Psychedelics: Risks vs. Mental Health Benefits
Jesse Hanson, Ph.D.
– Written by
Carrie Steckl, Ph.D.
and
Linda Armstrong
– on April 1, 2026
Psychedelics are no longer just relics of a bygone counterculture era. Today, these powerful mind-altering substances sit at the intersection of ancient ritual and modern science. In fact, they’re currently being explored for their therapeutic potential to treat conditions like depression, post-traumatic stress disorder (PTSD), and addiction. That said, their powerful effects come with real risks that deserve careful consideration.
This guide explores what psychedelics are and how they work, as well as the delicate balance between their therapeutic promise and potential dangers.
What are Psychedelics and Dissociative Drugs?
Psychedelics, also known as hallucinogens, are a diverse and rather loosely defined group of substances. While hundreds of naturally occurring and synthetic psychedelic compounds exist, they all share the ability to induce altered thoughts and sensory perceptions [1][2].
While psychedelics are typically consumed orally, some forms are smoked and others are injected [3]. Once taken, psychedelics work through various mechanisms in the brain to create their effects. For example, classic psychedelics like psilocybin and lysergic acid diethylamide (LSD) primarily interact with specific receptors related to serotonin.
At certain doses, these psychedelics create vivid visions, alter a person’s sense of self, and more. Similarly, dissociative drugs such as ketamine impact glutamate, which is another neurotransmitter. Effects vary, but often people feel disconnected from their body and environment [4].
Beyond these pharmacological differences, psychedelics also vary in terms of their legal status. The U.S. Drug Enforcement Administration classifies several psychedelics, e.g., LSD, psilocybin, 3,4-methylenedioxymethamphetamine (MDMA), and mescaline, as Schedule I controlled substances, meaning they have no currently accepted medical use and a high potential for abuse. However, others are classified as Schedule III, which have a low potential for misuse [5].
Complicating matter further, some states have begun decriminalizing possession of psilocybin and similar substances for personal use, while others have deprioritized enforcement of laws against them [4]. To appreciate the complexities surrounding psychedelics, it helps examine their ancient origins and the cultural shifts that eventually led to their criminalization.
History of Psychedelics
Naturally occurring psychedelics have a deep-rooted history in spiritual and medicinal rituals across the globe. For millennia, Indigenous peoples have used peyote, ayahuasca, psilocybin mushrooms, and more for their profound psychoactive properties [6].
Fast forward to 1943, when Swiss chemist Albert Hoffman discovered the effects of LSD. As a result, modern scientific interest ignited for two decades, and research actively explored LSD’s usefulness. However, the 1970 Controlled Substances Act effectively halted exploration by placing most psychedelics in the most restrictive drug schedule category: Schedule I [6].
Starting in the 2000s, however, a sort of psychedelic renaissance emerged, as researchers pushed to revive clinical trials for substances such as MDMA and psilocybin. Today, interest is once again rising in both therapeutic applications and public spheres [6].
While hallucinogen use remains relatively low compared to other substances, the 2024 National Survey on Drug Use and Health (NSDUH) shows that past-year hallucinogen use among people aged 12 and older rose from 2.7 percent in 2021 to 3.6 percent in 2024 [7].
How do Psychedelics Work?
While the mechanisms of action still aren’t completely understood, most researchers agree that psychedelices produce their mind-altering effects by disrupting normal brain communication patterns.
Classic psychedelics like psilocybin and LSD primarily target serotonin 2A receptors, which are involved in mood, perception, and cognition [6]. Meanwhile, dissociative drugs and most non-classical psychedelics like ketamine block NMDA receptors that transport glutamate [4].
However, one of the most intriguing aspects of psychedelics is their effect on the brain’s default mode network, a group of regions involved in introspection. This network is often overactive in people with depression, anxiety, and addiction.
Functional neuroimaging studies suggest that psychedelics can temporarily disrupt this pattern, allowing the network to reorganize in ways that promote more flexible thought patterns [6]. In a recent article from Harvard Health Publishing, one notable psychiatrist described this effect as rebooting a computer, prompting stuck patterns of thinking to shift and new perceptions to emerge [2].
