In a double blind randomized clinical trial with cross-over design, treatment using naratriptan will be compared to placebo within a group of 30 convicts with psychiatric disorders such as psychosis or psychopathy with repeated aggressive outbursts resistant to conventional psychopharmacologic and other psychotherapeutic treatment. Hypothesis is that addition of naratriptan to the individual treatment regime reduces aggression -and improves general outcome- as compared to addition of placebo and is well tolerated in this group and under these conditions.