The present inventionrelates to peptides derived fromhu-man Basic Proline-rich LacrimalPro-tein (BPLP), notably opiorphin, foruse as psycho stimulants. Thesepep-tides are useful in the treatment orprevention of diseases such asobses-sive-compulsive disorder (OCD),nar-colepsy, hypersomnia, vigilance drop,attention-deficit/hyperactivitydisor-der (ADHD), attention deficit and/orhyperactivity in adults and inchil-dren, depression, bipolar disease,dysthymic disorder and cyclothymicdisorder.