Research suggests that OCD involves problems in communication between the front part of the brain and deeper structures of the brain. These brain structures use a neurotransmitter (basically, a chemical messenger) called serotonin.
Obsessive compulsive disorder, or OCD, is an anxiety disorder which, like many anxiety disorders, is marked by low levels of serotonin. Serotonin, a type of neurotransmitter, has a variety of functions that make a deficiency a serious and anxiety producing issue.
Brain structure and function
Studies show that OCD patients have excess activity in frontal regions of the brain, including the orbitofrontal cortex (OFC) and anterior cingulate cortex (ACC), which could explain their intrusive thoughts and high levels of anxiety, respectively.
Combined this evidence suggests that OCD may be associated with both increased and decreased dopamine signaling, or that a unidirectional model may not be adequate.
Three brain areas – the orbitofrontal cortex (OFC), the anterior cingulate cortex (ACC), and the head of the caudate nucleus – have been consistently implicated in a large number of resting, symptom provocation, and pre/post-treatment studies of adults with OCD.
A consistent pattern emerged from the combined data: Compared with healthy volunteers, people with OCD had far more activity in the specific brain areas involved in recognizing that they were making an error, but less activity in the areas that could help them stop.
Is OCD Caused by a Chemical Imbalance? Changes in the neurochemical serotonin, as well as in the neurochemicals dopamine and glutamate, are likely present in OCD. Indeed, medications like the antidepressants known as selective serotonin reuptake inhibitors (SSRIs) improve symptoms for many people.
Researchers have found that obsessive-compulsive disorder (OCD), an anxiety condition, is linked to low levels of serotonin. Serotonin, a hormone/neurotransmitter, performs a variety of functions in the body, which is why a serotonin deficiency can lead to anxiety-provoking OCD symptoms.
Studies have shown that women with OCD are likely to have abnormal hormone levels and that these hormones play a role in triggering or worsening the condition.
Preclinical, neuroimaging and neurochemical studies have provided evidence demonstrating that the dopaminergic system is involved in inducing or aggravating the symptoms that are indicative of OCD.
We found that patients with OCD exhibited a deficit in mentalizing ability (cognitive empathy) compared to the control subjects.
In the United States, about 2.2% of the population will experience OCD sometime during their lives. Rates of OCD were found to be higher with women (1.8%) than men (0.5%). Childhood OCD has a stronger genetic link than adult-onset OCD, with up to 65% having a genetic link.
Etiology: Biological Models. Many investigators have contributed to the hypothesis that OCD involves dysfunction in a neuronal loop running from the orbital frontal cortex to the cingulate gyrus, striatum (cuadate nucleus and putamen), globus pallidus, thalamus and back to the frontal cortex.
Both the systematic review and meta-analysis suggest that cortisol levels are significantly higher in OCD patients than healthy individuals.
OCD is due to genetic and hereditary factors. Chemical, structural and functional abnormalities in the brain are the cause. Distorted beliefs reinforce and maintain symptoms associated with OCD.
Researchers know that OCD is triggered by communication problems between the brain's deeper structures and the front part of the brain. These parts of the brain primarily use serotonin to communicate. This is why increasing the levels of serotonin in the brain can help to alleviate OCD symptoms.
Compulsive behaviors related to OCD likely derive from a similar imbalance in the dopaminergic reward system. Perhaps continuous activation of the ventral striatum creates an undirected expectation for reward. The unfulfilled expectation causes an anxious feeling and an urge to satisfy the void.
It's an important scientific insight, but it's not a diagnostic test. The fact is, the vast majority of the time, a brain scan in someone with OCD looks completely normal.
Can OCD lead to brain damage? OCD fundamentally changes the brain, showing a significant reduction in grey matter density in some regions. In severe cases, this can permanently change how the brain works for patients with OCD. However, most people can lead normal and happy lives with therapy and medication.
Around the ages of 10 to 12 years, the first peak of OCD cases occur. This time frequently coincides with increasing school and performance pressures, in addition to biologic changes of brain and body that accompany puberty.
Of 10 155 persons with OCD (5935 women and 4220 men with a mean [SD] age of 29.1 [11.3] years who contributed a total of 54 937 person-years of observation), 110 (1.1%) died during the average follow-up of 9.7 years.
People with OCD often report a lack of confidence in their ability to make decisions or recall events correctly. It has been suggested that people with OCD may have an impaired ability to rely on the past.