Obsessive compulsive disorder (OCD) is a mental health disorder associated with persistent, intrusive thoughts (i.e., obsessions), accompanied by repetitive behaviors (i.e., compulsions) aimed at reducing the anxiety arising from obsessions. Past studies have showed that people diagnosed with OCD can present symptoms that vary significantly, as well as distinct brain abnormalities, reports MedicalXpress.

A team of researchers at the First Affiliated Hospital of Zhengzhou University recently carried out a study aimed at further exploring the well-documented differences among patients with OCD. Their findings, published in Translational Psychiatry, allowed them to identify two broad OCD subtypes, which are associated with different patterns in gray matter volumes and disease epicenters

The researchers recruited 100 individuals who had just been diagnosed with OCD for the first time and had not yet started treatment, along with 106 healthy individuals who received no psychiatric and medical diagnoses. They then used magnetic resonance imaging (MRI) to collect to collect structural imaging scans of all the participants' brains.

The results showed that the first subtype of OCD is associated with increased gray matter volume in areas of the brain involved in decision-making and emotional processing, such as the frontal gyrus and the amygdala.

The second subtype, in turn, was characterized by decreased gray matter volume in areas associated with self-referential thinking and cognitive function.

It was also found that these subtypes of OCD have different localization. The first is manifested in the middle frontal gyrus, while the second—in the corpus callosum and hippocampus. These differences may explain the differentiation of symptoms in patients with this disorder.