Here's a quote from an amazon.com review:
"This Perfect Day" is one of my all time favorite science fiction stories -- it's a shame it seems to be out of print.
The book is about a world where everyone is genetically engineered to be as similar as possible, the "global village" has been realized in its entirety, and the world is run by computer. People get "treatments" regularly (injected medications) designed to even their moods and make them conform to societal norms.
In a world where we drug our kids for "ADHD" and political correctness and sameness are celebrated, this story remains very prophetic indeed.
Levin doesn't make a single misstep here. It's utterly terrifying, because this is the way the world is headed. If you can find the book, please get it and read it."
From another site:
Ira Levin
This Perfect Day - 1966
Most of Levin's other works are primarily acts of great story- telling, avoiding any great pronouncements about the basic state of the human race in general. But his novel, This Perfect Day, is a radical departure. It has often been compared with Aldous Huxley's Brave New World, and George Orwell's 1984...