<span>The RNA world is the hypothesized format of chemical life that existed prior to our current DNA and RNA world. In the RNA world, RNA molecules formed in the primordial soup and began to evolve by self-replication and mutation. This led to increased complexity, natural selection of "better" RNA and diversification of RNA based life.</span>
Anxiety, overexcitement, inability to focus, poor coordination, and shaking are common side effects of substance abuse. The class of drugs includes cocaine, nicotine, ecstasy, and amphetamines.However, any drug when used that can cause euphoria or feeling “high” can become a drug of abuse.
I am not sure but here is a link to help you :)
https://www.ncbi.nlm.nih.gov/pubmed/22322095