How Does Uncertainty Drive Obsessive-Compulsive Behaviors?

What you need to know

• People with OCD may have difficulty predicting how their actions will affect the world around them
• This uncertainty can lead to repetitive checking behaviors and an overreliance on habits
• The model explains diverse OCD symptoms like intrusive thoughts, sensory sensitivities, and indecisiveness
• Understanding this core uncertainty may lead to new treatment approaches for OCD

A new model of obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is characterized by intrusive, distressing thoughts (obsessions) and repetitive behaviors or mental acts (compulsions). While we know quite a bit about the symptoms of OCD, researchers are still working to understand the underlying brain mechanisms that drive the disorder.

A team of scientists has proposed a new computational model that aims to explain the diverse symptoms of OCD. At its core, the model suggests that people with OCD have excessive uncertainty about how events unfold over time, especially how their own actions affect the world around them.

This uncertainty about cause-and-effect relationships, which the researchers call “transition uncertainty,” can explain many key features of OCD:

Doubt and repetitive behaviors

One hallmark of OCD is persistent doubt, even about simple actions the person has just completed. For example, someone might check multiple times that they’ve locked their front door, even though they remember doing it.

The model explains this as resulting from difficulty predicting the consequences of actions. If you’re very uncertain whether turning the lock actually secured the door, you’ll feel compelled to check again and again.

To demonstrate this, the researchers simulated a hand-washing scenario. As transition uncertainty increased in the simulation, the “agent” (representing a person with OCD) became more reliant on sensory feedback about hand cleanliness rather than memory of having just washed. This led to repetitive washing behaviors.

Importantly, the model showed that compulsive actions can paradoxically increase uncertainty, creating a self-reinforcing cycle. This matches the real experience of many people with OCD, who find that compulsions provide only temporary relief before doubt creeps back in.

Overreliance on habits

Another feature of OCD is excessive reliance on rigid routines or habits. The model suggests this develops as a way to cope with uncertainty about goal-directed actions.

If you’re very unsure about how your actions will play out, it becomes computationally expensive to plan ahead and make decisions. It’s easier to fall back on simple, learned habits - even if they’re not the most effective behaviors.

The researchers demonstrated this with simulations of a decision-making task. As transition uncertainty increased, the simulated agent showed more perseverative, habitual responses rather than flexible, goal-directed behavior.

Indecisiveness and exploration

Interestingly, the model predicts that in some situations, transition uncertainty will lead to the opposite of habits - excessive exploration and indecisiveness.

If you can’t rely on your understanding of cause and effect, you may need to gather more information before making decisions. You might also frequently change your mind as you second-guess yourself.

This fits with the clinical picture of OCD, where patients often struggle with indecisiveness alongside rigid habits. The model provides a framework for understanding when each type of behavior is likely to emerge.

Intrusive thoughts and sensory sensitivities

Beyond compulsive behaviors, the model also accounts for the intrusive thoughts and sensory issues common in OCD.

If you have high uncertainty about how events unfold, you’ll give more weight to unexpected sensory inputs or thoughts. Things that others would ignore as meaningless “noise” become highly salient and intrusive.

This could explain why people with OCD often report being bombarded by intrusive thoughts or hyper-aware of bodily sensations. It may also relate to increased sensitivity to sounds, textures, or other sensory stimuli.

Implications for treatment

Understanding transition uncertainty as a core feature of OCD opens up new avenues for treatment. Current therapies like exposure and response prevention are effective for many patients, but don’t work for everyone.

The researchers suggest that directly targeting transition uncertainty could be beneficial. This might involve cognitive training to improve cause-and-effect learning, or medications that affect relevant brain systems.

The model also provides a framework for understanding how existing treatments work. For example, antidepressant medications may help regulate the emotional impact of uncertainty, while cognitive-behavioral therapy may increase flexibility in habits.

Conclusions

• Difficulty predicting cause-and-effect relationships may underlie diverse OCD symptoms
• This “transition uncertainty” can explain compulsions, intrusive thoughts, and indecisiveness
• The model generates testable predictions about OCD behaviors in different contexts
• Targeting transition uncertainty directly could lead to new OCD treatments

While more research is needed to test the model’s predictions, it provides a promising unified theory of OCD. By bridging neuroscience, computation, and clinical symptoms, this work takes an important step toward better understanding and treating this challenging disorder.