Opposite links of positive and negative symptomatology with memory errors in schizophrenia

We wished to confirm and extend a previous correlational study of our group , suggesting that positive symptoms in schizophrenia were linked to an incr ease in certain types of memory errors, and negative symptoms to a decrease in other types of errors. A post-hoc analysis was conducted in 33 schizoph renic patients and 40 normal control subjects on memory errors collected in a free recall task and two types of recognition tasks. The memory errors w ere intrusions and list errors in free recall, and decision bias towards fa lse alarms in recognition, all assumed to reflect a source-monitoring failu re. In a first analysis, the patient sample was split along the median for positive symptoms as rated by the Scale for the Assessment of Positive Symp toms (SAPS). In a second analysis, it was split along the median for negati ve symptoms as rated by the Scale for the Assessment of Negative Symptoms ( SANS). Patients with high ratings of positive symptoms made more memory err ors (intrusions, list errors, false alarms) than those with low ratings, su pporting the hypothesis of a link between positive symptomatology and sourc e-monitoring failure. On the other hand, patients with high ratings of nega tive symptoms made fewer of these errors than the other patients. Fewer err ors were specifically associated with more affective flattening, alogia and anhedonia, whereas avolition was entirely unrelated to them. (C) 1999 Else vier Science Ireland Ltd. All rights reserved.