Association between the loudness dependence of auditory evoked potentials and age in patients with schizophrenia and depression

• Published in: Journal of international medical research Vol. 50; no. 7; pp. 30006052211097 - 3000605221109789
• Main Authors: Jang, Kuk-In, Kim, Sungkean, Lee, Chany, Chae, Jeong-Ho
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.07.2022; Sage Publications Ltd; SAGE Publishing
• Subjects: Hypotheses; Prospective Clinical Research Report; Schizophrenia; Serotonin; Schizophrenia; electroencephalography; loudness dependence of the auditory evoked potential; major depressive disorder; age; serotonergic activity
• ISSN: 0300-0605; 1473-2300
• DOI: 10.1177/03000605221109789

Objective Although serotonergic dysfunction is significantly associated with major depressive disorder (MDD) and schizophrenia (SCZ), comparison of serotonergic dysfunction in both diseases has received little attention. Serotonin hypotheses have suggested diminished and elevated serotonin activity in MDD and SCZ, respectively. However, the foundations underlying these hypotheses are unclear regarding changes in serotonin neurotransmission in the aging brain. The loudness dependence of auditory evoked potentials (LDAEP) reflects serotonin neurotransmission. The present study compared the LDAEP between patients with SCZ or MDD and healthy controls (HCs). We further examined whether age was correlated with the LDAEP and clinical symptoms. Methods This prospective clinical study included 105 patients with SCZ (n = 54) or MDD (n = 51). Additionally, 35 HCs were recruited for this study. The LDAEP was measured on the midline channels via 62 electroencephalography channels. Results Patients with SCZ or MDD showed a significantly smaller mean LDAEP than those in HCs. The LDAEP was positively correlated with age in patients with SCZ or MDD. Conclusions Changes in central serotonergic activity could be indicated by evaluating the LDAEP in patients with SCZ or MDD. Age-related reductions in serotonergic activity may be screened using the LDAEP in patients with SCZ or MDD.