Are there more than two syndromes in schizophrenia? A critique of the positive-negative dichotomy

A sample of 115 DSM-III-R schizophrenics was studied by means of the SANS and SAPS. A factor analysis from the nine subscales and two symptoms (inappropriate affect and poverty of content) and a review of the previous factor analyses suggest that schizophrenic symptoms cannot be appropriately classified into positive and negative syndromes. The low internal consistency of the SAPS suggests that the positive symptoms are not a homogeneous syndrome. Our results fit better with Liddle's model of three syndromes (negative, delusion-hallucination and disorganisation syndromes). It is argued that we are far from a valid classification of schizophrenic symptoms and the positive-negative dichotomy appears to be an oversimplification.