So far, studies have shown that there is clear difference between glutamate levels in individuals with OCD and those without the disorder. Researchers believe that this difference in levels may contribute to the obsessive and compulsive behaviors found in OCD.
One such study focuses on a glutamate transporter gene called SLC1A1. This particular gene regulates the flow of glutamate in the brain. “Variations in the gene might lead to alterations in that flow, perhaps putting a person at increased risk of developing OCD" (Gavin, 2006). This gene is the only one that has been consistently linked to OCD.
The most compelling evidence, thus far, supporting the role of glutamate in OCD comes from researchers at the Ruhr University in Germany. Here, they studied the cerebrospinal fluid (CSF) of individuals with OCD and compared it to that of healthy individuals. The findings revealed that glutamate levels were higher in those with OCD (Bloch, Coric, & Pittenger, 2010).
Numerous other studies have been conducted that reveal higher levels of glutamate in OCD patients. They have included the use of SPECT scans, PET scans, and fMRI imaging; each time showing more concentrated levels of glutamate.
Other methods of research include using glutamate-modulating agents which reduce the amount of glutamate that is released in the brain. These medications have been shown to reduce OCD symptoms in clinical trials, thus supporting the hypothesis that high levels of glutamate are related to OCD.