Dependency
Unlike most other psychedelics drugs, ketamine can produce an uncomfortable dependency.
The ketamine experience often gives the user a sense of being "on the verge" of discovering enlightenment, contacting an alien race, meeting God, breaking through, etc. Because this feeling can be quite strong, users are often compelled to go back "one more time." This can quickly result in using more in a sitting or more often than intended.
While ketamine is not physically addictive, it does produce similar effects to some of the addictive drugs, notably amphetamines and opiates. Someone using a low dose on a regular basis may quickly find they need it to feel normal.
A ketamine trip can be the ultimate escape; taking one to fantasy landscapes, other dimensions, beyond death, out of the body, or into oblivion. Its easy to see how this could quickly become a problem for someone with escapist/chemically dependant tendencies.
After many uses ketamine begins to exhibit different effects on its users. It may become more physical and less psychedelic, and the user may develop more and more difficulty remembering the experience. This can drive some people to use more often and/or in larger doses.
A few pointers in avoiding dependency: don't buy large quantities, set limits on how often you will use and stick to them, watch for dependant behavior and if you experience it quit using.
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