Xakra

Xakra (pronounced 'TSA-ʔ-krah', in the closest human approximation of the Kreen word), is a rare and potent substance found in the deserts of Athas. It is a crystalline mineral that can be powderized and refined into a powerful drug, with powerful hallucinogenic and psionic properties. Non-psionic users enjoy a euphoric high, but are also subject to intense hallucinations and delusions, and can become addicted to the substance. Psionic users, on the other hand, can harness the power of xakra to enhance their psionic abilities, and can, at least in theory, moderate its use to avoid the negative side effects. However, the substance is highly addictive, and even psionic users can become dependent on it, leading to a downward spiral of addiction and eventual death.