This review (2017) studied research literature on psychedelics and dreaming to systematically compare these two states of consciousness. It highlighted the broad overlap between dreaming and psychedelic states supporting the perception that psychedelics acutely affect dreamlike subjective experiences that may show long-term beneficial responses to psychosocial functioning and well-being.
Abstract
“Background: A resurgence of neurobiological and clinical research is currently underway into the therapeutic potential of serotonergic or ‘classical’ psychedelics, such as the prototypical psychedelic drug lysergic acid diethylamide (LSD), psilocybin (4-phosphoryloxy-N,Ndimethyltryptamine), and ayahuasca – a betacarboline- and dimethyltryptamine (DMT)-containing Amazonian beverage. The aim of this review is to introduce readers to the similarities and dissimilarities between psychedelic states and night dreams, and to draw conclusions related to therapeutic applications of psychedelics in psychiatry.
Methods: Research literature related to psychedelics and dreaming is reviewed, and these two states of consciousness are systematically compared. Relevant conclusions with regard to psychedelicassisted therapy will be provided.
Results: Common features between psychedelic states and night dreams include perception, mental imagery, emotion activation, fear memory extinction, and sense of self and body. Differences between these two states are related to differential perceptual input from the environment, clarity of consciousness and meta-cognitive abilities. Therefore, psychedelic states are closest to lucid dreaming which is characterized by a mixed state of dreaming and waking consciousness.
Conclusion: The broad overlap between dreaming and psychedelic states supports the notion that psychedelics acutely induce dreamlike subjective experiences which may have long-term beneficial effects on psychosocial functioning and well-being. Future clinical studies should examine how therapeutic outcome is related to the acute dreamlike effects of psychedelics.“
Authors: Rainer Kraehenmann
Summary
- INTRODUCTION
The tendency of dreams and psychedelic drugs to induce visionary experiences has inspired scientific and cultural development for thousands of years. It has been hypothesized that dreams may be understood as prototypical hallucinatory experiences.
The psychedelic lysergic acid diethylamide (LSD) may facilitate REMS in humans, and complex visual hallucinations are best treated by serotonergic antidepressants in narcolepsy. Therefore, therapeutic effects of psychedelics may be mediated by dreamlike experiences of the patients during psychedelic treatment.
2.1. Perception and Mental Imagery
Dreams are vivid, sensorimotor hallucinatory experiences that occur during sleep, when the brain is disconnected from the environment. According to Hobson’s activation-synthesis model, dreams are produced by chaotic bottom-up activation of sensory cortex in the brainstem during REMS, activation of the visual cortex, and secondary interpretation and synthesizing by mnemonic and higher-order frontal areas. The neurocognitive model views dreaming as the top-down product of higher-level mental imagery.
2.2. Emotion Activation and Fear Memory Extinction
Apart from profound visual effects, dreams are characterized by the activation of emotions. However, dreams are biased towards negative emotions, particularly anxiety, fear, and aggression, and serve an adaptive function by supporting the regulation of emotions, especially fear.
Fear extinction may be a crucial mechanism underlying the fear regulation function of dreaming, and may be related to the following cognitive processes: deconstruction of coherent episodic fear memories into isolated memory units, recombination of isolated memory units into a constant and phenomenologically coherent flow of dream imagery. Despite the mechanism of fear extinction, dreaming might also directly rewrite fear memories via memory reconsolidation. This can be done by providing non-fearful information immediately following fear memory retrieval.
2.3. Cognition
The waking state often finds dreams chaotic and difficult to comprehend because of cognitive bizarreness. This is related to the neural “signature” of REMS with random brainstem activation and secondary activation in higher-order areas (AIM model) and deactivation of the DLPFC and parietal cortex.
The evidence indicates that dreaming is a more fluid and flexible cognitive processing state than non-REMS and waking state, and that dreaming can be superior to wake cognition in tasks that require cognitive flexibility, formation of new associations, or insight into hidden abstract rules.
2.4. Sense of Self and Body
Dreaming always induces alterations in the sense of self and body. In REMS dreams, the dreamer is usually unaware that the content coming from the imaginative activity is only the product of his imaginative activity, and interprets the phenomena as coming from external reality.
In lucid dreaming, the subject is aware of the dream and can influence its content. This is related to increased phase synchrony and increased gamma frequency activity in the fronto temporal brain regions.
