A Review of Lysergic Acid Diethylamide (LSD) in the Treatment of Addictions: Historical Perspectives and Future Prospects

Liester opens with a concise historical and scientific background to lysergic acid diethylamide (LSD). The introduction traces LSD's discovery, early human self-experiments and animal observations, and situates the molecule chemically as a semisynthetic ergot derivative with potent psychoactive effects. It summarises basic pharmacokinetic features reported in the extracted text (onset 20–60 minutes, typical duration 8–12 hours, plasma half-life ~5.1 hours) and notes early hypotheses that linked LSD to a ‘‘model psychosis’’ because of its capacity to produce profound perceptual and cognitive changes. The introduction highlights a central tension motivating the review: although early clinical reports suggested LSD might assist psychotherapy and show benefit for addictions, widespread unregulated recreational use, adverse-event reports, and restrictive legal actions curtailed research. The paper therefore sets out to review LSD's pharmacology, phenomenology, historical clinical research in addictions, proposed mechanisms of anti-addictive action, and to assess whether renewed investigation is warranted.

The extracted text does not present an explicit Methods section describing a systematic search strategy, databases searched, eligibility criteria, or risk-of-bias assessment. From the content that follows, Liester appears to have conducted a narrative, historically oriented review that integrates pharmacology, animal and human experimental findings, clinical trials from the 1950s–1970s, later reviews and meta-analyses, and a brief account of regulatory and sociocultural history. Material covered in the review includes preclinical pharmacology and receptor binding data, gene-expression findings, phenomenological descriptions from human reports, summaries of early clinical programmes treating alcoholism and narcotic addiction, results from a small number of randomised trials and controlled studies, published reviews and a meta-analysis (notably Krebs and Johansen), and a description of later small clinical research including Swiss work in the 2000s. Because the paper is narrative rather than presented as a systematic review in the extracted text, details such as inclusion/exclusion criteria, search dates, and formal appraisal methods are not clearly reported.

Pharmacology and molecular effects: The review summarises LSD as an ergot-derived semisynthetic compound that binds broadly across serotonergic receptors (5-HT1A/1B/1D, 5-HT2A/2C, 5-HT5A, 5-HT6, 5-HT7) and also interacts with adrenergic, dopaminergic (D1, D2) and glutamatergic systems. Psychedelic effects are generally attributed to partial agonism at 5-HT2A receptors; downstream signalling pathways discussed include PLC, PLA2 and PLD routes, calcium-mediated kinases and PKC, and interactions with metabotropic glutamate receptors (mGluR2) that may form functional complexes with 5-HT2A. The extracted text reports single-dose changes in expression of immediate-early and related genes (for example c-fos, arc, NOR-1), implying effects on synaptic plasticity and intracellular signalling. Phenomenology and adverse events: Liester reviews common somatic, perceptual, emotional and cognitive effects described in clinical and experimental literature: autonomic changes, prominent visual alterations, synaesthesia, shifts in affect ranging from euphoria to panic, impaired judgment and increased suggestibility, and reports of transcendent or mystical experiences. Adverse psychiatric events are summarised from historical surveys and case series: a survey by Cohen found prolonged psychiatric reactions (>48 hours) occurred at rates of 0.8 per 1000 in normal volunteers and 1.8 per 1000 in patients; the review emphasises that deaths from direct LSD overdose are not documented in the extracted text, with fatalities more commonly linked to risky behaviours while intoxicated. Clinical research in addictions — alcoholism: Early clinical work from the 1950s and 1960s is described in detail. Osmond and Hoffer's inpatient series of 24 treatment-resistant alcoholics treated with a single 200–400 microgram dose reported 50% unchanged, 25% ‘‘improved’’ and 25% ‘‘much improved’’ on the criteria described. O’Reilly et al. treated 68 chronic alcoholics, reporting 26 patients (38%) abstinent in the two months before follow-up; methodological limitations were noted. Jensen’s early controlled pilot and follow-up trials are summarised: an initial 145-patient pilot with three groups reported higher abstinence and improvement rates in the LSD-treated group (for example 66% abstinent among the 58 traced LSD recipients versus 41% in a standard-therapy non-LSD control group), although loss to follow-up and other design problems were common. Pahnke et al. are reported to have used a randomised, double-blind protocol comparing an ‘‘active’’ dose (the extracted text reports 350–450 mg, which is likely a transcription or reporting error and the exact dose is not clearly reported in the extracted text) with a low-dose control (reported as 50 mg); independent raters found a statistically significant improvement (p < 0.05) in global adjustment and drinking behaviour at six months in the active group. Reviews and meta-analysis: The paper summarises subsequent methodological critiques and reviews. Mangini (1998) and Abuzzahab and Anderson earlier concluded the evidence base was inconsistent and inconclusive because of heterogeneous designs, inadequate controls and follow-up. Krebs and Johansen performed a quantitative meta-analysis of six randomised controlled trials (five double-blind) with a combined sample of 536 adults; of these, 325 received a single dose of LSD (reported dose range 210–800 micrograms) and 211 were controls (low-dose LSD, stimulants or non-drug control). That meta-analysis concluded a single dose of LSD compared favourably with available pharmacotherapies for alcoholism such as naltrexone, acamprosate or disulfiram, while also noting heterogeneity in session conditions and preparation/debriefing. Clinical research in narcotic addiction: A smaller literature is described. Ludwig and Levine randomised 70 detoxified ‘‘narcotic addicts’’ across five groups and reported short-term improvements in self-concept and coping that were not maintained at two months; abstinence was not assessed in that report. Savage and McCabe randomised 74 subjects to a halfway-house programme including a single 200–500 microgram LSD dose versus an outpatient group psychotherapy control; urine toxicology monitoring showed 25% abstinence at one year in the LSD group compared with 5% in controls, and reports linked successful community adjustment to having experienced a psychedelic peak. Set, setting, recreational use and legal history: The review emphasises the strong influence of mindset and environment on outcomes, and it recounts the broad cultural diffusion and recreational use of LSD in the 1960s, high-profile controversies, media sensationalism and the subsequent tightening of legal restrictions. These developments, together with concerns about unsupervised use and methodological shortcomings in early studies, are presented as important reasons research declined in the 1970s. Resurgence and recent small studies: The extracted text notes a limited resumption of research internationally from the late 1980s onward, with a small Swiss programme (2008–2011) that treated 12 subjects with life-threatening illness using therapeutic and placebo-dose sessions; all 12 reported benefits and none reported serious adverse effects in that programme as described in the extraction. Mechanistic hypotheses for anti-addiction effects: Liester groups proposed mechanisms into three partially overlapping hypotheses. The biochemical hypothesis posits modulation of the mesolimbic dopamine pathway through combined serotonergic and dopaminergic receptor actions, potentially restoring dopaminergic homeostasis. The psychological hypothesis emphasises LSD-facilitated psycholytic psychotherapy, increased emotional insight, reduced depression and anxiety, and improved access to repressed material. The transcendent hypothesis highlights the role of mystical or peak experiences in producing transformative shifts in attitudes and behaviour that may support long-term recovery.

