What is relapse in schizophrenia?

Relapse can be defined as "the return of a disease after partial recovery". This definition is directly applicable to schizophrenic disorder. Relapse in this condition can be evaluated at the symptomatic, phenomenological and behavioural levels. Relapse impinges on inter-personal, social and occupational spheres of the patient's activity. In turn, relapse has wider implications for the family in general, for the provision of medical and social facilities and for health economics. There are no generally accepted criteria for relapse but outcomes such as violence or suicide, extreme psychotic behaviour and rehospitalization have been used. Less obvious criteria include major and minor symptom worsening and prodromata. Relapse is a relative term and must take into account the following factors: the patient's condition before the original onset of illness; his level of functioning before the present episode; the severity of the relapse in terms of symptom severity, duration and interference with personal functioning; the appearance of any new symptoms or behaviour patterns; the type of treatment given prior to relapse, and hence relatively ineffective; the type of treatment given during relapse, and its efficacy. Relapses often follow a pattern which may be fairly specific to each individual patient. Social factors may have predictive power but these need validation in different samples.