An impairment of functional capacity and real-life functioning has widely been reported in patients with schizophrenia, even when clinical remission has been achieved. The relative contribution of negative symptoms and neurocognitive deficits to such an impairment is still debated.
In the present study, we investigated the relationships of functional capacity and real-life functioning with psychopathology and cognitive deficits in 35 schizophrenia patients, all treated with new-generation antipsychotics.
The MATRICS Cognitive Consensus Battery was used to assess cognitive functions. Real-life functioning was evaluated with the Quality of Life Scale (QLS). Functional capacity was assessed with the Performance-Based Skills Assessment-Brief (UPSA-B). Psychopathological dimensions were calculated from PANSS items. Multiple Regression Analyses (MRA) were conducted, in which dependent variables were the indices of functional capacity/real life functioning while independent variables were psychopathological dimensions, neurocognitive indices, general abilities and education.
The results of MRA on the QLS indices showed the following percentages of variance explained: negative psychopathological dimension, 64% for “intrapsychic functions” and 46% for “interpersonal relationships”; speed of processing, 13% for “work functioning” and 11% for “interpersonal relationships”; visual learning, 12% for “work functioning”; positive psychopathological dimension, 11% for “intrapsychic functions” and 5% for “interpersonal relationships”; working memory, 7% for “intrapsychic functions”. As to the MRA on UPSA-B total score, working memory explained 57% of the variance while speed of processing explained 12% of it.
Our findings suggest that both negative symptoms and cognitive impairment have a strong relationship with real-life functioning while cognitive impairment is the only aspect associated to functional capacity.