How Stress Becomes Anxiety and Depression

Note: The video summarized below is by a Brazilian clinical psychologist speaking in Portuguese (YouTube provides an English audio track). The content is relevant to anyone, regardless of language or country. The text here is our summary and interpretation, not an official transcript.

Stress is not the enemy

Stress is often treated as something to eliminate. It is not. Stress is an organic response — the body preparing to face a challenge or a threat. When you cross the street and see a loose pitbull, your amygdala, prefrontal cortex, and hippocampus read the situation as danger and send a signal to the hypothalamus. The hypothalamus releases CRH, which stimulates the pituitary to release ACTH, which tells the adrenal glands to produce cortisol. In parallel, the sympathetic-adrenal-medullary system releases adrenaline. Heart rate rises, pupils dilate, breathing speeds up.

This is the fight-or-flight response. It exists because our species survived because of it. We would not be here without stress.

Stress also improves performance. An athlete who enters a fight completely calm loses in seconds. A student who presents a paper with zero stress usually delivers something flat. A small amount of stress sharpens attention, mobilizes energy, and prepares the body to act.

Why stress becomes harmful

The problem is not stress itself. It is chronic stress without recovery.

The classic image is the zebra. A zebra grazing in the savannah smells a lion, triggers fight-or-flight, runs, escapes. Once the lion is gone and the zebra is safe, it reads the environment as safe, relaxes, and goes back to eating. Humans do not do this. If someone cuts you off in traffic at 6 a.m., you arrive at work and tell the story. At lunch, you tell it again. You keep releasing cortisol because your body does not know the danger is gone.

The researcher Bruce McEwen described this as allostatic overload: stress after stress, without recovery. The body reacts, cannot recover, reacts again. The healthy pattern is stress, recovery, stress, recovery. The harmful pattern is stress, stress, stress, stress.

The analogy with strength training is useful. You do not train the same muscle intensely every day. You create microlesions, then rest, eat, sleep — and the muscle grows during recovery. If you train the same group intensely every day without rest, you get injured. Stress works the same way.

What chronically high cortisol does

When cortisol stays elevated, it starts to affect the immune system. Natural killer cells — the front-line soldiers — are impaired. The production of T and B lymphocytes drops. This is why people often get sick after an intense week: when they finally relax, cortisol drops, but the immune system is also suppressed. The cold arrives.

Chronically high cortisol also interferes with insulin sensitivity, contributing to type 2 diabetes. It affects fat tissue and fatty acid release. It disturbs the feedback loop that should shut down the stress axis. Over time, the body may produce cortisol even when there is no challenge — hypervigilance, irritability, everything calling for attention. This is the road to anxiety. In other cases, the axis may exhaust itself and stop producing cortisol adequately — the road to depression.

The sequence is often described as: stress begins, becomes anxiety, and frequently reaches depression. Anxiety and depression are among the most disabling conditions worldwide. A 2022 article in The Lancet Psychiatry tracked the global burden of disease from 1990 to 2019 and found that anxiety and depressive disorders were the most disabling mental disorders in the world. In 2022, the WHO director-general stated that the main causes of the rise in anxiety and depression include stress. The pandemic did not create the problem — it revealed a hidden giant.

Why some people handle stress better

Response to stress varies. Genetics matter. Even stress during pregnancy can shape how quickly a child's stress axis is activated later. Some people respond to minimal triggers; others endure much more before reacting.

But environment matters just as much. A child who grows up with an adult who models calm problem-solving, who names emotions, who asks "what are you feeling?" instead of "just forget about it" — that child learns to identify, name, and manage emotions. A child who grows up with disproportionate reactions learns hypervigilance.

This is where the concept of stress inoculation comes in, developed by Donald Meichenbaum. The analogy is vaccination: exposure to a weakened version of the virus strengthens the immune system. With stress, small, manageable exposures build behavioral repertoire. A child who plays sports learns to win, lose, deal with frustration, and try again. A child who is shielded from all stress does not build this repertoire — and when life eventually presents a real challenge, they have nothing to draw on.

