Changes of auditory event-related potential P300 in patients with reactive depression and depressive neurosis

Wei QU; Xiting HUANG; Zongyao WU; Min HOU

ABSTRACT

BACKGROUND:

Reactive depression and depressive neurosis are both psychogenic emotional disorders, clinically manifested by memory deterioration,impaired concentration, slow reaction, and bradyphrenia, among other cognitive function impairments. These subjective experiences of such patients still need to be backed up for their actual presence by objective laboratory evidences, which,however, have been scarcely available to our current knowledge.

OBJECTIVE:

To investigate the changes of auditory event-related Potential (AERP) P300 in patients with reactive depression and depressive neurosis, and their correlation with cognitive function impairments.

DESIGN:

Case-controlled experiment.

SETTING:

Clinical Center of Psychological Counseling, Department of Neurology, Third Military Medical University of Chinese PLA.

PARTICIPANTS:

Forty normal control subjects were recruited from the staff of Southwest Hospital, Third Military Medical University between September 1997 and March 1998, including 21 male and 19 female subjects aged 20-50 years. Eighty patients were selected from the agematched outpatients of the same hospital seeking psychological counseling,including 40 with reactive depression (consisting of 29 male and 11 female patients) and 40 with depressive neurosis (consisting of 24 male and 16 female patients). From these patients 10 with abnormal P300 potential were randomly selected for followed-up study, including4 with reactive depression and4 with depressive neurosis.

METHODS:

All the patients and normal controls were subjected to conventional examination of AERP P300 in the Laboratory of Cerebral Electrophysiology, and psychological evaluation was carried out by specialists with the assistance of Zung Self-Rating Depression Scale.MAIN OUTCOME

MEASURES:

① Results of AERP P300 examination and scores of Zung Self-Rating Depression Scale in the 80 patients upon admission and 4 and 8 weeks after treatment, and results of AERP P300 examination in the control group. ② Results of AERP P300 examination and scores of Zung Self-Rating Depression Scale in the follow-up group.

RESULTS:

All subjects finished the study. The latency of all waves were remarkably prolonged in the patients as compared to the normal control group (P ＜ 0.05-0.01), with also lower amplitude of AERP than that of the control group; the amplitudes of N1, P2 and N2 waves, in general,tended to decrease to statistically significant levels. In reactive depression group, the amplitude of P3 wave was obviously lower than that of the control group [(10.39±4.40) vs (15.11±4.16) μV, P ＜ 0.001], and the amplitudes of all waves in the neurosis group was obviously lower than those of the control group. Comparison of the latency and amplitude of P3 in the follow-up group before and after treatment revealed no significant difference in the latency of P3 [(314.10±44.08) vs (295.4±20.74) ms, t=1.21, P ＜ 0.05], but the amplitude of P3 obviously increased after treatment to almost the normal level [(6.38±2.50) vs (14.22±2.51) μV, t=-7.012, P ＜ 0.001].

CONCLUSION:

Patients with reactive depression or depressive neurosis have cognitive function impairment, and auditory event-related potential P300 can be used as a reference for cognitive evaluation and therapeutic effect assessment in these patients.