The fascinating world of psychedelics: Exploring their history, effects, and future

Psychedelics have been used for centuries for medicinal and religious purposes. But, why has their use been banned and psychedelic research been scarce?
Tejasri Gururaj
An illustration of mushrooms and mental health
An illustration of mushrooms and mental health


Psychedelics have a long history of use in religious and spiritual ceremonies. Ancient cultures used natural psychedelics like cannabis, peyote, ayahuasca, and psilocybin (aka magic mushrooms) as medicine to induce an altered state of consciousness and connect with nature. 

Some indigenous people living in the Amazon basin have been using ayahuasca, a blend of the tropical liana Banisteriopsis caapi and other botanical ingredients, as a medicine and to communicate with the spirits of their ancestors. Similarly, some indigenous communities in America use peyote as a religious sacrament, and ancient Greek and Roman civilizations are thought to have used ergot (a fungus that grows on barley, rye, and other grains) in religious ceremonies. 

However, psychedelics in the West became more widespread in the middle of the 20th century. Researchers and intellectuals began using them to explore their effects on the human brain, and the practice eventually became a feature of the counterculture movement of the 1960s. Many "hippies" and others in the counterculture used psychedelics to explore new states of consciousness and probe the mysteries of the psyche.

As psychedelics spread beyond indigenous groups, there was also an increase in concern about their potential risks, such as addiction, abuse, and psychological distress. This eventually led to a ban on their use in many countries. 

The fascinating world of psychedelics: Exploring their history, effects, and future
The Amazonians have been using ayahuasca as a medicine and a way to connect with the spiritual world

In recent years, there has been a resurgence in the study and use of psychedelics for therapeutic purposes. Research has shown that psychedelics can have positive effects when used in controlled conditions to treat mental health conditions such as anxiety, addiction, and PTSD. 

Despite the growing evidence that psychedelics can have a valuable therapeutic use, there is a lot of controversy surrounding psychedelics and their use. Here we explore everything about psychedelics to understand them and their effects better.

What are psychedelics?

Psychedelics are a class of hallucinogenic substances that alter the state of mind of a person. This means they can affect a person's perception, moods, and thought processes. They can also induce temporary mental, visual, and auditory changes, leading to psychedelic experiences or "trips". 

Psychedelics are found in nature, but many can also be produced synthetically in a lab. Some examples of psychedelics found in nature include peyote, which contains a hallucinogen called mescaline, cannabis which contains tetrahydrocannabinol (THC - which is generally classed as a depressant but can have psychedelic effects), 'magic mushrooms', which contain psilocybin, ayahuasca, which contains dimethyltryptamine (DMT; as well as substances which inhibit the breakdown of DMT), and ergot, which contains lysergic acid. 

The fascinating world of psychedelics: Exploring their history, effects, and future
Magic mushrooms contain psilocybin which is a hallucinogen

Synthetic psychedelics include lysergic acid diethylamide (LSD), N, N-Dimethyltryptamine (DMT), and 3,4-Methyl​enedioxy​-methamphetamine (MDMA).

The main difference between psychedelics and other drugs is how they affect our brains. Psychedelics can lead to profound experiences, making a person feel interconnected. They can also involve vivid visual and auditory hallucinations and altered perceptions of time and space.

Other drugs, such as opioids, depressants, and stimulants, affect a person's behavior, physical sensation, and mood. They can cause euphoria, an increase in energy, and a sense of relaxation, but generally not have the same intense hallucinogenic experiences as psychedelics.

Additionally, psychedelics do not typically produce physical dependence or addiction. In fact, many studies have reported a decrease in cravings for some other addictive substances after a psychedelic experience, particularly in the case of tobacco and alcohol.

How do psychedelics work?

The fascinating world of psychedelics: Exploring their history, effects, and future
Albert Hofmann: The inventor of LSD

Swiss chemist Albert Hofmann was the first to synthesize and consume LSD in 1938 and 1943, respectively. Speaking of his experience using LSD, he said, "It gave me an inner joy, an open-mindedness, a gratefulness, open eyes, and an internal sensitivity for the miracles of creation. I think that in human evolution, it has never been as necessary to have the substance LSD. It is just a tool to turn us into what we are supposed to be."

Many users of psychedelics describe similar experiences. Psychedelics can cause visual and auditory hallucinations, changes in perception of space and time, and altered mood and emotions. Certain psychedelics, such as LSD and psilocybin, have chemical structures similar to serotonin, a neurotransmitter responsible for regulating mood and emotions and helping brain cells communicate. 

LSD binds to the serotonin receptors in the brain, which causes changes in mood, perception, emotions, and cognition. Several studies have confirmed that psychedelics act as agonists or partial agonists for serotonin receptors (serotonin receptor agonist is any compound that activates serotonin receptors when serotonin is absent). Studies have also shown that psychedelics like LSD may bind to dopamine receptors. Dopamine is a neurotransmitter that plays a role in reward, motivation, and pleasure, among other functions.

Many users of psychedelics report feeling a sense of interconnectedness with the world and a heightened sense of empathy and compassion. These effects are thought to result from the interaction of psychedelics with the prefrontal cortex, a brain region responsible for self-awareness and introspection, as shown in a study by Calvin Ly from the University of California, Davis, and his colleagues.

