The term psychedelic (Greek: psykhē “mind” and dēloun “make visible, reveal”) was coined by British psychiatrist Humphry Osmond in 1956. Broadly speaking, it refers to the subjective experience induced by psychoactive substances or certain practices (e.g. meditation, yoga, breathwork) that result in altered perception, changes in cognition and emotion, increased introspection and alterations in sense of self. However, the term psychedelic may be interpreted in a number of ways depending on context and culture. 

Psychedelic drugs are a class of psychoactive substances that are capable of inducing non-ordinary states of consciousness with profound alterations in perception, cognition and emotion. Psychedelic drugs are present in the natural world (plants, fungi, animals) or may be the product of chemical synthesis. One common distinction that is made with regards to psychedelic substances is between classical psychedelics and atypical psychedelics, which differ both in terms of pharmacology and the subjective effects they produce.

Classical psychedelics primarily target the brain’s serotonin system (most notably the 5-HT2A receptor) and are most commonly associated with the “archetypal” psychedelic experience, which may include geometric visual distortions and transformative/mystical experiences. Most classical psychedelics are studied for a range of psychiatric disorders and for their neurobiological effects.

Atypical psychedelics are similarly able to induce profound alterations of consciousness, but do so by different pharmacological mechanisms (e.g. Ketamine, Salvia divinorum). 

Classical psychedelics primarily target the brain’s serotonin system, most notably the 5-HT2A receptor. Examples of classical psychedelics include:

Lysergic acid diethylamide (LSD): a potent semi-synthetic psychedelic originally derived from ergotamine, an alkaloid of the parasitic fungus ergot that infects wheat and rye. It was first synthesized in 1938 at Sandoz laboratories by the Swiss chemist Albert Hoffmann, although he only discovered its psychedelics effects five years later on April 19th, 1943. LSD was used in clinical practice during the 1950s and 1960s, and is currently being studied for the treatment of mood disorders and addiction. 

Psilocybin: a naturally occurring compound found in certain species of mushrooms and sclerotia (truffles), belonging to the family Psilocybe. Their use in religious and spiritual practices by indigenous people in Central and South America presumably dates back thousands of years. When consumed, psilocybin is rapidly metabolized to psilocin, which is the primary psychoactive compound responsible for its psychedelic effects.

N,N-Dimethyltryptamine (DMT): a potent psychedelic compound that occurs naturally in a variety of plants and animals. When smoked, vaporized or administed intravenously, DMT can induce relatively short but extremely profound visionary experiences lasting 10 to 15 minutes. DMT is also the major psychoactive component in ayahuasca, a plant-based brew that is used in traditional South American shamanic practices.

Mescaline: a naturally occurring psychedelic compound found in several species of cacti, including Peyote and San Pedro. The substance has been used for religious and spiritual purposes by various indigenous American cultures for centuries. While the previously discussed classical psychedelics are classified as tryptamines, mescaline belongs to the chemical family of phenethylamines. 

Examples of atypical psychedelics include:

3,4-Methylenedioxymethamphetamine (MDMA): a synthetic compound which primarily produces its effects by increasing the levels of serotonin and dopamine in the brain. While originally synthesized in 1912, MDMA was rediscovered in 1976 by pioneering chemist Alexander Shulgin, who recognized its therapeutic potential. MDMA is currently being studied for the treatment of post-traumatic stress disorder (PTSD), showing promising results.

Ketamine: a synthetic dissociative anesthetic which has been used in medical care since the 1960s, primarily for the purpose of sedation during surgery. Its primary mechanism of action is the blocking of NMDA receptors, leading to altered sensory perception and dissociation from one’s environment. Ketamine has shown promise as a rapid-acting treatment for treatment-resistant depression. It has been approved for this purpose in several countries, including the Netherlands.

Ibogaine: a naturally occurring psychoactive substance found in the root bark of the Tabernanthe iboga shrub, which is native to Central and West-Africa. It is traditionally used in shamanistic rituals by the Bwiti tribes of Gabon. Ibogaine’s mechanism of action is complex and not fully understood, although it is known to act on the serotonin, dopamine and NMDA receptor systems in in the brain. It has shown promise as a treatment for addiction and withdrawal of opioids. 

Salvinorin A: a potent, naturally occurring substance which is found in the leaves of the Salvia divinorum plant, which is native to Oaxaca, Mexico. It is pharmacologically distinct from most psychedelics, being a highly selective agonist for the kappa-opioid receptor. When smoked, Salvinorin A has been shown to produce highly intense but short-lived alterations of consciousness, including dramatic alterations of time and space. Its mechanism of action and potential therapeutic applications are currently under investigation.

