Jacob Sullum on Prescriptions for Disaster or, The Omni-Incompetent State as linked to by LRC -- rendered below in brief by the feline that brung it to the blog ...

Some drugs are good,
Some drugs are bad.
Some users are happy :-),
Some users are sad :-( ...

Old folks' drugs are mostly still legal,
Young folks' drugs are mostly illegal.
So much high-minded legislation
Is meant to protect low-income children.

You're okay to say NO to some drugs;
The PTB will tell you which ones ...
If you dare say No to approved drugs,
The PTB may declare you insane.

Take drugs for the children's sake,
And for the same children's sake,
Lock 'em up and throw away the key
For using their minds independently.

While the elderly and incompetent make wishes,
The youthful and indiscreet make loaves and fishes.
While one generation may feed the next bullshit,
The next manages to gain sustenance from it.

... you know that you're over the hill
when your mind makes a promise your body can't fill ...