The human experience with a psychoactive substance is, by definition, intimate and qualitative. However, for this experience to be studied rigorously within the scientific realm, it must be translated into a quantifiable language. For decades, psychopharmacology has faced the challenge of measuring the ineffable: how a molecule alters perception, emotion, and thought. This process is not limited to asking “How did you feel?” but involves designing instruments capable of capturing the complexity of an altered state of consciousness with statistical precision.
In brief
- From qualitative to quantitative: Transformation of subjective experiences into measurable data using standardized scales.
- Key tools: Comparative analysis of instruments like ARCI, HRS, and VESSPA to differentiate pharmacological profiles.
- Substance differentiation: Identification of nuances between drugs with similar effects (e.g., 2C-B vs. MDMA) using specific subscales.
- Experimental context: Importance of the environment (laboratory vs. naturalistic) in modulating the results obtained.
From anecdotes to data: the birth of questionnaires
The starting point for any study on subjective effects lies in the collection of narratives. Experienced users are asked to describe what they lived through after the administration of a substance. From these testimonies, recurring patterns are extracted, and statements are formulated that can be validated or invalidated by the subject. These statements can be written in the positive (e.g., “I feel euphoria”) or the negative (e.g., “I do not feel anxiety”), usually responding via a numerical scale from 1 to 5, where the value indicates the intensity of the phenomenon.
This methodology has led to specific inventories designed for each class of drug. The most emblematic is the ARCI (Addiction Research Center Inventory), which groups effects into dimensions such as sedation, euphoria, dysphoria, and cognitive alterations. On the other hand, to evaluate cannabis derivatives, the PSI has been developed, focusing on phenomena like perceptual distortions or paranoia. However, the evaluation of hallucinogens and entactogens requires more specialized instruments.
HRS and VESSPA: Instruments to explore altered states
In the field of hallucinogens, two fundamental scales stand out. The first is the HRS (Hallucinogen Rating Scale), designed to measure dimensions such as somaesthesia, affect, volition, cognition, and visual or auditory perception. Its structure allows for the detection of whether a substance primarily induces changes in the physical body or in the mental experience.
The second relevant tool is the VESSPA (Subjective Effects Assessment of Substances with Abuse Potential), developed by researchers at the IMIM in Barcelona. This questionnaire addresses aspects such as sedation, anxious somatization, perceptual changes, and psychotic symptomatology. Its utility lies in its ability to distinguish between pleasant or social effects versus potential adverse reactions.
It is crucial to understand that these instruments are not mere lists of symptoms, but complex matrices where each item contributes to defining a global profile. For example, within the “affect” scale of the HRS, one can find items regarding modifications in the sense of closeness toward others or experiences of profound awe.
The case of 2C-B: A revealing comparative study
To illustrate the practical application of these tools, it is instructive to analyze a study conducted by our research group on the compound 2C-B. The objective was to characterize its psychological effects and compare its profile with other known substances such as MDMA, amphetamine, ayahuasca, and Salvia divinorum.
Volunteers completed both the HRS and the VESSPA after the administration of the substance. The results showed that 2C-B generated high scores in “perception” within the HRS, confirming its potent visual and auditory capacity. However, its scores in “somaesthesia” (physical sensations) were lower compared to other visionary drugs.
An interesting finding emerged when comparing 2C-B with Salvia divinorum: both substances showed similar profiles in several dimensions, but Salvia obtained lower scores in “volition,” which indicates a greater difficulty in interacting with the immediate environment. In contrast, 2C-B allowed for a higher degree of control and social connection.
When analyzing the VESSPA data, it was observed that 2C-B scored very high in “pleasure and sociability” and extremely low in “psychotic symptomatology.” This last piece of data is relevant from a harm reduction perspective: it confirms anecdotal testimonies from users regarding the manageability of this substance, despite its potent hallucinogenic action.
Nuances between similar substances
The comparison with MDMA offered fascinating results. Although both compounds are entactogens, their profiles differ notably on the “perception” scale, where 2C-B outperformed MDMA. Likewise, differences were detected in the “affect” dimension: while MDMA showed high scores in laboratory studies (a cold and controlled context), 2C-B obtained higher results in naturalistic settings.
This discrepancy underscores a fundamental principle: context decisively influences the subjective experience. A laboratory environment can generate anxiety or rigidity, while a naturalistic setting favors relaxation and emotional openness. Therefore, any interpretation of data must always consider the conditions under which they were collected.
Critical reading and harm reduction
The use of these scales does not seek to replace personal experience, but to provide it with a more solid interpretive framework. Understanding that a substance like 2C-B shares certain stimulant effects with amphetamines (energy, activity), but differs in its perceptual and anxiety profile, allows users to make more informed decisions.
The distinction between “acute effects” and “post-acute sequelae” is also vital. In the mentioned study, symptoms such as insomnia or anxiety were identified that could persist for up to 48 hours after ingestion. Recognizing these patterns helps to properly plan the integration period following consumption.
Finally, it is important to remember that no scale guarantees identical results in all individuals. Biological and psychological variability introduces a factor of unpredictability inherent to the use of psychoactive substances. Therefore, the information provided by these instruments should serve as an educational guide and not as an absolute prescription.
Editorial closing
Psychonautics is nourished by the dialogue between personal experience and scientific knowledge. By understanding how drug effects are measured, we transcend mere curiosity to access a deep understanding of our own chemical mind. These tools remind us that behind every altered experience are complex neurobiological processes that deserve to be respected and studied with prudence.
In a world where access to new substances is increasingly easy, literacy in psychopharmacology becomes an indispensable tool for navigating this territory safely. The next time you experience any subjective effect, remember that your experience is part of a vast body of global knowledge.
