Dreams and psychedelics: neurophenomenological comparison and therapeutic implications

Kraehenmann frames this paper as a focused review comparing night dreams, especially REM sleep dreaming, with states induced by classical serotonergic psychedelics (LSD, psilocybin, ayahuasca). Earlier research has noted overlapping phenomenology and some shared neurophysiology—perceptual alteration, vivid imagery, emotional activation, changes in self-experience and memory processes—leading to the suggestion that dreams may be a prototypical hallucinatory state and psychedelics may function as "experimental dreams." The introduction summarises hypotheses linking serotonergic systems to both sleep regulation and psychedelic action, and proposes that psychedelic therapeutic effects might be mediated in part by their dreamlike experiential qualities. The paper sets out to review literature on dreaming and on psychedelic states separately, then to compare them systematically in terms of perception and imagery, emotion and fear-memory processes, cognition, and self/body experience. Finally, Kraehenmann intends to draw therapeutic implications for psychedelic-assisted treatment based on the neurophenomenological overlap between these states.

This work is presented as a short narrative review rather than a systematic review; the extracted text does not provide a formal methods section, search strategy, inclusion criteria, or date range for literature retrieval. Instead, the study logic is to summarise prior neurophysiological and phenomenological findings about dreaming and about classical serotonergic psychedelics, and then to perform a conceptual, section-by-section comparison before drawing implications for clinical applications. Kraehenmann integrates multiple types of evidence: theoretical models of dreaming (for example, activation-synthesis and neurocognitive models), human neuroimaging and electrophysiology studies (fMRI, EEG, TMS), psychopharmacological experiments (including controlled drug studies of LSD and ayahuasca), animal research on neuroplasticity and fear extinction, and historical clinical observations about psychotherapeutic uses of psychedelics. Where available, specific experimental findings are cited to support claims (for example, fMRI work on ayahuasca and LSD, EEG markers of lucid dreaming, and psychopharmacological measures of cognitive effects), but no explicit appraisal of study quality or formal meta-analytic pooling is reported in the extracted text.

Kraehenmann organises empirical findings into parallel domains for dreams and psychedelic states. Perception and mental imagery: Dreams are described as vivid, predominantly visual, sensorimotor hallucinatory narratives occurring with the brain disconnected from external input. Two competing models are discussed: activation-synthesis (bottom-up brainstem-driven activation subsequently synthesised by cortical areas) and the neurocognitive/top-down imagery model (dreaming as organised, internally generated simulation). For psychedelics, the review reports disruption of cortico-striato-thalamo-cortical inhibitory gating leading to sensory disinhibition and hallucinations, and emphasises 5-HT2A receptor activation on cortical pyramidal neurons as a primary mechanism. Neuroimaging studies cited include ayahuasca work showing increased activation in primary visual cortex during imagery comparable with perception, and LSD studies linking visual hallucinations to activity in primary visual cortex. The author discusses competing bottom-up, top-down, and mixed models for psychedelic imagery, noting evidence for both elementary primary-visual phenomena and highly structured, personality-influenced imagery. Emotion activation and fear-memory extinction: Both REM dreaming and psychedelics robustly engage emotional processing networks, notably amygdala, hippocampus and anterior cingulate cortex. Dreams are proposed to support fear-extinction processes by re-exposing the dream self to conditioned stimuli in a safe, simulated context and by permitting recombination of memory fragments to form new extinction memories; reconsolidation processes are also discussed. Psychedelics are reported to intensify emotional experience and modulate fear- and threat-related neural circuits, with animal evidence that psychedelics enhance BDNF-dependent neuroplasticity and may facilitate extinction of conditioned fear. The review suggests a plausible mechanism in which psychedelic-facilitated retrieval of fear memories, when followed by safe, positive reprocessing in a therapeutic setting, could promote extinction or adaptive reconsolidation. Cognition: REM dreaming is linked to "cognitive bizarreness" and reduced prefrontal control, with deactivation of dorsolateral prefrontal cortex (DLPFC) and reduced high-frequency gamma synchrony; yet dreaming may permit more fluid associative processing and creative insight. Psychedelics dose-dependently impair vigilance and working memory but can increase associative reasoning, metaphorical thinking and creative problem solving. Neurophysiological correlates include decreased DLPFC oscillatory activity and altered frontal connectivity. A specific experimental finding cited is that LSD increased formal measures of cognitive bizarreness in a guided imagery task, and this increase correlated with reported loss of self-boundaries and cognitive control. Sense of self and body: Both states alter self-experience, producing depersonalisation, loss or weakening of body boundaries, and in some cases nondual or transpersonal awareness. REMS typically produces a strong, single-minded first‑person immersion with reduced metacognition, whereas lucid dreaming restores reflective awareness and is associated with increased frontotemporal gamma activity and precuneus activation. Psychedelics can produce experiences ranging from numbness and depersonalisation to self-transcendence, and can enable a shift from a narrative, self-centred perspective toward a minimal or transpersonal self. Experimental and clinical observations suggest these self-related changes are tightly coupled with perceptual and emotional alterations. Similarities and differences: The synthesis highlights four main overlaps—vivid visual imagery, activation of emotional/fear memories, reduced logical but increased associative cognition, and marked changes in self and body sense. Key differences noted are that elementary geometric percepts are common under psychedelics but rare in ordinary REM dreams, external sensory input influences psychedelic experiences (especially with eyes open) whereas dreams are decoupled from the environment, and that psychedelics and lucid dreaming tend to preserve greater clarity and metacognitive capacity than typical REMS dreams. The author also points to neurophysiological distinctions such as stronger primary visual cortex activation with psychedelics and the role of 5-HT2A receptor-mediated prefrontal activation and increased PFC–visual cortex connectivity in psychedelic hallucinations. Therapeutic-relevant findings: Kraehenmann draws together evidence that dream processes (exposure to fear memories in safe simulated contexts, recombination for new extinction memories, and facilitation of insight) have therapeutic potential. Psychedelics may enable similar processes—enhanced emotional retrieval, neuroplasticity, and altered self-perspective—and historical clinical approaches combining psychedelics with psychotherapy (psycholytic therapy) are discussed. No quantitative efficacy results or pooled effect sizes are reported in the extracted text; the author references recent clinical studies of psilocybin, LSD and ayahuasca in depression and anxiety as supportive but does not provide aggregated data in this extract.

