3 Reasons You Burnout Every December
Psychologists say year-end exhaustion is common and largely preventable once you understand what's driving it.
By Mark Travers, Ph.D. | December 29, 2025
For many people, December feels like a sprint to the finish line before the calendar flips. Work deadlines, social obligations, travel plans, shopping lists and year-end evaluations all collide in a compressed emotional and cognitive space during this time. So, what starts out as a burst of excitement often leads to major burnout, which often carries into January.
This year-end burnout is not a subjective or isolated phenomenon. Research on stress suggests that it's part of a deeper, predictable stress response cycle that accumulates over time and peaks when demands before the New Year are highest. The key concepts that help explain this phenomenon are allostatic load, emotional burnout and the effects of prolonged cognitive strain. Here's how each of them affect your well-being.
1. Burnout Due To Biological 'Wear and Tear'
To understand the December burnout cycle, we first need to understand allostatic load: a term scientists use to describe the cumulative biological burden that chronic stress places on the body. Allostatic load reflects how repeated or prolonged stress responses, especially when there is insufficient recovery, can produce wear and tear on multiple physiological systems.
In a 2020 systematic review of allostatic load research, scientists reviewed hundreds of studies and concluded that allostatic overload — when stress exceeds the body's ability to adapt — is associated with poorer physical and mental health outcomes across a broad range of populations.
Every stressful demand, whether it's work pressure, emotional conflict, financial strain or social expectations, activates our stress response systems. These systems release hormones like cortisol and adrenaline to help you cope in the moment. But when stressors are constant and recovery is minimal, as they tend to be at the end of the year, this elevated activation becomes physiological "wear and tear" that eventually undermines your resilience.
In other words, your body literally collects stress effects over time. As a result, December's stacked demands can push you into a state of allostatic overload that feels like being burned out at the level of your nervous, immune and metabolic systems.
2. Burnout Due To End-Year Emotional Exhaustion
Psychologists define burnout as a psychological syndrome that emerges in response to prolonged stress, especially the kind that feels uncontrollable or unsupportive. The most widely accepted framework describes three core dimensions of burnout:
- Emotional exhaustion. Feeling drained, fatigued and unable to recover.
- Depersonalization or cynicism. Withdrawing emotionally from people or responsibilities.
- Reduced personal efficacy. Feeling less competent or effective.
Research shows that emotional exhaustion tends to build over time, especially when daily demands continue without adequate psychological or physical recovery. Many people experience this exhaustion as "not even caring anymore" — even about things that used to matter.
And December amplifies this pattern. You don't just have routine stressors; you have stacked emotional demands (holiday hosting, gift expectations or planning time with multiple social circles) and the psychological pressure of trying to "finish strong." That combination exhausts emotional reserves faster than earlier in the year.
What's especially important is that burnout is not just a feeling. It measurably affects how the brain and body function. Chronic stress and burnout affect cognitive processes such as attention, working memory and executive control, which are the very systems needed to stay organized and focused under pressure.
3. Burnout Due To Brain Fog
One of the most common complaints in late December is "brain fog." The symptoms of this condition include difficulty concentrating, making decisions, remembering details or staying mentally sharp.
Research suggests that emotional exhaustion is linked to measurable declines in cognitive performance. A longitudinal study published in Stress & Health found that emotional exhaustion, the core component of burnout, was negatively related to cognitive performance in tasks that assess attention, memory and executive functioning.
Chronic stress affects the areas of the brain responsible for these functions, including regions like the prefrontal cortex, which governs planning, focus and decision-making. When stress hormones like cortisol are elevated for too long, these systems operate less efficiently. Although the brain can adapt in the short term, prolonged activation leads to cognitive fatigue, or the sense that your mind just hasn't got "enough juice" left to manage complex tasks.
In December, the cognitive load doesn't just come from one source. It can actually stem from several places, including:
- Work deadlines and evaluations
- Social planning and obligations
- Financial decisions and lifestyle expectations
- Emotional processing related to year-end reflection
All of these compete for the same limited cognitive and emotional resources. When those resources run low, it feels like your brain is running on low power, even if you managed earlier stresses fine.
The Hidden Reason Making Your Year-End Burnout Worse
There's also a psychological component that amplifies this physical-stress cycle. At the end of the year many, people review their accomplishments, compare themselves with others and set New Year resolutions.
These reflection cycles can create a cognitive gap between reality and expectations that feels stressful. And when people perceive a mismatch between demands and their ability to cope, stress escalates and recovery becomes harder.
In theory, two people can have the same external demands, but the one who feels less in control or less supported will show stronger signs of burnout and allostatic load accumulation. This pattern is consistent with foundational stress theory and empirical studies that connect chronic stress with both emotional exhaustion and physiological wear and tear.
The good news is that research on burnout and allostatic load suggests several evidence-based approaches to interrupt this cycle:
- Prioritize recovery. Rest isn't indulgent when stress has been chronic; it's corrective. Sleep, downtime and restorative activities help your body shut down prolonged stress responses.
- Set boundaries. December often feels all-or-nothing. Reducing commitments in one area can preserve emotional and cognitive resources where they matter most.
- Support social connection. Psychosocial resources such as supportive relationships can buffer stress effects and may reduce physiological burden.
- Practice mindfulness and intentional breaks. Mindfulness practices have been shown to enhance cognitive functioning under stress and can help reset emotional reactivity.
- Reflect compassionately. Year-end reflection can be healthy, but if it becomes a comparison trap or judgment cycle, it adds to stress rather than alleviating it.
The New Year will come whether you feel ready or not. But by understanding the mechanisms behind the December crash, and taking steps to mitigate them, you can step into the next chapter with greater resilience, not just relief.
The December burnout might be the main reason behind your brain fog. Take the science-backed Brain Fog Scale to know if it's a cause for concern.
If burnout feels familiar, your instincts may be asking for rest and recalibration. Discover your symbolic guardian animal that reflects how you recover and restore your energy: Guardian Animal Test
A similar version of this article can also be found on Forbes.com, here.