⚠️ This is not medical advice. If you or someone you know is struggling with depression, please seek professional help.
What depression is — and what it is not
People feel sad. Many of us go through dark phases — periods when life seems pointless, joy disappears, and even getting out of bed feels hard. This, too, is part of being human. Most of us find our way through this crisis. We grieve, we struggle, and eventually we recover.
But for some, the crisis does not pass. The sadness does not lift. What was a phase becomes a permanent state — a heaviness that never leaves. An absence of joy that persists for weeks, months, years. A daily, exhausting struggle just to keep functioning, to maintain the appearance of a normal life.
That struggle drains everything. And when all strength is spent, when the weight becomes unbearable, death can begin to look not like an end — but like a release.
Depression is not a bad mood, and it is not weakness. It is an illness — as real as a broken bone, but invisible, and therefore far too often dismissed. Many people with depression want exactly what everyone else wants: to get up in the morning, go to work, laugh with friends, and feel present in their own lives. Often, that is precisely what they cannot do. It is a disability of the mind — wanting without being able to.
Every case is unique — yet three groups?
Every case of depression is different. Every person carries their own history, their own chemistry, their own darkness. But in trying to understand and treat this illness, it helps to think in broad categories — not because they are precise, but because they reveal something important about where we stand and where we might go.
Classification is a tool, not a truth. It helps researchers and clinicians navigate complexity — not by capturing every individual case, but by revealing patterns that guide treatment. No classification can do justice to a single person’s experience. But without some orientation, it is easy to lose your bearings — especially in unfamiliar terrain.
Very loosely — and with all the caveats that come with simplifying something as complex as the human mind — we can identify three broad groups.
The first group responds to medication. Antidepressants — SSRIs, SNRIs, tricyclics — can relieve symptoms by acting on neurotransmitter systems involved in mood regulation. The effect is not instant, not perfect, and often comes with side effects. But it works. Therapy accompanies and supports the process, helping patients understand their patterns and build resilience. For this group, the existing system functions — not flawlessly, but meaningfully.
The second group does not respond to conventional medication. The pills do little or nothing. But therapy reaches them. A skilled therapist, the right approach — cognitive behavioral therapy, psychodynamic therapy, EMDR — can make a real difference. The path is longer, harder, and demands more from both patient and therapist. But there is a path.
The third group is the one psychiatry struggles with most. These are the treatment-resistant patients. Conventional medication fails them. And therapy — no matter the method, no matter the therapist — cannot break through. The patient sits in the room, but remains unreachable. Something does not connect. Neither chemistry nor conversation finds a way in.
For decades, this third group had almost nowhere to turn. And one of the reasons lies in a political decision made half a century ago.
The War on Drugs — no war without victims
In the 1970s, the War on Drugs lumped fundamentally different substances together under one label.
On one side: opiates — heroin, morphine, and their many derivatives — with high addiction potential and a numbing, sedating effect. Substances used since antiquity to dull pain and consciousness.
On the other side: psychedelics — substances with a very different profile. They do not primarily numb or sedate. Psilocybin has been used for centuries in spiritual and ceremonial contexts, especially in Mesoamerica. LSD, while synthesized only in 1938, was derived from compounds associated with ergot (Mutterkorn), a fungus with a long and complex history in Europe.
One category tends to suppress consciousness; the other can radically alter it. Treating them as if they belonged to the same medical and social category was not just scientifically imprecise — it was also a political decision that stalled research for decades and may have delayed help for many patients.
A door reopening
After nearly half a century of suppression, psychedelic substances are being studied again with scientific rigor. The results, particularly for psilocybin, are becoming harder to dismiss.
Psilocybin, the active compound in certain mushrooms, is not a new discovery. Indigenous cultures have used psilocybin-containing mushrooms for centuries. But modern clinical trials — at Johns Hopkins, Imperial College London, the Central Institute of Mental Health (ZI) in Mannheim, and the Charité in Berlin — are producing data that is increasingly difficult to ignore.
In one of the largest and most recent studies on treatment-resistant depression — the EPIsoDE study, led by the ZI in Mannheim in cooperation with the Charité and the MIND Foundation, conducted from 2021 to 2024 — the study team reported a clinical response in about 30 percent of participants receiving psilocybin-assisted therapy. In that context, “response” means that depression scores on a standard clinical scale fell by at least 50 percent — after one or two 25 mg doses of psilocybin, embedded in psychotherapy, over a twelve-week period.
The effects range across a wide spectrum: some patients become more open and more reachable during subsequent therapy sessions — as if the wall has become thinner. Others experience a profound shift in perspective, a loosening of the rigid thought patterns that define depression. And in some cases, researchers describe a rapid and substantial reduction in symptoms that had persisted for years, sometimes after a single session.
How it works
Psychedelics like psilocybin act primarily on the brain’s serotonin system, specifically the 5-HT2A receptor. In the body, psilocybin is converted into psilocin, the compound that produces the actual pharmacological effect.
