-six OCD patients and 35 healthy controls were included in this study. The patients were administered Hamilton Depression Rating Scale (HDRS) and Yale-Brown Obsession Compulsion Scale (Y-BOCS) to determine the severity of depression and OCD, respectively. Venous blood samples were collected, and serum zonulin and claudin-5 levels were measured.

The mean serum claudin-5 level was significantly higher without a significant difference between age, sex, and body mass index, whereas serum zonulin level was not different from the control group in OCD patients.

In conclusion, the current research indicates that claudin-5 is enhanced in OCD patients and this finding may contribute to the role of blood-brain barrier in the pathogenesis of OCD.