Riatine was a drug that suppressed emotions.
When applied to Trevans and other humanoids with similar genetics for short-term use, Riatine suppressed negative emotions, such as anger, fear and grief. It also induced a susceptibility to hypnotic suggestion. It had no other short-term side-effects and did not impair coordination or judgment. It was also non-addictive.
- The text of the TNG novel: Survivors describes Treva as inhabited by a "humanoid culture of undetermined origin". The back-cover blurb, however, states that it was an isolated human colony, likely confusing it with the novel's lost human colony of New Paris (Turkana IV). If true, then Trevans are indeed humans, or closely related, and Riatine may work on humans as well.
However, it was not recommended for long-term use, as it inhibited the user's capacity for all emotions, including love, and reduced their assertiveness and free will. Lacking the ability to express emotions, long-term users lost a sense of independence and often turned to other drugs in order to feel emotion again. These problems faded once the user stopped taking the drug, but withdrawal resulted in a sudden release of all the suppressed emotions. It had no physical withdrawal systems.
Riatine was used in psychiatric therapy to handle excessive negative emotions, such as anger and grief. It was also often used to aid sleep-learning.
In the mid-24th century, Riatine was mass-produced on Treva by companies owned by President Nalavia and her cronies. It was publically labeled as a water purifier and distributed to the water supplies of all the planet's cities. The drug kept much of the Trevan population docile, unresisting, and suggestible to government propaganda. Worker efficiency also improved, as the people were undistracted by positive or negative feelings. Entertainment and a wide variety of intoxicating drugs supplied their lost emotions. (TNG novel: Survivors)