Compulsive hoarding
Obsessive-compulsive disorders are treated with various serotonergic antidepressants including the tricyclic antidepressant clomipramine and various SSRI medications. With existing drug therapy, OCD symptoms can be controlled, but not cured. Several of these compounds (including paroxetine, which has an FDA indication) have been tested successfully in conjunction with OCD hoarding.
Harris Isbell
the clinical use of opiate antagonists (e.g., nalorphine/Nalline and naloxone/Narcan) as treatment for opiate overdoses, 
the ability of methadone to alleviate opiate withdrawal symptoms,
rapid tolerance but lack of physical dependence with LSD,
cross-tolerance between LSD and psilocybin,
and the ability of pure THC to cause marijuana-like effects.
New pharmaceutical substances were assayed (in the prisoner population) for their abuse and addiction (substance dependence) potential (medications for pain, cough, and diarrhea were of particular concern), and this information was utilized by groups such as the World Health Organization.