Associations between daily living skills, cognition, and real-world functioning across stages of schizophrenia; a study with the Schizophrenia Cognition Rating Scale Japanese version

Abstract

Cognitive function is impaired in patients with schizophrenia-spectrum disorders, even in their prodromal stages. Specifically, the assessment of cognitive abilities related to daily-living functioning, or functional capacity, is important to predict long-term outcome. In this study, we sought to determine the validity of the Schizophrenia Cognition Rating Scale (SCoRS) Japanese version, an interview-based measure of cognition relevant to functional capacity (i.e. co-primary measure). For this purpose, we examined the relationship of SCoRS scores with performance on the Brief Assessment of Cognition in Schizophrenia (BACS) Japanese version, a standard neuropsychological test battery, and the Social and Occupational Functioning Assessment Scale (SOFAS), an interview-based social function scale.Subjects for this study (n = 294) included 38 patients with first episode schizophrenia (FES), 135 with chronic schizophrenia (CS), 102 with at-risk mental state (ARMS) and 19 with other psychiatric disorders with psychosis. SCoRS scores showed a significant relationship with SOFAS scores for the entire subjects. Also, performance on the BACS was significantly correlated with SCoRS scores. These associations were also noted within each diagnosis (FES, CS, ARMS).These results indicate the utility of SCoRS as a measure of functional capacity that is associated both with cognitive function and real-world functional outcome in subjects with schizophrenia-spectrum disorders.

Early Intervention and a Direction of Novel Therapeutics for the Improvement of Functional Outcomes in Schizophrenia: A Selective Review

“…The cognitive function is impaired in ARMS patients as well as in first-episode and chronic schizophrenia patients ( 6 ). In particular, the verbal memory and executive functions of ARMS subjects who later developed psychosis were reported to be lower than in those who did not develop psychosis ( 77 – 79 ).…”

“…Other important factors include neurocognitive dysfunctions ( 3 – 6 ), negative symptoms ( 7 , 8 ), and alterations in brain morphology ( 9 – 11 ). Although antipsychotic medications are effective for reducing positive psychotic symptoms, these symptoms including first-rank symptoms showed no significant correlation with the outcome of schizophrenia patients ( 2 , 3 ).…”

Effect of Transcranial Direct Current Stimulation on Functional Capacity in Schizophrenia: A Study Protocol for a Randomized Controlled Trial

“…Functional capacity, or daily-living skills, has been reported to provide one of the most important factors affecting social consequences in patients with schizophrenia ( 6 , 27 ). As stated before, tDCS is a safe method of brain stimulation and has been reported to improve several domains of cognition in schizophrenia ( 18 – 22 ).…”

Electrophysiological Evidence in Schizophrenia in Relation to Treatment Response

“…Also, prolonged latency of P300 has been associated with performance on tests of verbal learning ( 13 ) and verbal fluency ( 51 ). It is important that these domains of cognition are related with functional capacity and real-world functions ( 9 , 52 ). Further, a correlation has been reported between P300 amplitudes and functional capacity ( 53 ).…”