"this thing called librium that she's on"
Chlordiazepoxide capsules
Creative Commons Attribution Share AlikeChlordiazepoxide capsules - Credit: Literaturegeek

At different points in the narrative, both of Catherine's parents refer to the lithium that she takes as librium.

Lithium is a drug used to stabalize mood in depressive and bipolar illnesses (see bookmark for page 258).

Librium (whose generic name is Chlordiazepoxide) is a drug with sedative and hypnotic properties which is used to relieve anxiety.