LDDM, that is low-dose dextromethorphan. This drug is in the same class as naltrexone; dextrorotatory morphinans, along with naloxone and the metabolic product of dextromethorphan, hydroxy-dextromethorphan. All of these, along with the endogenous opioids dynorphin and methionine enkephalin, have the property of somehow diminishing the activation of microglial cells in the brain by aggregated proteins or some other unknown substance(s). It is thought that microglial activation, with their production of ROS (reactive oxygen species) and certain cytokines like TNF-alpha start a vicious cycle of injuring neurons which, in turn, secrete other substances which further activate the microglial cells. This general process is now thought to contribute to the progressive nature of several neurodegenerative diseases such as PD, MS, AD, ALS and ?? Recently, LDN has also been shown to effectively control Crohns' disease, another inflammatory condition, by a group at Penn State Med Center.

The really weird property of these microglial-calming substances is that they are apparently effective at impossibly low concentrations, femto-molar. Also, the most effective way to take them (at least naltrexone and dextromethorphan) is once a day, preferably at bedtime. Whatever receptors respond to them apparently require a short "spike" of the drug, after which the effect (still not fully understood) occurs.

This is how I understand it, anyhow. Literature links to the scientific work that has been done can be found on the web at LDN.org, or on postings on this forum by AshleyK or myself.

Robert