Reactive psychosis and other brief psychotic episodes.

Modern classification systems have ignored the reactive psychoses, and little has been published using this concept during the last years. Nevertheless, the term is of interest in clinical practice where its presence is dependent on clinical skills and empathy. It is also important for a general understanding of the development of psychosis. The delineation from other acute psychoses needs clarification. Studies on reliability and validity are promising, but need extension. Traditionally, the concept of reactive psychosis has hardly been used outside Scandinavia, and it is encouraging that interest in brief psychoses seems growing in other cultures as well.