Showing papers in "Neuropsychobiology in 2004"
TL;DR: Escitalopram treatment was similar to venlafaxine treatment with respect to efficacy and was better tolerated by patients in primary care and when treatment was completed after 8 weeks.
Abstract: This 8-week, randomised, double-blind study compared the efficacy and tolerability of escitalopram to that of venlafaxine XR in primary care patients with major depressive disorder. The efficacy of es
170 citations
TL;DR: In this review, both clinical and preclinical data are presented to highlight types of noradrenergic dysfunction observed in individuals with PTSD and the role ofnoradrenaline dysregulation in the acquisition/initiation, and maintenance of hyperarousal and reexperiencing symptom clusters in PTSD are addressed.
Abstract: Post-traumatic stress disorder (PTSD) is a serious psychiatric illness that may develop in individuals after exposure to a traumatic event. Recent data suggest that trauma and/or long-term stressors can cause alterations in the functioning of neuroanatomical structures and neural networks throughout the central nervous system. Specifically, dysregulation in central and perhaps, peripheral noradrenergic neural networks has been implicated as the cause of specific symptom clusters in the pathophysiology of PTSD. In this review, both clinical and preclinical data are presented to highlight types of noradrenergic dysfunction observed in individuals with PTSD. Additionally, the role of noradrenaline dysregulation in the acquisition/initiation, and maintenance of hyperarousal and reexperiencing symptom clusters in PTSD will be addressed.
152 citations
TL;DR: The possible contribution of stimulatory environmental conditions to the neuropsychobiological effects of MDMA is considered, which may heighten the likelihood of adverse neuropsychological sequelae in recreational ecstasy users.
Abstract: MDMA (3,4-methylenedioxymethamphetamine) or ‘ecstasy’ is a ring-substituted amphetamine derivative, which is widely used as a recreational drug, most particularly at dances and raves. Around 80–95% of
139 citations
TL;DR: The electroencephalographic effects of two intravenous sedative/hypnotic drugs, propofol and thiopental, were studied at three stable blood concentrations in 52 normal healthy volunteers and strong frontal-central rhythms apparent in this state are described using a quantitative description of oscillatory systems underlying the rhythm.
Abstract: The electroencephalographic effects of two intravenous sedative/hypnotic drugs, propofol and thiopental, were studied at three stable blood concentrations in 52 normal healthy volunteers. The higher concentration resulted in unresponsiveness (lack of response to auditory/tactile stimuli) in all subjects. This report describes the strong frontal-central rhythms apparent in this state using a quantitative description of oscillatory systems underlying the rhythm. These rhythms occur when sedative drug concentrations are greater than those producing the well-described increase in broadband β-power associated with many sedative drugs. Propofol induces rhythms in the α-range, while thiopental produces rhythms in the β-range. Quasistationary for a period of about 1 h, these rhythms exceed the baseline α-rhythm in power. By their resonant nature, these propofol-induced rhythms are analogous to ‘the classic α-rhythm’, but quantitative characteristics of the underlying oscillatory systems are different. Baseline properties of the oscillatory system underlying the initial resting α-rhythm recover completely as drug concentration decays to negligible values.
137 citations
TL;DR: It is suggested that lower trait anxietyMore readily induces meditation with a predominance of internalized attention, while higher trait anxiety more readily induces Meditation with a majority of relaxation.
