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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The P300 wave is one of the cognitive components of the event-related potential (ERP) that is used to investigate the cognitive processes, and which can be used to study patient populations with a variety of psychiatric disorders. Its clinical utility has been increased by the identification of factors that contribute to the variability in its amplitude and latency. However, its value as a diagnostic index has not been entirely established. It can provide a useful recording of patients' information processing, and indicate the severity of the clinical state and its possible evolution. It can also assist in determining what therapeutic approach to adopt. In the present review, the findings in the literature concerning interindividual variation in the P300 wave are first described; several variables significantly influence the amplitude and latency of this wave, such as age, gender, intelligence and personality. Following this, the relevance of the data in the literature on the clinical applications of P300 in psychopathology is examined, including the studies undertaken to obtain an objective diagnostic index for mental disorders and also those carried out to assess the problems concerning the interpretation of information connected with the mental pathologies examined. P300-associated findings on dementia, schizophrenia, depression, alcoholism, drug addiction, anxiety disorders (panic disorder, obsessive-compulsive disorder, and post-traumatic stress syndrome) and on personality disorders (schizoid, antisocial or borderline personality disorder) have been examined in detail.
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PMID:[The p300 cognitive event-related potential. II. Individual variability and clinical application in psychopathology]. 1101 95

Event related potentials have been examined in depression and Alzheimer disease like clinical utility. To evaluate the influence of visual and auditory stimuli on the P300 latency we studied 12 patients with major depression, 12 patients with Alzheimer disease and 12 normal subjects. The experimental tasks applied was, first a series of 300 auditory stimuli, 255 (85%), with tones of 1,000 Hz, and considered as the frequent stimulus, whereas 45 (15%) were tones of 2,000 Hz and referred as the rare stimulus. A second series of 300 visual stimuli, 255 (85%) that were black circles on a white background, and considered the frequent stimulus (9 cm diameter, 200 ms duration), whereas 45 (15%) were black squares on a white background and referred as the rare stimulus (9 cm diameter, 200 ms duration) in the centre of a computer screen. The results show an increase of P300 latency in depressive and Alzheimer patients during auditory and visual tasks. Differences were found in reaction time to visual or auditory stimuli in Alzheimer disease. These results are consistent with an impairment in brain function in depressive patients that is associated with cortical hypoactivity and deficits in perceptive, auditory or visual, functions, whereas deterioration in Alzheimer's disease is sensorymotor, according to the slowness latency in the reaction time.
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PMID:Deficit in sensory motor processing in depression and Alzheimer's disease: a study with EMG and event related potentials. 1103 20

It is of interest to record event-related potentials in the course of transient global amnesia (TGA) because the hippocampus and diencephalon, generally considered to be the sites of the dysfunction responsible for the amnesic episodes are also considered as two possible generators of the P300 wave. However, the only four cases reported so far in the literature showed an intact auditive P300 in three cases and an intact auditive P300 with reduction of visual P300 in one case. Here are reported four new cases. The P300 wave was readily identifiable in all four cases, without any amplitude reduction, thus suggesting that the condition did not entail inactivation or functional depression of P300 generators. Concerning P300 latency, in one case it was delayed but became normal after the ictus. In the second case, the latency, although within normal limits, shortened after the ictus. In the third and the fourth cases, the latency, initially within normal limits, remained unchanged. These apparently disparate results should be analysed in the light of the results of isotope measurement of cerebral blood flow during the amnesia, which are also inconsistent but most frequently indicate bilateral temporal or thalamic flow reduction. It remains to be determined in the future whether the stability or change in the P300 will make it possible to predict the brain region involved in transient global amnesia, which could perhaps vary from one patient to another.
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PMID:[The recording of cognitive evoked potentials during and after transient global amnesia: report of three cases]. 1143 73

A single auditory stimulus in a passive ignore condition elicits a P3 potential (passive P3) that shares similar morphology with the classical P3 (P300 or P3b) in the active auditory 'oddball' paradigm. Since the classical P3 is correlated with introversion, anxiety, or sensation seeking, it was hypothesized that the passive P3 is correlated with sensation seeking personality. Therefore, 39 healthy subjects aged from 15 to 57 years and free from depression, were asked to answer Zuckerman's sensation seeking scales (SSS), and undergo an auditory event-related potential procedure with a single stimulus. In all subjects, a clear passive P3 appeared at three midline electrodes that shared similar latency and amplitude to the classical P3. The SSS total and experience seeking subscale scores were positively correlated with N1 amplitude at Fz. In contrast, the SSS total and some subscale scores were negatively correlated with the passive P3 amplitudes at the three electrodes. The sensation seeking personality effects on the passive P3 might be via a cortical inhibition process during memory updating, which are considered to be involved in the classical P3.
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PMID:Sensation seeking correlates of passive auditory P3 to a single stimulus. 1152 56