Psychedelics can produce intense and unpredictable psychological effects that can be distressing or even traumatic for some individuals. This can include feelings of anxiety, paranoia and confusion, as well as experiences of ego dissolution and depersonalization. Additionally, there is a risk of harm associated with the behavior changes that can occur during a psychedelic experience. For example, individuals may become disoriented or lose their inhibitions, which could lead to accidents or risky behaviors.

Finally, psychedelics can have physical side effects such as nausea, vomiting, and increased heart rate and blood pressure. In rare cases, they may also trigger a psychotic episode or exacerbate underlying mental health conditions. It is important to note that the risks associated with psychedelics can vary widely depending on the individual, the drug, the dose, and the setting in which they are used. We do not recommend the use of psychedelics without the guidance of a trained professional.

Most psychedelics are not considered to be physically addictive, meaning that they do not produce the same type of physical dependence that is associated with substances like opioids or alcohol. However, it is possible to develop a psychological dependence on particular substances, particularly if they are used frequently. The use of psychedelics can be risky in individuals with a history of substance use disorders, as they may be more vulnerable to developing problematic patterns of use or experiencing negative consequences. 

Microdosing refers to the practice of taking sub-perceptual doses of a psychedelic substance (e.g. LSD, psilocybin) every few days or on a regular schedule, typically for the purpose of improved mood, increased creativity, productivity or general well-being.

Although microdosing has significantly increased in popularity in recent years, its effectiveness remains a topic of much debate. While anecdotal evidence suggests microdosing has a range of potential health benefits, studies tend to show inconsistent results. Moreover, there is a lack of large-scale, randomized controlled studies on microdosing. Many studies that have been conducted so far have been relatively small, self-reported and subject to various biases, which limits their generalizability.  

This remains one of the fundamental and most debated questions in psychedelic science.

As of yet, there is no definitive answer. However, in recent years several different different models and theoretical frameworks have been formulated to explain how psychedelics produce their subjective effects.

Note: this overview is highly simplified and incomplete, and different proposed models may not be mutually exclusive.

1. Serotonin 2A receptor binding

One of the most consistent and widely accepted findings is that classical psychedelics bind to the 5-HT2A receptor. This receptor subtype is widely distributed in the neocortex and is involved in a variety of physiological and psychological processes including mood regulation, perception, cognition and sensory processing. Its modulation is believed to be responsible for alterations in perception, cognition and emotion, although the exact mechanism remains unclear.

2. Default Mode Network disruption

Another hypothesis suggests that psychedelics work by disrupting the default mode network (DMN), a brain network that is active during self-referential thinking and mind-wandering. The DMN is thought to be responsible for generating a sense of self, which some choose to refer to as the ego. Disrupting this network is thought to induce a state of ego dissolution, leading to profound alterations in sense of self and subjective experiences of unity.

3. Brain entropy

The entropic brain hypothesis proposes that psychedelics increase the entropy (disorder) of brain activity, leading to a breakdown of normal patterns of thought and perception. This hypothesis suggests that the brain operates on a fine line between order and chaos, and that psychedelics may push the brain towards a more chaotic state, leading to altered states of consciousness.

4. Altered predictive processing

The predictive processing theory is a framework in cognitive neuroscience which posits that the brain is constantly generating predictions about the world based on prior experience and incoming sensory information. It has been suggested that psychedelics may disrupt ordinary predictions by altering the balance between top-down and bottom-up processing, leading to a wide range of perceptual and cognitive effects. 

It is a common misconception that psychedelics are legal in the Netherlands. Although its policies surrounding drug use are more liberal than in most countries, most psychedelics are illegal under the Opium Act. Psilocybin-containing truffles are a notable exception: following the mushroom ban in 2008, truffles remain unregulated and can be purchased in smartshops by those 18 years of age. The substances 5-MeO-DMT and salvia divinorum are also legal to purchase. Other psychedelics such as LSD, MDMA, DMT and ketamine are illegal to purchase under Dutch law, although the possession and consumption of small quantities will generally not be prosecuted. The Dutch government has allowed research into the therapeutic use of psychedelics such as psilocybin, ketamine and MDMA, for certain mental health conditions. It’s important to note that the laws and regulations surrounding drug use in the Netherlands can be complex, and it’s always recommended to check the current laws and guidelines before engaging in any activities involving drugs. 