Abstract: Meditation is a specific consciousness state in which deep relaxation and increased internalized attention coexist. There have been various neurophysiological studies on meditation. However, the personal predispositions/traits that characterize the properties of meditation have not been adequately studied. We analyzed changes in neurophysiological parameters [EEG coherence and autonomic nervous activity using heart rate variability (HRV) as an index] during Zen meditation, and evaluated the results in association with trait anxiety (assessed by Spielberger's State-Trait Anxiety Inventory) in 22 healthy adults who had not previously practiced any form of meditation. During meditation, in terms of mean values in all subjects, an increase in slow alpha interhemispheric EEG coherence in the frontal region, an increase in high-frequency (HF) power (as a parasympathetic index of HRV), and a decrease in the ratio of low-frequency to HF power (as a sympathetic index of HRV) were observed. Further evaluation of these changes in individuals showed a negative correlation between the percent change (with the control condition as the baseline) in slow alpha interhemispheric coherence reflecting internalized attention and the percent change in HF reflecting relaxation. The trait anxiety score was negatively correlated with the percent change in slow alpha interhemispheric coherence in the frontal region and was positively correlated with the percent change in HF. These results suggest that lower trait anxiety more readily induces meditation with a predominance of internalized attention, while higher trait anxiety more readily induces meditation with a predominance of relaxation.
131 citations
TL;DR: There was a significant increase in serum SOD, serum MDA and a decrease in plasma ascorbic acid in schizophrenic patients as compared to control subjects, and the trend altered significantly after the treatment with atypical antipsychotics.
Abstract: There is evidence to suggest the derangement of the oxidant and antioxidant defense system in schizophrenia. The present study examined the effect of atypical antipsychotics on lipid peroxidation, superoxide dismutase (SOD) and ascorbic acid. For this purpose, a prospective, open-label, 8-week study design was utilized. Serum SOD, serum malondialdehyde (MDA) and plasma ascorbic acid were estimated. Schizophrenic patients (n = 48) were compared with age- and sex-matched healthy volunteers (n = 40). There was a significant increase in serum SOD, serum MDA and a decrease in plasma ascorbic acid in schizophrenic patients as compared to control subjects. The trend altered significantly after the treatment with atypical antipsychotics. The results of the Brief Psychiatric Rating Scale for schizophrenia also improved with the treatment. The findings indicate an involvement of free radicals in schizophrenia and its modification by treatment with atypical antipsychotics. This study can also be used as a predictor of drug response by atypical antipsychotics in schizophrenia.
128 citations
TL;DR: The present results suggest the involvement of unimodal and heteromodal association cortex and limbic structures in the psychological effects elicited by ayahuasca.
Abstract: Ayahuasca, a South American psychotropic plant tea obtained from Banisteriopsis caapi and Psychotria viridis , combines monoamine oxidase-inhibi
115 citations
TL;DR: It is suggested that genetic variants of the BDNF gene may play a role in specific cognitive functions, but not in overall intelligence, as tested in a cohort of 114 healthy young Chinese females.
Abstract: Brain-derived neurotrophic factor (BDNF), a member of the nerve-growth-factor family, plays an important role in neuronal survival and development, and it can modulate serotonergic activity. Further, BDNF has been implicated in the expression of personality traits and in cognitive function. We tested the associations between functional BDNF Val66Met genetic variants, and personality trait and intelligence in a cohort of 114 healthy young Chinese females. Subjects with the Val/Val genotype had a significantly higher mean performance IQ than Val/Met carriers, especially for the Object Assembly subtest. No significant association was demonstrated for the BDNF polymorphism and any of the Tridimensional Personality Questionnaire personality-factor scores, including harm avoidance. These results suggest that genetic variants of the BDNF gene may play a role in specific cognitive functions, but not in overall intelligence. In contrast to a recent report, however, this polymorphism does not appear to be associated with the neuroticism-related personality trait.
113 citations
TL;DR: The present study suggests that the functional COMT Val158Met genetic polymorphism contributes to individual differences in the personality traits novelty seeking and reward dependence.
Abstract: Human personality traits, which are substantially heritable, may be modulated by monoamine neurotransmitters. It has been demonstrated that the catechol-O-methyltransferase (COMT) V
110 citations
TL;DR: The hypothesis that the basic neurophysiology responsible for the P300 amplitude in cocaine-dependent individuals is associated with impulsivity independent of a history of childhood conduct disorder symptoms is supported.
