Brave New World, by Aldous Huxley:

What is soma?

Soma is a drug that is handed out for free to all the citizens of the World State. In small doses, soma makes people feel good. In large doses, it creates pleasant hallucinations and a sense of timelessness. The citizens of the World State are encouraged to take soma by “hypnopaedic” sayings like “A gram is better than a damn.” When they experience strong negative emotions, citizens take a soma “holiday” to distract them from the unpleasant feelings. John sees soma as a tool of social control. He says that taking soma makes the citizens of the World State “slaves.”

https://www.sparknotes.com/lit/bravenew/key-questions-and-answers/#none