The Science Behind Overthinking

Have you ever been told, "You're overthinking it"? It's not just you. Even if we haven't labelled it as such, many of us have experienced overthinking. Overthinking is a term used to describe repetitive, unproductive contemplation. As thoughts could be about a variety of subjects, research has traditionally distinguished between “rumination” about the past and present and “anxiety” about the future. Regardless of the terminology we use, what we are referring to are persistent thought loops that don't seem to have an end. 

If you think you’re the only one up at night, replaying that conversation from earlier in the day, in your head—you’re not alone. We have all experienced some instances or periods of overthinking. In fact, research(https://news.umich.edu/most-women-think-too-much-overthinkers-often-drink-too-much/) suggests that 73% of 25-35-year-olds overthink. Studies(https://graziadaily.co.uk/life/real-life/women-active-brains-overthinking-study/) also show that women tend to overthink more than men do. Given that we all have a tendency to overthink, some perhaps more than others, let’s understand how our biology and psychology play a role in overthinking. 

What Is The Science Behind Overthinking?

From an evolutionary standpoint, the brain functions to encourage overthinking as a means of problem-solving. Brain chemicals like dopamine, adrenaline, serotonin, and cortisol participate in initiating and sustaining these cyclical loops of thoughts. Simply put, dopamine is a chemical associated with reward and motivation. 

Adrenaline is a stimulator, serotonin is “the feel-good hormone” and mood regulator, and cortisol is the stress hormone. Dopamine promotes the notion of problem-solving and hence initiates the loop in an effort to reward the brain. When you're striving to solve the problem, adrenaline is released as a source of energy, and you become pumped. The mind loop is augmented by serotonin as new options are emerging. When the loop produces no effects or solutions, serotonin is blocked, and cortisol is released. Cortisol causes a stress response and unhealthy rumination is brought on by this. 

Overthinking may present as “rumination” about the past or “anxiety” about the future. Two groups of neural networks in the brain play an important role in regulating experience: the Default Mode Network (DMN) and the Direct Experience Network. When our attention wanders while we are engaged in a routine task, the default network is activated. It engages in brooding, imagining, and planning. It tends to shift thoughts or consider experiences or reflections from the past or future. When you are not considering the past or the future, the direct experience network is active. When you are completely mindful of the present moment, you are living in the now. For instance, when you feel the water striking you in the shower or the bristles of your toothbrush on your teeth. 

While some degree of overthinking is common to us all, excessive rumination or worry can significantly impact our minds and bodies. 

Types Of Overthinking

Overthinking shows up in distinct patterns. Overgeneralising stretches one bad moment into a sweeping rule,  a missed deadline becomes “I always fail,” turning a single slip into destiny. Catastrophising fast-forwards to the worst-case scenario; a strange car noise becomes an unaffordable repair and looming disaster. All-or-nothing thinking insists on extremes: if the outcome isn’t perfect, it’s worthless, with no space for gradual progress. 

Automatic negative thoughts (ANTs) are snap, involuntary judgments like “I’ll never be good enough” after a small mistake; they feel factual in the moment despite thin evidence and keep attention glued to threats.

These styles often stack. You might overgeneralise after a small error, catastrophise the fallout, and then write off the whole day because it wasn’t flawless. The result is a loop of doubt, indecision, and anxiety that drowns out nuance and slows decisions.

Recognition is the first interrupt. Label the pattern, test the thought against evidence, and look for a middle ground between “disaster” and “perfection.” These patterns behave like habits or reflexes, so they take practice to unlearn, but with awareness and repetition, they loosen their grip, and your inner dialogue becomes more balanced. The aim is to think more helpfully.

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What Causes Overthinking?

Overthinking has multiple roots, some internal and some situational. It often co-occurs with anxiety and depression, particularly generalised anxiety disorder (GAD), where everyday events trigger persistent, excessive worry. Trauma can prime the nervous system for hyper-vigilance; the mind then overanalyzes as a coping strategy to regain a sense of safety and control. Personality and belief factors matter too: perfectionism sets unrealistically high standards and harsh self-judgement, while low self-esteem fuels second-guessing and fear of being judged. And acute or chronic stress loads the mind with unfinished concerns, making rumination more likely.

These influences often interact. Mounting stress can erode resilience, amplifying perfectionistic tendencies, which then spiral into anxious forecasting. Pinpointing the drivers helps you match solutions — from therapy for trauma and anxiety to skills like cognitive restructuring, boundary-setting, and practical stress management — so the habit of overthinking loosens its grip and decision-making becomes calmer and clearer. 

How Does Overthinking Affect Mental Health? 

