Obsessive-compulsive disorder (OCD) is a psychological condition characterized by repeated behaviors, such as constant washing of the hands or repeated thoughts, that the individual has little control over. These repeated behaviors – also known as “rituals” – are a result of an underlying brain dysfunction that is not yet understood.
Now, a recent study from scientists in the UK has reported the use of a mathematical model that they think helps get to the root cause of OCD. Their findings suggest that people with OCD develop an internal, accurate sense of how things work – but they do not use this knowledge to guide their behavior.
“This study shows that the actions of people with OCD often don’t take into account what they’ve already learned,” says senior author Benedetto De Martino, principal investigator of the Brain Decision Modeling Lab at University College London.
The study involved almost 50 volunteers – roughly half with OCD and half without – playing a video game in which they had to catch coin-like objects in a bucket. The important factor was that the coins only came from one area on the screen. Although both groups stated they were confident they knew where the coins were coming from, the participants with OCD would second-guess themselves and constantly move the bucket around.
These findings show the dissociation between beliefs and actions in individuals with OCD. Through measuring this degree of “uncoupling,” the researchers found that the severity of OCD symptoms can be predicted as well. “This was very surprising to me,” De Martino says. “It’s the first time anyone has been able to calculate the degree of dissociation and show that it correlates with the severity of the disease.”
De Martino’s research is focused on determining the mechanism responsible for the connection between confidence and action. His lab studies how certainty guides decision-making. For example, if you just washed your hands thoroughly, you’ll likely believe that your hands are clean. “But we suspect that in people with OCD, this link is broken,” De Martino explains. “Someone with OCD will tell you that they know their hands are clean, but nevertheless they can’t stop washing them. Two things that are normally linked together – confidence and action – have become uncoupled.”
Understanding the mechanism behind this disorder is imperative to helping those that suffer from it. This research may help lead to better diagnosis of OCD and possibly more effective treatments down the road as well.