The loudness dependence of the auditory evoked potential (LDAEP) in schizophrenia, bipolar disorder, major depressive disorder, anxiety disorder, and healthy controls.
BACKGROUND
Serotonergic dysfunction in schizophrenia, bipolar disorder, major depressive disorder, anxiety disorder, and healthy controls was evaluated by measuring the activity of the loudness dependence of the auditory evoked potential (LDAEP).


METHODS
The 357 subjects who were evaluated comprised 55 normal controls, 123 patients with major depressive disorder, 37 with bipolar disorder, 46 with schizophrenia, 37 with panic disorder (PD), 31 with generalized anxiety disorder (GAD), and 28 with post-traumatic stress disorder (PTSD).


RESULTS
LDAEP was significantly stronger in healthy controls than in patients with either bipolar disorder (p=0.025) or schizophrenia (p=0.008), and significantly stronger in patients with major depressive disorder than in those with bipolar disorder (p=0.01) or schizophrenia (p=0.03). LDAEP did not differ significantly between patients with major depressive disorder and healthy control subjects (p=0.667), or between healthy control subjects and patients with anxiety disorder, including PD (p=0.469), GAD (p=0.664), and PTSD (p=0.167).


CONCLUSIONS
The findings of the present study reveal that patients with major psychiatric disorders exhibit different strengths of LDAEP according to their serotonin-related pathology. Studies controlled for psychotropic medication, menstruation cycle, and smoking are needed.
Park
Young-Min
YM
Department of Psychiatry, Inje University, Ilsan Paik Hospital, 2240 Daehwa-dong, Ilsanseo-gu, Goyang 411-706, South Korea.
Lee
Seung-Hwan
SH
Kim
Sangrae
S
Bae
Sung-Man
SM
D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001008:Anxiety Disorders / Q000503:physiopathology*; D001714:Bipolar Disorder / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008144:Loudness Perception / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011930:Reaction Time; D012559:Schizophrenia / Q000503:physiopathology*; D055815:Young Adult