Psilocybin and ego-dissolution

“AIMS the experience of a compromised sense of ‘self’, termed ego-dissolution, is a key feature of the psychedelic experience. this study aimed to validate the ego-dissolution inventory (edi), a new 8-item self-report scale designed to measure ego-dissolution. additionally, we aimed to investigate the specificity of the relationship between psychedelics and ego-dissolution. method sixteen items relating to altered ego-consciousness were included in an internet questionnaire; eight relating to the experience of ego-dissolution (comprising the edi), and eight relating to the antithetical experience of increased self-assuredness, termed ego-inflation. items were rated using a visual analog scale. participants answered the questionnaire for experiences with classical psychedelic drugs, cocaine and/or alcohol. they also answered the seven questions from the mystical experiences questionnaire (meq) relating to the experience of unity with one’s surroundings. results six hundred and ninety-one participants completed the questionnaire, providing data for 1828 drug experiences (1043 psychedelics, 377 cocaine, 408 alcohol). exploratory factor analysis demonstrated that the eight edi items loaded exclusively onto a single common factor, which was orthogonal to a second factor comprised of the items relating to ego-inflation (rho = -0.110), demonstrating discriminant validity. the edi correlated strongly with the meq-derived measure of unitive experience (rho = 0.735), demonstrating convergent validity. edi internal consistency was excellent (cronbach’s alpha 0.93). three analyses confirmed the specificity of ego-dissolution for experiences occasioned by psychedelic drugs. firstly, edi score correlated with drug-dose for psychedelic drugs (rho = 0.371), but not for cocaine (rho = 0.115) or alcohol (rho = -0.055). secondly, the linear regression line relating the subjective intensity of the experience to ego-dissolution was significantly steeper for psychedelics (unstandardized regression coefficient = 0.701) compared with cocaine (0.135) or alcohol (0.144). ego-inflation, by contrast, was specifically associated with cocaine experiences. finally, a binary support vector machine classifier identified experiences occasioned by psychedelic drugs vs. cocaine or alcohol with over 85% accuracy using ratings of ego-dissolution and ego-inflation alone. conclusion our results demonstrate the psychometric structure, internal consistency and construct validity of the edi. more…”

“Users of psychedelic drugs often report that their sense of being a self or ‘i’ distinct from the rest of the world has diminished or altogether dissolved. neuroscientific study of such ‘ego dissolution’ experiences offers a window onto the nature of self-awareness. we argue that ego dissolution is best explained by an account that explains self-awareness as resulting from the integrated functioning of hierarchical predictive models which posit the existence of a stable and unchanging entity to which representations are bound. combining recent work on the ‘integrative self’’ and the phenomenon of self-binding with predictive processing principles yields an explanation of ego dissolution according to which self-representation is a useful cartesian fiction: an ultimately false representation of a simple and enduring substance to which attributes are bound which serves to integrate and unify cognitive processing across levels and domains. the self-model is not a mere narrative posit, as some have suggested; it has a more robust and ubiquitous cognitive function than that. but this does not mean, as others have claimed, that the self-model has the right attributes to qualify as a self. it performs some of the right kinds of functions, but it is not the right kind of entity. ego dissolution experiences reveal that the self-model plays an important binding function in cognitive processing, but the self does not exist.’”

“The apz questionnaire was developed in order to explore hypotheses on ascs. first, in a series of 11 experiments using different induction methods on 393 healthy ss, the hypothesis was tested that ascs have major dimensions in common irrespective of the mode of their induction. in the international study on altered states of consciousness (isasc) the external validity of the experimental results was assessed. the isasc was carried out on a total of 1,133 ss in 6 countries. the main results of the experimental studies were corroborated in the field studies. the results show that the common denominator of ascs is described by 3 oblique dimensions, designated as oceanic boundlessness, dread of ego dissolution, and visionary restructuralization. the reliability and validity of the scales are satisfactory. tested versions of the apz scales are available in english (uk, us), german, italian, and portuguese. psychometrically as yet untested versions exist in dutch, finnish, french, greek, spanish, and russian.”