Researchers suspect that the substance strengthens connections between brain regions that normally do not communicate much, while temporarily disrupting the default mode network — sometimes described as the brain’s autopilot, or the inner narrator that, in depression, can become a relentless critic. Established patterns of information processing may loosen. For a limited window, the brain may become more flexible, making it easier to step out of rigid loops and form new associations.
The goal is not the psychedelic experience itself. It is what follows: the dissolution of rigid thought patterns, the emergence of new perspectives and insights, and — ideally — a lasting improvement in depressive symptoms.
Beyond psilocybin
Psilocybin is the most advanced in clinical research, but it is not alone. LSD (lysergic acid diethylamide), first synthesized in 1938, is being studied again — for generalized anxiety disorder and for existential anxiety in cancer patients. DMT (dimethyltryptamine) is also under investigation for treatment-resistant depression. When administered on its own, DMT can produce intense but short-lived experiences, often lasting only 15 to 30 minutes; ayahuasca, which contains DMT in a different pharmacological context, lasts much longer.
All of these are classic psychedelics. They share a common mechanism — action on the serotonin system — and a common requirement: they must be administered in controlled settings, embedded in psychotherapy, and accompanied by experienced therapists.
Not a miracle cure
For a group of patients who had been told, implicitly or explicitly, that nothing more could be done, psilocybin-assisted therapy may change that picture. It does not help everyone. But for some patients, it offers a form of hope grounded in evidence rather than wishful thinking.
The clinical protocols are careful and deliberate: the substance is administered in controlled settings, with trained therapists present, preceded by preparation and followed by integration sessions. It is not taken like an aspirin. It is a guided process — and for those it reaches, the results can be profound.
One thing is paramount in any psychedelic experience: the setting. A safe environment in which the person feels sheltered and protected is not a nice-to-have — it is essential. During a psychedelic session, a person’s state of mind can become unusually sensitive to the surroundings. This is why clinical trials insist on trained therapists, familiar rooms, and careful preparation. Without that safety, the same substance that may help can also do harm.
That said, the risks should not be understated. Improper use can trigger acute anxiety, psychotic episodes, and in rare cases lasting perceptual disturbances. People with a predisposition to psychosis should not take psychedelics. These are not substances to experiment with casually — non-medical use carries significant risks to mental health and safety.
Neither psychiatric medications nor psychedelics are harmless. Both intervene deeply in brain chemistry. But the risk profiles are very different. Conventional antidepressants — SSRIs, SNRIs, tricyclics — often come with chronic side effects: weight gain, emotional blunting, sexual dysfunction, and discontinuation symptoms; in some cases they are also associated with an increased risk of suicidal thoughts, particularly in young patients. These are not trivial trade-offs. They are burdens many patients carry, sometimes for years.
Psychedelics, by contrast, are not taken daily. They are administered in one or two sessions, under supervision, embedded in therapy. They carry acute risks — the hours of the experience itself can be intense and disorienting — but they do not produce the same chronic side-effect burden associated with daily medication. Classic psychedelics are generally considered to have low addictive potential. And when the setting is right, patients often describe the aftermath not as numbness, but as clarity.
Closing the gap
In Germany, treatment with classical psychedelics is currently only permitted within approved clinical trials at university institutions or pharmaceutical companies. The substances fall under the Narcotics Act (Betäubungsmittelgesetz) and are illegal outside of medical-scientific contexts.
There is, however, one exception. Since July 2025, the ZI in Mannheim and the OVID clinic in Berlin offer psilocybin treatment for treatment-resistant depression under a compassionate use program — a regulatory pathway that allows the use of unapproved medications for patients with severe or life-threatening conditions who have exhausted all other options and cannot participate in a clinical trial. The treatment is inpatient, strictly regulated, and based on safety protocols developed through years of clinical research.
If the results of ongoing Phase 3 studies are positive, psilocybin could receive regulatory approval for the treatment of depression in Germany within the next three to five years. In other countries, the timeline remains uncertain — progress depends not only on science but on political will, which is far less predictable.
The cost of waiting
At this point, the greatest obstacles are not only scientific. They are also political and cultural. Psilocybin remains a controlled substance in most countries. Research is advancing, but access is glacial. Patients who could benefit are waiting for bureaucracies to catch up with the evidence.
Delay has a human cost. Depression kills — through suicide, through the slow erosion of physical health, through the destruction of relationships and of a person’s ability to function. Treatment-resistant depression is not a mild inconvenience. It is an emergency.
The scientific case is becoming stronger. The question is whether society will act on it — or whether stigma and inertia will continue to outweigh suffering.
Treating the whole
Perhaps there is a broader lesson here. Modern medicine has a tendency to treat the human body like a machine — identify the broken part, fix it, move on. A pill for this, a procedure for that. This approach is efficient and measurable. But it can also miss something essential.
A human being is not a machine. Mind and body are not separate systems that merely share a chassis. They are deeply entangled. What we call “psyche” and what we call “physique” are not two different things so much as two sides of the same coin.
The promise of psychedelic-assisted therapy is not just a new drug. It is also a reminder that healing sometimes means treating the whole person — not just a symptom or a score on a scale, but a human being in all their complexity.
Much of the clinical information in this article is based on material published by the Central Institute of Mental Health (ZI) in Mannheim.