Define Similar

The New York Times has an article out on "Bath Salts" the grey-market desigern drug stimulant that has been banned by 38 states.

Bath salts contain manmade chemicals like mephedrone and methylenedioxypyrovalerone, or MDPV, also known as substituted cathinones. Both drugs are related to khat, an organic stimulant found in Arab and East African countries that is illegal in the United States.

They are similar to so-called synthetic marijuana, which has also caused a surge in medical emergencies and been banned in a number of states. In March, the Drug Enforcement Administration used emergency powers to temporarily ban five chemicals used in synthetic marijuana, which is sold in the same types of shops as bath salts.

Now to my knowledge, MDPV has nothing to do chemically, behaviorally, or pharmacologically with synthetic cannabinoids that were banned by the DEA. So how are they similar? they're synthetic psychoactives and have an inflated market share becuase their traditional behavioral analogues are criminalized.

Full disclosure: I designed and conducted experimental animal research with a synthetic cannabinoid WIN-55215,2 on its effects on memory.