Kraehenmann interprets the overarching overlap between dreaming and psychedelic states as supporting the idea that psychedelics acutely induce dreamlike subjective experiences that may contribute to longer-term improvements in psychosocial functioning and wellbeing. He emphasises the psychological functions of dreams—emotion regulation, fear extinction, memory recombination and enhanced self-relevant processing—and proposes that similar mechanisms may operate during psychedelic-assisted therapy, especially when frightening or traumatic material is retrieved and reprocessed within a safe, trusting therapeutic context. The review positions its conclusions relative to existing literature by noting convergent neurophysiological findings (limbic engagement, prefrontal modulation, gamma activity in lucid dreaming, 5-HT2A-mediated cortical effects) while acknowledging that precise mechanisms are not fully established. Kraehenmann suggests specific avenues for future research, such as neuroimaging studies designed to disentangle top-down versus bottom-up contributions to psychedelic hallucinations (for example using dynamic causal modelling) and studies directly testing whether the acute dreamlike qualities of psychedelic sessions predict therapeutic outcome. Key limitations and cautions acknowledged in the text include the incomplete understanding of underlying neurobiological mechanisms and the absence of systematic methodological detail in this short review. Safety considerations are also emphasised: psychedelics are powerful modulators of consciousness and can have adverse long-term effects if used outside professional supervision, a historic lesson exemplified by Timothy Leary. The author therefore highlights the importance of therapeutic framing, trained support, and the potential value of integrating psychedelics with imagery-based psychotherapeutic techniques such as guided affective imagery or psycholytic approaches. Overall, Kraehenmann concludes that conceptualising psychedelic experiences as experimentally induced, lucid-like dream states is useful for understanding their phenomenology and potential therapeutic mechanisms, and he calls for clinical studies that explicitly examine the relationship between acute dreamlike experience and clinical outcomes.

The paper concludes that the substantial phenomenological and neurobiological overlap between dreaming and psychedelic states supports the view that psychedelics produce acute dreamlike subjective experiences which may underlie therapeutic benefits. Kraehenmann notes supportive evidence from recent clinical studies of psilocybin, LSD and ayahuasca in mood and anxiety disorders and recommends future trials that assess how acute dreamlike effects relate to treatment outcome. He suggests that fostering a lucid-dreaming-like mindset during psychedelic therapy may enhance processes central to psychotherapy—self-understanding and psychological insight—and thereby facilitate symptom reduction and behavioural adaptation.