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  • New research investigates how idle time can spur rumination (a key symptom of depression) in some people.
  • Thought pattern differences emerged between those with high and low tendencies to ruminate.
  • When left alone for 10 minutes, people prone to ruminating had more thoughts that were negative, self-oriented, and focused on the past.
  • Ruminators also had longer negative thoughts and shorter positive thoughts.
  • Researching wandering thoughts can improve our understanding of mental health, informing treatments and coping methods.

The thoughts that arise when we’re left alone are an important part of our inner world. They help shape our experience of ourselves and the world around us.

Researchers still aren’t sure how thoughts arise and unfold over time despite the importance of wandering thoughts.

New research published by Scientific Reports in September 2021 sought to learn more by studying how the rumination process unfolds during distraction-free idle time for different people.

Analyses showed that just 10 minutes of idle time was enough to capture the brooding process and that some — but not all — people started ruminating in this time. Some key differences emerged between the thoughts that arose for high-ruminators and low-ruminators.

The findings emphasize the importance of taking healthy mental breaks, offering future implications for diagnosing and treating mental health conditions like depression.

Some people find it easier to be alone with their thoughts than others. Rumination — the tendency to become fixated or stuck on particular, often negative, thoughts — is one challenge that can arise. This thinking style is linked with mental health conditions, including depression.

Researchers at the University of Arizona recorded and analyzed more than 2,000 thoughts from 78 undergraduate students. Each subject was instructed to voice their thoughts aloud for 10 minutes while seated alone in a room free of distractions.

“We were interested in exploring how brooding arises and unfolds during unprompted breaks,” said study co-author Jessica Andrews-Hanna, PhD, an assistant professor in the Department of Psychology at the University of Arizona, in an interview with Psych Central.

“Breaks are thought to be an important way to strengthen our memories, improve our attention, and reduce our stress.”

Participants who scored higher on a rumination questionnaire — labeled as having “high trait brooding” — expressed more negative, self-focused, and past-oriented thoughts during 10-minute sessions.

People with high trait brooding had more negative thoughts than positive ones, with negative thoughts becoming increasingly more narrow in topic over time. They also had longer negative thoughts and shorter positive thoughts.

Not everyone experiences brooding, however. Most participants in the study spent 10 minutes of idle time thinking about the present or the future in a neutral manner.

Some subjects even said their creativity flourished during the downtime and that a break from the busyness of the world felt healthy and productive.

“We gained real-time access to participants’ inner thoughts as they occurred and were able to look at the content and dynamics of those thoughts and their relation with particular outcomes,” lead author Quentin Raffaelli, a graduate student in the Department of Psychology at the University of Arizona, told Psych Central.

The findings, according to the researchers, have implications for the decline in mental health during COVID-19. “We saw a steep rise in depression and anxiety [during lockdowns], paralleling a lot more idle time on our hands,” Andrews-Hanna said.

People with depression are more likely to experience ruminative thinking in their downtime.

The negativity bias — our tendency to fixate more on negative versus neutral or positive stimuli — is also more common among people with depression.

“It’s not only what we think about that matters, but also the manner in which we think about it,” said Raffaelli. “Having negative thoughts is a normal aspect of life, but remaining stuck with those thoughts for extended periods of time is unhealthy.”

Research in the default mode network (DMN) shows that this region of the brain is active during rumination. The DMN seems to play a role in the process of turning our thoughts, attention, and emotion inward.

“We’re interested in understanding how the default mode network supports the different types of thoughts that emerge when people take breaks,” Andrews-Hanna said.

“We hope to be able to distinguish different brain network patterns that support healthy versus unhealthy forms of thinking, and ultimately target unhealthy thinking styles with therapies that work to rebalance the brain.”

Ruminative thinking is often linked to past-oriented thoughts, but that doesn’t mean happiness and contentment exist only in present-oriented thinking.

“One may feel a sense of being present while experiencing thoughts about a different timeline,” Raffaelli explained. “This relates to the notion of being mindful of the thoughts that arise, whatever they are.”

Mindfulness teaches us how to observe ourselves in the present moment without judgment, which can help diminish maladaptive thought patterns. Observing a thought about a past event while remaining grounded in the present is less likely to have a negative effect. Some people use meditation for depression symptoms.

“The more we can stay in the present moment, the more we can avoid rumination,” Melissa Shepard, MD, a board certified psychiatrist based in Charlotte, North Carolina, told Psych Central.

“When we focus on the past, we often focus on negative things that occurred or what we wish had been different,” Shepard said. “Feelings of regret and helplessness can make us feel like we have less control over what happens in the present, which can contribute to depression.”

Taking short breaks throughout the day to let your mind wander can be a positive or negative experience — depending on your mental well-being.

Those prone to ruminative thinking are more likely to get trapped in cycles of negative thoughts about themselves and their past, while others might find downtime to be creative and productive.

But taking a mental break to voice your thoughts can also be therapeutic, according to the new research.

“This was an exciting unanticipated aspect of our study, and it supports some exciting literature on the power of labeling one’s emotion and journaling,” said Andrews-Hanna. “Perhaps we could all afford to talk to ourselves more often.”