Default mode network (DMN)

The fascinating world of psychedelics: Exploring their history, effects, and future
Areas of the brain in the DMN as seen on an MRI

The default mode network (DMN) is a network of brain areas hypothesized to be part of a functional system. They may have a role in self-referential thinking, memory, and daydreaming. Generally, this network has higher levels of activity when we are awake but not focused on the outside world or working on a specific task and lower levels of action when we are paying attention to a particular job. Psychedelics are suspected of activating the DMN, which disrupts its regular activity. 

The disruption may be responsible for the user feeling at one with the universe and for the boundaries between the self and the outside world becoming less distinct. This is known as ego dissolution and is explained in great detail in a study led by Robin L. Carhart-Harris from Imperial College London.

In the same study, Calvin Ly and his colleagues found that psychedelics such as ketamine can increase the connectivity between different brain regions by promoting the growth of neurons. This increased connectivity may underlie the synesthesia-like experiences that some users of psychedelics report, where sensory experiences become mixed or blended, such as seeing sound or hearing colors.

Potential therapeutic uses of psychedelics

Several psychedelics are currently being studied for their potential therapeutic uses, including in treating depression, anxiety, PTSD, and addiction. Their therapeutic efficacy is hypothesized to be due to the drugs' ability to stimulate or promote neuroplasticity, which is the ability of the brain to change and adapt.

palerlotus via GIPHY

A review study by Abigail E. Calder and Gregor Hasler from the University of Fribourg concluded that psychedelics could stimulate the growth of neurons, particularly in the cerebral cortex, which is the outer part of the brain. They further suggest that psychedelics can open a window of neuroplasticity lasting for a few days, with the neuroplastic changes persisting for at least a month. Because the changes occur experience-dependent, the psychological impact may continue over time.

Many clinical trials have reported positive results using psychedelics to treat various conditions such as PTSD or depression. A study led by Alicia L. Danforth from the Harbor-UCLA Medical Center found that autistic adults treated with MDMA-assisted psychotherapy for social anxiety had significantly less anxiety after the treatment. 

In another study led by Robin L. Carhart-Harris from Imperial College London, psilocybin in a clinical setting showed positive results for treatment-resistant depression. During the treatment, they also noticed improvements in anxiety and anhedonia (the reduced ability to experience pleasure). However, some patients noticed side effects like headaches and nausea. 

Psychedelics have also been used to treat PTSD, with several dies concluding it is safe and may actuate the benefits of psychotherapy for treating PTSD. Potential future applications of psychedelics in therapy include their use in treating addiction, eating disorders, and obsessive-compulsive disorder.

The fascinating world of psychedelics: Exploring their history, effects, and future
Psychedelics have shown positive results when used for treating depression

Although many studies have shown positive results for using psychedelics for treating anxiety, depression, and PTSD, none of them have explored the long-term effects of their use. Social taboos and legal bans on the use of psychedelics make it difficult for scientists and academics to conduct long-term studies.

Risks and side effects

While psychedelics have shown promise in treating various mental health conditions, their use is not without risks and side effects. The most significant psychological impact is the one of a 'bad trip'. This involves experiencing terror, psychoses, paranoia, and anxiety, which can persist even after the psychedelics wear off. In rare cases, psychedelic-induced psychosis can be more or less permanent in some people.

Similarly, some people experience a flashback called hallucinogen-persisting perception disorder (HPPD). The flashbacks can happen up to a year (or longer) after taking the drugs and involve reliving certain visual parts of the drug trip. 

Physical risks associated with psychedelic use include overdose and drug interactions. While overdosing on psychedelics is not typically fatal, it can result in various adverse effects, such as nausea, vomiting, psychosis, and confusion. Additionally, psychedelics can interact with other drugs, including prescription medications, resulting in dangerous or life-threatening complications.


The long-term effects of psychedelics are still poorly known because most studies on them are short-term. However, some experts think that psychedelics can trigger manic or psychotic episodes in people with a history of schizophrenia or bipolar disorder in their family. Other studies argue that there are no long-term risks associated with psychedelic use.

It is worth noting that the risks associated with psychedelic use appear to be relatively low compared to those other drugs, including alcohol and opioids. Additionally, many risks associated with psychedelics can be mitigated through careful use, proper dosing, and medical supervision.

The bottom line is we need more long-term studies to properly understand the complexities of how psychedelics work on the brain.


According to some researchers, a psychedelic renaissance has the potential to change healthcare institutions and society at large toward more sympathetic cause-and-effect strategies that promote human wellbeing. Many psychedelic users agree that psychedelics can help us be a more empathetic and compassionate society.

The fascinating world of psychedelics: Exploring their history, effects, and future
Some people believe that psychedelics can take us towards a more sympathetic society

Psychedelic research has a long way to go, and the first step may be to make it easier for researchers to study them further. It is also necessary to ensure that they are only used in professional clinical settings for research or treatment.

In conclusion, a cautious but curious approach to psychedelics can take us closer to maximizing their therapeutic potential.

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