5.3: The Third Wave of Psychedelic Science

The present section introduces and summarizes modern clinical and neuroscience research on psychedelic drug effects. While the focus of this paper is not to review previous research, summarizations are kept minimal, with the sole intention of capturing the essence of these two branches. This is important to the efforts of this paper because it establishes the foundation for why these substances should be used in research, which is (unfortunately) still a controversial topic in psychology.

Clinical Science

The resurgence of psychedelic research was pioneered by clinical scientists and psychotherapists. In clinical research, psychedelics are paired with psychoanalysis to catalyze change in patients’ perception and perspective of themselves, life events, and their own suffering. Essentially, psychedelic substances generate an altered state whereby the agent is having a meaningfully-heightened experience. Here, he/she can process internal struggles from a unique emotional and cognitive state in order to transform them (with the help of a psychotherapist) into a self-narrative that is agentic and empathetic, rather than disempowering and critical.

“…psychedelics engage the self in a humanistic transformative process which is (somewhat) transparent and meaning-respecting, rather than performing sub-personal surgery on the constituent parts of a passive self.” Chris Letheby (2015) comparing the nature of healing with psychedelics to other pharmacological interventions.

Illnesses that have been ameliorated by psychedelic therapies include OCD (Moreno et al., 2006), near-death anxiety and depression (Ross et al., 2016; Gasser, Kirchner, & Passie, 2014), and addiction (Vollenweider and Kometer, 2010; Garcia-Romeu, Griffiths, & Johnson 2014; Bogenschultz et al., 2015; Krebs & Johansen, 2012). While all of these disorders may share neurophysiological underpinnings, they are also likely linked by their common and interrelated symptomology. The concept of demoralization may encompass the possible commonalities between these disorders, and is defined here as the inability or lack of will to adaptively cope due to a real or perceived lack of control over his/her situation, as well a loss of life meaning and/or purpose (Vehling, 2017).

Results from psychedelic-assisted psychotherapy have shown (generally) that psychedelic experiences tend to result in an enhanced sense of insight, meaning, and agency over ones choices and actions. Evidence also suggests that psychedelic experiences might ‘loosen the grip’ of maladaptive coping, (drug/alcohol dependency, unhealthy patterns of thoughts and behaviors) through an experiential and neurophysiological ‘re-perceiving’ and ‘re-wiring’ process, respectively.

Clinical research has proven beyond a doubt that these substances can be used to treat mental illness in a way unlike any other pharmacological intervention. The multidisciplinary framework and holistic approach of this treatment makes it a unique and effective method that empowers individuals and produces lasting effects on cognitive and emotional processing.

Neuroscience

The neurophysiological effects of psychedelic molecules are highly complex and widespread, causing direct and indirect effects across functional networks in the brain (Tagliazucchi et al., 2014). As this is not the focus of this paper, I will briefly summarize modern ‘big-picture’ theories of the psychedelic state at the brain level rather than delve into the details of neuropharmacology (for an in-depth review of the neuropharmacology of psychedelics, see Martin & Nichols, 2016; Halberstadt, 2015)

“…5-HT2A receptor agonism leads to desynchronization of oscillatory activity, disintegration of intrinsic integrity in the [default mode network] and related brain networks, and an overall brain dynamic characterized by increased between-network global functional connectivity, expanded signal diversity, and a larger repertoire of structured neurophysiological activation patterns.” Swanson (2018)

Carhart-Harris and colleagues (2014) proposed the Entropic Brain Theory (EBT), which seeks to explain a given conscious state by its corresponding levels of entropy in the brain. Entropy is a measure of a systems physical order/disorder and informational certainty/uncertainty. EBT proposes that the phenomenological qualities of a conscious state can be mapped onto a scale ranging from low entropy (high order/high certainty) to high entropy (low order/low certainty) (Carhart-Harris et al., 2014). While normal waking consciousness is ‘sub-critical,’ and stable, psychedelic states are characterized by instability and uncertainty. This theory comes out of a series of neuroimaging studies that suggests these substances cause a diversification of functional networks (Tagliazucchi, 2014), as well as desynchronization of networks that would normally ‘suppress’ entropy, sustain a coherent sense of self, and maintain informational certainty about oneself, others, and the world (Muthukumaraswamy et al., 2013; see Carhart-Harris et al., 2014; Carhart-Harris, 2018 for a full description of this theory).

Complementary to EBT, Swanson’s (2018) call for a unified theory of psychedelic drug effects expresses promise (as well as highlights some major contradictions), in predictive processing (PP) theories (Muthukamaraswamy et al., 2013; Pink-Haskes et al., 2015; Friston, 2010; Corlett, 2009). PP accounts of psychedelic drug effects extend out from the theory that normal conscious states are a sort of ‘controlled hallucination’ whereby the brain is simulating reality based on accurate predictions of sensory information (Clark, 2015). In PP models, the brain’s higher cortical structures seek to minimize prediction error in the brain by generating top-down signals that ‘match’ and inhibit lower-level processing in order to make sense of and accurately represent sensory information and bodily states (Friston, 2010, Clark 2013). The psychedelic state is therefore a ‘less controlled’ hallucination (Swanson, 2018) as a result of the hyper excitation of the cortex, therefore producing dream-like internal simulations of reality (see Swanson, 2018 for an in-depth review of predictive processing theories of psychedelic drug effects; Friston, 2010; Clark 2015). Exactly why and how psychedelics alter PP is largely unknown.

Summary

Clinical and neuroscience fields have provided deep insight into the nature of psychedelic drug effects. Perhaps one of the most significant and consistent findings is the ability for these substances to catalyze immense change, cognitively and neurophysiologically. It is critical to acknowledge that the nature of that change, will be partially dependent on the individual’s unique experiences, prior neural structure, and then subsequent integration processes. While the phenomenological effects of psychedelics are highly complex and likely underpinned by an amalgamation of altered processing, cognitive-behavioral tasks may help to tease out which cognitive processes are being effected across individuals.