Technically, ketamine is not classified as a psychedelic medicine, but rather a dissociative anesthetic. However, ketamine does have psychedelic effects at higher doses. Classical psychedelics include psilocybin or magic mushrooms, LSD, DMT, and mescaline, which work on a specific serotonin receptor. Ketamine, on the other hand, is an NMDA receptor antagonist that modulates glutamate levels. Interestingly, both ketamine and classical psychedelics result in similar changes in the brain that are correlated with antidepressant effects.

The word psychedelic means mind manifesting, and many people experience a psychedelic journey as having aspects that reveal unconscious material, like memories, symbols, and fantasies. Many people find the content of this psychedelic material to be rich with potential for learning about themselves, others, and the world.

For many, the experience of ketamine may have psychedelic qualities. In fact, I’ve heard some patients say that ketamine reminded them of LSD, or is the most psychedelic experience they have ever had. The ketamine experience seems to vary tremendously from person to person. Some may see different colors and shapes or have a vivid waking dream-like quality. For others, there may be a pleasant feeling of floating. Still, others feel a profound sense of healing, love, and empathy. One patient recently told me that she became multiple galaxies. Another patient visited massive cathedrals filled with spiritual light.

Although most people feel relaxed with ketamine, occasionally one may find ketamine anxiety provoking, especially for those that try to hold onto control. In this way, ketamine is similar to other psychedelics, as the experience of an altered state may be scary, and it is vital to enter into the experience with a prepared mindset. In psychedelic-assisted psychotherapy as well as ketamine-assisted psychotherapy, spending time preparing for the journey can bring a more powerful experience.

Interestingly, both ketamine and other psychedelic medicines create two similar changes in the brain that are correlated with their antidepressant effects. First, both ketamine and psychedelics result in a state of brain neuroplasticity. This means that nerve cells in the brain are growing and making new connections. It is thought that new learning can take place during this neuroplastic window, which lasts about 72 hours post-ketamine infusion.

A second change that occurs with both ketamine and psychedelics, is a decrease in the default mode network. The default mode network is the circuitry in our brain that is involved in depressive thinking and rumination. When one worries about oneself in the past or the future, there is increased activity in the default mode network. Not surprisingly, turning down the default mode network is correlated with improved mood. The combination of having one’s usual negative thoughts decreased, plus having new nerve growth and connections likely plays a powerful role in changing negative habits and patterns.

In summary, although ketamine works through a different receptor than classical psychedelics, ketamine, and psychedelic medicine have much in common. First, the experience itself may be mind-altering and psychedelic. Second, there is a definite overlap in terms of creating a neuroplastic state and decreasing the default mode network. And perhaps most importantly, many patients are benefitting from the incredible healing potential of these medicines. For most patients, psychedelics and ketamine are not magic bullets. But, they do offer the potential for overcoming existential, personal, and interpersonal suffering.