B Kanchanatawan, S Thika, G Anderson, P Galecki and M Maes,
Progress in neuro-psychopharmacology & biological psychiatry, Jan 2018 03
The aim of this study was to assess the neurocognitive correlates of affective symptoms in schizophrenia. Towards this end, 40 healthy controls and 80 schizophrenia patients were investigated with six tests of the Cambridge Neuropsychological Test Automated Battery (CANTAB), assessing spatial working memory, paired-association learning, one touch stocking, rapid visual information (RVP), emotional recognition test and intra/extradimensional set shifting. The Hamilton Depression (HDRS) and Anxiety (HAMA) Rating Scales and the Calgary Depression Scale for Schizophrenia (CDSS) as well as the Positive and Negative Syndrome Scale (PANSS) were also used. There were highly significant associations between all 6 CANTAB tests and HDRS, HAMA and CDSS (except RVP) scores. The most significant items associating with neurocognitive impairments in schizophrenia were self-depreciation (CDSS), fatigue, psychomotor retardation and agitation, psychic and somatic anxiety (HDRS), fears, cognitive symptoms, somatic-muscular, genito-urinary and autonomic symptoms and anxious behavior (HAMA). The selected HDRS and HAMA symptoms indicate fatigue, fears, anxiety, agitation, retardation, somatization and subjective cognitive complaints (SCC) and are therefore labeled "FAARS". Up to 28.8% of the variance in the 6 CANTAB measurements was explained by FAARS, which are better predictors of neurocognitive impairments than the PANSS negative subscale score. Neurocognitive deficits in schizophrenia are best predicted by FAARS combined with difficulties in abstract thinking. In conclusion, depression and anxiety symptoms accompanying the negative and positive symptoms of schizophrenia are associated with neurocognitive deficits indicating disorders in executive functions, attention, visual memory, and social cognition. Neurocognitive deficits in schizophrenia reflect difficulties in abstract thinking and FAARS, including subjective cognitive complaints.