Liester interprets the assembled evidence with cautious optimism. The review acknowledges that early clinical reports often suggested clinically meaningful benefits of LSD-assisted interventions for alcoholism and, to a lesser extent, narcotic addiction, and that some randomised data and a later meta-analysis indicate a signal of efficacy when a single supervised high-dose session is integrated with psychosocial support. At the same time, the author stresses that much of the early literature suffered from methodological limitations: variable diagnostic specificity, heterogeneous dosing and session conditions, inconsistent follow-up durations, substantial loss to follow-up, and limited use of blinded raters in many studies. The paper places these limitations in historical context, noting that regulatory standards (for example the FDA’s later requirement for double-blind trials) and the rapid social and political backlash against psychedelics in the 1960s affected research methods and the volume of work conducted. Liester argues that some criticisms of the historical literature should be reinterpreted with that context in mind, but he does not dismiss methodological weaknesses. Safety concerns, the potential for adverse psychiatric reactions, and the impact of unsupervised recreational use are discussed as real constraints that must be addressed in modern research. On implications, the review calls for renewed, rigorous clinical research into LSD for addictions. The author suggests contemporary study designs should incorporate careful participant selection, standardised preparation and integration procedures, blinded assessment where possible, and systematic adverse-event monitoring. Liester also highlights opportunities to learn from other traditions and medicines (for example ayahuasca, ibogaine, mescaline) and proposes cross-cultural collaboration with experienced healers as one possible avenue for developing safe, culturally informed approaches. Overall, the discussion frames renewed investigation as justified but to be undertaken with scientific rigour and attention to safety and social context.

Liester concludes that addictions remain a major global health burden and that existing pharmacological treatments have substantial limitations. Despite the methodological flaws and social controversies that curtailed mid-20th century research, a reappraisal of historical and more recent evidence suggests that LSD, when used in controlled clinical settings combined with psychotherapeutic support, may have therapeutic potential in the treatment of addictions. The extracted text states that cautious optimism is warranted and that further well-designed research into LSD’s potential as an addiction treatment is justified.