Unidentified cause of psychic obsessive-compulsive disorder identified

Obsessive-compulsive disorder triggered by lack of protein?
Many people suffer from obsessive-compulsive disorder, such as the need to constantly wash their hands or to arrange the items in the household always in a certain way. Scientists at the Julius-Maximilians-Universität Würzburg have now discovered a possible cause for the occurrence of such obsessive-compulsive disorder. "If a molecular pathway in the brain region of amygdala is too strongly activated, it can lead to obsessive-compulsive disorder," according to the Würzburg University.

Obsessive-compulsive disorders often seem like a harmless tick to other people, but can lead to significant impairments in everyday life. They are massively restricted by the obsessive thoughts and compulsive actions and not infrequently also show physical consequences. The research team led by Professor Kai Schuh from the Physiological Institute of the University of Würzburg has now identified a missing protein as a possible cause of obsessive-compulsive disorder in a recent study. The study was published in the journal "Molecular Psychiatry".

Although thorough hygiene is generally appropriate, in some people the fear of dirt and germs leads to a washing compulsion that they can not resist. (Image: Alexander Raths / fotolia.com)

Foundations of obsessive-compulsive disorder studied
Some people are very afraid of dirt and pathogens, which causes them to wash, explains the scientists. They always wash their hands or their bodies, but after washing, the fear of new dirt comes back quickly. "Those affected can no longer find a way out" and "they can not change their behavior even when skin irritation or wounds have already appeared through the many washings", according to the Würzburg University. The research team led by Prof. Schuh has now investigated the basics of obsessive-compulsive disorder and discovered a molecular pathway as possible.

New therapy options are in demand
According to the researchers, around two percent of the population suffer from obsessive-compulsive disorder at least once in their lives. The compulsive thoughts, which are compensated by recurring, ritualized acts of compulsion, usually result in significant impairments in everyday life. They are often treated with antidepressants - similar to depression, eating disorders and other psychiatric illnesses. However, the effect of the drugs "is non-specific, so not tailored to the causes of the disease," explain the scientists. Therefore, new treatment options are needed that have a more targeted effect and fewer side effects.

Single protein with far-reaching influence
The prerequisite for new therapeutic options is a better understanding of the basics of obsessive-compulsive disorders. Therefore, the researchers from Würzburg used a mouse model to investigate which signaling cascades at the molecular level have an influence on the development of obsessive-compulsive disorder. In their experiments, the researchers were able to prove "that only a lack of the protein SPRED2 can cause an excessive cleanliness behavior," reports Prof. Schuh. The protein SPRED2 occurs in all cells of the body and occurs particularly concentrated in the brain - in the basal ganglia and the amygdala region.

Special signal path overly active
Normally, according to the researchers, the SPRED2 protein inhibits an important cell signaling pathway. If the protein is missing, the so-called Ras / ERK-MAP-kinase cascade is discharged with a higher activity than in the normal case. This in turn triggered an excessive cleanliness behavior in the mouse model. "It is above all the brain-specific initiator of the signaling pathway, the receptor tyrosine kinase TrkB, which is increasingly active here and causes the overshooting reaction of the downstream components," says biologist Dr. Melanie Ullrich in the press release of the University of Würzburg. This finding also opens up new treatment options, because with an inhibitor, the overly active signal cascade in the animal model was calmed down, which led to a reduction of the compulsive acts.

Possible drug already available
The study results are particularly significant because so far no clear trigger for obsessive-compulsive disorder has been identified, the researchers report. The combination of obsessive-compulsive disorders with the Ras / ERK-MAP-kinase signaling cascade revealed for the first time, according to the researchers, new therapeutic approaches. "Because there are already drugs that inhibit this cascade and some of which are approved for the treatment of humans," report Prof. Schuh and colleagues. The corresponding drug is actually a cancer drug, since the overactivation of the Ras / ERK-MAP-kinase cascade often also forms a trigger of cancer, said Dr. med. Melanie Ulrich. Now it must be clarified, "whether such drugs also act against obsessive-compulsive disorder and whether they bring benefits in terms of side effects." (Fp)