“RATIONALE ayahuasca is a psychotropic plant tea from south america used for religious purposes by indigenous people of the amazon. increasing evidence indicates that ayahuasca may have therapeutic potential in the treatment of mental health disorders and can enhance mindfulness-related capacities. most research so far has focused on acute and sub-acute effects of ayahuasca on mental health-related parameters and less on long-term effects. objectives the present study aimed to assess sub-acute and long-term effects of ayahuasca on well-being and cognitive thinking style. the second objective was to assess whether sub-acute and long-term effects of ayahuasca depend on the degree of ego dissolution that was experienced after consumption of ayahuasca. results ayahuasca ceremony attendants (n = 57) in the netherlands and colombia were assessed before, the day after, and 4 weeks following the ritual. relative to baseline, ratings of depression and stress significantly decreased after the ayahuasca ceremony and these changes persisted for 4 weeks. likewise, convergent thinking improved post-ayahuasca ceremony up until the 4 weeks follow-up. satisfaction with life and several aspects of mindfulness increased the day after the ceremony, but these changes failed to reach significance 4 weeks after. changes in affect, satisfaction with life, and mindfulness were significantly correlated to the level of ego dissolution experienced during the ayahuasca ceremony and were unrelated to previous experience with ayahuasca. conclusion it is concluded that ayahuasca produces sub-acute and long-term improvements in affect and cognitive thinking style in non-pathological users. these data highlight the therapeutic potential of ayahuasca in the treatment of mental health disorders, such as depression.”

“Ego-disturbances have been a topic in schizophrenia research since the earliest clinical descriptions of the disorder. manifesting as a feeling that one’s ‘self,’ ‘ego,’ or ‘i’ is disintegrating or that the border between one’s self and the external world is dissolving, ‘ego-disintegration’ or ‘dissolution’ is also an important feature of the psychedelic experience, such as is produced by psilocybin (a compound found in ‘magic mushrooms’). fifteen healthy subjects took part in this placebo-controlled study. twelve-minute functional mri scans were acquired on two occasions: subjects received an intravenous infusion of saline on one occasion (placebo) and 2 mg psilocybin on the other. twenty-two visual analogue scale ratings were completed soon after scanning and the first principal component of these, dominated by items referring to ‘ego-dissolution’, was used as a primary measure of interest in subsequent analyses. employing methods of connectivity analysis and graph theory, an association was found between psilocybin-induced ego-dissolution and decreased functional connectivity between the medial temporal lobe and high-level cortical regions. ego-dissolution was also associated with a ‘disintegration’ of the salience network and reduced interhemispheric communication. addressing baseline brain dynamics as a predictor of drug-response, individuals with lower diversity of executive network nodes were more likely to experience ego-dissolution under psilocybin. these results implicate mtl-cortical decoupling, decreased salience network integrity, and reduced inter-hemispheric communication in psilocybin-induced ego disturbance and suggest that the maintenance of ‘self’or ‘ego,’ as a perceptual phenomenon, may rest on the normal functioning of these systems. hum brain mapp, 2015. © 2015 wiley periodicals, inc.”

“Introduction: it is a basic principle of the ‘psychedelic’ treatment model that the quality of the acute experience mediates long-term improvements in mental health. in the present paper we sought to test this using data from a clinical trial assessing psilocybin for treatment-resistant depression (trd). in line with previous reports, we hypothesized that the occurrence and magnitude of oceanic boundlessness (obn) (sharing features with mystical-type experience) and dread of ego dissolution (ded) (similar to anxiety) would predict long-term positive outcomes, whereas sensory perceptual effects would not. material and methods: twenty patients with treatment resistant depression underwent treatment with psilocybin (two separate sessions: 10mg and 25mg psilocybin). the altered states of consciousness (asc) questionnaire was used to assess the quality of experiences in the 25mg psilocybin session. from the asc, the dimensions obn and ded were used to measure the mystical-type and challenging experiences, respectively. the self-reported quick inventory of depressive symptoms (qids-sr) at 5 weeks served as the endpoint clinical outcome measure, as in later time points some of the subjects had gone on to receive new treatments, thus confounding inferences. in a repeated measure anova, time was the within-subject factor (independent variable), with qids-sr as the within-subject dependent variable in baseline, 1-day, 1-week, 5-weeks. obn and ded were independent variables. obn-by-time and ded-by-time interactions were the primary outcomes of interest. results: for the interaction of obn and ded with time (qids-sr as dependent variable), the main effect and the effects at each time point compared to baseline were all significant (p = 0.002 and p = 0.003, respectively, for main effects), confirming our main hypothesis. furthermore, pearson’s correlation of obn with qids-sr (5 weeks) was specific compared to perceptual dimensions of the asc (p < 0.05). discussion: this report further bolsters the view that the quality of the acute psychedelic experience is a key mediator of long-term changes in mental health. more specifically, future therapeutic work with psychedelics may consider investigating ways which enhance mystical-type experience and reduce anxiety, given the growing evidence that this serves the efficacy of the treatment model.”

