The metamorphosis of schizophrenia: from chronicity to vulnerability.

On the evidence of long-term follow-up studies of cohorts of patients in Europe the outcome of schizophrenia appears to be changing from chronicity to an episodic course with a more favourable outlook. While the reasons for this change are unclear it is suggested that schizophrenia is characterized essentially by a state of vulnerability to the disorder. This vulnerability may or may not give rise to an episode of illness, depending on the incidence of triggering life event stressors and on the moderating influences of social networks, ecological factors, and premorbid personality. The traditional view of schizophrenia as an essentially chronic condition reflects not so much the natural history of the disorder as iatrogenic influences, lack of satisfactory extra-mural care, the accumulation of a relatively small proportion of truly chronic illnesses and the failure to recognize the termination of an episode of illness in patients with poor premorbid personalities. Evidence for the episodic nature of schizophrenia is presented.