Ketamine may be the flower girl that is walking down the isle toward a marriage of biological and psychological psychiatry. We say this because the science tells us that Ketamine has a strong biological effect in benefiting patients. At the same time, it is somewhat of an hallucinogen, and has been described as an abreactive drug, that is, a drug that brings into consciousness thoughts and feelings that may be hard to access in ordinary states. In effect, Ketamine leads to a chemically induced hypnotic state. To date most research focuses on the biology of the drug alone and the research, though promising, tells us that the dramatic benefit Ketamine provides for depressed patients is short lived. The problem is that most of this research neglects the variable of psychological intervention as a part of the Ketamine experience.
Let's begin by asking what is the subjective experience of taking Ketamine like? The drug is rapid acting and its subjective effects last only about an hour. These days the drug is typically administered via nasal spray and the dose is incremented every 5 minutes or so to the desired amount, typically around 100 mg. Early on, before blood levels have ramped up, the drug is very relaxing and has a mild alcohol-like effect. About 20 minutes into the experience some patients, but not all, may notice a mild mind altering effect. What seems to happen is that subjects will feel 'in the moment.' Perceptions, rather than the making sense of perceptions predominate. I'll explain. Imagine an adult walking by a grandfather clock. All of the perceptions that amount to noticing the clock get consolidated in a summation: oh, there's a clock, it's 12:15, and the adult moves on. Contrast this with a small child. The child, if young enough, will not understand the function of the clock, rather, he'll notice its form, the sounds emanating, the swinging of the pendulum, etcetera. Ketamine seems to temporarily induce this more childlike way of experiencing the world.
The ketamine experience peaks in about 30 minutes, and most patients feel pretty much themselves in an hour. About half of patients will notice an improvement in mood as early as the first day.
Let's elaborate for a bit on what the drug does physically. First, Ketamine likely effects brain circuits in similar areas and ways that common antidepressants do. But the action of Ketamine goes beyond this. It seems to promote the growth of fresh neuronal connections in the brain, remarkably, within minutes. A young scientist, Conor Liston, has used very sophisticated imaging techniques in living mice to actually visualize this process.
So how do we connect the psychological and biological impact of Ketamine? Start with the notion that the Ketamine experience is chemically induced hypnosis. Then imagine two possibilities. In a conventional Ketamine clinic the patient is sitting under the influence of the drug with a technician who is monitoring the patient medically. This patient has little or no psychological interaction with others- I know of one case in which a patient sat playing Sudoku throughout her session! In contrast, imagine the patient sitting with a therapist who utilizes the time to facilitate the patient making useful psychological connections. In this case, the biological impact of the drug is causing synaptic growth which is likely modulated by the patient's thoughts. What happens between patient and therapist influences the biological effect of the drug.
Ketamine is currently approved as a therapy to treat treatment resistant depression, but is also showing promise in the treatment of PTSD, anxiety, as well as drug and alcohol dependence. It is an exciting drug not only because of its interesting biological properties, but also because its benefits seem to be enhanced by astute psychological intervention.
A graphic from Dr. Liston's work using sophisticated imaging techniques- 2 photon laser scanning microscopy, to visualize synaptic connections in the living mouse brain . Moving from left to right. Healthy synaptic connections, impaired connections as a result of exposing the mouse to chronic stress, reconstitution of healthy connections minutes after Ketamine exposure.