Early-versus adult-onset schizophrenia as a predictor of response to neuroscience-informed cognitive training

Background: Developmental stages characterized by greater neural plasticity might be critical periods during which the effects of cognitive training (CT) could theoretically be maximized. However, experiencing a first episode of schizophrenia during childhood or adolescence (ie, early-onset schizophrenia [EOS]) may reduce the brain's ability to benefit from CT. This study examined the effects of EOS versus onset at > 18 years of age (ie, adult-onset schizophrenia [AOS]) as a predictor of response to CT and the relationship between duration of illness and cognitive improvements. Methods: This study is a secondary analysis of data from 2 randomized trials that examined the cognitive effects of neuroscience-informed auditory training (AT) exercises in 84 outpatients with schizophrenia (26 EOS, 58 AOS, recruited between 2004 and 2014). Results: There was a significant effect of time in all cognitive domains (F > 10.22, P < .002). The effect of EOS was significant only for verbal learning and memory (F = 5.79, P = .018). AOS increased the mean change score by 5.70 points in this domain, whereas EOS showed no change (t = -2.280, P = .025). However, the difference between AOS and EOS was no longer statistically significant after control for multiple comparisons. Shorter duration of illness was associated with greater improvement in problem solving in the AOS group (r = -0.27, P = .040). Conclusions: Auditory training is effective in improving cognition in both EOS and AOS. Treatment effects in all cognitive domains were similar, with the exception of verbal learning and memory. This result requires replication. Cognitive training provided earlier in the course of the illness results in greater improvements in executive functions.