“Both psychedelics and meditation exert profound modulatory effects on consciousness, perception and cognition, but their combined, possibly synergistic effects on neurobiology are unknown. accordingly, we conducted a randomized, double-blind, placebo-controlled study with 38 participants following a single administration of the psychedelic psilocybin (315 μg/kg p.o.) during a 5-day mindfulness retreat. brain dynamics were quantified directly pre- and post-intervention by functional magnetic resonance imaging during the resting state and two meditation forms. the analysis of functional connectivity identified psilocybin-related and mental state–dependent alterations in self-referential processing regions of the default mode network (dmn). notably, decoupling of medial prefrontal and posterior cingulate cortices, which is thought to mediate sense of self, was associated with the subjective ego dissolution effect during the psilocybin-assisted mindfulness session. the extent of ego dissolution and brain connectivity predicted positive changes in psycho-social functioning of participants 4 months later. psilocybin, combined with meditation, facilitated neurodynamic modulations in self-referential networks, subserving the process of meditation by acting along the anterior–posterior dmn connection. the study highlights the link between altered self-experience and subsequent behavioral changes. understanding how interventions facilitate transformative experiences may open novel therapeutic perspectives. insights into the biology of discrete mental states foster our understanding of non-ordinary forms of human self-consciousness and their concomitant brain substrate.”

“The oav-questionnaire is a visual analogue scale with 66 items that measures 3 aetiology-independent dimensions of altered states of consciousness (asc’s): ‘Oceanic boundlessness’ (ose), ‘dread of ego dissolution’ (aia) and ‘visual restructuralization’ (vus). it is a psychometrically improved version of the apz-questionnaire, which has become the international standard for the assessment of ascs. in this study, the factorial structure and reliability of the oav-questionnaire was critically examined using a large pooled dataset from a series of psychological and psychophysiological investigations between 1992 and 2008 in which ascs were induced in healthy volunteers by either psilocybin (115-350 mug/kg p.o.) (n = 323), ketamine (6-12 mug/kg min i.v.) (n = 162) or mdma (1.5-1.7 mg/kg p.o.) (n = 102). principal factor analysis with three factors and oblique rotation distributed 90% of the items to their hypothesized factor in the psilocybin and in the combined drug group. however, vus-items measuring facilitated recollection, imagination and changed meaning of percepts loaded higher on the oav-factor than on the vus-factor in all drug-sub-groups. furthermore, scree-plot and parallel-analysis suggested that more than 3 factors have to be extracted to account for the variance between the items. a confirmatory factor analysis (cfa) with simple structure clearly rejected the original factorial structure and disproved unidimensionality in all scales with the strongest rejection in the vus-scale. we developed an improved model with 9 factors measured by 47 items. multiple group cfa and mimic-modelling demonstrated acceptable model fit and partial measurement invariance in all drug-subgroups. satisfactory homogeneity and reliability of these newly developed scales could also be confirmed in all available data sets. we suggest to revise the existing factorial structure according to our newly developed model.”

“The oav-questionnaire is a visual analogue scale with 66 items that measures 3 aetiology-independent dimensions of altered states of consciousness (asc’s): ‘Oceanic boundlessness’ (ose), ‘dread of ego dissolution’ (aia) and ‘visual restructuralization’ (vus). it is a psychometrically improved version of the apz-questionnaire, which has become the international standard for the assessment of ascs. in this study, the factorial structure and reliability of the oav-questionnaire was critically examined using a large pooled dataset from a series of psychological and psychophysiological investigations between 1992 and 2008 in which ascs were induced in healthy volunteers by either psilocybin (115-350 (mu)g/kg p.o.) (n = 323), ketamine (6-12 (mu)g/kg min i.v.) (n = 162) or mdma (1.5-1.7 mg/kg p.o.) (n = 102). principal factor analysis with three factors and oblique rotation distributed 90% of the items to their hypothesized factor in the psilocybin and in the combined drug group. however, vus-items measuring facilitated recollection, imagination and changed meaning of percepts loaded higher on the oav-factor than on the vus-factor in all drug-sub-groups. furthermore, scree-plot and parallel-analysis suggested that more than 3 factors have to be extracted to account for the variance between the items. a confirmatory factor analysis (cfa) with simple structure clearly rejected the original factorial structure and disproved unidimensionality in all scales with the strongest rejection in the vus-scale. we developed an improved model with 9 factors measured by 47 items. multiple group cfa and mimic-modelling demonstrated acceptable model fit and partial measurement invariance in all drug-subgroups. satisfactory homogeneity and reliability of these newly developed scales could also be confirmed in all available data sets. we suggest to revise the existing factorial structure according to our newly developed model.”