Drug counselors insist that they would rather work with and treat any other kind of addiction. There is controversey as to whether or not cocaine produces more toxic psychoses than other drugs. But they do occur and are frightening. They are characterized by paranoia and do characterize the drug crazed addict pretty well. One can kill good friends this way thinking that they are narcs etc.
Amphetamines are the poor man's cocaine and have essentially the same characteristics of abuse.
Tolerance develops quicky so that huge doses may be taken. This also encourages cyclic use. The tremendous boom in use has made pharmacologists work like mad to characterize the effects and toxicities. It is very difficult to work with as it is carried by protein, is heavily metabolized into a large number of products and the pure oil is unstable in air. It has been classified by some as a sedative-hypnotic with only mild tolerance development.