Beyond their immediate effects, psychedelics also appear to enhance neuroplasticity, i.e., the brain’s ability to form new neural connections. This increased flexibility may help people develop fresh insights, break free from rigid thought patterns, and make lasting behavioral changes [1]. It’s this combination of acute experience and prolonged brain changes that makes psychedelics so promising for mental health treatment.
Effects of Psychedelics
The effects of psychedelics vary widely depending on the substance, dose, and context of use. Factors such as mindset and environment, often called set and setting, also shape perception of the experience. While some experiences are described as meaningful or even transformative, other experiences are seen as confusing or distressing [1][4].
While the differences between positive and adverse effects are somewhat subjective, perceived positive effects include [1][4]:
- Visual and auditory distortions
- Hypersensitivity to light, sound, and touch
- A slowed or altered perception of time
- Synesthesia (i.e., merging of different senses), such as “seeing” sounds
- Feelings of intense happiness, oneness, or spiritual unity
- Vivid memories or new personal insights
- Feelings of detachment from the self
Despite these potentially positive effects, psychedelics can also produce significant distress, which is more common when they’re used in uncontrolled settings or without professional supervision [4].
Potential adverse effects of psychedelics include [1][4][8].
- Delusions and feelings of confusion, paranoia, and dissociation
- Hallucinogen persisting perception disorder (HPPD), characterized by ongoing visual disturbances or “flashbacks”
- Dangerous behavior resulting from impaired judgment or fear
- Headaches, nausea, and increases in heart rate and blood pressure
- Fear and anxiety
Importantly, illicitly manufactured substances may contain dangerous contaminants like fentanyl, which pose a risk of overdose and death. In addition, any contaminants may produce additional effects of their own [4].
Classic Psychedelics
Unlike dissociative drugs or other mood-altering substances that might affect glutamate or dopamine, classic psychedelics interact with the brain’s serotonin system to produce a similar set of sensory and cognitive shifts. The experience typically comprises vivid visual hallucinations and a dissolved sense of self [6].
Based mostly on insights from the UC Berkeley Center for the Science of Psychedelics the following sections explore several well-known classic psychedelics, each with its own history, effects, and emerging role in research.
Ayahuasca
Ayahuasca is made by combining the Banisteriopsis caapi vine with plants like the Psychotria viridis shrub that contain N,N-dimethyltryptamine (DMT). Indigenous peoples across South America and elsewhere have used ayahuasca for over a thousand years to treat various spiritual and medical conditions. However, in the United States, ayahuasca therapy and use are illegal, as DMT is a Schedule I controlled substance [1].
The ayahuasca experience often includes positively perceived effects, such as vivid visions, sensory distortions, and slowed perception of time. However, use also carries physical risks, such as shaking, vomiting, and significantly increased blood pressure. Plus, ayahuasca can have dangerous interactions with medications like SSRIs and may exacerbate psychiatric disorders such as schizophrenia. Despite these concerns, research in structured settings suggests it may help treat addiction, anxiety, and treatment-resistant depression [1].
DMT
Found naturally in many plants, DMT produces an intense but brief experience, often lasting only 20 to 30 minutes, causing a near-instantaneous shift in sensory perception. People frequently report detachment from their physical surroundings, entering what feels like an alternate reality filled with intricate geometries [1].
Despite its short window of action, DMT carries significant physical and psychological risks, including sharp increases in blood pressure and heart rate. The intensity of the experience can also lead to overwhelming confusion or a temporary loss of one’s sense of self [1].
LSD
LSD is perhaps the most well-known and potent synthetic psychedelic. A tiny amount can trigger a “trip” that lasts up to 12 hours. This experience is characterized by vivid visual patterns, a warped sense of time, and a profound shift in thought processing and emotions. However, that same intensity can also lead to “bad trips” marked by paranoia or overwhelming anxiety [1].
