Nancy Andreasen Has Proposed a Classification Scheme for Schizophrenia That

Nancy Andreasen has proposed a classification scheme for schizophrenia that divides schizophrenic disorders into two categories,based on the predominance of negative versus positive symptoms.Results from research studies which have investigated this method of classification suggest that most patients

A) exhibit mainly positive symptoms.
B) alternate between positive and negative symptoms.
C) exhibit mainly negative symptoms.
D) exhibit both types of symptoms.