Reversible cerebral vasoconstriction syndrome (RCVS) is a condition defined by severe sudden-onset headaches, typically ‘thunderclap’ headaches, caused by multifocal cerebral vasoconstriction. Various triggers have been described, including illegal substances, medication and infections. We observed a 27 year old man that suddenly developed severe headaches during admission to a psychiatric ward, where RCVS was diagnosed as most likely clinical cause. He was given nimodipine with rapid and full symptom remission. We aim to highlight this rare, but important, neurological syndrome and its various psychiatric risk factors.