MAR 21, 2017 5:16 AM PDT

OCD Patients Have Trouble Perceiving Safe Situations

Obsessive Compulsive Disorder, or OCD, is a debilitating neurobiological condition where a person is driven to do things in a very rigid way, often being unable to deviate from a set routine. It can present with intrusive thoughts and an irrational need to perform behaviors again and again, beyond what is necessary. In some cases it manifests in constant hand washing, anxiety over events that are not stressful to most people and a need to have things arranged in a very particular way. If people who have OCD are not able to control their environment, the resulting anxiety and stress can be disabling.  In some cases it can make just going about a normal day exhausting. It affects men and women equally and as much as 2% of the population will deal with it at some point. It is far beyond someone being “finicky” or “difficult.”

One form of therapy that patients with OCD often undergo is exposure therapy.  The goal in this kind of therapy is to place the OCD patient in a situation where they must confront and experience the stimuli that triggers their fear and stress. For instance a patient may have to touch a dirty sink or other surface and not be allowed to immediately wash up. While some patients have success with this approach it’s not uncommon for the disorder to surge up again when the patient is stressed by other events. Two recent studies from the UK could explain why this re-training and exposure approach doesn’t always stick.

In the first bit of research, scientists at Cambridge’s Behavioural and Clinical Neuroscience Institute tested 43 OCD patients and 35 similar but healthy volunteers. The study was designed to see if people diagnosed with OCD could learn that a situation is perfectly safe, even if they perceive it as stressful and frightening,  The study examined the differences in “threat learning” and “safety learning.” In people who have no mental health issues the process of learning what is safe and what is dangerous goes on without disruption. The same does not seem to be the case in those who have OCD. The ability of the brain to see a situation as safe is impaired in these patients.

Volunteers in the study underwent functional MRI studies, while being shown different colored (red and green) faces. In some cases they received a mild electric shock, causing them to learn which faces posed no threat and which would cause a shock and consequently were remembered as dangerous. Later in the study the faces that initially came with the shock were swapped with the ones without. OCD patients had difficulty learning which faces were non-threatening in the first part of the study, they simply could not adequately grasp the concept of safety.  After the swap, the OCD patients were unable to distinguish which faces were dangerous and which were safe. Neurotypical patients did not have this difficulty and were able to re-learn the differences when the images and shocks were swapped.The scans showing brain activity confirmed this. In OCD patients the activity in the ventromedial prefrontal cortex, an area of the brain that processes threats and safety, was reduced

The second study, also at Cambridge University, looked at “cognitive flexibility” which is the ability to process thoughts appropriately. This work showed that communication between areas in the brain across neural pathways may be impaired in patients with OCD. This disrupted connectivity could be responsible for the rigidity of routines that shows up in some cases of OCD. Professor Trevor Robbins, who is the Head of Psychology at Cambridge was the senior author on both papers and explained, “When we look at this two studies together, we can see that there is a clear imbalance between key regions at the front of the brain in people with OCD. These may underlie some of the symptoms of inflexibility that we commonly see in patients with this condition.” The video below explains in more detail.

Sources: University of Cambridge New Scientist  Proceedings of the National Academy of Sciences  Journal Biological Psychiatry National Anxiety Foundation 

About the Author
Bachelor's (BA/BS/Other)
I'm a writer living in the Boston area. My interests include cancer research, cardiology and neuroscience. I want to be part of using the Internet and social media to educate professionals and patients in a collaborative environment.
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