[Solved] What are the contraindications for the use of psilocybin?

The use of psilocybin — as applied in a psilocybin session or truffle ceremony — requires careful medical and psychological screening. Although many people benefit from psychedelic therapy, there are clear contraindications where use is advised against or even excluded. Below is an overview of the main risks, supported by both scientific sources and insights from Triptherapie.

1. Psychiatric history
Individuals with a personal or family history of psychotic disorders such as schizophrenia, schizoaffective disorder, or bipolar disorder type I are at increased risk of exacerbation or triggering of psychosis. Recent severe substance dependence (alcohol or drugs) can also negatively affect safety and outcome. Therefore, people with this background are usually excluded from participation in a truffle session or other psilocybin guidance (source).

2. Cardiovascular and neurological disorders
Psilocybin temporarily increases heart rate and blood pressure, which can be risky for people with untreated or severe cardiovascular disease such as arrhythmias, previous heart attacks, strokes, or severe hypertension. Epilepsy and other neurological disorders are also contraindications due to the risk of seizures (source).

3. Medication interactions
Various medications can have dangerous interactions with psilocybin. This applies particularly to:

• MAO inhibitors (e.g. tranylcypromine), which increase the risk of serotonin syndrome.
• Tricyclic antidepressants (TCAs such as amitriptyline), which can block or enhance the effects of psilocybin.
• Lithium, which can lead to severe seizures in combination with serotonergic psychedelics.
  Participation in psychedelic sessions is prohibited when using these substances. not allowed without medical coordination and tapering (source).

4. Special population groups
Pregnant women and breastfeeding women are excluded due to a lack of safety data. Minors are also generally not eligible, because brain development continues well past puberty and the long-term effects of psilocybin on young brains are insufficiently known.

Summary
A psilocybin session is not suitable for people with:

• Psychotic disorders (personal or in the family)
• Serious heart or brain conditions
• Recent severe addiction problems
• Use of contraindicated medication such as lithium or MAO inhibitors
• Pregnant or breastfeeding women
• Minors

At Triptherapie, all clients are therefore screened in advance via a mandatory intake form, so that safety, effectiveness, and suitability can be properly assessed. This ensures that your psychedelic journey — if you are suitable for it — becomes a safe and healing experience.

The contraindications for psilocybin are indeed of great importance and must be taken seriously. The existing lists are fundamentally correct, but more nuance is needed from both neuropharmacology and clinical practice.

Psychiatric contraindications

Psychiatric contraindications are often misunderstood in the public debate. Schizophrenia and type I bipolar disorder are clear contraindications, but it is not as black and white as “ever had psychosis = never psilocybin”. There are subtle gradations.

Risk of psychosis: Psilocybin acts primarily via 5-HT2A receptors, leading to increased thalamic input and cortical desynchronization. This can exacerbate psychotic symptoms in people with a vulnerable predisposition. Nevertheless, individuals with mild depressive or anxious traits, without a personal or family history of psychosis, have a significantly lower risk than is often assumed. Moreover, studies, such as that by Hopkinset al., demonstrate that careful screening and preparation can further reduce the risk.

The distinction between a is also important acute psychosis and psychotic traits. People with borderline personality disorder (BPD) may experience brief pseudopsychotic symptoms under stress, but this is fundamentally different from a primary psychotic disorder. BPD is indeed a risk factor for psilocybin use, but primarily due to the potential destabilization of self-image. Ego dissolution in BPD can reinforce existing identity diffusion, which can be psychologically disruptive.

Cardiovascular contraindications

Psilocybin can increase blood pressure and heart rate, but the underlying mechanism is more nuanced than often thought. The drug does not act primarily sympathomimetic (like adrenaline), but causes:

1. Vasoconstriction via 5-HT1B/D receptors in blood vessels
2. Increased emotional arousal with sympathetic activation
3. Possibly increased endothelin-1 production

Therefore, someone with well-controlled hypertension (for example, 140/90 mmHg on medication) must be assessed differently than someone with untreated high blood pressure. The general contraindication “hypertension” often fails to adequately address this nuance. With Triptherapie, this is carefully screened for; psilocybin is not automatically unsafe in these cases.

Epilepsy

Epilepsy is not a uniform condition. Photosensitive epilepsy, in which flashes of light can trigger a seizure, has a different risk profile than temporal lobe epilepsy. Psilocybin can increase cortical excitability, which could theoretically trigger a seizure, but the actual risk varies significantly by subtype.

Medication interactions

This is one of the most important but often underestimated areas.

Lithium: The combination with psilocybin is often considered dangerous. Lithium affects multiple neurotransmitter systems, and theoretically, this could lead to serotonin syndrome. However, to date, there are no documented cases in the clinical literature. The possibility exists, but the actual incidence is unknown.

SSRIs and SNRIs: This is where the large gray area lies. In various therapeutic studies (such as at UCSF), patients continue to use their SSRIs. Although an SSRI inhibits serotonin reuptake, in practice, psilocybin often appears to be less potent in this group, presumably due to receptor downregulation. The combination is generally not dangerous, but it is less effective.

MAO inhibitors: This combination is indeed downright risky. MAO inhibitors block the breakdown of serotonin, which means psilocybin can lead to a longer and stronger trip. 

Other medical points of attention

1. Liver disease: Psilocybin is primarily metabolized in the liver via the MAO-A enzyme. In liver cirrhosis, this can lead to accumulation and prolonged action.
2. Kidney disease: Less relevant, because psilocybin is not renally cleared, but fluid and electrolyte balance remain important.
3. Hyperthyroidism: Not an absolute contraindication, but the increased metabolism and heart rate can exacerbate symptoms.
4. Diabetes: Neither is it a direct contraindication, but prolonged fasting prior to a session can disrupt blood sugar levels.

Timing after medication tapering

After stopping antidepressants, some receptors remain dysregulated. Research suggests that a waiting period of at least two weeks after tapering off SSRIs or SNRIs is advisable to allow the serotonergic receptors to resensitize. This can make the difference between a stable and a risky experience.

Pregnancy and breastfeeding

These are rightly absolute contraindications. Psilocybin crosses the placenta, and its effect on fetal neurogenesis is unknown. Use during pregnancy or breastfeeding is therefore advised against.

Psychological screening and preparation

Psychological preparation is at least as important as the medical screening. Someone with unresolved trauma can enter an acute dissociation under psilocybin. This is not immediately medically dangerous, but it can cause significant psychological damage. Therefore, intake interviews, in which both medical and emotional stability are assessed, are essential.

Conclusion:
Standard contraindication lists are valuable as a first filter, but their practical application requires medical and psychological expertise. Not every contraindication automatically implies an absolute ban. Many risks do not arise from psilocybin itself, but from interactions with pre-existing conditions, medication, or insufficient preparation. A professional intake and guidance make the difference between risk and safety in this regard.