Psychedelic-assisted psychotherapies for certain mental health conditions like depression and PTSD are currently still being studied in clinical trials, meaning they have not yet been implemented in mental health care (GGZ). In September of 2021 a nasal spray containing esketamine (Spravato) was approved for patients suffering from treatment-resistant depression. 

Due to the legal status of psilocybin-containing truffles in the Netherlands, there are several retreat centers and psychedelic guides where it is possible to legally undergo a psychedelic experience. It is important to note that these providers are generally not qualified to treat serious mental health disorders. If you are suffering from a mental health condition, we recommend you to consult your general practitioner. 

In the past decade there has been a steady increase in the amount of psychedelic studies being done in the Netherlands. Some notable examples include the following:

• MAPS-sponsored trials of MDMA-assisted psychotherapy for PTSD at the ARQ National Psychotrauma Center 
• COMPASS-sponsored trials at UMC Utrecht studying psilocybin-assisted psychotherapy for treatment-resistant depression
• UMC Groningen comparing the efficacy of esketamine to electroconvulsive therapy (ECT) and the efficacy of esketamine for treating suicidal ideation
• APRA founder Marco Aqil investigating the sensory effects of psilocybin at the Spinoza Center for Neuroimaging in Amsterdam
• PRSM Lab in Leiden conducting basic neurocognitive research to understand the working mechanisms underlying psychedelic substances
• Maastricht University studying the effects of microdosing, cannabis and novel psychoactive substances (NPS). 

First step: join APRA! Besides forming a local community of students with an interest in psychedelic science, we maintain good relationships with many psychedelic researchers in the Netherlands. Becoming a member and joining our academic and social events is a great way to meet people active in the field and becoming more familiar with the Dutch landscape of psychedelic research. This can be very valuable if you are considering a career in psychedelic science or therapy. Moreover, APRA membership will grant you access to our database of Dutch researchers currently active in psychedelic science. 

Depending on the research objectives and inclusion criteria, you may be able to participate in currently ongoing psychedelic studies. We regularly post opportunities to participate in psychedelic research on our website and social media. Institutions that are regularly recruiting include Psychopharmacology Maastricht and the CHDR (Leiden). 

In short, our mission consists of three goals:

1. Providing high-quality education about developments in psychedelic science to students, researchers and anyone with an academic interest in psychedelics.

2. Reducing unscientific stigma within academia and normalizing the status of education and research in this field.

3. Fostering a community of likeminded individuals and promoting the start of an interdisciplinary research effort within the Amsterdam institutions

For a more expansive description of our philosophy, see core principles. 

Great question! We are always looking for more volunteers to become actively involved in the association. A good first step is to sign up for our membership. After signing up you will be able to join our regular meetings and join the Slack workspace, where much of our organizational work takes place. APRA is structured into four different departments: Event management, Public relations, Research and Community coordination. You are more than welcome to volunteer in a department that is most suited to your personal skills and interests. For any other requests, suggestions or collaboration proposals please use the contact form.

Currently we are not able to provide academic internships. However, we are planning on launching a pilot programme to support Amsterdam-based university students who are interested in writing their thesis about psychedelic science. We will keep you posted about this via our website and social media channels. 

Unfortunately we are not in a position to make referrals to psychedelic guides or therapists. In the Netherlands, psychedelic-assisted therapies are still being researched and have not yet been approved in mental health care (GGZ). It will likely take several years before psychedelic therapies are fully implemented and accessible to those in need. For some, it may be possible to participate in a clinical trial if the inclusion criteria are met. Although there is a range of options with regards to psychedelic guides and retreat centers, we do not provide specific recommendations and want to stress that they are not a substitute for health care professionals. If you are suffering from a mental health condition, we recommend you to consult your general practitioner (huisarts). 

Our primary focus is currently on education, although many APRA members are involved in psychedelic research conducted by other institutions. Recently APRA founder Marco Aqil has started recruiting participants for an fMRI study with psilocybin at the Spinoza Centre for Neuroimaging in Amsterdam. If you are interested in participating, send an email to [email protected]. 

If you support our cause but are not interested in membership, you are welcome to support APRA by making a financial donation. APRA is a registered non-profit organisation and is entirely run by volunteers. All donations and membership contributions are fully reinvested in covering organisational costs. We deeply appreciate your support. If you have other means or proposals that may be beneficial to APRA, do not hesitate to reach out to contact us.