Abstract: Previous studies report reduced amplitude of the P300 event-related potential in cocaine-dependent individuals. Cocaine dependence is also associated with increased impulsivity, possibly due to deficits in cognitive function that are associated with reduced P300 amplitude. In the current study, the relationship between cocaine dependence, impulsivity, and P300 amplitude were examined. An auditory oddball event-related potential task along with self-report (Barratt Impulsiveness Scale version 11) and behavioral laboratory (Immediate and Delayed Memory Task) measures of impulsivity were assessed in healthy controls (n = 14) and subjects who met DSM-IV criteria for current cocaine dependence (n = 17). P300 amplitude was reduced and self-reported and behavioral laboratory impulsivity scores were elevated among the cocaine-dependent group compared to controls. There was a positive correlation between the questionnaire and behavioral laboratory measures of impulsivity, and a negative correlation between impulsivity measures and P300 amplitude. The correlation between self-reported impulsivity scores and P300 amplitude remained after taking into account the number of childhood conduct disorder symptoms. This study supports the hypothesis that the basic neurophysiology responsible for the P300 amplitude in cocaine-dependent individuals is associated with impulsivity independent of a history of childhood conduct disorder symptoms.
102 citations
TL;DR: The findings demonstrate that carriage of the low-activity S allele is associated with extremely violent criminal behavior in Chinese males, and suggests that the 5-HTT may be implicated in the mechanisms underlying violent behaviors.
Abstract: The neurotransmitter, serotonin, has been implicated in aggressive behavior. The serotonin transporter (5-HTT), which reuptakes serotonin into the nerve terminal, plays a critical role in the regulation of serotonergic function. Previous western reports have demonstrated that the low-activity short (S) allele of the 5-HTT gene-linked polymorphic-region (5-HTTLPR) polymorphism is associated with aggressive behavior and associated personality traits. In the present study, we investigated this 5-HTTLPR genetic polymorphism in a group of Chinese males who had been convicted for extremely violent crime (n = 135) and a normal control group (n = 111). The proportion of S-allele carriers was significantly higher in the criminal group than in the controls (p = 0.006). A significant association was not demonstrated for the relationship between the 5-HTTLPR polymorphism and antisocial personality disorder, substance abuse or alcohol abuse in the criminal group. Our findings demonstrate that carriage of the low-activity S allele is associated with extremely violent criminal behavior in Chinese males, and suggests that the 5-HTT may be implicated in the mechanisms underlying violent behaviors.
TL;DR: A course of bilateral ECT ameliorated white matter integrity in frontal brain regions in patients with depression before ECT treatment compared with controls, suggesting a strong relationship with the antidepressant action of ECT.
Abstract: This study was conducted to elucidate the effects of electroconvulsive therapy (ECT) on frontal white matter in late-life depressed patients. Diffusion tensor imaging was performed on 8 late-life depressed patients and 12 healthy age-matched controls. The patients were scanned before and after a course of ECT. Fractional anisotropy (FA) was determined in the frontal and temporal regions and the corpus callosum. A significant white matter FA reduction was found in widespread frontal and temporal brain regions in patients with depression before ECT treatment compared with controls. A significant increase in frontal white matter FA was seen following ECT treatment. A course of bilateral ECT ameliorated white matter integrity in frontal brain regions. This suggests a strong relationship with the antidepressant action of ECT.
TL;DR: The hypothesis that the –1438A/G polymorphism of the promoter region of the serotonin 2A receptor (5-HTR2A) gene is associated with MDD patients in a Korean population is supported.
Abstract: This study investigated the possible effect of the –1438A/G single-nucleotide polymorphism in the promoter region of the serotonin 2A receptor (5-HTR2A) gene on major depressive disorder (MDD) in a Ko
TL;DR: The findings of the study suggest that antipsychotics may improve the subtle disruption in the middle cerebellar peduncles in patients with schizophrenia.
