Naturalistic use of psychedelics does not modulate processing of self-related stimuli (but it might modulate attentional mechanisms): An event-related potentials study.

Classic psychedelics are able to profoundly alter the state of consciousness and lead to acute experiences of ego dissolution - the blurring of the distinction between representations of self and the external world. However, whether repeated use of psychedelics is associated with more prolonged and permanent modifications to the concept of self remains to be investigated. Therefore, we conducted a preregistered, cross-sectional study in which experienced psychedelics users (15 or more lifetime experiences with psychedelics; N = 56) were compared to nonusers (N = 57) in terms of neural reactivity to a Self-name (i.e., each participant's own name) stimulus, which is known to robustly activate a representation of self. Two control stimuli were additionally used: an Other-name stimulus, as a passive control condition in which no reaction was required, and a Target-name stimulus, to which participants provided a manual response and which thus constituted an active control condition. Analysis of the amplitude of the P300 ERP component evoked by the Self- or Target-names revealed no difference between the psychedelics users and nonusers. However, psychedelic users exhibited increased P300 amplitude during perception of Other-names. In addition, in comparison to nonusers, psychedelics users exhibited a smaller increase in P300 amplitude when processing the task-relevant Target-names (in relation to both Self- and Other-names). Therefore, our data suggests that regular naturalistic use of psychedelics may not be related to long-term changes in the representation of self, but it might potentially affect the allocation of attentional resources to task-relevant stimuli.

The relation between naturalistic use of psychedelics and perception of emotional stimuli: An event-related potential study comparing non-users and experienced users of classic psychedelics.

BACKGROUND: Previous research has suggested that controlled administration of psychedelic substances can modulate emotional reactivity, enhancing positive and diminishing negative emotions. However, it is unclear whether similar effects are associated with using psychedelics in less-controlled naturalistic environments. AIMS: This cross-sectional study investigated the neural markers associated with the perception of emotional stimuli in individuals with extensive experience of naturalistic psychedelic use (15 or more lifetime experiences), comparing them to non-users. METHODS: Electroencephalography (EEG) signals were recorded from two groups: experienced psychedelics users (N = 56) and non-users (N = 55). Participants were presented with facial images depicting neutral or emotional expressions (anger, sadness, and happiness). Event-related potential (ERP) components were analyzed as indices of emotional reactivity. RESULTS: Psychedelic users were characterized by significantly lower amplitudes of the N200 component in response to fearful faces, in comparison to non-users. In addition, interaction effects between Group and Emotional expression were observed on N170 and N200 amplitudes, indicating group differences in the processing of fearful faces. However, no significant between-group differences emerged in the analysis of later ERP components associated with attention and cognitive processes (P200 and P300). CONCLUSIONS: The results suggest that naturalistic use of psychedelics may be linked to reduced reactivity to emotionally negative stimuli at the early and automatic processing stages. Our study contributes to a better understanding of the effects related to using psychedelics in naturalistic contexts.

Call for evidence-based psychedelic integration.

The use of psychedelics for various purposes was common in different civilizations throughout human history and has been explored scientifically for more than a century. Although the applications of psychedelics show promise in the treatment of various psychiatric and neurological indications, as well as in facilitation of well-being and personal growth, several psychedelic-related risks and challenges have also been identified. Psychedelic integration (PI) refers to various practices that serve to either minimize harms or maximize benefits associated with psychedelic use. PI is also recognized as a substantial part of psychedelic-assisted therapy (PAT), following preparation to and facilitation of the psychedelic experience. In the context of clinical/psychotherapeutic practice, several PI models/methods have already been proposed. However, while a number of these models/methods are theory-driven, or have a history of clinical application, each lack any empirical support and thus cannot be described as evidence based. This is to the disadvantage to countless people who had and who will have their psychedelic experiences in various contexts, as the prevalence of using psychedelics increased in recent years and is expected to grow further. Therefore, consistent with general recommendations for developing and implementing evidence-based mental health practices, this article calls for scientific efforts to the development, examination, and evaluation of psychedelic integration models/methods. This article also briefly summarizes the current literature on psychedelic integration, provides a list of exemplary avenues that research on psychedelic integration might take, as well as anticipates and discusses the limitations and challenges of PI-focused research. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Naturalistic use of psychedelics is related to emotional reactivity and self-consciousness: The mediating role of ego-dissolution and mystical experiences.

