About ketamine
On the World Health Organization's list of essential medicines, ketamine has a proven track record of being a safe medication when used appropriately. In psychiatry there seems to have been a rift formed at some point where there became a clear divide in the clinician culture: medication vs psychiatric; and hopefully we are coming back around to a healthy balance of: both (or when one or the other). Medications can be an important part of a treatment plan or in some cases maintaining wellness. While our understanding of how ketamine is effective for some mental health disorders is still theoretical, there are some reasonable suggestions from study data.
Acts on glutamate receptors
Glutamate is the body's main excitatory neurotransmitter in the body. The glutamate system appears to be implicated in a number of mental health syndromes, to what extent and how, seems less clear. As well as perhaps what factors create the offset in these systems. We all know stress can make us sick, as Abdallah et al speak to as it relates to something like depression. [1,2] Phil Skolnick has spent a considerable amount of energy in his career investigating the relationships between mental health and the glutamate system (NMDA receptors) at one point discovered that in animals treated with common "antidepressants" such as Prozac or Zoloft, that the "anti-depressant" activity was only seen once the NMDA receptors became suppressed, which is what we think ketamine at least in part does as an NMDA receptor antagonist. [3] in recent years, the NMDA receptor antagonist class of medication has brought other potential options to help treat depression.
Neuroplasticity
An also apparently increasingly popular notion amongst those interested in the potential of these medicines: neuroplasticity. A number of studies have shown that ketamine can increase the production of brain-derived neurotrophic factor (BDNF), which plays a role in neuroplasticity, synaptic connectivity, and resilience to stress. This is thought to be one of the ways that ketamine may allow for some psychotherapies to help in modifying perspectives that may contribute to an unwell state. [4]
Inflammatory pathways
Ketamine has been shown to prevent the activation of inflammatory pathways and reduce the release of pro-inflammatory cytokines, or put more simply seems to prevent inflammation and reduce inflammation. This is not the first time we have seen inflammation associated with depression.
Rapid acting
The benefit from treatment with ketamine can often be seen quickly, as quickly as by the time the treatment session is completed or within the next few days. While not everyone responds to ketamine treatment, preliminary data suggest a response rate of at least 50%. Although the response can be rapid, sometimes the effects do not. To extend response, some people will return for "maintenance" medication treatments or when combined with psychotherapy, may provide longer-term benefit.
Conclusion
While there are several areas of investigation as to how the medication is effective for mental health conditions, it remains theoretical as the "monoamine hypothesis" was. In psychiatry, there don't appear to be many silver-bullet-like options and the approach needs to include a multivariate perspective or approach. As complex as the human body is, it seems more reasonable to consider that instead of being due to any one or the other of these things, the effectiveness can be found in the synergistic effect produced by all of these known and potentially more unknown factors working together to create the result.