Abstract: Diffusion tensor imaging (DTI) was used to investigate subtle disruption in the middle cerebellar peduncles in patients with schizophrenia. Fractional anisotropy (FA) was measured in 25 patients with schizophrenia and 21 healthy subjects using DTI. The FA of the right and left middle cerebellar peduncles was significantly lower in the schizophrenic patients compared to healthy subjects. FA in the left middle cerebellar peduncles was significantly correlated with the dosage of neuroleptics in patients with schizophrenia. There were no significant differences of mean diffusivity in the right and left middle cerebellar peduncles between patients with schizophrenia and healthy subjects. The findings of the study suggest that antipsychotics may improve the subtle disruption in the middle cerebellar peduncles in patients with schizophrenia.
TL;DR: It is unlikely that the BDNF Val66Met polymorphism plays a major role in the pathogenesis of AD in the Chinese population and findings do not support previous findings that homozygosity for the 66Val allele confers an increased risk for AD.
Abstract: Because of a decrease in central brain-derived neurotrophic factor (BDNF) levels in Alzheimer's disease (AD) and the important role of BDNF in neuronal survival, BDNF may represent a candidate gene conferring susceptibility to AD. Recently, a functional BDNF Val66Met polymorphism has been associated with AD in an Italian population. In the present study, we investigated a possible role of this BDNF polymorphism in the susceptibility of AD or AD onset in a Chinese population. Comparing AD patients and controls, the distribution of the BDNF genotypes and alleles did not differ significantly. The onset age was not significantly different comparing the three BDNF genotype groups. Our negative findings suggest that it is unlikely that the BDNF Val66Met polymorphism plays a major role in the pathogenesis of AD in the Chinese population and do not support previous findings that homozygosity for the 66Val allele confers an increased risk for AD. Further studies with genetic variations in BDNF relating either to AD-associated depression or to the AD treatment response are suggested.
TL;DR: The caudate nucleus of depressed suicide victims seems to be the brain region with the highest alteration of the serotonergic system, and hence with the most diagnostic sensitivity, and further studies on suicidality and depression should focus on the functionality of the caUDate nucleus.
Abstract: Serotonin 5-HT2A and 5-HT4 binding parameters and their second messengers 1,4,5-inositol triphosphate (IP3) and cyclic adenosyl monophosphate (cAMP) were studied in the frontal cortex, hippocampus, caudate nucleus and amygdala of 19 control subjects and 19 antidepressant-free, violent suicide victims. A significantly higher number of 5-HT4 receptors and higher second messenger cAMP concentrations were found in the frontal cortex and caudate nucleus of the depressed suicide victims as compared with the control group. Furthermore, significantly increased 5-HT2A binding sites and IP3 concentrations were noted in the caudate nucleus of the suicide victims, together with a significantly reduced number of 5-HT2A binding sites, higher binding affinity and increased IP3 concentrations in the hippocampus. No significant alterations in 5-HT4 and cAMP or in 5-HT2A and IP3 concentrations were observed in the amygdala. The caudate nucleus of depressed suicide victims seems to be the brain region with the highest alteration of the serotonergic system, and hence with the most diagnostic sensitivity. Further studies on suicidality and depression should focus on the functionality of the caudate nucleus.
TL;DR: It is concluded that the 5-HT1Dβ receptor may play a role in the pathophysiology of OCD and cause significant OC symptom exacerbation with the response to sumatriptan being more robust.
Abstract: We have conducted a pharmacological challenge experiment in 10 medication-free obsessive compulsive (OC) disorder (OCD) patients. We used a placebo-controlled paradigm for m-chlorophenylpiperazine (mC
TL;DR: The results showed that disgust-inducing and fear-inducing scenes provoked a similar activation pattern in comparison to neutral scenes, which included the thalamus, primary and secondary visual fields, the amygdala, the hippocampus, and various regions of the prefrontal cortex.
