Objective To study the relationship between the serum homocysteine ( Hcy ) levels in patients with first-episode depression and event related potentials ( ERP ) P300.Methods 117 first-episode depressive patients were selected as the case group,and 110 healthy volunteers were selected as the health control group,the de-termination of serum Hcy levels in the two groups were detected by enzyme linked immunosorbent assay,measured by the Shenzhen Brain Master brain evoked potential system to complete the visual P300.Results The serum Hcy levels of the case group was (14.0 ±9.8)μmol/L,which was higher than (10.5 ±7.5)μmol/L of the health control group (t=-3.087,P <0.05).The N1,N2 incubation period of the case group were (91.4 ±18.6) ms,(235.4 ± 30.5)ms,respectively,which were longer than (88.6 ±13.0)ms,(204.3 ±20.3)ms of the health control group(t=1.305,8.990,all P<0.01);The P3 incubation period of the case group were (359.5 ±30.0)ms,which was longer than (327.2 ±41.8)ms of the health control group(t=6.685,P<0.05).The target P3,non-target P2 amplitude of the case group were (4.1 ±2.0)μV,(4.2 ±1.9)μV,respectively,which were singnificantly lower than (6.8 ± 3.8)μV,(6.6 ±3.6) μV of the health control group( t=-6.694,-6.485,all P<0.01).The P2 incubation period of Hcy case group was (194.4 ±13.6) ms,which was longer than (163.1 ±21.8) ms of the non Hcy case group(t=8.486,P<0.01).The P3 incubation period of Hcy case group was (357.0 ±24.5)ms,which was longer than (337.1 ±45.5)ms of the non Hcy case group(t=2.645,P<0.05).The target P3,non-target P2 amplitude of the Hcy case group were (5.4 ±1.5)μV,(5.2 ±1.2) μV,which were significantly lower than (5.8 ±3.8)μV, (5.4 ±3.2)μV of the Hcy case group(t=-0.745,-0.208,all P<0.01).Conclusion The serum Hcy levels in patients with first-episode depression increased, and P300 latency, amplitude decreased, the cognitive function is related to Hcy metabolism disorder and depression damage.

Objective:To explore the role of objective teaching guided by immersion education theory in the practice teaching of undergraduates majoring in psychiatry.Methods:Two classes of undergraduates majoring in psychiatry in Batch 2018 were randomly selected as the study group and the control group. A total of 35 students in the control group had traditional teaching, and 37 students in the study group had objective teaching guided by immersion education theory, both with half a semester of teaching. After the teaching, the theoretical knowledge examination scores and skills assessment scores, comprehensive ability (self-learning ability, communication ability, clinical thinking, innovation ability, and humanistic care ability), and teaching satisfaction of the two groups were compared. SPSS 26.0 was used for t-test, Chi-square test, and rank sum test. Results:After the teaching, the theoretical knowledge examination scores (basic medicine, clinical medicine, clinical psychology, and psychiatry), skill assessment scores (physical examination, and mental examination), self-learning ability, communication ability, clinical thinking, innovation ability, and humanistic care ability of the study group were all higher than those of the control group ( P<0.05). The teaching satisfaction degree of the study group was higher than that of the control group, and the difference was statistically significant ( P<0.05). Conclusion:Objective teaching guided by immersion education theory can improve the scores of professional theoretical knowledge scores and skills assessment scores of undergraduates majoring in psychiatry, and improve teaching satisfaction.