Overthinking is associated with depression and anxiety. A study conducted by researchers from the University of California, San Diego found that people who overthink tend to ruminate about their problems more than those who don't. They also had higher levels of anxiety and depression. In fact, rumination—the repetitive thought process—is one of the leading factors in developing chronic depression. Rumination can also exacerbate feelings of shame, guilt, and worry as they cause a false perception of things going wrong, even when they aren’t. 

Overthinking often presents a common symptom of anxiety, and it's not uncommon for people who experience anxiety to analyse their situation in great detail before they can make decisions or take action. This can cause more anxiety as they struggle with their thoughts, which then leads back to overthinking—and so on. This cycle of overthinking may create an endless loop of self-doubt or negative thought patterns that can be incredibly challenging to cope with. 

Signs And Symptoms Of Overthinking

Here are some signs that you might be thinking too much: 

1. You can’t think about anything else: If you begin and end your day with a worry on your mind, you’re likely overthinking. These intrusive thoughts might consume you to the point that they interfere with work and relationships.
2. You’re focusing on things you can’t control: Sometimes the success or failure of your decisions can hinge on factors outside your locus of control. If you’re overthinking, you might focus on these elements and refuse to finalise choices until you find a way to dictate the outcome, which is an impossible task.
3. You’re second-guessing your decisions: After you’ve made a decision, overthinking may cause you to feel overwhelmed with self-doubt about whether you made the right choice. You may also dwell on the potential consequences of a wrong choice.
4. You feel mentally exhausted: Overthinking creates a negative feedback loop that saps your mental energy. You might feel like you’re cycling through potential options and their outcomes, leaving you feeling anxious and unable to decide.
5. You can’t relax: If you’re prone to overthinking, you might feel significant stress and experience tension throughout your body. You may notice your jaw clenching and your shoulders tightening. These symptoms could also interfere with your sleep. 

The short-term effects of overthinking can build over time, creating long-term consequences that affect your physical health, mental health, and overall well-being.

How To Stop And Overcome Overthinking

The first step is awareness, noticing when your thoughts spiral and asking yourself whether they’re helpful or harmful. Practical strategies include setting aside “worry time” to contain anxious thinking, practising mindfulness to focus on the present, and writing down your thoughts to create distance from them. Simple grounding activities, such as deep breathing, walking, or journaling, can also calm racing thoughts.

If overthinking is linked to deeper issues like anxiety or depression, therapy can be highly effective. Cognitive Behavioural Therapy (CBT), for example, teaches skills to identify distorted thoughts and replace them with healthier ones. Over time, these strategies help you reduce stress, improve decision-making, and build resilience against future thought spirals.

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Frequently Asked Questions

Is overthinking genetic?

There is no single “overthinking gene,” but genetics can influence personality traits like anxiety sensitivity, which make someone more prone to overthinking. Combined with life experiences and environment, these inherited traits may increase vulnerability to rumination and excessive worry.

Does overthinking need therapy?

Not always. Occasional overthinking is normal, but if it interferes with sleep, decisions, or well-being, therapy can help. Approaches like Cognitive Behavioural Therapy (CBT) provide practical tools to challenge unhelpful thought patterns and reduce excessive worry.

How to deal with overthinkers?

Supporting an overthinker requires patience and empathy. Encourage them to talk openly, gently redirect unhelpful spirals, and suggest grounding activities. Avoid dismissing their concerns; instead, validate their feelings while reminding them that not all thoughts require action.

What is the biggest problem for overthinkers?

The biggest challenge is paralysis. Overthinkers often struggle to act because they’re caught in endless loops of doubt and “what ifs.” This can delay decisions, drain energy, and heighten stress, creating a cycle that is hard to break without intentional strategies.

Can overthinking be serious?

Yes. Chronic overthinking can contribute to mental health conditions such as anxiety and depression. It can also affect physical health, leading to fatigue, headaches, or sleep disturbances. If persistent, it may require professional intervention.

Do overthinkers have a high IQ?

Not necessarily. Some research suggests a link between analytical thinking and higher intelligence, but overthinking is more about anxiety and worry than intellect. Intelligent people may overanalyse, but being an overthinker is not proof of high IQ.

Can overthinking cause anxiety?

Yes, overthinking and anxiety often reinforce each other. Excessive rumination creates stress, which activates the body’s fight-or-flight response, intensifying anxious feelings. This feedback loop can worsen both anxiety and overthinking if left unaddressed.

What happens when you overthink too much?

Constant overthinking can drain mental energy, disrupt sleep, and impair focus. It heightens stress hormones like cortisol, which may affect physical health over time. Prolonged overthinking can also damage self-esteem and increase vulnerability to anxiety and depression.

If you are seeking help for overcoming overthinking or for your mental health, we encourage you to talk to a professional. For every step of the process, we are here for you.