Introduction
Psychedelic therapy has attracted significant interest and different perspectives over the years. It involves the controlled use of psychedelic drugs, such as Lysergic Acid Diethylamide (LSD) and Psilocybin for the treatment of psychiatric illnesses and mental health conditions (Johns Hopkins Medicine, 2025). Concerns about Psychedelic therapy emerged in the 1890s, when mescaline (also known as 3,4,5-trimethoxyphenethylamine) began to surface. This was due to its strong side effects including hallucinations, distorted perception and recognition.
Psychedelic drugs are a category of hallucinogens that alter thought processes and distort sensory perceptions. These are a subsection of psychoactive drugs, but more specifically substances that alter an individual’s psyche, leading to changes in mood, perception, and thought patternThese types of drugs can come with many risks and side effects as individuals describe experiencing intense emotions including fear and hallucinations (McLean Hospital, 2024).
Fast forward to present day and LSD is now a substance being investigated for its therapeutic potential for mental health as well as its impact on enhancing brain function. Further research led to the discovery of lysergic acid diethylamide (LSD), a type of psychedelic drug developed by Dr Albert Hofmann. Scientists and researchers began investigating the effects of LSD and other common psychedelics, seeking to understand their therapeutic potential in treating psychiatric and mental health disorders. This growing interest also sparked ethical debates, while the misuse of these drugs increased, raising safety concerns. Consequently, political pressures escalated, ultimately leading to the prohibition of psychedelics during the 1960s and 1970s. LSD is now primarily studied in research contexts for its potential applications in mental health treatment and in advancing understanding of brain function.
A brief history of Psychedelics
Hallucinogens have been integral to religious practice since the beginning of humanity, with archaeological evidence highlighting the use of plants and fungi in shamanistic rituals. In some traditions, mushrooms were preserved in honey and later consumed, sometimes incorporated into ceremonial foods such as chocolate. It was widely believed that consuming these substances opened a communication pathway between the living and the spiritual realm, enabling the summoning of gods for their healing abilities. Shamans were regarded as highly skilled healers and spiritual leaders, often fulfilling roles that combined medicinal, psychological, and religious functions. One example of psychedelic substances being used medicinally is Ergot, a fungus with vasoconstrictive properties. Ergot contains lysergic acid, a chemical precursor to LSD.
In the late 19" century psychedelics regained medical interest, particularly with the study of mescaline derived from the peyote cactus. Dr Briggs documented his experience a year after ingesting the peyote cactus. His account attracted attention of a pharmaceutical company, which subsequently promoted research into the plant’s therapeutic applications. (Raposo, 2020)
Current Research in Psychedelic Therapy
Psychedelic therapy is experiencing a surge in research, with clinical trials and studies exploring the therapeutic potential of psilocybin, MDMA, and ketamine (Rey,S., 2024). Although regulatory approval remains limited, progress continues in 2025, with major contributions from institutions such as Imperial College London, Johns Hopkins University and MAPS (Imperial College London, 2025) (Johns Hopkins Medicine, 2025)
Psilocybin remains the most extensively studied psychedelic. Recent clinical trials have shown that it can significantly improve symptoms of treatment-resistant depression, with sustained improvements observed after one or two guided therapeutic sessions (Sessa & Worthley, 2016) Researchers at Imperial College are conducting the UK’s first clinical trial on psilocybin-assisted therapy, aimed at preventing relapse among individuals recovering from opioid addiction, particularly during the vulnerable post-detox phase (Pronovost-Morgan, Greenway, & Roseman, 2025).
MDMA-assisted psychotherapy has yielded promising results in treating post-traumatic stress disorder (PTSD). A Phase 3 trial reporting that 71% of participants no longer met diagnostic criteria for PTSD one year after treatment (Kishon et al., 2024). However, the FDA declined approval in 2024, due to methodological concerns(Rey, 2024) In response, researchers, including those at Imperial College London, are developing the Reporting of Setting in Psychedelic Clinical Trials (ReSPCT) guidelines, which are designed to standardise the reporting of psychosocial variables in psychedelic trials (Mitchell et al., 2023)
Ketamine, already approved for treatment-resistant depression, continues to be investigated for broader indications, including bipolar depression, suicide, and alcohol use disorder (Stringer, 2024) (Tani, 2025). A recent randomised study involving Imperial researchers also examined the role of music in ketamine-assisted psychotherapy, suggesting that experiential context significantly shapes therapeutic outcomes (Greenway et al., 2025).
Ultimately, as psychedelic therapy transitions from an experimental approach to an evidence-based practice, ongoing research will continue to shape its role in modern psychiatry.
Ethics and Safety
Whilst a heavily controlled clinical setting reduces the risk of harm, no drug can be considered completely harmless. An article examining whether safety and innovation can coexist in drug development concluded that ‘a drug is considered safe when its risks are tolerable for the user (NIDA,2024). For instance, MDMA can exacerbate pre-existing mental health conditions such as depression or anxiety in vulnerable individuals. Even individuals without prior mental health conditions may experience temporary low mood during the comedown phase, although such effects are generally not life-threatening. Although the illegality of psychedelics has influenced public perceptions of their ethical status, medical professionals have developed rigorous methods of regulating their administration in therapeutic contexts. A controlled clinical environment also helps to minimise side effects by ensuring the purity and dosage accuracy of these substances. Currently, there is potential for the future legalisation of psychedelics; however, this process is likely to be protracted and complex (Rey,2024), (Sessa & Worthley,2016).
References
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