BACKGROUND: Psychedelics are able to acutely alter emotional reactivity and self-consciousness. However, whether the regular naturalistic use of psychedelics can be linked to more persistent trait-level changes in these domains remains an open question. AIM: To test the hypotheses that (1) using psychedelics is related to higher positive and lower negative emotional reactivity; and (2) an adaptive pattern of self-consciousness, including diminished public self-consciousness and rumination, and increased reflection and self-awareness; and (3) these relations are mediated by the intensity of past ego-dissolution and mystical experiences. METHOD: An online survey including questions about the history of psychoactive substance use; questionnaires measuring trait levels of emotional reactivity and self-consciousness; questionnaires for retrospective assessment of ego-dissolution and mystical experiences. Data collected from 2516 participants (1661 psychedelics users) were analyzed using robust linear regression and mediation analysis. RESULTS: A higher number of lifetime uses of psychedelics predicted greater positive and lower negative emotional reactivity; also, in the domain of self-consciousness, it predicted greater reflection and internal state awareness, and reduced rumination tendency and public self-consciousness. Finally, the intensity of past mystical and ego-dissolution experiences mediated almost all the observed relationships between the lifetime number of psychedelics uses and psychological variables. CONCLUSIONS: Lifetime psychedelics use predicts an adaptive pattern of trait-level emotional reactivity and self-consciousness. Ego-dissolution and mystical experiences are essential in understanding the long-lasting psychological effects of psychedelics use. Our findings might potentially explain previous observations of increased well-being in psychedelics users.

Who Is at Risk of Developing Cannabis Dependence? Findings From an Extensive Online Study on Cannabis Users.

OBJECTIVES: Although frequency of cannabis use is considered to be the strongest risk factor for developing cannabis dependence, only up to half of daily users become dependent. In this study, we explored an array of risk factors and moderators of cannabis dependence symptoms from the International Classification of Diseases, Tenth Edition endorsed by participants. METHODS: A sample of 1,635 cannabis users completed an Internet survey consisting of measures of cannabis and other drug use. Multiple linear regression with a backward elimination method was employed to identify predictors of cannabis dependence symptoms. After that, a series of hierarchical multiple regression analyses were performed to test the predictive validity of the interactions between frequency of cannabis use and other predictors. RESULTS: Frequency of cannabis use appeared to be the strongest predictor of developing cannabis dependence symptoms; other significant predictors of cannabis dependence symptoms were substance-dependency-related treatment seeking, mental health problems in the family and pattern of substance use. Duration of cannabis use, relationship status, and drug use history in the family were identified as significant moderators of the relationship between frequency of cannabis use and the number of cannabis dependence symptoms. CONCLUSIONS: This study confirms that the frequency of cannabis use is the strongest predictor of cannabis dependence symptoms but this relationship is significantly moderated by three abovementioned factors.

No relationship between frontal alpha asymmetry and depressive disorders in a multiverse analysis of five studies.

For decades, the frontal alpha asymmetry (FAA) - a disproportion in EEG alpha oscillations power between right and left frontal channels - has been one of the most popular measures of depressive disorders (DD) in electrophysiology studies. Patients with DD often manifest a left-sided FAA: relatively higher alpha power in the left versus right frontal lobe. Recently, however, multiple studies failed to confirm this effect, questioning its reproducibility. Our purpose is to thoroughly test the validity of FAA in depression by conducting a multiverse analysis - running many related analyses and testing the sensitivity of the effect to changes in the analytical approach - on data from five independent studies. Only 13 of the 270 analyses revealed significant results. We conclude the paper by discussing theoretical assumptions underlying the FAA and suggest a list of guidelines for improving and expanding the EEG data analysis in future FAA studies.