What Happens To Your Brain When You're On Psychedelics


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What Are Psychedelic Drugs?

Psychedelic drugs, also known as hallucinogens, are a group of substances that alter perception, cognition, energy levels, and mood. Many people take them to attain spiritual experiences.

They can be chemically-based, like ketamine, or plant-based, like DMT. Though many people use psychedelics recreationally, certain substances are being studied as a potential treatment for conditions like post-traumatic stress disorder, depression, and anxiety

Psychedelics vary in how they impact an individual’s brain. Here are common short-term and long-term effects to expect for many major substances. 


Lysergic acid diethylamide (LSD) is a chemically-made hallucinogen that was first synthesized in the 1930s. Many psychiatrists investigated it as a potential treatment in the 1950s and 1960s, and it’s been studied more recently to alleviate symptoms of various mental illnesses.

How LSD Affects the Brain

Studies have shown that in the short-term, LSD can reduce left amygdala (the part of the brain that experiences emotions) reactivity to fearful stimuli. It can also enhance empathy, and increases connectivity between brain areas that are typically dissociated. LSD connects the primary visual cortex with other brain areas, which may be responsible for hallucinations.

In one long-term study, 16 participants took a single dose of LSD and reported back one and 12 months afterward. At 12 months, the participants reported increased levels of well-being, altruism, and positive mood. Furthermore, 10 of the 14 remaining participants reported that taking LSD was one of the most meaningful experiences of their lives.

These findings suggest that there may be sustained alternations in neural connectivity that produce lasting changes in perception, mood, and behavior. However, further studies are required to discern LSD’s objective effects on brain function.


Ketamine is an anesthetic that’s increasingly being studied as an effective treatment for treatment-resistant depression

How Ketamine Affects the Brain

Neuroimaging studies have found that ketamine can increase activity involved in reward processing, and decrease activity in areas that control self-monitoring.

Some studies have pointed out that ketamine can produce psychosis-like symptoms. One finding administered intravenous ketamine to 27 participants, and had them self-report psychosis-like symptoms via the Psychotomimetic States Inventory (PSI). Many of them reported increases in metrics such as delusional thinking, perceptual distortion, and mania.

In the long-term, ketamine use may pose additional risks. In one review, long-term ketamine use (both recreationally and for medical purposes) was associated with impairments in memory and executive functioning.


Magic mushrooms are a type of fungi that contain psilocybin, a naturally-occurring hallucinogen. 

How Psilocybin Affects the Brain

Studies have shown that psilocybin has the potential to reduce anxiety and increase positive mood. In one finding, 12 participants were assessed one day before, one day after, and one month after receiving a 75 mg dose of psilocybin. After one month, they reported higher levels of positive emotions and lower levels of anxiety when compared to the baseline.

Psilocybin may also be beneficial in the long run. One study had cancer patients participate in psilocybin-assisted psychotherapy, and after 4.5 years, 60% to 80% of the participants met the criteria for clinically significant reductions in depression and anxiety.


Dimethyltryptamine, known commonly as DMT, is a naturally-occurring psychedelic that’s found in plants and animals, including humans.

DMT is the hallucinogenic component in ayahuasca, a South American plant used in rituals. Its effects are shorter than other psychedelics, lasting about an hour.

How DMT Affects the Brain

In the short term, DMT can lead to mixed outcomes. One study found that DMT, when used recreationally, could alleviate anxiety and produce feelings of euphoria. However, DMT can also produce acute cardiovascular distress, and may lead to paranoia in certain individuals.

Long-term effects of DMT include structural changes to brain areas responsible for attention, with subjective reports of change in personality.

In a study that measured MRI reports of the brains of regular ayahuasca users, many participants reported increases in spiritual feelings. These findings are limited in that they are correlational, and further research is required to determine DMT’s lasting effects in a controlled setting.  


Mescaline occurs naturally in cacti plants throughout the southwest United States, Mexico, and South America. Like DMT, it has traditionally been used by Native Americans in religious ceremonies and to alleviate certain physical ailments.

How Mescaline Impacts the Brain

One study that assessed mescaline’s acute effects on regular users found that it led to self-reported improvements in depression, PTSD, and anxiety symptoms. Many respondents also classified mescaline use as one of the most meaningful experiences of their lives.

Low Potential for Abuse

Long-term findings on the effects of mescaline use are limited. However, one study pointed out that compared to other psychedelics, mescaline use has a low potential for abuse and can lead to improvements in mental health.


Methylenedioxymethamphetamine (MDMA), also known as “molly” or ecstasy, is a synthetic drug. It’s been popular in rave and music festivals since the 1970s. Ecstasy has a high potential for abuse when compared to other psychedelics. 

How Ecstasy Affects the Brain

Ecstasy produces an immediate feeling of pleasure by releasing the neurotransmitters dopamine and serotonin. Dopamine is responsible for reward and motivation, while serotonin is associated with happy and calm feelings.

Neuronal Damage Is Possible

Unfortunately, studies have found that this abnormal regulation of brain transmitters, as well as increased oxidative stress, while under the influence of ecstasy can lead to neuronal damage.

Researchers are examining the impact of MDMA-assisted psychotherapy on individuals with PTSD. Findings indicate that at 12 months after receiving two to three doses of 75mg to 125 mg, participants continue to show symptom improvement.

However, other sources have pointed out that long-term effects of ecstasy can include depressive symptoms and memory deficits. Further studies are required to determine the lasting effects of ecstasy on the brain within a controlled setting. 

Getting Help

Though there is evidence for the therapeutic benefit of certain psychedelics, it’s important to note that these have occurred in clinical settings under specific dosages. 

Long-term misuse or abuse of psychedelics can lead to a variety of adverse outcomes, including persistent psychosis, visual disturbances, paranoia, distorted thinking, and Hallucinogen Persisting Perception Disorder—recurring visual disturbances or flashbacks that can occur more than a year after drug use.

If you or someone you know is struggling with psychedelic abuse, speak to your doctor about receiving treatment. This will often include cognitive-behavioral therapy (CBT) to address thought patterns, and medication to reduce psychological symptoms. 

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By Brina Patel
Brina Patel is a freelance writer from Sacramento, California. Prior to writing full-time, she worked as an applied behavior analysis therapist for children on the autism spectrum. She leverages her own experiences researching emotions, as well as her personal challenges with chronic illness and anxiety, in her storytelling, with the hope of inspiring others to take better charge of their overall wellness and understand themselves on a deeper level.