Researchers have found that the absence of a protein could trigger obsessive-compulsive disorder (OCD) that can lead to repetitive ritualised behaviour such as washing hands or body time and again.

"We were able to show in mouse models that the absence of the protein SPRED2 alone can trigger an excessive grooming behaviour," said Professor Kai Schuh from the Institute of Physiology at the Julius-Maximilians-Universitat (JMU) Wurzburg in Bavaria, Germany. Schuh believes that this finding is crucial as no clear trigger for this type of disorder has been identified until now. 

Previous research pointed to multiple factors being responsible for developing OCD. Occurring in all cells of the body, the protein SPRED2 is found in particularly high concentrations in regions of the brain, namely in the basal ganglia and the amygdala. Normally, the protein inhibits an important signal pathway of the cell, the so-called Ras/ERK-MAP kinase cascade. When it is missing, this signal pathway is more active than usual.

The findings could lead to new treatment for the disorder characterised by persistent intrusive thoughts.Like depression, eating disorders and other mental diseases, OCD is treated with anti-depressants. 

However, the drugs are non-specific, that is they are not tailored to the respective disease. Therefore, scientists have been looking for new and better targeted therapies that have fewer side effects.

"Our study delivers a valuable new model that allows the disease mechanisms to be investigated and new therapy options for obsessive-compulsive disorders to be tested," Schuh said.