Negative symptoms: future developments of the concept.

The concept of negative symptoms has become increasingly important since it was reintroduced into psychiatric thinking several years ago. As the possible significance of negative symptoms has become clarified, the complexity of this concept has also become apparent. In dealing with this complexity, major progress has been made in describing negative symptoms more reliably and in taking steps toward identifying possible biological correlates. But two other particularly important directions also need to be pursued. First, psychosocial factors need to be explored further both in terms of their etiological contributions to negative symptoms and in the way these symptoms influence psychosocial aspects of the evolution of disorder and recovery. Secondly, more attention must be focused on the potential that negative symptoms have for providing an understanding of the interface between biological, psychological, and social processes in psychiatric disorder. In these ways the study of negative symptoms may contribute major clues to the nature of psychopathology, its etiologies, and its course.