Posted by linkadge on December 30, 2020, at 14:32:03
In reply to ADs vs ketamine » linkadge, posted by Mtom on December 27, 2020, at 10:17:40
Yes, that is possible (different patients responding to different mechanisms).
That being said, the evidence for the monoamine hypothesis is very weak. Close to 70 years of studies have not found any conclusive evidence of a serotonin deficit, for example. That's not to say that that serotonergic system is not involved.
A new theory, involving g-proteins in lipid rafts appears to be promising. This study suggests that standard SSRIs cause alterations in lipid rafts that take days to weeks for effect, whereas ketamine produces the same changes within minutes or hours.
https://www.sciencedaily.com/releases/2018/06/180621172450.htm
Ketamine also causes regional changes in glutamate function that also happen with SSRIs (albeit in a much slower fashion).
Interestingly, failure of standard ADs is a predictor of failure to ECT. I would imagine that if ECT was used as a front line treatment, it would work rapidly for ~70% of patients. If you took a pool of resistant patients, then the efficacy would be much lower.
Other fast acting agents include SAMe (within days) or agmatine (within hours).
Linkadge
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thread:1113112
URL: http://www.dr-bob.org/babble/20201025/msgs/1113163.html