This model proposes that the biological cause of OCD is a hyperactivation of the frontostriatal circuitry, which leads to exaggerated concerns about danger, hygiene and harm[2]. This theory is supported by 3 main lines of evidence: first, disruptions or polymorphisms in the glutamate system (yet to be determined) may lead to a hyperexcitatory effect of glutamate[1-3]; second, increased concentrations of dopamine may result in higher levels of activated of D1 receptors, which will consequently overactivate the direct pathway[3]; third, a hypersensitisation of the 5-HT1B receptor may lead to a decrease in serotonin levels and a subsequent impairment in the communication within the circuit, which would explain why some SSRIs improve OCD symptoms[3]. Nonetheless, there is still a lack of evidence to support this model. The precise genetic causes are yet to be determined, and larger studies and replications are needed.
…show more content…
Its basis is that the unwanted cognitive intrusions (unpleasant thoughts and images) found in OCD are experienced by most people in the general population[1, 2]. While healthy individuals regard them as meaningless events, OCD patients appraise them as real threats posed by the individual, leading to an obsession and, consequently, a compulsive behaviour to avoid any harmful events associated with the intrusion[1, 2]. An example would be an image of stabbing their own child. While most people would just ignore it, some might think that the intrusion will lead to them losing control and actually carrying it out. This appraisal leads to stress and anxiety, and motivates the person to suppress the intrusion (for example, by replacing the image with a pleasant one) and to prevent any harmful events that may arise from the intrusion (e.g., by avoiding all knifes and constantly checking the safety of the child)[1,
Its basis is that the unwanted cognitive intrusions (unpleasant thoughts and images) found in OCD are experienced by most people in the general population[1, 2]. While healthy individuals regard them as meaningless events, OCD patients appraise them as real threats posed by the individual, leading to an obsession and, consequently, a compulsive behaviour to avoid any harmful events associated with the intrusion[1, 2]. An example would be an image of stabbing their own child. While most people would just ignore it, some might think that the intrusion will lead to them losing control and actually carrying it out. This appraisal leads to stress and anxiety, and motivates the person to suppress the intrusion (for example, by replacing the image with a pleasant one) and to prevent any harmful events that may arise from the intrusion (e.g., by avoiding all knifes and constantly checking the safety of the child)[1,