Abstract: We investigated subjective and hemodynamic responses towards disgust-inducing, fear-inducing, and neutral pictures in a functional magnetic resonance imaging study. Within an interval of 1 week, 24 male subjects underwent the same block design twice in order to analyze possible response changes to the repeated picture presentation. The results showed that disgust-inducing and fear-inducing scenes provoked a similar activation pattern in comparison to neutral scenes. This included the thalamus, primary and secondary visual fields, the amygdala, the hippocampus, and various regions of the prefrontal cortex. During the retest, the affective ratings hardly changed. In contrast, most of the previously observed brain activations disappeared, with the exception of the temporo-occipital activation. An additional analysis, which compared the emotion-related activation patterns during the two presentations, showed that the responses to the fear-inducing pictures were more stable than the responses to the disgust-inducing ones.
TL;DR: The findings suggest that the expression of DRD3 mRNA is reduced in schizophrenia and bipolar disorder, supporting the hypothesis of distorted homeostasis of dopamine receptor subtypes in psychotic disorder.
Abstract: Previous studies found an elevation of the dopamine D3 receptor (DRD3) mRNA as determined in peripheral lymphocytes in schizophrenic patients The aim of this study was to test the hypothes
TL;DR: It seems that nonorganic insomnia, due to anxiety inherent in Asperger syndrome, is responsible for the low sleep quality in these subjects.
Abstract: Asperger syndrome (AS) is a neurodevelopmental disorder belonging to autism spectrum disorders Both children and adults with AS have subjective impairment in the initiation and continuity of sleep, and studies using objective assessment are sparse Twenty young AS adults with frequent complaints of low sleep quality were compared to 10 age-, gender- and education-matched controls without sleep complaints using polysomnography and spectral power analysis of slow-wave sleep AS subjects displayed a similar polysomnographic profile as compared with controls In spectral power analysis, a statistically nonsignificant trend towards decreased relative delta power and increased theta power in slow-wave sleep was found in the AS group It seems that nonorganic insomnia, due to anxiety inherent in AS, is responsible for the low sleep quality in these subjects
TL;DR: A significantly lower frequency in TT genotype in patients with major depression than in normal controls is found when the genotypes of T-182C polymorphism were classified into two groups: TT group versus TC + CC group (p = 0.019).
Abstract: Noradrenergic and serotonergic abnormalities have long been implicated in patients with major depression. The novel selective norepinephrine reuptake inhibitor reboxetine has been shown to be at least as effective as imipramine, desipramine and fluoxetine in the treatment of major depression. It is suggested that the dysfunction of the norepinephrine transporter (NET) may be related to major depression. Although the transcriptional activity related to the NET gene expression is little known, it may be a good candidate gene for major depression. Therefore, we investigated whether the T-182C polymorphism of the NET gene is associated with major depression in a Korean sample of 112 major depression patients compared with 136 healthy controls. We found a significantly lower frequency in TT genotype in patients with major depression than in normal controls when the genotypes of T-182C polymorphism were classified into two groups: TT group versus TC + CC group (p = 0.019). This result suggests that the T-182C polymorphism in the NET gene might be associated with major depression.
TL;DR: The present study provided the first line of direct evidence suggesting that the CHRM5 gene combined with the CHRNA7 gene may be linked to schizophrenia.
Abstract: Most antipsychotic drugs act on the forebrain by blocking dopamine receptors. In rodents, the M5 muscarinic receptor (CHRM5) is important for prolonged dopamine release. We typed polymorphisms in CHRM5 and alpha7-nicotinic receptor (CHRNA7) genes on 15q13 in 82 Canadian families having at least 1 schizophrenic patient. Using the Family-Based Association Test, we performed haplotype analysis of the 2 loci and found biased transmission in schizophrenia (z = -2.651, p = 0.008). In the families tested, the 2 cholinergic genes interacted to affect schizophrenia in combination, while neither was sufficiently alone to confer susceptibility. Our present study provided the first line of direct evidence suggesting that the CHRM5 gene combined with the CHRNA7 gene may be linked to schizophrenia.
