Frontier in Pharmacology recently published a study by Swiss and German researchers who argued that lysergic acid diethylamide (LSD) increases primary process thinking. So what does that mean?
Primary process is part of an early meta-psychological theory posited by Sigmund Freud, and the researchers described it as follows: "There exist two distinct modes of psychic functioning: primary process and secondary process. It is broadly believed that... secondary process is a hierarchically higher-level cognitive mode which fulfills an adaptive, reflective, rule-bound function and thus inhibits lower-level, automatic, motivation- and emotion-driven primary process. Under altered psychophysiological conditions such as dreaming, hypnosis, meditation, sensory deprivation, respiratory maneuvers, trance, psychosis, and epilepsy, primary process may become the prevailing cognitive mode."
Psychedelics "activate mental processes which are closely related to primary process, such as vivid, dreamlike imagery, basic emotions, and bizarre thinking," and previous studies suggest that LSD stimulates 5-HT2A receptors, which in turn increases primary process. The European researchers sought to test the connection between LSD, primary process and 5-HT2A activation.
For the study, 19 men and six women between the ages of 20 and 34 took either 1) LSD, 2) a placebo, or 3) LSD + ketanserin. The latter drug is a 5-HT2A antagonist that would block LSD-induced activation of the serotonin-class receptor, thus testing its role in increasing primary process. Seven hours after receiving the dosage, the participants then took a 30-minute mental imagery task measured by primary index (including symbolism, visual representation, unlikely combinations) and the Altered State of Consciousness rating scale (spiritual experience, blissful state, disembodiment). What happened?
Compared with the placebo, LSD increased primary process thinking and correlated with an altered state of consciousness. Alternatively, those who took LSD and ketanserin together experienced none of these effects. This suggests the 5-HT2A antagonist blocked the increase in primary process, thus reconfirming the idea that activating the receptor with LSD does account for the increase.
Per the researchers, "The main finding of this study was that LSD increased primary process thinking, a lower-level, automatic, motivation- and emotion-driven mode of mental organization which is characterized by image fusion; unlikely combinations or events; sudden shifts or transformations of images; and contradictory or illogical actions, feelings, or thoughts…. Furthermore, we found that the effect of LSD on primary index was completely blocked by ketanserin."
The study also found that "secondary process thinking during psychedelic states appears preserved" while noting other studies that suggest psychedelics increase neural activity in cortical areas of the brain. "Therefore," the study argued,"psychedelic states may be best conceptualized as hybrid states of consciousness which share features of both dreaming and waking consciousness."
Based on this additional finding, the researchers added, "The close neurophenomenological similarity between psychedelic states and lucid dreaming may shed some light on the therapeutic potential of psychedelic-induced experiences: They… induce conscious learning experiences that promote self-knowledge and psychological insight."
Several studies suggest that patients with treatment-resistant mental health disorders often experience breakthroughs when therapies are paired with psychedelics. The current study ultimately asks the question, does increased primary process thinking play a role in these breakthroughs?
Image credit: Ron English.