Can Psychedelics Cause Seizures

Exploring the Risk Factors


The material below is not intended to provide medical advice and we don’t encourage the illegal use of any substances. Most psychedelics are potentially illegal substances, and we do not encourage the use of these substances where it is against the law. Due to the high demand for the subject, we created this article for educational purposes. The intent of the content is to help you start learning about the subject.

Psychedelics can cause seizures in some individuals, particularly those with a personal or family history of epilepsy. Additionally, taking street-bought hallucinogenic drugs can also lead to seizures if they contain dangerous substances mixed with the psychedelic. It is important to be aware of these potential risks and to educate individuals about the dangers of using psychedelics, especially those purchased on the street.

Psychedelics and Epilepsy

A recent study found that taking certain psychedelics, like psilocybin and LSD, could increase the risk of seizures in people with a personal or family history of epilepsy. The study examined data from over 600 U.S. adults who reported using classic psychedelics and found that 1.5% reported seizures while using them. The researchers noted that a family history of epilepsy was a significant factor in this risk. While the incidence of psychedelic-related seizures in the general population is low, the study highlights the importance of informing exclusion criteria in psychedelic trials and educating individuals who use psychedelics outside of research settings.

The study aims to understand the prevalence and risk factors of classic psychedelic-related seizures. The research, conducted on a representative sample of the US population with regard to sex, age, and ethnicity, found that among the respondents who reported lifetime classic psychedelic use, 1.5% reported classic psychedelic-related seizures. The risk of seizures is higher for people with a personal or family history of epilepsy. Also, respondents who reported seizures while using a classic psychedelic had often co-used antidepressants, mood stabilizers, or opioid replacement therapies. The study could inform exclusionary criteria for clinical trials on classic psychedelics.

There has also been cases where a patient who consumed a street-bought hallucinogenic drug, thinking it was LSD, experienced seizures. Although traditional hallucinogenic drugs like marijuana and LSD are not usually associated with seizures, newer synthetic hallucinogenic drugs can cause seizures. In this case, the patient was positive for cannabinoids and opioids in a urine toxicology screen. However, further testing revealed the presence of 2,5-dimethoxy-4-chloroamphetamine (DOC), which is an amphetamine-derived phenylethylamine. The case is significant because there are several new hallucinogenic street drugs that can cause unexpected effects, including seizures, and can be difficult to detect using standard urine toxicology screening tests.

How to minimize the risk of seizures when using psychedelics

Check source and purity of psychedelic substance

It’s important to stay away from street drugs as they can contain unknown substances that can be harmful to your health. Even if you believe you are taking a traditional drug like LSD, it’s important to exercise caution and be aware of the potential risks. Additionally, the mixing of different substances in street drugs can cause unexpected effects, including seizures, which can be difficult to detect using standard urine toxicology screening tests. It’s always best to consult with a medical professional before consuming any substance to ensure your safety.

Seek medical advice if you have epilepsy and are thinking to use psychedelics

It is crucial to exercise caution and seek medical advice if you have epilepsy or suspect you may have the condition and are considering using psychedelic substances. The combination of epilepsy and psychedelic drugs can significantly increase the risk of seizures, making it essential to consult with a healthcare professional to understand the potential risks and ensure proper management of the condition.

What is a seizure?

A seizure is usually defined as a sudden alteration of behavior due to a temporary change in the electrical functioning of the brain. Normally, the brain continuously generates tiny electrical impulses in an orderly pattern.

Types of seizures

There are different types of seizures. Generalized onset seizures affect both sides of the brain at the same time, while focal onset seizures start in one area or group of cells in one side of the brain. Focal onset aware seizures happen when a person is awake and aware during a seizure, while focal onset impaired awareness seizures happen when a person is confused or unaware during a seizure. Unknown onset seizures happen when the beginning of a seizure is not known. Different symptoms during a seizure involve movement, like sustained rhythmical jerking movements, or non-motor symptoms, like changes in sensation or thinking. If someone doesn’t know what type of seizure they have, they can talk to their doctor.

Causes of seizures

Seizures are caused by abnormal electrical activity in the brain. There are many possible causes of seizures, including abnormal levels of sodium or glucose in the blood, brain infection, brain injury, congenital brain defects, brain tumors, drug abuse, electric shock, epilepsy, fever (particularly in young children), head injury, heart disease, heat illness, phenylketonuria (PKU), poisoning, street drugs, stroke, toxemia of pregnancy, toxin buildup in the body due to liver or kidney failure, very high blood pressure, venomous bites and stings, and withdrawal from alcohol or certain medicines after using them for a long time. In some cases, no cause can be found, which is called idiopathic seizures. Idiopathic seizures are usually seen in children and young adults, but can occur at any age. If seizures continue repeatedly after the underlying problem is treated, the condition is called epilepsy.

It is essential to focus on drug abuse, street drug use, and epilepsy as potential causes of seizures, as current academic research and clinical trials suggest that although psychedelics themselves may not cause seizures, they can increase the risk of seizures when combined with other unknown substances, particularly in individuals who are chronic heavy street drug users or have epilepsy.

