Study Uncovers What Drives Compulsive Behavior

A new study is challenging long-held beliefs about what drives compulsive behavior.

In the research, scientists observed that certain rats continued performing repetitive actions even after those actions no longer produced a reward. Traditionally, such behavior has been viewed as a breakdown in self-control — a so-called “habit loop” in which actions become automatic and difficult to stop.

But the new findings suggest the process may be more complex.

According to ScienceDaily, researchers at the University of Technology Sydney discovered that inflammation in a key decision-making region of the brain actually made the rats’ behavior more deliberate — not more automatic. The change was linked to astrocytes, star-shaped support cells in the brain that multiplied during inflammation and disrupted nearby neural circuits.

The results suggest that some compulsive behaviors may stem from excessive or misdirected control rather than a simple loss of control. In other words, the brain may be overthinking actions instead of running on autopilot.

Compulsive behavior refers to repetitive actions a person feels driven to perform, often against their own wishes or best interests. These behaviors can persist even when they no longer provide satisfaction or reward and are commonly associated with conditions such as obsessive-compulsive disorder, addiction, and certain eating disorders. Millions of people worldwide are affected.

For years, scientists believed compulsive behaviors — such as repeated hand-washing or gambling — became ingrained habits that occurred automatically without conscious decision-making. Neuroscientist Laura Bradfield noted that brain imaging studies have shown inflammation in the striatum, a region involved in action selection, in people with compulsive disorders.

To explore the link, researchers induced inflammation in the same brain region in rats. The outcome surprised them. Instead of becoming more habit-driven, the animals became more thoughtful in their choices.

"Surprisingly, the animals became more goal-directed and continued to adjust their behavior based on outcomes, even in situations where habits would normally take over," said Bradfield.

The team traced the effect to astrocytes. When inflammation was triggered, these support cells multiplied and interfered with nearby circuits that regulate movement and decision-making.

The findings could open new avenues for treating compulsive disorders. Researchers suggest that therapies targeting astrocytes or reducing brain inflammation may offer potential benefits. Lifestyle strategies known to reduce inflammation — such as regular exercise and improved sleep habits — may also play a supportive role.

"Our findings offer a new explanation for these behaviors, which goes against the accepted view. Based on this, it's possible that new treatments and interventions can be developed that more effectively treat these diseases and disorders," said Bradfield.