Obsessive-compulsive disorder is characterized by two things: the unwanted and intrusive thoughts– the obsessions, and the ritual repetitive behaviors– the compulsions– which meant to somehow alleviate or reduce the anxiety and distress.

When someone is afflicted with OCD, the widely accepted theory is that three distinct parts of the brain are functioning abnormally:

  • the orbitofrontal cortex, or OFC, which sort of acts as an internal “error detection system”,
  • the anterior cingulate gyrus, or ACG, which somehow functions to govern emotional and motivational responses,
  • and the caudate nucleus, which acts as an internal gear shift of sorts, letting you carry on with your day after tasks are done.

The interesting thing is, while there are many types of OCD, and various manifestations in terms of obsessions and compulsions from patient to patient, the underlying biological cause for all cases of obsessive-compulsive disorder seems to have been isolated specifically to these distinct regions of the brain.

The Orbitofrontal Cortex

The orbitofrontal cortex, or OFC, is part of the brain’s frontal lobe and is responsible for letting you know when you’ve done something correctly, or when you’ve made a mistake.

Behavior psychologists at Oxford University have found that the OFC among rhesus monkeys would fire when the monkeys perform tasks properly and were expecting a reward (in this case, a bit of fruit juice).

At one point, scientists gave the monkeys salt water instead of the juice even when they have performed the tasks as instructed. Interestingly, the orbital cortex lit up with greater intensity and stayed lit up longer.

The conclusion: the orbitofrontal cortex is your brain’s error detection system. When it fires up, it gives you a feeling that “something might be wrong”.

The Anterior Cingulate Gyrus

When the OFC lights up, it sends a signal to another area of the brain called the anterior cingulate gyrus, or ACG.

As part of the limbic system, the anterior cingulate gyrus has many functions associated with it, including emotional processing as well as the vocalization of emotions. It is also involved in our decision-making processes, helping us plan appropriate actions and responses to the various scenario.

When the ACG is stimulated (in this case, by signals coming from the OFC), it gives you this feeling of unease that prompts you to act and do something to rectify the situation.

The Caudate Nucleus

Once you’ve corrected the mistake, a third area known as the caudate nucleus is activated.

The caudate nucleus is part of our brain’s basal ganglia, which plays an important role in various functions including procedural learning, associative learning, and inhibitory control of actions.

Activating the caudate nucleus allows the brain to switch gears, marking our tasks or actions as done, and allowing us to forget about it, and move on to other activities.

The OCD Brain

Brain scans of OCD patients show that these three key brain areas– the orbitofrontal cortex, the anterior cingulate gyrus, and the caudate nucleus– are all hyperactive or overstimulated.

What this means is the “something is wrong” feeling, and all the anxiety and worry that comes with it, are abnormally strong. This explains why even incredibly trivial imperfections or the most random thoughts would make an OCD-afflicted person feel dread or an impending sense of doom.

And even if the person does something to correct their perceived mistake, that feeling doesn’t go away, because the OCD brain simply can’t shift to the next task, greatly adding to the anxiety and distress.

OCD Can Be Treated

Fortunately, there are effective treatment protocols available for people with OCD. If you suspect you or a loved one might have obsessive-compulsive disorder, OCD Test to rule out (or confirm) your suspicions.

Work with a properly accredited OCD specialist, clinician, or therapist to get an official diagnosis. The goal is to get treatment as soon as you are able.

OCD patients who have had treatment earlier on have shown to lead relatively healthy, happy, and fulfilling lives, as they have learned to better master their obsessions and compulsions.