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Other Risks and Side Effects of Psychedelic Use


In a study that excluded people with mental health diagnoses, side effects that were observed were short-lived, associated with higher doses of the drug and weren’t plentiful. There were no long-term negative effects, 8 to 16 months after initial dosages. In a review from the Netherlands, they found that dependence potential and acute and chronic toxicity were low. A different article states that in high doses, there is a larger potential for fear (31%) and paranoia (17%). (21)  

The relationship between psilocybin use and psychological distress like suicidal thinking, planning and attempts was also examined through a study by Hendricks at al., showing that groups that used psilocybin only (as opposed to a combination of other drugs or nonpsilocybin psychedelics) had reduced suicidality and improved mood. (21)

Some physical side effects that are short-term are: numbness (typically in the face), faster heart rate and higher blood pressure, dry mouth (sometimes preceding nausea and vomiting), muscle weakness and twitching, exaggerated reflexes, higher or lower body temperature, drowsiness, yawning, and loss of urinary control. However, though longer-term research is limited, the studies that have been done do not suggest that there are long-term negative effects.

Mental side effects include a distorted sense of reality, euphoria, hallucinations, introspection, panic, psychosis and dissociation. Not every person will experience the same set of side effects, and even a person having multiple trips can have different side effects from trip to trip. The mental side effects like distortion, euphoria, introspection and hallucinations are often the desirable sensations that a person seeks out when taking psilocybin.

Finally, there are some reported psilocybin mushroom-related deaths. Psychedelics are not toxic at standard doses, but can become harmful at very large doses. Psilocybin-only related deaths are fewer than psilocybin and other drugs. The few (less than 10) reported deaths are from jumping off high buildings, becoming too cold, and overdose of mushrooms.


Though there are mental health and spiritual benefits to taking ayahuasca, there are some side effects to be aware of. Most of the side effects are considered to be part of the experience and are not necessarily something to be discouraged by but rather made aware of.

The most commonly reported side effect of drinking ayahuasca tea is nausea, vomiting and diarrhea. This is seen as purging negative thoughts, emotions and traumas that have accumulated in the individual’s lifetime. Nonetheless, it can be a distressing experience and one should be informed of this risk before pursuing an ayahuasca experience. There may also be exhaustion in the subsequent days after the trip.

Psychological effects can include paranoia and panic, which can affect your trip in a negative way and impact any positive experiences you want to experience. However, this is not to state that the presence of these effects will nullify all positive takeaways from the experience. In a study of 40 subjects, 7 reported severe psychological reactions during their trip, including some psychotic symptoms. Upon follow-up, those with psychiatric conditions had improved and those without were not worse off than before.

Other reported factors are increased heart rate and blood pressure, and those with heart conditions should take precautions here as the side effects can be dangerous. As a hallucinogen, ayahuasca users also report changes in body perception like tingling feelings or dizziness, and changes in body temperature, but are temporary and last only as long as the trip.


The effects of LSD vary from person to person, as everyone’s physiology and metabolism operate differently. However, aside from the typical physical and mental effects, there can be some risks that you may want to consider before your trip.

If you have schizophrenia, there are higher chances of experiencing psychotic symptoms. This can also be the case regardless of mental health conditions if you take a big dose.

Some psychedelics and hallucinogens, LSD included, can cause Hallucinogen Persisting Perception Disorder (HPPD). HPPD can cause recurring flashbacks of the hallucinations, for a long time, sometimes weeks or years.

Though overdose is very unlikely, it is possible and you can recognize it through shallow/irregular breathing, high body temperature, aggression, irregular heartbeat, chest pain, delusions, seizures and loss of consciousness. Overdose can be a catalyst in severe psychosis, but there is no lethal dose of LSD, so risk of death is absent.

Those struggling with mood issues should be aware that extreme changes can happen. This doesn’t necessarily mean mood issues will worsen, but it is a possibility. Anxiety or depression can result from using LSD, during or after a “trip,” particularly a bad one.

Brief overview of psychedelics

Psychedelics are a class of powerful, mind-affecting substances commonly referred to as hallucinogens. They alter cognitive processes like consciousness and perception, besides affecting a person’s thoughts, mood, and emotions. LSD, Mescaline (derived from Peyote cacti), Ayahuasca, MDMA, Ketamine, and Psilocybin (derived from so-called ‘magic’ mushrooms) are some of the most well-known psychedelics. Some of these are naturally occurring while others are artificially synthesized. 

Humans have been using psychedelics since prehistoric times in a variety of social, cultural, and ritual contexts. Early research into the therapeutic properties of these drugs peaked in the two decades between 1950 and 1970. Multiple studies in this period showed promising results in the use of psychedelics to treat a host of mental health issues. However, a 1971 decision by the UN Convention on Psychotropic Substances led to psychedelics being outlawed in almost every country, putting a stop to their further testing even under laboratory conditions. 

Over the past few years, the legalization of medical cannabis in several state and national jurisdictions around the world has led to a resurgence of academic and clinical interest in these elusive substances. Researchers from Johns Hopkins Medicine in the US have recently reported that patients with major depression show benefits of psilocybin-assisted therapy for up to a year. Multiple other studies have found psychedelics effective in treating anxiety, treatment-resistant depression, eating disorders, substance abuse, and post-traumatic stress disorder (PTSD), among other mental health ailments. 

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