Relation between remission status and attention in patients with schizophrenia

Patients with schizophrenia in remission have shown significantly higher levels of neurocognitive function than patients not in remission. However, previous studies have mainly examined the association between neurocognitive function and the remission status of schizophrenia without considering the time component of the definition for remission using cross-sectional methods. The purpose of this study was to investigate the relations between remission status with considering time components and three cognitive functions of intellectual ability, memory and attention, which were examined before fulfilling the remission criteria, using longitudinal methods.

We assessed the remission status using the Positive and Negative Syndrome Scale (PANSS) on the same patients twice: at recruitment and at 6 months after the first PANSS assessment. Cognitive tests were performed within 3 months after recruitment. At recruitment, 337 patients were enrolled. Of the patients, 63 patients were followed up and completedthe first and second PANSS assessments and three cognitive tests at the end of study.

Of the patients, 33 patients fulfilled the remission criteria, while 30 patients did not fulfill the criteria. Patients in remission showed significantly higher levels of 2-digit (P = 0.020) and 3-digit (P = 0.015) Continuous Performance Test scores, attention/concentration in the Wechsler Memory Scale-Revised (P = 0.034) and processing speeds in the Wechsler Adult Intelligence Scale-III (P = 0.047) than patients not in remission. Additionally, these cognitive scores were positively correlated with each other (P < 0.05).

Our findings suggest that patients who achieve remission may demonstrate a pre-existing higher level of attention than patients who do not achieve remission.