TL;DR: The results support Zuckerman’s personality model for the sensation-seeking trait and show a lack of significant correlations between the measures of aggressiveness-hostility and hormones.
Abstract: To evaluate the relationship between sex hormones and aggressiveness, hostility and sensation seeking we studied 30 healthy males. Using a standardised technique of radioimmunoassay, we obtained blood
TL;DR: A new allele-specific PCR-based genotyping procedure was established and there was a significant difference in the genotype distribution between major depressive disorder patients and healthy volunteers, and the C/C genotype was associated with lesser susceptibility tomajor depressive disorder.
Abstract: Norepinephrinergic neurotransmission in the central nervous system appears to have a major impact on the symptomatology in major depressive disorder and the human norepinephrine transporter (NET) gene is one of the key candidates for genetic studies in major depressive disorder. The authors established a new allele-specific PCR-based genotyping procedure and examined whether the NET T-182C polymorphism was associated with the susceptibility to major depressive disorder in a Japanese population. This study included 145 patients with major depressive disorder (according to DSM-IV) and 164 healthy volunteers. There was a significant difference in the genotype distribution between major depressive disorder patients and healthy volunteers (p = 0.02), and the C/C genotype was associated with lesser susceptibility to major depressive disorder. The NET T-182C polymorphism may be in part related to the pathophysiology of major depressive disorder in a Japanese population.
TL;DR: Two research traditions, the one on Asperger syndrome (AS) and the other on alexithymia, have produced similar findings independently of each other indicating a possible association between these two phenomena.
Abstract: Two research traditions, the one on Asperger syndrome (AS) and the other on alexithymia, have produced similar findings independently of each other indicating a possible association between these two phenomena. Both conditions are also associated with impaired initiation and continuity of sleep. Twenty AS adults were compared with 10 healthy controls using the Toronto Alexithymia Scale and the Basic Nordic Sleep Questionnaire. AS subjects were significantly more alexithymic and reported lower sleep quality as compared with controls. AS and alexithymia are associated although the mediating factors are unknown. It is possible that alexithymic traits predispose to anxiety, which in turn lowers the sleep quality in AS adults. Alternatively, low sleep quality might be due to AS itself.
TL;DR: It is concluded that the CYP2D6*10 C188T polymorphism may be associated with the susceptibility to the occurrence of TD induced by typical antipsychotics, especially in male patients, and may also be correlated with AIMS scores in TD patients.
Abstract: Typical antipsychotic treatment had been postulated to be a risk factor for the susceptibility to tardive dyskinesia (TD). The cytochrome P-450 debrisoquine/sparteine hydroxylase (CYP2D6) metabolizes a majority of antipsychotics and exhibits various phenotypes on enzymatic activities from poor metabolizers to ultrarapid metabolizers. The various phenotypes are encoded by polymorphic genetic variants on the CYP2D6 gene. Although several studies had explored the association between the CYP2D6*10 C188T polymorphism, which encodes the phenotype intermediate metabolizers, and TD in Orientals, the findings were inconclusive. In the present study, we examined the relationship between the CYP2D6*10 C188T polymorphism and the TD occurrence in 216 Chinese schizophrenic patients (113 patients with TD and 103 patients without TD) and explored the correlation between the TD severity assessed by the Abnormal Involuntary Movement Scale (AIMS) and each C188T genotype in the 113 TD patients. Using logistic regression analysis, we found a modest association (p = 0.045) between TD and C188T genotypes. This positive finding was only observed in male patients (p = 0.001), but not in females. Our findings also support the correlation between AIMS scores and C188T polymorphism within the TD group after adjusting for confounding effects with the multiple regression analysis (p = 0.033). We concluded that the CYP2D6*10 C188T polymorphism may be associated with the susceptibility to the occurrence of TD induced by typical antipsychotics, especially in male patients, and may also be correlated with AIMS scores in TD patients.