The role of the adult is not to eliminate stress but to accompany the child through it. A teacher, a coach, a parent — someone who helps the child name the emotion, accept it, and work with it. Anger, for example, can be transformed into indignation: "this is not going to happen again, what do I need to train to prevent it?" That is a skill, and it is learned.

What actually helps

Exercise is the most consistent strategy. It increases serotonin (mood, emotional regulation), dopamine (motivation), and beta-endorphins (pleasure, pain relief). It provides a useful distraction — different from scrolling, because it interrupts rumination. It improves blood flow to the brain, supports angiogenesis and neurogenesis, and increases the number of connections between neurons. It prepares the body to face daily challenges.

Sleep and diet are equally important. Good sleep hygiene — no screens one or two hours before bed, no stimulants at night, a consistent schedule — is essential. The brain cleans itself during sleep and consolidates memory. Without it, the next day starts depleted.

Meditation helps identify emotions before they become tension. Most people are not trained to name what they feel. Meditation creates a small gap between stimulus and reaction — enough to notice "I am anxious" before the body locks into tension.

Daily recovery matters too. A short walk around the block, a few minutes of contemplation, a slow meal without the phone. These are not luxuries — they are the recovery phase that prevents allostatic overload.

Screens and the modern trap

Screens are not inherently bad, but the way they are used matters. A 2025 study in the Revista Paulista de Pediatria followed adolescents aged 12 to 15 in public schools in Paraná, Brazil. Those who spent up to two hours a day on screens for recreation had baseline levels of stress, anxiety, and depression symptoms. At four hours, stress symptoms rose 25%, depressive symptoms 35%, and anxiety symptoms 25%. At more than six hours, stress rose 49%, depressive symptoms 88%, and anxiety 50%.

The mechanism is not mysterious. Blue light suppresses melatonin and delays sleep. The nervous system is hyperstimulated. Coffee, used to stay awake, blocks adenosine signaling and hides fatigue. The result is a cycle: less sleep, less recovery, more stress, more screens.

What helps is not prohibition but redirection. Family meals without television. Conversations about the day. Shared activities — sports, theater, cinema, a walk in the park. Adolescents who practice physical activity with their parents are more likely to maintain an active lifestyle in adulthood. The goal is not to eliminate screens but to reduce time and replace it with experiences that activate reward and reduce cortisol.

A Jungian reading

Analytical psychology does not speak directly of stress or anxiety. It speaks of conflict between conscious and unconscious, and of activated complexes.

A complex is a cluster of memories, emotions, and reactions organized around a theme. When something touches that theme — a word, an image, an event — the complex activates, and reactions emerge that may surprise the person.

Jung began studying this through word association tests in 1903. He would say a word and measure response time, skin resistance, heart rate, and breathing. The body responded before the person could explain why. From there, Jung developed the idea that the unconscious has its own autonomy.

In this view, symptoms are not enemies to be eliminated. They are messages. Fear of public speaking, fear of delivering a project, a feeling of inferiority — these point to something in the unconscious that wants to be seen. The work is to integrate it: to bring it into consciousness, understand it, and elaborate it. Dreams are one of the bridges, appearing in symbols that only the dreamer can decode.

The goal is not to expel discomfort but to grow through it. Challenges, threats, and anguishes are material for self-knowledge. The question is not "how do I stop feeling this?" but "what is this bringing me?"

What this means in practice

Stress is not the enemy. Chronic stress without recovery is. The path from stress to anxiety to depression is not inevitable — it depends on how the body and the environment respond.

The practical directions are not glamorous: exercise, sleep, eat well, keep a routine, name emotions, recover between challenges, reduce screen time, and build relationships that support you. None of this eliminates stress. All of it builds the repertoire to handle it.

The deeper point is that comfort is not safety. Avoiding small stressors feels good now and shrinks you later. Facing them, at a manageable level, is what makes you durable.