The course of anhedonia during 10 years of schizophrenic illness.J Abnorm Psychol. 2002 May; 111(2):237-48.JA
Although anhedonia has been proposed to be a trait-like characteristic in schizophrenia patients, its persistence and stability have not been tested using multiple assessments over a multiyear period. Specific definitions of anhedonia vary across studies, and relationships between different types of anhedonia as well as their relationship to schizophrenic symptoms over the course of illness have not been addressed. The current research, using prospectively collected longitudinal data covering a 10-year span for 127 individuals with schizophrenic illness, found that (a) physical, but not depressive, anhedonia is a stable characteristic over a 10-year period; (b) physical anhedonia does not show strong and consistent relationships with psychotic, negative, or depressive symptoms; and (c) the relationship between some premorbid characteristics and physical anhedonia are significant even 10 years into the course of illness.