How Cannabis Interacts With Psychedelics and the Memory

Cannabis has long been a topic of interest and controversy in psychiatry. Mark Viner, MD, has explored the clinical implications of cannabis medicine. He has worked with the Clinical Society of Cannabis Clinicians and the International Alliance of Medicinal Cannabinoids to provide insights into how cannabis compares with other psychoactive substances.

Before discussing the psychiatric impact of cannabis, it is essential to define cannabis comprehensively. Prescription cannabinoids differ from whole-plant cannabis extracts like Rick Simpson oil. The pharmacological effects vary widely depending on the form—isolates of tetrahydrocannabinol (THC) and cannabidiol (CBD), high-potency extracts, or different plant parts such as the inflorescence, leaves, stems, bark, and roots. Administration routes further complicate the picture, with options including oral, topical, and even intravenous.

An underappreciated area of concern is the interaction between cannabis and psychiatric medications. For instance, cannabis can exacerbate serotonin syndrome when combined with Selective Serotonin Reuptake Inhibitors. Similarly, while some phytocannabinoids exhibit antipsychotic properties, their effects on schizophrenia and bipolar disorder remain ambiguous. Combining cannabis with hallucinogens, a growing trend among patients experimenting with microdosing, can be particularly hazardous, sometimes resulting in severe toxic reactions.

Polypharmacy involving cannabinoids presents another challenge. Patients often mix THC, CBD, and lesser-known cannabinoids like cannabigerol (CBG) in high-potency extracts. Although cannabis is frequently contrasted with hallucinogens, it has a distinct neurobiological profile, particularly in terms of withdrawal and neuronal effects. Unlike classic psychedelics, which promote synaptic growth and dendritic branching (as seen with ketamine), cannabis appears to prune neurons. This pruning process may be beneficial in specific psychiatric conditions, much like controlled demolitions allow for rebuilding rather than perpetual renovations.

In conditions involving traumatic memories, such as posttraumatic stress disorder, this pruning effect may offer therapeutic potential. Research from Stanford highlights the role of cell taxonomy in psychiatric disorders, suggesting that targeted removal of dysfunctional neurons could be beneficial. Just as inadequate pruning is linked to autism and dementia, controlled neuronal pruning via cannabis could serve as a novel approach for conditions characterized by maladaptive memory retention.

While cannabis has a well-documented impact on memory, this effect might be a double-edged sword. For patients burdened by severe trauma, strategic memory modulation could provide relief. As research advances, psychiatry must remain open to both the risks and potential benefits of cannabis in mental health treatment.

This is part 4 of a multipart series. You can view part 1 here, part 2 here, and part 3 here.

Dr Viner is a practicing physician who has been working with psychiatric patients in the state of Nevada for over 25 years. He served as a clinical professor of psychiatry and behavioral sciences at the University of Nevada School of Medicine.