The presence of DMT in human blood and urine has been conclusively reported in a number of papers (Riceberg and van Vunakis, 1978). For many years, its presence in urine was tied to people with schizophrenia and psychosis (Jacobs and Presti, 2005). There is no question that DMT is naturally produced in the human body. The enzymes necessary to produce DMT from tryptamine and serotonin--N-methyltransferase (NMT) and indolethylamine N-methyltransferase (INMT)--as well as the mRNA necessary to produce the enzymes have been shown to exist in human tissues outside the brain.
Sensical is in fact a valid antonym for nonsense. It is a word, and you can use it. It is in the Oxford English Dictionary. It's use is traced back to 1797.
For other uses, see Word (disambiguation). In linguistics, a word is the smallest element that can be uttered in isolation with semantic or pragmatic content (with literal or practical meaning). This contrasts deeply with a morpheme, which is the smallest unit of meaning but will not necessarily stand on its own.