Rumination: the scientific name for spinning thoughts — and why the brain does it at all

In the shower in the evening you run the same film again: a conversation from three days ago, the sentence you should have phrased differently, the feeling that you’ve messed something up again. You aren’t looking for a solution — the conversation is over. And yet the thoughts keep coming back, like the tongue to a sore tooth. Why on earth does the brain do this?

Psychology has a precise name for this phenomenon: rumination. The word comes from Latin — ruminare means to chew the cud, the way a cow chews the same grass over and over. And few topics in psychology in recent decades have been researched as thoroughly: we know who ruminates more often, what rumination does to mood, to the body and to decision-making, and — most importantly — we know how it differs from healthy thinking about oneself.

In this piece I’ll go deep into that science. How rumination became a subject of research in the first place, why it isn’t the same as self-reflection, why women on average know it better than men, and what can be done about it. If you are more interested in the general picture of spinning thoughts, you’ll find it in my main piece on overthinking — here the two of us go a step further, to the mechanism itself.

The earthquake that revealed the power of brooding

The story of research into rumination is inseparable from one name: Susan Nolen-Hoeksema, a psychologist at Stanford and Yale, who in the 1980s put forward Response Styles Theory. Her idea was simple and bold: what matters is not only what happens to us and how we feel about it, but what we do with our mood once it appears. Some people respond to low spirits by turning their attention inward — “why do I feel like this, what does it say about me, what will come of it” — while others prefer to distract themselves, take action or seek company. She named the first style the ruminative response.

And then nature offered her a cruelly natural experiment. In October 1989 the strong Loma Prieta earthquake shook the San Francisco area. Nolen-Hoeksema had luck within the misfortune: only a few weeks earlier she had measured, in a group of students, their usual style of responding to distress and their mood. Ten days after the earthquake, and then again seven weeks later, she measured them once more. The result, published in 1991, became a classic: those who had already shown a ruminative style before the earthquake had markedly more depressive and stress symptoms afterwards — even once she accounted for how badly affected they were and what their mood had been beforehand. The stressful event was the same for everyone; the difference lay in what their minds did with it afterwards.

Larger longitudinal studies followed. In research with more than a thousand adults from the community, Nolen-Hoeksema (2000) showed that rumination doesn’t only prolong existing depressive episodes but predicts new ones: people who ruminated more at the first measurement were more likely, a year later, to develop a depressive episode, and had more mixed anxiety symptoms. Rumination turned out to be something like smoking in lung disease — not the sole cause, but a risk factor that can be measured in advance.

Why brooding “pays off” for the brain at all

If rumination is so harmful, why hasn’t evolution erased it? Because at its core lies something useful: the ability to return in our minds to what is unresolved. Problems that stay open deserve attention — the brain marks unfinished tasks as important and keeps returning them to consciousness until they are settled. With concrete, solvable problems this is an excellent system.

Rumination is that system, stuck. Instead of a solvable problem (“how should I open this conversation tomorrow”), attention glues itself to unanswerable questions (“why am I like this”, “why does this always happen to me”). Because there is no answer, the loop doesn’t close — and the brain obediently serves the question up again. It feels as though we are doing something: after all, we are “thinking about the problem”. Research shows the opposite. Sonja Lyubomirsky and Nolen-Hoeksema (1995) showed in a series of experiments that people in a low mood generate worse solutions to interpersonal problems after a few minutes of rumination, are more pessimistic about the future and less willing to actually carry out their (otherwise good!) solutions. Brooding behaves like problem-solving but works as its opposite — I write about that difference in more detail in my piece Thinking is not solving.

Brooding and reflection: not every thought about yourself is the same

Here comes the most important turn in this scientific story. If thinking about yourself is harmful, then what about self-reflection, journals, therapy? Aren’t all of those also “turning attention inward”?

The answer was offered in 2003 by Wendy Treynor, Richard Gonzalez and Nolen-Hoeksema, when they statistically broke down the rumination questionnaire and found two separate components within it. The first they called brooding: passively comparing your situation with an unreachable standard (“why can’t I do what others can”, “why do I react like this”). The second they called reflection: deliberately, curiously turning towards yourself with the aim of understanding (“I sit down and think through what is going on inside me”). The difference is not cosmetic. In longitudinal data, brooding predicted more depression over time; reflection was in the short term associated with slightly more low mood — looking inward is not always pleasant — but in the long term with fewer depressive symptoms. The same turn inward, two completely different outcomes.

The British researcher Edward Watkins showed in an extensive review article (2008) where the dividing line runs: in the mode of processing. Harmful repetitive thinking is abstract and evaluative — it circles around “why me”, “what does this mean”, “what if it never changes”. Constructive thinking is concrete and process-oriented — “what exactly happened”, “what can I do differently next time”, “what is the first step”. Abstract thinking generalises a difficulty into a verdict about yourself; concrete thinking takes it apart into something you can get hold of. Same topic, different angle — and in the research even a short exercise in shifting from “why” to “how” measurably changes mood and problem-solving performance.

