Comparison of Auditory Brainstem Response (ABR) findings in drug-naïve schizophrenia patients and healthy comparison subjects.

Background: Schizophrenia is associated with neurophysiological impairments, including auditory brainstem response (ABR) abnormalities. Prior studies often include medicated patients, potentially confounding results.

Objective: This case-control study investigates ABR parameters in drug-naïve schizophrenia patients and explores their correlation with symptom severity.

Methods: We conducted a case-control study comparing 30 drug-naïve schizophrenia patients and 30 age-, sex-, and hearing threshold-matched healthy controls. ABR recordings using click stimuli at 90 dB HL and 50 dB HL assessed absolute latencies (Wave I, III, V) and interpeak intervals (I-III, III-V, I-V) for both ears. Symptom severity was evaluated using the Positive and Negative Syndrome Scale (PANSS). Correlation analysis between ABR parameters and PANSS scores was performed using Pearson's test.

Results: Groups were comparable in age and sex (p > 0.05). Schizophrenia patients exhibited significantly prolonged Wave V latencies compared to controls at 90 dB HL (p = 0.005) and 50 dB HL (p = 0.008). No significant differences were observed in interpeak latencies (p > 0.05). A moderate positive correlation was found between prolonged Wave V latency (90 dB HL) and PANSS-positive symptom scores (r = 0.42, p = 0.01).

Conclusions: Drug-naïve schizophrenia patients demonstrate delayed ABR Wave V latencies at high and low stimulus intensities, independent of antipsychotic medication. The correlation with positive symptom severity suggests ABR may reflect disease specific neurophysiological dysfunction, supporting its potential as an objective biomarker for schizophrenia.