So far the causes of Obsessive Compulsive Disorder (OCD) have not been completely understood. But recently an OCD research paper has been published on Nature magazine and it suggested that OCD may be due to a malfunction of a gene which codes for a protein involved in synapse function. What is a synapse? As we know, brain contains millions of neurons and glia cells. Synapse is a specialized structure that one neuron is used to connect to another neuron. In another words, synapse is an important structure for neuron-to-neuron communication. If something wrong with synapses, the whole neural network will not function properly. If you are interested in knowing the causes of Obsessive Compulsive Disorder, you may like reading the full article at the provided link above.