Lithium Carbonate (Li2CO3) is a real-life mood stabilizer, which the Dwarfers used to overcome t
he effects of ink from a Despair Squid.
Used on Earth for many years in the treatment of various psychiatric disorders, it was the drug of choice for the Starbug crew when they became severely depressed by the hallucinogenic venom of the squid. They had a cylinder of Lithium Carbonate aboard which they were able to administer through face masks.
Later, when they were trapped in a group hallucination that was about to make them commit suicide, Holly managed to convince Kryten to activate what he thought was a fire extinguisher. In reality, it was the cylinder of Lithium Carbonate that was released into the cabin, snapping the Dwarfers out of their delusional state (RD: Back To Reality).