While LSD remains a Schedule I substance, its long history of use in both 1960s counterculture and early psychiatric research has made it a central focus for modern scientists looking at how psychedelics might treat depression and existential distress [1].
Mescaline
Mescaline is a naturally occurring psychedelic found in several cactus species, such as the peyote. Unlike the quick hit of DMT, a mescaline experience is a long, slow burn that can last up to 12 hours. This Schedule I substance produces visual and auditory hallucinations as well as an altered sense of time.
However, some people also report a sort of “geometrization” of 3-D objects that makes them particularly distorted. Despite these effects, research suggests that when paired with therapy, mescaline might help treat substance use disorders, anxiety, and depression [1].
Psilocybin
Psilocybin is a naturally occurring compound found in more than 100 mushroom species. Usually consumed orally, it lasts up to eight hours. Sharing the signature effects of other classic psychedelics, psilocybin is a Schedule I substance.
Some states have recently legalized specific psilocybin services or decriminalized the substance. Plus, recent studies suggest that when combined with therapy, psilocybin may help treat conditions such as depression, anxiety, PTSD, and substance use disorders [1].
Non-Classical Psychedelics
Non-classical psychedelics can alter mood, perception, and consciousness, but unlike classic psychedelics, they don’t primarily act on serotonin 2A receptors [6]. Instead, they affect other systems in the brain, acting on glutamate pathways or influencing the release of serotonin, dopamine, and norepinephrine [4].
Legally, many non-classical psychedelics are classified as Schedule I drugs, but others such as ketamine are placed in Schedule III due to accepted medical uses despite their risks [5]. Together, these differences highlight the complexity of this category, where similar experiences can arise from very different biological mechanisms.
The following sections, based largely on UC Berkeley insights, delves into several well-known non-classical psychedelics.
Ibogaine
Ibogaine is a naturally occurring psychoactive compound found in the root bark of the Tabernanthe iboga shrub, which is native to Central and West Africa. It interacts with multiple systems in the brain, including serotonin, dopamine, glutamate, and opioid pathways.
Often described as a waking dream, the resulting experience can unfold over a day or more. During this time, people may experience vivid visual sequences, including detailed recollections of past memories, followed by a period of deep reflection and lingering mental and physical effects that can last for days [1].
While it’s a Schedule I substance, ibogaine has drawn recent attention for its potential to interrupt substance use disorders, with some studies suggesting it may reduce withdrawal symptoms and cravings for opioids and other substances. At the same time, however, ibogaine has been linked to effects such as nausea, tremors, mania, seizures, and dangerous cardiac effects [1].
Ketamine
Ketamine is a synthetic drug that has long been used as an anesthetic in medical settings. At lower doses, ketamine can alter perception and create a dreamlike state, while higher doses may lead to a more intense dissociative experience often described as feeling detached from the body or environment [1].
In recent decades, ketamine has gained attention for its potential in mental health treatment. Research suggests it may provide rapid relief for conditions such as depression, suicidal thoughts, PTSD, and obsessive-compulsive disorder (OCD). A ketamine derivative, esketamine (aka Spravato), was approved by the FDA in 2019 as a nasal spray for treatment-resistant depression, marking a significant shift in how these substances are viewed in medicine [1].
Still, ketamine carries risks and is a Schedule III substance. Side effects can include dizziness, nausea, and impaired memory, and repeated use outside of medical supervision has been linked to dependence and other health concerns [1][4].
MDMA
MDMA is a synthetic drug that produces both stimulant and psychedelic-like effects. However, in contrast to classic psychedelics, MDMA can elevate mood and enhance emotional openness. First synthesized in 1912, MDMA gained attention decades later when it was used in psychotherapy settings before becoming popular as a recreational drug in the 1980s. But in 1985, it was classified as a Schedule I substance, halting most clinical use [1].
More recently, research has revisited its therapeutic potential, with studies suggesting it may help people process trauma more effectively when combined with therapy. At the same time, MDMA carries risks, including increased heart rate and blood pressure, and its mood-enhancing effects contribute to its potential for misuse [1].
