Background

Deficits in cognition, social cognition, and motivation are significant predictors of poor functional outcomes in schizophrenia. Evidence of durable benefit following social cognitive training is limited. We previously reported the effects of 70 h of targeted cognitive training supplemented with social cognitive exercises (TCT + SCT) verses targeted cognitive training alone (TCT). Here, we report the effects six months after training.

Methods

111 participants with schizophrenia spectrum disorders were randomly assigned to TCT + SCT or TCT-only. Six months after training, thirty-four subjects (18 TCT + SCT, 16 TCT-only) were assessed on cognition, social cognition, reward processing, symptoms, and functioning. Intent to treat analyses was used to test the durability of gains, and the association of gains with improvements in functioning and reward processing were tested.

Results

Both groups showed durable improvements in multiple cognitive domains, symptoms, and functional capacity. Gains in global cognition were significantly associated with gains in functional capacity. In the TCT + SCT group, participants showed durable improvements in prosody identification and reward processing, relative to the TCT-only group. Gains in reward processing in the TCT + SCT group were significantly associated with improvements in social functioning.

Conclusions

Both TCT + SCT and TCT-only result in durable improvements in cognition, symptoms, and functional capacity six months post-intervention. Supplementing TCT with social cognitive training offers greater and enduring benefits in prosody identification and reward processing. These results suggest that novel cognitive training approaches that integrate social cognitive exercises may lead to greater improvements in reward processing and functioning in individuals with schizophrenia.

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.

Trial registration

ClinicalTrials.gov identifiers: NCT00312962, NCT00694889​​.