In recent years, exploration of the distinction between positive and negative symptoms of schizophrenia has provided a fruitful basis for attempts to relate the clinical features of schizophrenia to the accumulating evidence of brain abnormalities in schizophrenic patients. By 1982, there was an extensive body of evidence supporting the hypothesis that negative schizophrenic symptoms, such as poverty of speech and flatness of affect, were associated with substantial brain abnormalities, such as increased ventricular to brain ratio, and extensive cognitive impairment (Crow, 1980; Andreasen & Olsen, 1982). However, at that stage there were several fundamental unanswered questions about the nature of negative symptoms, and their relationship to indices of brain abnormality. This paper presents some findings of a series of studies initiated in 1982 to seek answers to some of these questions.
Adjunctive treatment for cognitive impairment in patients with chronic schizophrenia: a double-blind, placebo-controlled study
