Obsessive Compulsive Disorder (OCD) affects 2-3% of the population. OCD is characterized by the appearance of repeated, persistent, unwanted and often anxiogenic ideas or images, on average around the age of 20 (around 14 in 25% of cases). These obsessions are often accompanied by repetitive behaviours that are supposed to neutralize the anxiety and anxiety that result from the obsessions, the compulsions. OCD is considered a disease of behaviour, thinking and emotion. Approximately one third of patients with OCD have had or are still having ICTs.
Psychological Mechanisms of OCD
The psychological mechanisms of tocs are fairly well known and identified. The majority of obsessive compulsive behaviours are linked to irrational fears about danger or risk to oneself or others. The notion of responsibility or even guilt for what might happen is permanent in patients, they are too invested in their own safety and that of others.
These fears lead to recurrent, unwanted and highly anxiogenic obsessions, thoughts or images in the patient, and most concern the dramatic consequences of possible errors in the patient’s behaviour or actions in terms of accident or death.
Most OCD patients are aware that their obsessions are unrealistic but are unable to escape them.
Compulsive ritual mechanisms of OCD
In order to alleviate or eliminate these obsessions, patients set up compulsive ritual mechanisms, which must be carried out precisely. Irrational fear of contamination by viruses or bacteria, for example, can lead to excessive repetitive behaviours in OCTs, such as washing hands for a minimum of 2 hours a day or showering according to a very precise protocol, soaping 17 times each armpit, 20 times each foot starting with the right and starting the ritual again from the beginning at the slightest mistake or if one loses count.
These rituals can result in the patient devoting more than 8 hours per day, leading to social disruption, loss of employment and social suffering.
Working, eating and meeting other people are very difficult activities. Taking the example of driving a car, some patients have to retrace their steps 20 times to be sure that they have not killed anyone on the way and have to check in several media outlets over several days that no accident has taken place at the time of their trip.
Again, as with obsessions, most OCD patients are aware that they will not die of an infection unless they know 17 times each armpit, but the need to perform these rites is irrepressible to calm their anxiety and fear.
These obsessive compulsive behaviours trap patients in a vicious circle, the obsession leads to a ritual, which once carried out generates new obsessions.
From a more scientific perspective, this behavioral dysfunction appears to stem from what researchers call “pervasive doubts,” which are probably due to a breakdown in the control of the uncertainty involved in decision-making.
At Paris Brain Institute
The “Neurophysiology of repetitive behaviors” team, led by CNRS researcher Eric BURGUIERE, aims to identify the brain dysfunction that causes pathological doubt and to understand why and how repetitive behaviors appear and become “automated.”
Using a translational approach in experimental models and OCD patients, and using brain imaging, the team’s researchers have demonstrated the essential role of two brain regions in this pathology.
The orbital-frontal region is involved in the development of the pervasive doubt that causes repetitive checking behavior, while deeper brain regions called “basal ganglia” are more involved in managing emotions.
The objective of this research team is also to understand how the activity of neurons in these regions is disrupted in obsessive compulsive disorders.
Using Functional Magnetic Resonance Imaging (fMRI) and Magnetoencephalography (MEG) recordings, researchers have shown that neuronal activity in these areas of the brain is greatly increased in OCD patients.
fMRI is a brain imaging technique that measures the activity of neurons in areas of the brain that are called upon when a person performs a task such as reading, moving a limb or looking at images by measuring the increase in blood flow in those areas.
MEG can also be used to measure brain activity during a spot by measuring the electromagnetic field emitted by active neurons.
One of the hypotheses to explain this hyperactivation of these brain regions is based on a disturbance of the levels of neuromediators (molecules indispensable for the passage of information from one neuron to another) such as serotonin, dopamine and still vasopressin.
