You're pushing hard and still burning out. Your genes may be the reason.

Your COMT gene controls an enzyme that breaks down the stress hormones epinephrine and norepinephrine, plus dopamine and other neurotransmitters. Think of it as your nervous system’s off switch. After a threat passes, COMT quiets your alarm system so you can rest and recover.

If you carry the slow variant (Val158Met homozygous), roughly 25% of people with European ancestry do, your nervous system stays activated much longer after a stressor ends. Your stress hormones linger in your bloodstream. Your heart rate stays elevated. Your mind stays in alert mode. You feel wired even when you’re sitting still.

Over months or years, this constant low-level activation drains your adrenal glands and your willpower. You feel perpetually on edge. You can’t fully relax even on vacation. Your fatigue is partly nervous system fatigue. You’re exhausted not from overwork alone, but from never really switching off.

FKBP5 codes for a protein that sits on your cortisol receptors and helps your body turn off the stress response once the danger has passed. It’s part of your HPA axis feedback loop, the mechanism that brings cortisol back down to baseline.

When you carry the rs1360780 variant, present in roughly 30% of the population, this feedback mechanism becomes sluggish. Your cortisol spikes normally when you encounter stress, but it doesn’t drop back down as quickly as it should. A minor frustration or work setback that would leave most people’s cortisol back to normal in a few hours can leave yours elevated for hours or even days.

You notice this as a lingering sense of dread or agitation after a stressful meeting. Your nervous system feels stuck in second gear. Nights are hard; you replay the day obsessively. And over time, chronically elevated cortisol accelerates burnout, impairs your immune system, and makes it harder for your body to recover from anything.

SLC6A4 codes for the serotonin transporter, the protein that recycles serotonin back into nerve cells so it can be used again. Serotonin is your mood buffer, your resilience chemical. Under chronic stress, serotonin availability drops, and without it you become more vulnerable to mood collapse and emotional flatness.

If you carry the 5-HTTLPR short allele variant, roughly 40% of people carry at least one copy, your cells recycle serotonin less efficiently. This means your available serotonin pool depletes faster under sustained stress. You feel the burnout hit differently: not just tired but emotionally numb, unable to find pleasure in things you normally enjoy, more reactive to minor setbacks.

You may notice that your mood deteriorates suddenly once work stress hits a certain threshold. You lose your ability to bounce back emotionally. Small frustrations feel overwhelming. Motivation evaporates not gradually but in a cliff-like drop. This is the serotonin pattern of burnout.

MTHFR controls the enzyme that converts dietary folate and B12 into their active, methylated forms. Your cells depend on these methylated forms for producing energy (ATP), synthesizing neurotransmitters, and managing inflammation. Without efficient MTHFR function, all three of these processes slow down.

If you carry the C677T variant, present in roughly 40% of people with European ancestry, your enzyme runs at only 60-70% efficiency. You can eat a perfect diet rich in greens and B vitamins and still be functionally B-vitamin depleted at the cellular level. Your mitochondria produce less ATP. Your neurons produce less serotonin and dopamine. Your body struggles to manage the inflammatory load of chronic stress.

You experience this as a deep, unrelenting fatigue that doesn’t respond to more sleep or better nutrition. You may also notice brain fog, slow recovery from workouts, and mood instability. The problem is not your work ethic or your sleep habits. It’s that your cells are running on a fraction of the energy they should be.

BDNF codes for brain-derived neurotrophic factor, a protein that supports the growth and resilience of neurons under stress. When stress hits, BDNF helps your brain adapt, learn from the experience, and recover emotionally. It’s your neuroplasticity gene.

If you carry the Met66 variant, roughly 30% of people do, your brain produces less BDNF, particularly under stress conditions. This means your nervous system has a harder time bouncing back from chronic pressure. Your brain becomes less adaptable. You feel stuck in negative thought patterns. Recovery from burnout takes longer because your brain’s natural repair mechanisms are weaker.

People with this variant often report that recovery from workplace stress feels slower and harder than it seems to be for colleagues. Burnout hits you deeper. It takes longer to feel like yourself again. You may struggle more with rumination or negative self-talk during high-stress periods.

SOD2 codes for manganese superoxide dismutase, an enzyme that sits inside your mitochondria and protects them from oxidative damage. Your mitochondria are your cells’ power plants. Chronic stress generates free radicals that damage mitochondrial DNA. SOD2 is your mitochondria’s first line of defense.

If you carry the Val16Ala variant, roughly 40% of people with European ancestry do, your mitochondrial antioxidant protection is roughly 40% less efficient. Over time, oxidative damage accumulates inside your mitochondria. They produce less ATP. Your cells become progressively more fatigued. Stress depletes them faster than normal mitochondria can recover.

You experience this as an energy deficit that feels cellular rather than psychological. You may notice that even light activity leaves you wiped out for hours afterward (post-exertional malaise). Your recovery from stress is slow. Your baseline energy feels lower than it should be despite adequate sleep and nutrition.