The correlation between event-related potentials (P300) and activities of daily living was studied in Parkinson's disease. The P300 of 30 patients with Parkinson's disease and 118 normal subjects were recorded. All patients were evaluated by the Mini-Mental State, Kana-hiroi Test, word fluency, Raven's Coloured Progressive Matrices, Osaka Memory Scale, revised Wechsler Adult Intelligence Scale, self-rating depression scale, state-trait anxiety inventory, and Functional Independence Measure. Eight patients showed prolonged P300 latencies. P300 latency showed relationships to the Mini-Mental State (p < 0.05) and cognitive items of the Functional Independence Measure (p < 0.05). P300 amplitude showed a relationship to performance IQ (p < 0.005), Raven's Coloured Progressive Matrices (p < 0.01) and motor items of the Functional Independence Measure (p < 0.05). It was concluded that P300 should be useful in predicting difficulties with activities of daily living in patients with Parkinson's disease.
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PMID:Relationships between event-related potentials (P300) and activities of daily living in Parkinson's disease. 1179 95

Eighteen patients with schizophrenia and 18 patients with affective disorders (depression) underwent regisTration of auditory event-related potentials (ERPs) recording in oddball paradigm. All the patients were in remission. In both groups of the patients, the N100 ERPs amplitudes to non-target stimuli were significantly smaller and N200 and P300 latencies were longer than in 18 normals. In the patient's group with affective disorders, prolongation of P200 and N100 ERPs latencies to target stimuli has been found. The group of patients with schizophrenia was characterized by P300 amplitude reduction. The results show stimuli processing decrease in patients with affective disorders, while in patients with schizophrenia a cognitive function disturbance was recorded.
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PMID:[Auditory evoked potentials in patients with schizophrenia and affective disorders]. 1184 25

Noninvasive electrophysiological neuroimaging applied to cognitive components of event-related potentials (ERPs) may differentiate between structural and energetic processes related to information processing. The structural level, revealed by the location of the local maxima of the current source density distribution, describes the time-dependent network of activated brain areas. The magnitude of the source strength, a measure of the energetic component, describes the allocation of processing resources. ERPs were recorded in an odd-ball paradigm and low-resolution brain electromagnetic tomography (LORETA) was applied for standard and target ERP components. In a group of 60 menopausal depressed patients of 45-60 years of age, reduced P300 source strength was observed bilaterally, temporally and medially prefrontally reaching to rostal parts of the anterior cingulate, compared with 29 age-matched controls. In a double-blind, placebo-controlled study, 2 mg of the antidepressant citalopram induced a significant increase of P300 source strength in the (left) prefrontal cortex and precuneus compared with placebo, reaching to the posterior cingulate. Similar increases were observed after 800 mg S-adenosyl-L-methionine (SAMe) administered intravenously in ten young healthy subjects aged 22-33, and they were even more pronounced in ten elderly healthy subjects aged 56-71. Thus, ERP-tomography identified changes in energetic sources in brain areas predominantly involved in depression and in antidepressant action.
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PMID:Structural and energetic processes related to P300: LORETA findings in depression and effects of antidepressant drugs. 1257 74

This study assessed the cognitive brain function measured by the cognitive P300 auditory event-related potentials (ERPs) in female fibromyalgia (FM) patients and compared the results with those from healthy age and education-matched controls. The relationship of the P300 potentials to the pain threshold of patients was also investigated. The P300 component of the auditory ERPs were studied in 11 female FM patients and 10 age and education-matched healthy controls. None of the patients were taking antidepressants such as amitriptyline or serotonin-reuptake inhibitors. The P300 latencies of the patients were not significantly different whereas the N2P3 amplitudes were significantly lower than the controls. The P300 latencies in the patients negatively correlated with the total myalgic scores (TMS) (r= -0.73) and the control point scores (CPS) (r=-0.85). On the other hand, the P300 amplitudes showed a significant correlation with the TMS (r=0.61) and the CPS (r=0.60). There was no significant correlation between the anxiety and depression scores with the P300 latency or amplitudes. These results showed cognitive impairment, which was mainly expressed by the lower N2P3 amplitudes in patients with FM, and its clinical relevance requires further research.
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PMID:Auditory p300 event-related potentials in fibromyalgia patients. 1261 80

We used event-related potentials (ERPs) to probe the effects of feedback in a hypothesis testing (HT) paradigm. Thirteen college students serially tested hypotheses concerning a hidden rule by judging its presence or absence in triplets of digits and revised them on the basis of an exogenous performance feedback. ERPs time-locked to performance feedback were then examined. The results showed differences between responses to positive and negative feedback at all cortical sites. Negative feedback, indicating incorrect performance, was associated to a negative deflection preceding a P300-like wave. Spatiotemporal principal component analysis (PCA) showed the interplay between early frontal components and later central and posterior ones. Lateralization of activity was selectively detectable at frontal sites, with a left frontal dominance for both positive and negative feedback. These results are discussed in terms of a proposed computational model of trial-to-trial feedback in HT in which the cognitive and emotive aspects of feedback are explicitly linked to putative mediating brain mechanisms. The properties of different feedback types and feedback-related deficits in depression are also discussed.
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PMID:Feedback in hypothesis testing: an ERP study. 1280 63

A single-trial analysis of event-related potentials (P300) of 21 depressives was performed in comparison with matched controls. The purpose was to confirm previous results revealing an overall reduction of the single-trial P300 amplitude in depression despite fewer elicited single-trial P300 waves in schizophrenics. The result of the present study is in line with our previous investigation implicating a general reduced P300 amplitude on single trials of depressive patients. Therefore, it appears possible to differentiate depressives and schizophrenics by measuring event-related potentials and applying a single-trial analysis of them.
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PMID:A confirmatory study on the mechanisms behind reduced P300 waves in depression. 1282 38


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