Psychedelics and Mental Health Treatment
Psychedelics are drawing renewed attention as potential tools in mental health care, especially for conditions that have been difficult to treat with traditional approaches. Research suggests that substances such as psilocybin, LSD, MDMA, and ketamine may help address disorders including depression, anxiety, PTSD, and substance use disorders when used in carefully controlled settings [6].
Much of the related mental health therapy takes place within a structured approach known as psychedelic-assisted therapy. In these settings, participants undergo preparation sessions, followed by guided dosing experiences in a controlled, supportive environment. Later, integration sessions help participants process what they experienced.
During psychedelic-assisted therapy sessions, people may revisit memories, experience shifts in perspective, or develop deeply meaningful emotional or spiritual insights. These effects, combined with increased neuroplasticity, may help people break out of rigid thought patterns and develop new ways of relating to themselves and others [6].
At the same time, this treatment remains complex and somewhat controversial. While early findings are promising, psychedelics can also produce intense and troubling psychological effects. Risks include distressing experiences, potential worsening of certain mental health conditions, and the possibility of misuse outside of clinical settings [4].
Depression Treatment
Modern research is increasingly focusing on psychedelics as a breakthrough for mood disorders, particularly for people with treatment-resistant depression. According to an article from the American Psychological Association (APA), roughly one-third of people struggling with depression do not find relief from standard antidepressants or traditional talk therapy alone [9].
For these people, psychedelic substances like esketamine and psilocybin offer a different approach. Rather than numbing symptoms, these compounds appear to increase neural flexibility, essentially helping the brain move out of the rigid, repetitive thought loops characteristic of deep depression [10].
What’s more, studies have shown that psilocybin-assisted therapy can lead to significant and lasting reductions in depressive symptoms, sometimes after just one or two high-dose sessions [2].
Similarly, a 2021 study published in the New England Journal of Medicine found that people with moderate to severe major depressive disorder who were given two doses of psilocybin performed equally well after six weeks compared to those who took daily doses of escitalopram, a common antidepressant [11].
Addiction Treatment
Psychedelics are also being explored as a potential approach to treating substance use disorders. Early research and reviews suggest that substances such as psilocybin, ayahuasca, and ibogaine may help reduce cravings and support long-term behavior change when combined with therapy [12].
Some findings are especially striking. In one study, a single dose of ibogaine was associated with reduced opioid withdrawal symptoms. Participants in other studies have also reported significant relief from substance use after psychedelic-assisted treatment, though results vary depending on the substance and setting [12].
Trauma Reprocessing and PTSD
An estimated 40% to 60% of people with PTSD do not respond to first-line medications such as SSRIs, and many struggle to benefit from trauma-focused therapies [9]. Substances like MDMA and psilocybin have shown promise in early research, with studies suggesting they may reduce PTSD symptoms and improve emotional processing when used alongside therapy. In clinical trials, MDMA-assisted therapy has been associated with significant reductions in PTSD severity [6].
One reason these treatments may be effective is how they influence emotional and fear-based processing in the brain. MDMA, for example, is known to increase feelings of trust, empathy, and emotional openness while reducing activity in brain regions linked to fear and anxiety. The theory is that this combination can make it easier for people to revisit traumatic memories without becoming overwhelmed, allowing those memories to be processed in a safer and more manageable way [6].
Psychedelic-assisted therapy also appears to enhance learning and neuroplasticity, which may help people reshape long-standing patterns of thought and emotional response tied to trauma. Together, these effects suggest a different therapeutic pathway, one that focuses not just on symptom reduction but on how trauma is stored and experienced in the mind and body [6].
Psychedelic Retreats
As interest in psychedelics grows, curiosity around exploring these substances has also increased, though where to begin is often unclear. Outside of clinical settings, psychedelic retreats have emerged as one option for guided experiences, often held in countries where certain substances are legal or tolerated and involving supervised dosing sessions supported by facilitators.
