Self-Entropic Broadening Theory: Toward a New Understanding of Self and Behavior Change Informed by Psychedelics and Psychosis

Classic psychedelic-assisted therapy has attracted growing attention because trials and population-level analyses suggest these substances can produce enduring psychological and behavioural benefits across diverse conditions, including substance use disorders, depression, end-of-life anxiety, and demoralisation. At a biological level, research indicates classic psychedelics promote neuroplasticity and have anti-inflammatory effects, offering plausible mechanisms for lasting change. Paradoxically, these same compounds have a long history of being described as psychotomimetic; early investigators proposed using psychedelics to model psychosis "from the inside," and subsequent empirical work has noted acute overlaps between psychedelic states and features of early psychosis. Dourron and colleagues set out to resolve this psychotomimetic–psychedelic paradox by proposing self-entropic broadening (SEB) theory. SEB synthesises existing frameworks—notably entropic brain theory (EBT), REBUS, and broaden-and-build theory—by arguing that both classic psychedelics and early psychosis instantiate an entropic processing style (broadened attentional scope, decreased predictability and hyperassociative thinking), but diverge in the degree and direction of self-focus. The review aims to characterise shared cognitive and neural features, specify where and why trajectories differ, and suggest testable predictions and research priorities to explain when entropic states lead to flourishing versus languishing.

The paper is a theoretical, narrative review and synthesis rather than a primary empirical study. The extracted text does not report a formal systematic search strategy, databases searched, or explicit inclusion/exclusion criteria typical of a systematic review or meta-analysis. Instead, the authors integrate findings from diverse literatures—psychedelic clinical trials and naturalistic studies, psychosis research (especially first-episode psychosis and ultrahigh-risk cohorts), neuroimaging and neurophysiology studies, animal work, and conceptual models such as EBT, REBUS, and broaden-and-build theory. Scope and definitional choices are reported: the review focuses primarily on first-episode psychosis (FEP) and prodromal/ultrahigh-risk (UHR) states to avoid confounding from chronic antipsychotic exposure, and defines "classic psychedelics" as substances whose characteristic subjective and cognitive effects derive largely from serotonin 2A receptor (5-HT2AR) agonism (for example, DMT, psilocybin, LSD, mescaline). The authors draw on experimental pharmacology (including receptor-blocking studies), clinical trial outcomes, qualitative follow-ups, neuroimaging (fMRI, PET) and electrophysiology, and selected animal models to build SEB theory. Analytic approach is conceptual: Dourron and colleagues identify an "entropic processing" construct (reduced filtering, broadened attention, hyperassociative thought, altered salience) and then examine its manifestations across domains (learning/attention, salience attribution, creativity, thalamic connectivity, large-scale networks, and self-experience). Where quantitative findings are available in the extracted text (e.g., select prevalence figures, correlations, and experimental blockade effects), these are cited to support theoretical claims, but no pooled meta-analytic statistics or formal risk-of-bias assessments are reported in the available extraction.

The authors assemble empirical and phenomenological evidence to characterise two core components: entropic processing and differential self-focus. Entropic processing is described as a reduction in schema-driven filtering that broadens attentional scope, increases information richness, and fosters hyperassociative thinking and altered salience. Evidence cited includes acute increases in neural entropy under LSD and psilocybin that predict later increases in openness, language becoming more entropic during LSD, and parallels with early psychosis and creative cognition. Behavioural tasks show shared cognitive signatures: both psychosis and acute psychedelic states demonstrate impaired selective attention and increased attention to irrelevant stimuli (for example, Stroop impairments), and both show altered learning attributable to reduced filtering. Altered salience is reported across both states. In psychosis, aberrant salience is linked empirically to dopaminergic dysregulation and predicts transition in UHR samples; the Aberrant Salience Inventory (ASI) and laboratory tasks capture dimensions such as senses sharpening and impending understanding. Classic psychedelics reliably change the appraisal of ordinary stimuli—sometimes increasing perceived meaning—and recent work has observed increases in aberrant-salience measures during acute LSD; many of these psychedelic effects appear to be mediated via 5-HT2AR signalling and can be attenuated by ketanserin. On creativity, the review notes mixed findings: acute psychedelic administration often impairs formal creativity-task performance (likely due to reduced executive control) while producing subjective feelings of insight; postacute or long-term increases in creative tendencies are plausible but not definitively demonstrated. Neuroimaging data suggest that psychedelic-induced reorganisation of the default mode network (DMN) and increased between-network connectivity may underlie hyperassociative cognition. Thalamic and large-scale network findings are summarised. Classic psychedelics and psychosis both show thalamic–sensorimotor hyperconnectivity in resting-state studies, and under psychedelics this hyperconnectivity correlates with altered perceptual vividness and meaning (one LSD study reported a correlation of about r = 0.58 between thalamic–sensory hyperconnectivity and "changed meaning of percepts"). The DMN is implicated in self-referential processing: acute decreases in DMN integrity are commonly observed with psychedelics and have been linked to ego-dissolution and acute insights, whereas DMN alterations in schizophrenia vary by illness stage (early increases in within-network connectivity versus later decreases). The authors note inconsistent correspondence between imaging modalities (PET, fMRI, MRS), complicating interpretation of prefrontal activity findings. A central empirical contrast concerns self-experience. Psychosis is characterised by a self-disturbance syndrome comprising hyper-reflexivity (exaggerated self-conscious monitoring), diminished self-presence (feelings of unreality or non-mineness), and "disturbed grip" on experience; these features are linked to delusion formation, poor functional outcomes, and suicidality. By contrast, classic psychedelics typically reduce self-focus (hyporeflexivity, ‘‘ego dissolution’’ or "small self" states), while often preserving or even increasing a sense of self-presence; these changes predict enduring therapeutic benefits across clinical indications (for example, correlations between mystical-type or oceanic-boundlessness scores and improvements in depression, anxiety in cancer, and substance use outcomes). The authors cite qualitative interview data and long-term follow-ups where participants report increased appreciation of ordinary life, renewed activity engagement, improved social connectedness, and behaviour change. Neuropharmacological nuances are highlighted. Dopaminergic sensitisation—exemplified by stimulant-induced psychosis and amphetamine challenges—maps well to the self-focused, delusion-prone phenotype. By contrast, classic psychedelic effects hinge on 5-HT2AR agonism, and many subjective and network-level effects (including certain thalamic and DMN alterations) are attenuated by 5-HT2A antagonists like ketanserin. The review also discusses atypical findings: chronic high-frequency LSD exposure in animal models can produce long-lasting changes reminiscent of psychosis, and 5-MeO-DMT (with higher 5-HT1A affinity) shows phenomenological differences and a high rate of brief reactivations in naturalistic use. The review documents prevalence and clinical statistics drawn from the literature: example figures include common delusional themes in FEP (being harmed/attacked/killed 55%, being monitored/followed 48%, being talked/laughed at 30%), high rates of substance-induced psychosis in stimulant users (pooled estimates cited include 42.7% lifetime prevalence of substance-induced psychosis in methamphetamine use disorder and 55.6% for lifetime cocaine-induced psychosis in one meta-analysis), and high rates of self-reported long-term benefit after challenging psychedelic experiences (in one survey 84% reported benefit from their most challenging experience). Finally, the authors identify candidate neural substrates for further work—the claustrum, thalamic subnuclei, and interactions among DMN, frontoparietal control network and salience networks—and review limitations in the existing neuroimaging literature (small samples, limited subnuclear thalamic analyses, and modality discrepancies).

