People prone to depressive states and chronic stress have a significantly higher risk of developing Alzheimer’s disease and other forms of dementia
Because this is not just about feeling terrible, apathy, or not wanting to get out of bed.
Even a short-term rise in stress hormones can temporarily affect memory and lower performance on cognitive tests.
But when these states become chronic, it is already a deep biochemical process in the brain and body — one that stimulates the production of free radicals and inflammatory processes in the brain.
The problem is made worse by the fact that when people talk about treating depression, the first thing that comes to mind is antidepressants.
Imagine this: depression, which is itself a risk factor for developing dementia, is “treated” with antidepressants — while some of these drugs may themselves increase the risk of triggering medication-induced dementia.
More on this in the article about medication-induced dementia.
A vicious circle
Stress itself is not harmful.
More than that, it is an essential part of survival, because it pushes the brain and body into action.
Chronic stress is a completely different story.
With prolonged stress, the brain is exposed to toxic effects at the biochemical level.
And often, the problem is that depression and chronic stress, once they settle in, do not simply leave on their own.
They go deeper and take memory, speed of thinking, and joy in life with them.
I am sure that if people understand how long emotional lows destroy intelligence, it will become a reason for each of them to return to a resourceful state faster.
So first, I will explain.
How the Structure of the Brain Changes During Chronic Stress and Depression
Destructive processes accelerate. Cognitive abilities decline, memory worsens, and the ability to think clearly suffers.
Cortisol and the Destruction of the Hippocampus
Cortisol is the stress hormone.
We need it to survive in extreme situations, but when stress is chronic, cortisol simply does not have time to leave the body.
And it is toxic to the brain, especially to the hippocampus — the area responsible for memory and learning.
Under the influence of cortisol, the hippocampus can even shrink in volume.
Neurotransmitter Deficiency
Depression lowers the levels of serotonin, dopamine, and acetylcholine.
These chemical compounds regulate mood, the ability to remember new information, and learning.
A deficiency of these substances causes “cognitive slowing” — the feeling that the brain works like an old laptop that keeps freezing.
Homocysteine and Inflammation of the Brain’s Blood Vessels
During depression and stress, homocysteine levels rise.
Homocysteine is an amino acid that damages the walls of the brain’s blood vessels and causes inflammation.
Poor vessels = poor blood flow.
The brain receives too little oxygen and too few nutrients, and that leads straight to where you already understand.
Free Radicals and Mitochondrial Damage
An excess of corticosteroids, a group of stress hormones, increases the production of free radicals.
They, in turn, damage mitochondria — the energy stations of brain cells.
Less energy for neurons means a higher risk of neurodegeneration.
Why Depression and Chronic “Dormant” Stress Happen
These are far from only the traditionally psychological causes: childhood trauma, loss, chronic conflicts — internal and external — and so on and so forth.
So what other causes can there be?
- Physiological: disrupted neurotransmitter metabolism, hormonal imbalances.
- Genetic: if someone in the family suffered from depression, the risk is higher.
- Lifestyle: isolation, lack of physical activity, poor nutrition, lack of sleep.
What to Do? 4 Strategies That Work
It is not worth fighting depression and chronic stress by relying only on medication, therapy sessions, or sitting for hours in the lotus position.
There are four strategies that create “anchors” for your brain:
- Sleep: normalizes serotonin and lowers cortisol.
- Physical activity: increases dopamine, endocannabinoids, and BDNF.
- Low-carbohydrate nutrition: supports serotonin synthesis and reduces inflammation.
- Cognitive load: normalizes activity in the amygdala.
Each of these factors works as part of a single system that supports psychological comfort.
At the same time, they work synergistically: they help increase BDNF levels, normalize the HPA axis, and increase neurotransmitter synthesis.
Sleep
Sleep is the foundation.
Quality sleep stabilizes emotional regulation, reduces the stress response, and restores cognitive functions.
Chronic lack of sleep is associated with an increased risk of depression and anxiety.
Biochemical processes
- Normalization of neurotransmitters: serotonin is the precursor of melatonin, which controls circadian rhythms. Lack of sleep disrupts this process, worsens emotional regulation, and increases the risk of depression.
- Regulation of stress hormones: quality sleep lowers cortisol levels and restores balance in the hypothalamic-pituitary-adrenal axis, the HPA axis, which regulates the stress response.
- Stimulation of neuroplasticity: during deep sleep, or NREM sleep, synapses are restored and BDNF, brain-derived neurotrophic factor, increases. BDNF supports neuroplasticity and the growth of new neurons.
Restoring damaged neural circuits helps reduce vulnerability to depressive states and stress.
Training / Sport
Regular physical activity has an antidepressant effect that is comparable in effectiveness to antidepressants.
Exercise reduces anxiety and increases resilience to stress.
Biochemical processes
- Increased neurotransmitter synthesis: physical activity supports serotonin and dopamine synthesis and release, and increases norepinephrine, improving concentration and cognitive abilities.
- Stimulation of the endocannabinoid system: the popular myth about “endorphin euphoria” is outdated. In reality, the feeling of “runner’s high” is caused by endocannabinoids, such as anandamide.
- Normalization of cortisol levels: moderate physical activity lowers cortisol and normalizes the work of the HPA axis. Excessive training can increase cortisol, but after recovery its level drops.
- Stimulation of neuroplasticity, BDNF: physical activity, especially aerobic exercise, increases BDNF production, improving the growth and strengthening of neural connections, especially in the hippocampus.
Food
The quality and quantity of substances that come in with food directly affect mental health.
Deficiency of key nutrients, such as omega-3 fatty acids and B vitamins, increases the risk of depression and anxiety.
Biochemical processes
- Neurotransmitter synthesis: the brain cannot synthesize neurotransmitters “out of thin air.” It needs amino acids, vitamins, fatty acids, and minerals, which we receive from food. Tryptophan is the precursor of serotonin. Tyrosine is the precursor of dopamine.
- Omega-3 fatty acids: omega-3, especially DHA, regulates the function of serotonin receptors and reduces inflammation in the brain. Omega-3 deficiency is associated with an increased risk of depression.
- Antioxidants and vitamins: B vitamins, including B6, B9, and B12, take part in homocysteine metabolism. Antioxidants, such as vitamins C and E, protect the brain from oxidative stress.
Cognitive Load
Mental exercises — learning, reading, solving problems — help increase stress resilience and reduce depressive states.
Biochemical processes
- Stimulation of neuroplasticity: cognitive load increases BDNF levels, which supports the formation of new synapses and neurons, especially in the hippocampus. Neuroplasticity increases resilience to stress and depression.
- Regulation of the amygdala: mindfulness practices reduce activity in the amygdala, lowering anxiety and fear. These changes improve emotional regulation.
- Reduction of cortisol levels: cognitive exercises reduce cortisol levels and decrease hyperactivity of the HPA axis.