EXPERTS Q&A

Your brain does more than think—it also mirrors how your emotions rise and fall from one day to the next.

A new University of Michigan study suggests that the way people manage information in their minds—combined with how and when they went through puberty—can shape daily patterns of stress, anxiety and low mood well into adulthood.

The federally funded research, which appears in the Journal of Affective Disorders, followed participants’ emotions daily for 100 days, capturing a real-time panorama of emotional ups and downs. Unlike traditional mental health studies that rely on a single survey snapshot, this approach revealed how distress and anxiety fluctuate in everyday life—and how those fluctuations differ from person to person.

The study found that emotions don’t occur in isolation. Instead, daily distress is filtered through both cognitive skills, such as working memory—the brain’s ability to hold and use information—and earlier biological and social experiences, especially puberty. Together, these factors helped explain not just how distressed people felt on average, but how stable or volatile their emotions were over time.

Patterns also differed by gender, according to the findings. Women who matured later than their peers and had strong working-memory skills showed the lowest overall distress and the greatest emotional stability, while men who matured earlier and had weaker working memory experienced the largest swings in anxiety and distress across the 100 days. 

Two of the study’s co-authors—Natasha Chaku, a University of Michigan postdoctoral researcher now an assistant professor at Indiana University, and Adriene Beltz, a U-M psychology professor—discuss what these findings reveal about adult mental health.

Why did you choose to track people’s emotions every day for 100 days (vs. one year) instead of using a traditional one-time mental health survey?

Chaku: We decided to track people’s emotions every day for 100 days because emotions can vary a lot from day to day and a single survey can’t capture those changes. One-time surveys only give a snapshot of how someone remembers feeling, usually aggregated over a relatively long period of time like “the last two weeks,” which can be biased or inaccurate. Frequent, daily assessments let us capture more time-locked emotions as people go about their everyday lives. 

Beltz: In this study, we specifically tracked daily negative emotions like distress. This allowed us to measure a unique aspect of distress—its fluctuations, or how much it changes from day-to-day. Our past work has shown that lability (mood swings) in negative emotions and depressive symptoms is important. For instance, think about how you might plan a meeting with a co-worker or friend who has consistently high negative emotions (low fluctuations) versus how you’d plan that meeting with a co-worker or friend who has seemingly unpredictable negative emotions (high fluctuations). 

Your study shows that puberty timing can influence emotional patterns well into adulthood. How should adults think about early life experiences when reflecting on their current mental health?

Chaku: Puberty isn’t just a childhood milestone; it has long-lasting effects on health and well-being. Adults should understand that the ways in which their bodies mature and change during adolescence as well as when those changes happened, the context in which they happened, and how they coped with those changes may have set them on paths that have long-term effects on how they deal with, and interpret, stress as adults. 

Beltz: Here’s an example: Girls go through puberty before boys, on average. That means the earliest maturing girls are the first of all their peers to experience puberty, and many of the changes they experience are visible to others. Upon seeing those changes, others may interact differently with them—ranging from their parents to their older classmates. If those early maturing girls spend time with older classmates, then they may be treated in ways or participate in activities that they may not be cognitively prepared for, including sexual activity and substance use. Those experiences and activities can end up characterizing their adolescence, and having life consequences that last well beyond it.

Chaku: Crucially, though, those early life experiences don’t determine adult mental health, as daily distress is influenced by many other biological, psychological and social factors, too. 

Beltz: Absolutely, puberty is just one piece of the mental health puzzle for some people.

Were there moments in the data that challenged assumptions about gender, emotional resilience or mental health stability?

Beltz: I suspected that our findings would center early-maturing girls and late-maturing boys. The scientific literature shows over and over again that they are unfortunately at risk for negative mental health experiences, especially the ones we measured in this study (aspects of distress, anxiety and depression) because they experience puberty on their own. Because girls generally mature before boys, early maturing girls are the first of all their peers to experience the changes of puberty, and late maturing boys are the last of all their peers to go through puberty. Thus, the social experiences surrounding puberty are often most dramatic for those teens. Instead, the data told a different story—one about late maturing girls and early maturing boys. This is likely because we focused on understanding what influences negative emotion fluctuations (not just levels of negative emotions as in the vast majority of the literature).

Chaku: Yes. Like Dr. Beltz, I expected there to be more associations between pubertal timing and average levels of distress and anxiety because of past findings in the literature. But the majority of our findings (with the exception of general distress) concerned symptom fluctuations. Examining symptom fluctuations is rare and even though puberty and working memory have both been linked with mental health, it wasn’t clear that either would be associated with changes in symptoms over days. It was also interesting that puberty qualified associations between working memory and daily symptoms. In other words, working memory was only associated with symptom fluctuations in adults who matured early or late. That suggests that symptom fluctuations depend on a combination of factors including aspects of cognitive ability (e.g., working memory) and developmental processes (e.g., pubertal timing).

What do the emotional “ups and downs” you measured actually look like in daily life—for example, at work, relationships or handling pressure?

Beltz: What we call “ups and downs” are changes from day-to-day in general distress, anxiety and the lowness of depression. For example, most of our findings concerned general distress, and that would look like worry, irritability and self-blame being different from one day to the next, sometimes drastically so. We also found daily changes in anxiety were meaningful for men, focusing on the physical symptoms of stress, such as chest tightness and heart racing. 

The study’s other co-authors were Ran Yan and Chelsea Kaplan of U-M, and Katherine Foster of the University of Washington.

The investigation was supported in part by the National Institutes of Health grant UL1TR002240 (Beltz); Rachel Upjohn Clinical Scholars award from the U-M Eiisenberg Family Depression Center (Beltz); and a Strategic Translational Research award from the U-M Eisenberg Family Depression Center (Chaku).