Dourron and colleagues interpret the assembled evidence to propose SEB theory: entropic processing (a broadened attentional scope and hyperassociative cognition) is common to both classic psychedelic states and early psychosis, but divergent trajectories arise from differences in self-focus. In this account, psychosis exemplifies entropic processing coupled with increased self-focus (hyper-reflexivity, heightened self-relevance), which fosters maladaptive meaning-making and delusion formation and predicts poorer long-term outcomes. By contrast, classic psychedelics tend to produce entropic processing alongside decreased self-focus (hyporeflexivity, experiences of unity or ‘‘small self’’), which can enable self-distant reflection, psychologically meaningful insights, broadened thought-action repertoires and the building of enduring psychosocial resources, thereby supporting lasting improvements in wellbeing. The authors position SEB relative to prior models: it synthesises and extends entropic brain theory, REBUS, broaden-and-build theory and accounts invoking awe, proposing that decreases in self-focus are the crucial modulator that explains why superficially similar entropic states can lead to flourishing after psychedelic exposure but to illness trajectories in psychosis. They acknowledge neuropharmacological heterogeneity—dopaminergic sensitisation and aberrant dopamine signalling are central in many psychosis presentations and stimulant-induced psychosis, whereas 5-HT2AR agonism is primary for classic psychedelic effects—and argue that multiple ‘‘pharmacological roads’’ can lead to overlapping cognitive phenomenology. Key limitations are acknowledged: SEB is a heuristic model rather than a definitive mechanistic account; the review is not a systematic meta-analysis and the extracted text does not provide a formal search or selection method; entropic processing and reductions in self-focus are not unique to psychedelics and can occur in awe, mindfulness, flow or other states; and extremes in either direction (excessive reduction of self-focus or chronic heavy psychedelic exposure) may have adverse consequences. The authors also emphasise gaps in the evidence base—limited systematic empirical work linking specific acute phenomenology to long-term behaviour change, mixed neuroimaging findings across modalities, sparse studies of thalamic subnuclei and claustrum function, and insufficient qualitative work directly comparing psychosis and psychedelic experiences. From these premises, the review outlines empirical recommendations: use experience-sampling methods to link acute self-focus and entropic indices to real-world outcomes; apply psychosis-derived tasks and measures (e.g., Salience Attribution Test, Aberrant Salience Inventory, Examination of Anomalous Self-Experience) to psychedelic research and vice versa; employ quantitative linguistic markers (entropy in speech, first-person pronoun usage) to index entropic processing and self-focus; test whether adjunctive behavioural interventions delivered in the postacute window amplify enduring gains; and deploy causal neuroimaging tools such as real-time fMRI neurofeedback to probe the DMN and other networks' roles in self-experience. The authors emphasise that confirming SEB's predictions would have implications for optimising therapeutic contexts and for distinguishing risky from reparative entropic experiences.

The authors conclude that SEB theory offers a parsimonious resolution of the psychotomimetic–psychedelic paradox by locating the critical distinction not in entropic processing per se but in how self-focus is altered within entropic states. Classic psychedelics tend to broaden attentional scope while reducing self-focus, fostering self-distant reflection, insights and the building of psychosocial resources; early psychosis combines entropic processing with heightened self-focus, promoting maladaptive meaning-making and worse outcomes. They advocate for rigorous empirical testing of SEB's predictions and for research that bridges psychosis and psychedelic literatures to better understand mechanisms that drive flourishing versus languishing after high-entropy mental states.