TL;DR: A new Brodmann area (BA) delineation approach was applied to FDG-PET scans of autistic patients and healthy volunteers to examine relative glucose metabolism (rGMR) during performance of a verbal memory task to examine group differences in frontal lobe and temporal lobe regions.
Abstract: A new Brodmann area (BA) delineation approach was applied to FDG-PET scans of autistic patients and healthy volunteers (n = 17 in each group) to examine relative glucose metabolism (rGMR) during performance of a verbal memory task. In the frontal lobe, patients had lower rGMR in medial/cingulate regions (BA 32, 24, 25) but not in lateral regions (BA 8-10) compared with healthy controls. Patients had higher rGMR in occipital (BA 19) and parietal regions (BA 39) compared with controls, but there were no group differences in temporal lobe regions. Among controls, better recall and use of the semantic-clustering strategy was associated with greater lateral and medial frontal rGMR, while decreased rGMR in medial-frontal regions was associated with greater perseverative/intrusion errors. Patients failed to show these patterns. Autism patients have dysfunction in some but not all of the key brain regions subserving verbal memory performance, and other regions may be recruited for task performance.
TL;DR: The results indicate that a combined therapy with amitriptyline and citalopram may be particularly beneficial for patients with TTH, migraine and comorbid depression that do not respond to monotherapy.
Abstract: Antidepressants are used to treat chronic daily headache disorders such as migraine and chronic tension-type headache (TTH), which are often associated with depression and anxiety. Here, we studied th
TL;DR: Electroencephalographic data show that heroin-dependent subjects have increased relative beta-2 power and increased left intrahemispheric gamma coherence compared with control subjects, which may reflect underlying changes in brain function due to long-term drug abuse and premorbid characteristics.
Abstract: Previous studies have shown that drug abuse is associated with altered brain function. However, studies of heroin abuse-related brain dysfunctions are scarce. Electroencephalographic (EEG) power and coherence analyses are two important tools for examining the effects of drugs on brain function. In the present study, we compared EEG power and coherence measures of 18 abstinent heroin-dependent subjects with those of 12 healthy control subjects. Furthermore, within the heroin group, associations between heroin use in the past, heroin craving and these EEG measures were studied. The results show that heroin-dependent subjects have increased relative beta-2 power and increased left intrahemispheric gamma coherence compared with control subjects. Furthermore, coherence measures showed correlations with clinical variables. These EEG abnormalities may reflect underlying changes in brain function due to long-term drug abuse and premorbid characteristics.
TL;DR: Although the changes in P300 and N200 induced by sleep deprivation are due to sleepiness, which may slow cognitive processing and decrease the efficiency of mental processing, the increase in P200 may be related with increased anxiety, negative mood, and fatigue.
Abstract: This study investigated the psychophysiological effects of sleep deprivation on auditory event-related potentials (AERPs) and their relationship with psychological parameters. Twenty-four subjects remained awake for 37 h under continuous surveillance. In the mornings and the evenings of 2 consecutive study days, AERPs were recorded and 4 self-rated scales (sleepiness, fatigue, anxiety, and mood) were quantified. The latencies of P300 and N200 were significantly prolonged (p < 0.001) and their amplitudes decreased (p < 0.05) as a consequence of sleep deprivation. However, the only significant change in N100 and P200 was an increase in the P200 amplitude (p < 0.05). The increase in the latencies of P300 and N200 were correlated with increased sleepiness (p < 0.05), and the increase in P200 amplitude was correlated with negative mood, anxiety, and fatigue (p < 0.05). Although the changes in P300 and N200 induced by sleep deprivation are due to sleepiness, which may slow cognitive processing and decrease the efficiency of mental processing, the increase in P200 may be related with increased anxiety, negative mood, and fatigue.