New research published in Scientific Reports provides insights into the long-term negative psychological effects of psychedelic drugs. The study, which selectively focused on negative outcomes to counter the hype surrounding psychedelic drugs, helps to identify potential risk factors for persistent anxiety, panic, and other psychological issues following the use of substances such as LSD, MDMA, and psilocybin.
The motivation behind this study emerged from the growing interest in the therapeutic potential of psychedelic drugs for treating mental illnesses. Despite the promising results in controlled research settings, the majority of psychedelic use occurs outside these controlled environments. This discrepancy raised concerns that the positive outcomes highlighted in research might not fully represent the range of effects these substances can have, particularly when used in less controlled, everyday settings.
Study author Rebecka Bremler of the Centre for Psychedelic Research at Imperial College London told PsyPost that there was “a lack of research into this topic – at least when we started the project in 2021. There was (is) all of this amazing research on psychedelics positive effects on mental health, and some on acute challenging experiences (‘bad trips’) with psychedelics and what may contribute to them, but not so much on long-term negative psychological responses (which is what we focused on here).”
“We wanted to find what may be potential risk factors for having these experiences, but also for people who had had them to be heard. The latter was one of the reasons why we included extended participants quotes in the article: to tell it in their own words as much as possible.”
To investigate this, Bremler and her colleagues launched a two-phase study. Initially, they reached out through social media platforms, including Reddit and Twitter, targeting forums and individuals interested in psychedelic experiences.
Participants were selected based on their reported experiences of negative psychological symptoms lasting over 72 hours following psychedelic use. The drugs in question included LSD, psilocybin (found in magic mushrooms), DMT, ayahuasca, 5-MeO-DMT, mescaline, and MDMA/ecstasy. The study emphasized the need for participants to be adults, fluent in English, and having access to the internet and an email address.
The first phase of the study was an online questionnaire, open from November 2021 to April 2022, where participants provided consent and then completed a series of questions. Out of 84 individuals who started the survey, 32 completed it in full. The survey included the Challenging Experience Questionnaire (CEQ) to measure the intensity of any negative experiences during psychedelic use.
Following this, a smaller group was selected for in-depth interviews. Out of 20 contacted, 15 participants, including a range of genders and ages, completed interviews. These semi-structured interviews, conducted by experienced mental health professionals, delved deeper into the participants’ experiences with psychedelics.
The questionnaire responses showed higher than average scores on the CEQ, indicating more severe challenging experiences compared to other studies. Anxiety and panic were the most frequently reported symptoms.
The interviews painted a more detailed picture of these experiences. Many participants described their acute psychedelic experiences as negative or frightening, commonly referred to as ‘bad trips.’ This was particularly true for those who had taken classic psychedelics like LSD. The interviews also uncovered additional symptoms not listed in the survey, such as derealization (feeling disconnected from reality) and intense flashbacks of the psychedelic experience.
A significant part of the study was understanding the risk factors that might contribute to these negative outcomes. Key factors included the dosage and purity of the drugs, frequency of use prior to the negative experience, drug quality concerns, and polysubstance use. Moreover, personal and family mental health history played a crucial role, as did the environment in which the psychedelic was taken. Stressful or unsafe environments, negative expectations, and lack of social support during or after the experience were all identified as contributing factors.
“The potential risk factors that we identified based on the interviews were very similar to what previous research has found to be risk factors for having a challenging acute experience or ‘bad trip,'” Bremler explained. “All but one participant who had used a classic psychedelic also talked about having a difficult acute psychedelic experience, and then what they described as something similar to a trauma response in the following weeks, months or even years.”
“We know from previous research that psychedelics make us more sensitive to our environment – both external and internal (internal meaning, for example, mental health, previous life experiences, or even our mood that day). So, it makes sense that there’s a potential to have lasting negative effects on mental health, just as it can have positive effects.”
The new findings are in line with a similar study, published in PLOS One. That study found that experiencing a more challenging trip and being in an unguided setting at the time of the psychedelic experience were associated with a greater range of subsequent psychological difficulties.
However, the study is not without its limitations. The researchers noted the challenges in gathering data on such a sensitive topic, including the reliance on self-reported experiences and potential inaccuracies in recalling past drug use. The study’s sample size was also relatively small.
Looking ahead, the researchers call for more comprehensive studies with larger sample sizes and diverse participant groups to further explore the long-term effects of psychedelics. They also suggest that future research should focus on specific symptomatology or diagnoses arising post-psychedelic use. This could involve more innovative methods like interviewing next-of-kin or carers to provide a more rounded understanding of these experiences.
“Important remaining questions to address would, for example, be to further investigate the potential risk factors that we found here,” Bremler said. “There’s so much more to research in this field, and this ‘other’ side of psychedelics is just as important to know more about as the positive side — especially as psychedelic treatment becomes legal.”
The study, “Case analysis of long‑term negative psychological responses to psychedelics“, was authored by Rebecka Bremler, Nancy Katati, Parvinder Shergill, David Erritzoe, and Robin L. Carhart‑Harris.