A TMS study by Voss et al. showed that fronto-temporal current stimulation in the lower gamma band at around 25 and 40 Hz during REMS induced lucid dreaming, and that the precuneus showed the strongest increase in activation during lucid compared to non-lucid REMS.
Nondual awareness is an empty mind with no phenomenological content, where there is no affect and cognition, and where any sense of physical boundaries is dissolved. It may also occur during dreaming and deep sleep.
3.1. Perception and Mental Imagery
Classical psychedelics are a unique class of psychoactive drugs that induce states of altered perception, thought, and feeling. They do this by disrupting inhibitory cortico-striato-thalamocortical feedback loops, which in turn leads to a failure to filter, inhibit, and screen out external and internal stimuli.
Psychedelics cause sensory overload and hallucinations in higher-level cortical regions, and also cause spontaneous neuronal excitation. Using fMRI, de Araujo et al. [81] showed that ayahuasca increases activation in the mental imagery network, including early visual areas, parahippocampal gyrus, middle temporal cortex, and frontal cortex, and that ayahuasca-induced changes in primary visual cortex are preceding and leading the activation patterns in higher-level areas.
Contrary to the notion that psychedelic-induced visual hallucinations are caused by bottom-up driven neuronal activity, there is substantial evidence that psychedelics induce visual hallucinations primarily via neuronal activation of prefrontal cortical or temporal areas as well as top-down spreading of activation to parietal and primary visual regions.
The neural mechanisms underlying psychedelic-induced hallucinations are likely to be top-down driven, elementary hallucinations, influenced by primary visual cortex, and bottom-up driven, highly structured, thematically elaborated, and strongly determined by personality aspects.
3.2. Emotion Activation and Fear Memory Extinction
Consistent evidence indicates that psychedelics intensify and broaden emotional experiencing, and that they may facilitate extinction of conditioned fear memory via effects on memory modulation and reconsolidation, especially if the conditioned fear memory is retrieved and modified by positive, self-protective information within a trustful interpersonal context.
3.3. Cognition
Psychedelics impair vigilance and induce cognitive dysfunctions, including reduced attentional performance, increased distractibility, and reduced spatial working memory. Despite these cognitive deficits, evidence from animal and human studies indicates that psychedelics may enhance cognition, including associative reasoning, thinking in metaphors and symbols, and creative problem solving.
3.4. Sense of Self and Body
Psychedelics induce a broad range of alterations in the sense of self, including loss of self and body boundaries, self-control, and volition, which are similar to depersonalization, a psychotic-like psychosomatic syndrome. Psychedelic-induced changes in the sense of self and body are frequently paired with changes in perception and imagery.
Psychedelics induce a shift from a self-centered perspective to a selflessness-perspective, which may generate a transpersonal self-perspective and reduced helplessness or anxiety when confronted with challenging memories or fantasies.
4.1. Similarities and Differences Between Dreams and Psychedelic States
The comparison between dreams and psychedelic states shows that both consciousness states share some similarities, including vivid imaginary experiences, activation of emotional memories and affects, decrease in logical reasoning and increase in associative reasoning, similar with creative thinking, and loss of sense of self.
There are some differences between psychedelic states and normal REMS dreams, such as the presence of geometric forms and abstract movements, and the presence of clear consciousness, which means remembrance and reflection of current and past circumstances and relationships.
Although both dreams and psychedelic states share a common phenomenological and neurobiological basis, there are also some differences between them. Lucid dreams show a comparable degree of perceptual clarity and metacognitive capacity.
4.2. Therapeutic Implications
Psychedelic states share many characteristics with lucid dreaming, and dreams intensify self-relevant processes. These self-relevant processes are key to promote self-knowledge and ensuing therapeutic change.
LSD was of primary value in enabling the patient to transcend his learned social judgments and establish contact with his real self. This contact led to the patient discovering resources for growth and fulfilment.
When using psychedelics, precautions and safety aspects should be taken into account, given that psychedelics are potent modulators of consciousness states, and given that previous history has shown that the self-enhancing effects of psychedelics might also have adverse long-term effects if not provided within a supervised professional setting.
CONCLUSION
The overlap between dreaming and psychedelic states supports the notion that psychedelics acutely induce dreamlike subjective experiences which may have long-term beneficial effects on psychosocial functioning and well-being.