Impact of baseline early auditory processing on response to cognitive remediation for schizophrenia

Early auditory processing (EAP) has increasingly become a focus of efforts to identify biomarkers of treatment response in schizophrenia. EAP deficits lead to poor functional outcome via impaired cognition, and treatments that target EAP may drive downstream cognitive improvements. Assessment of baseline need provides an opportunity for cognitive remediation (CR) programs that give EAP training to personalize treatment and optimize its impact. This initial efficacy study examined the differential benefit of EAP training for those with and without baseline EAP deficits as defined by performance on the Tone Matching Test.

103 outpatient adults diagnosed with schizophrenia or schizoaffective disorder were classified as having intact (48.5%) or impaired (51.5%) EAP and randomized to a CR program with restorative exercise plans that either included EAP training (N = 49) or did not (N = 54). Cognitive and functional outcomes were measured post-treatment and 3 months later.

Only in EAP impaired participants was there a significant benefit from EAP training on verbal learning. Treatment condition did not significantly impact global cognitive or functional outcomes for either EAP group. Cognitive gains partially mediated the relationship between gains in EAP and functional capacity.

These findings support the importance of addressing basic auditory deficits when attempting to remediate higher order auditory impairments such as verbal learning. In addition, they highlight the need for routine assessment of EAP in cognitive remediation participants, as well as the need for more effective programs to reverse these impairments.