What are the effects of chronic, high-level use?
Chronic, high-level use (e.g., 500-1000mg daily) tends to result in several undesirable effects. Psychological dependence is certainly possible and there are numerous examples of this occurring (3-5; also personal communications). Physical dependence is debatable, but if it does occur, it is probably with very high dose levels (1000mg per day and up) as a result of chronic NMDA blockade (see <5.3> below). Amotivational syndrome has been reported (usually when the drug wears off). Memory problems seem to be fairly common (but seems to resolve upon stopping DXM use). At least one chronic user (1500-2000mg daily), with no history of psychological problems, developed a strong dependence upon DXM and severe depression, leading to a suicide attempt and several months in drug rehabilitation. This is not at all common, but cannot be ignored. Exactly why some individuals seem to have drug dependence problems with DXM is unknown; it may be a function of chronic high- level use, or it may be a fu
