A prospective case-control study of the ERPs in depression

Objective To explore the event-related potentials (ERPs) P300 is changeable or not before and after treatment. Methods 99 cases of patients with first onset of depression diagnosed by DSM-Ⅳ as case group,and 100 cases matched with patients as control group were collected. P300 of two groups were obtained before and after treatment for 6 weeks,12 weeks,24 weeks. T test was used to analysis the difference of indicators of P300 among groups; repeated measure analysis of variance was used to analysis the longitudinal changes. Results shorter latency of N2-P3 ( (P ＜ 0.01 ); and lower amplitude of N2, P3, N2-P3 (P ＜ 0. 05 ), higher amplitude of P2-tency and a upward one in N2-P3 latency in the four periods; a upward trend could also be found in P3, N2-P3 amplitude, but there were no statistical differences(P ＞ 0. 05 ). The results of paired-samples t test: P3, N2-P3 amplitude in case group were higher after treatment for 6 weeks than before, the difference was significant (P ＜ 0.01 ); no significant results were found in P300 latency or amplitude between the 62 cases of depression after treatment for 24 weeks and the 65 normal controls selected (P ＞ 0. 05 ). Conclusion P300 latencies and amplitudes tend to be partly recovered after the acute treatment in patients with depression, but after the long-term therapy not clear. Key words: Depression; Event related potential; Citalopram