Contingent negative variation of mood disorder patients

Studies on brain-evoked potential and contingent negative variation （CNV） in mood disorder remain controversial. To date, no CNV difference between unipolar and bipolar depression has been reported. Brain-evoked potentials were measured in the present study to analyze CNV in three subtypes of mood disorder （mania, unipolar depression, and bipolar depression）, and these results were compared with normal controls. In the mania group, CNV amplitude B was greater than in controls, and the depression group exhibited lower CNV amplitude B and smaller A-S＇2 area, and prolonged post-imperative negative variation latency. The CNV comparison between unipolar and bipolar depression found that the prolonged post-imperative negative variation latency was only in unipolar depression. These results suggest that prolonged post-imperative negative variation latency is a characteristic of unipolar depression, and CNV amplitude change is a state characteristic of mood disorder patients.

Effects of acute aerobic exercise on response preparation in a Go/No Go Task in children with ADHD:An ERP study

Purpose： The purpose of this study was to investigate the impact of acute exercise on reaction time and response preparation during a Go/No Go Task in children with attention deficit hyperactivity disorder （ADHD）. Methods： Nineteen children with ADHD （aged between 8 and 12 years old） undertook a 30-min intervention that consisted of treadmill running or video-watching presented in a counterbalanced order on different days. A Go/No Go Task was administrated after exercise or video-watching. Results： The results indicated a shorter reaction time and smaller contingent negative variation （CNV） 2 amplitude following exercise relative to the video-watching. For event related potential （ERP） analyses, greater CNV l and CNV 2 amplitudes in response to No Go stimuli in com- parison to Go stimuli was observed in the video-watching session only. Conclusion： These findings suggest that acute exercise may benefit children with ADHD by developing appropriate response preparation, particularly in maintaining a stable motor preparatory set prior to performing the given task.

Characterization of event-related potentials in obsessive compulsive disorder patients: Comparison with depression and generalized anxiety disorder patients

BACKGROUND： Study results of event-refated potential in obsessive compulsive disorder （OCD） remain controversial, potentially as a result of different instruments utilized and their differing technical characteristics. OBJECTIVE： To investigate the differences in several common event-related potentials, Le. contingent negative variations, P300, and mismatch negativity （MMN）, in OCD patients, depression patients, generalized anxiety disorder （GAD） patients, and healthy controls. DESIGN, TIME AND SETTING： A case-control study was performed in the Department of Electrophysiology, Shanghai Mental Health Center from May 2002 to December 2005. PARTICIPANTS： A total of 38 OCD patients, 20 depression patients, and 18 GAD patients, who were diagnosed according to the criteria of Chinese Classification of Mental Disorders （Version 3）, formulated by the Chinese Psychiatry Association, were selected from the Outpatient Department of Shanghai Mental Health Center. Patients with two or more the above diseases were excluded. In addition, 28 healthy people, gender and age matched, were selected as controls. METHODS： Contingent negative variations, P300, and MMN were recorded by a Nicolet Spirit Instrument. All electrodes were attached at Cz according to the Intemationa11020 system, with the mastoid leads as reference and Fpz as ground. MAIN OUTCOME MEASURES： Amplitude and latency of contingent negative variations, P300, and MMN. RESULTS： The contingent negative variations, P300, and MMN were different （P 〈 0.01）. OCD patients showed an increased MI amplitude compared with controls, depression, and GAD patients （P 〈 0.01）. Target P300 amplitudes were significantly lower in OCD, depression, and GAD patients compared with controls （P 〈 0.01）. Moreover, N2 latency and latency of MMN were prolonged in OCD and depression groups compared with controls （P 〈 0.05）. CONCLUSION： Event-related potentials were different in depression, GAD, and OCD patients and healthy controls. In particular, OCD patients exhibited unique characteristics.

FOLLOW-UP STUDY OF THREE COGNITIVE POTENTIALS OF DEPRESSION AND ANXIETY DISORDERS

To investigate the variations of contingent negative variations （ CNV）, P300 and mismatch negativity （MMN） in depression and anxiety disorders. Methods CNV, P300 and MMN were recorded from 44 depressive patients using Nicolet Spirit Instrument, and were compared with that of 32 anxiety patients and 28 normal controls（NC）. 21 of depressive patients and 18 of anxiety patients were followed up by 2.5 months with the same evoked potentials. Results 1. Compared with NC, all patients in acute episode showed decreased M1 of CNV amplitude, delayed P3 latency and decreased P3 amplitude of P300, and delayed MMN latency and decreased MMN amplitude ; 2. The follow-up study of evoked potentials revealed that abnormal P3 of P300 and MMN latencies were significant between depressed patients in remission status and NC group but not P3 of P300 and MMN amplitudes, and M1 of CNV and P3 of P300 amplitudes and P3 of P300 and MMN latencies are not significant between anxiety patients in remission and NC group. Conclusion Delayed P3 of P300 and MMN latencies in depression show state and trait markers, while those variations in anxiety correlate with clinical status of anxiety state.