Why women ruminate more — and what about friends

One of the most consistent findings in this field is a gender difference: women on average report more rumination than men, and Nolen-Hoeksema used this in part to explain the well-known fact that depression is about twice as common in women. But be careful — this finding calls for nuance. The difference is an average, not a destiny: a great many men ruminate and a great many women don’t. Moreover, research doesn’t attribute the difference to “female nature” but to a web of circumstances: girls are more often taught that it is their job to take care of relationships and other people’s moods, women on average carry more chronic burdens and have less sense of influence over their circumstances — and where there is less power to act, there is more room left for brooding. Men, meanwhile, more often redirect their version of spinning thoughts into work, sport or alcohol, which doesn’t look like rumination on a questionnaire, even though the inner loop keeps running.

Particularly interesting is a phenomenon the developmental psychologist Amanda Rose (2002) named co-rumination: chewing over problems together in close friendships — returning again and again to the same difficulty, encouraging each other to spin it out, circling together around feelings instead of steps forward. Her research with adolescents showed a double-edged outcome: co-rumination deepens closeness and the quality of a friendship, while at the same time raising symptoms of anxiety and depression — more markedly in girls than in boys. A conversation meant to relieve you can therefore even strengthen the loop if nothing shifts within it. This doesn’t mean you shouldn’t talk to your friends about your troubles — it only means that the difference between “we looked at it together and cleared something up” and “we’re going round the same thing for the tenth time” is the same as with brooding alone.

What rumination does to the body

Rumination is not only a mental habit — it is a physiological event too. The body’s stress response is designed for events that happen and pass. Rumination, however, prolongs the stressor: the event lasts five minutes, the brooding five hours, and all that time the body responds as though the event were still happening. Researchers call this perseverative cognition — persistent thinking as the bridge along which short-lived stress becomes a chronic burden.

A meta-analysis by Peggy Zoccola and Sally Dickerson (2012) showed that rumination after stressful events is consistently associated with higher and longer-lasting cortisol levels — the stress hormone doesn’t settle, because the brain keeps telling the body that the threat is still there. This also includes slower recovery of heart rate and blood pressure after stress, and worse sleep: brooding in the evening is one of the most reliable predictors of trouble falling asleep, which I write about in more detail in my piece on overthinking before sleep. If we add the findings on its links with anxiety — a review by Nolen-Hoeksema and colleagues (2008) connects rumination not only with depression but also with anxiety disorders, binge eating and alcohol misuse — it becomes clear why researchers today treat it as a transdiagnostic process: a common denominator running beneath different diagnoses.

How we work with rumination in therapy

The good news: because rumination is a habit of thinking and not a character trait, it can be changed. Edward Watkins and colleagues even developed a specially adapted form of cognitive behavioural therapy, rumination-focused CBT, which targets not the content of thoughts (“is this thought true?”) but the process of brooding itself: when it is triggered, what it serves, and how to replace the abstract “why” style with a concrete “how”. In a randomised trial with people who had residual depression after treatment (2011), this approach significantly reduced symptoms and relapse rates compared with usual care.

In the therapy room, though, rumination is not merely a technical problem. When I look with someone at what the brooding revolves around, a theme almost always emerges that deserves genuine attention — an unresolved relationship, an old grudge against oneself, grief that never had room. Brooding is often a way of touching a theme without really taking hold of it: we circle it because we are afraid to look at it straight on. That is why working with rumination in my practice is never just “stop brooding”, but also: what is this circle protecting? What would you feel if it stopped? It often turns out that beneath the rumination there is an emotion waiting — and once it is given room, the circle slows down by itself. A similar dynamic is described in my pieces on the inner critic and on anxious thoughts.

Five handholds for everyday use

What can you take from all this science for yourself — starting today?

• Recognise the loop by its shape, not its content. Ask yourself: is this thinking leading anywhere new, or am I visiting the same station for the third time? Turning on the spot is rumination, however important the subject is.
• Swap “why” for “what now”. Watkins’s shift from abstract to concrete: instead of “why did I react like that again”, ask “what exactly happened and what is one small step forward”.
• Give worry an appointment. Postponed worry is one of the best-tested techniques against brooding — I’ve described how it works step by step in the worry postponement exercise.
• Move your body, not just your attention. Rumination flourishes best in passivity. A walk, exercise, even tidying up interrupt the physiological state in which the loop turns — and research on behavioural activation confirms this consistently.
• In conversations, look for a shift, not just a vent. With co-rumination, you and your friend can also say: “We’ve analysed this enough — what would actually help now?”

When it’s time to get help

If brooding is taking your sleep, colouring most of your days, or has fused with listlessness and a sense that there is no way out, don’t wait for it to spin itself out — longitudinal research unfortunately shows that a ruminative style tends to entrench itself without intervention. A conversation with a therapist can be exactly the new element the loop needs in order to open: someone who doesn’t brood with you but helps you look at what is driving the circle. If you’d like to explore that with me, you can read more about individual therapy or simply write to me through the contact page.

And until then: the next time you catch yourself in the shower with the same film, don’t scold yourself — that would only be another round of brooding. Just name it: “Ah, rumination.” Even that, research shows, is the first step out of the circle: you cannot change a process until you can see it.