Approaches vary widely. Some retreats draw from traditional or Indigenous practices, while others follow more wellness-oriented models that incorporate meditation, breathwork, and psychological support. In addition, platforms such as Psychedelics.com and BookRetreats.com can help locate and compare retreat options across different regions.
However, unlike clinical environments, psychedelic retreat settings are not consistently regulated. This lack of standardization means there are no uniform requirements for screening, facilitator training, safety protocols, or integration support. As a result, these factors can vary significantly between programs, which may increase the risk of adverse outcomes.
For this reason, careful research is essential. Speaking directly with facilitators, connecting with multiple past participants, and reviewing online reviews may provide useful insight.
Thus, consulting with a general practitioner or qualified healthcare provider beforehand may help identify potential risks, particularly in the presence of underlying medical conditions or a history of serious mental illness. Screening for mental health conditions can also be an important step in determining whether psychedelic experiences are appropriate.
Potential for Addiction and Misuse
While rare, use of psychedelics can result in a hallucinogen use disorder (HUD). The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) reveals that HUD affects about 0.1% of people age 12 or older in the United States, with slightly higher rates among younger adults [3].
Some psychedelic substances, such as MDMA, certainly have the potential for misuse, particularly given the euphoria they can cause [2]. Dissociative drugs like ketamine have also been linked to cravings and withdrawal symptoms when used outside of medical supervision [4]. Plus, many of these substances can cause severe impairment, which means careful use and supervision are necessary [2].
Thus, while some psychedelics show low addiction potential, their powerful effects and evolving legal status mean that careful use, education, and ongoing research are essential.
Moving Forward with Clarity and Caution
Psychedelics are no longer confined to the margins of science and culture. They’re being studied, debated, and cautiously integrated into conversations about mental health, offering both promise and uncertainty.
However, they’re not for everyone. While some substances show potential to reshape how conditions like depression, PTSD, and addiction are treated, their effects remain complex and highly dependent on context, support, and individual factors.
So as interest grows, so does the need for balance. Psychedelics aren’t simple solutions, and their risks are real, especially outside of structured settings. A safe path forward requires careful research, ethical practice, and informed decision-making. With the right safeguards, psychedelics may be valuable tools in mental health care, but their role will continue to evolve as science and society catch up with their possibilities.
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References
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- Grinspoon. P. (2021, June 22). Back to the future: Psychedelic drugs in psychiatry. Harvard Health Publishing, Harvard Medical School. https://www.health.harvard.edu/blog/back-to-the-future-psychedelic-drugs-in-psychiatry-202106222508.
- American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed., text rev.). https://doi.org/10.1176/appi.books.9780890425787.
- National Institute on Drug Abuse. (2023, April). Psychedelic and dissociative drugs. National Institute on Drug Abuse. https://nida.nih.gov/research-topics/psychedelic-dissociative-drugs.
- Drugs.com. (2024, September 24). Controlled substances & CSA schedules. Drugs.com. https://www.drugs.com/csa-schedule.html.
- Brian S. Barnett, MD, Erin E. Mauney, MD and Franklin King, MD. (2025). Psychedelic-assisted therapy: An overview for the internist. Cleveland Clinic Journal of Medicine March 2025, 92 (3) 171-180; DOI: https://www.ccjm.org/content/92/3/171.
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- STringer, H. (2024, June 1). The emergence of psychedelics as medicine. American Psychological Association. https://www.apa.org/monitor/2024/06/psychedelics-as-medicine.
- De Gregorio D, Aguilar-Valles A, Preller KH, et al. (2021). Hallucinogens in Mental Health: Preclinical and Clinical Studies on LSD, Psilocybin, MDMA, and Ketamine. J Neurosci. 2021;41(5):891-900. doi:10.1523/JNEUROSCI.1659-20.2020. https://pmc.ncbi.nlm.nih.gov/articles/PMC7880300.
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Jesse Hanson, Ph.D.
– Written by
Carrie Steckl, Ph.D.
and
Linda Armstrong
– on April 1, 2026