Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 43
Filter
1.
J Affect Disord ; 184: 209-15, 2015 Sep 15.
Article in English | MEDLINE | ID: mdl-26112330

ABSTRACT

AIM: Even though numerous studies have focused on the effects of self-stigma on patients with schizophrenia, little is known about self-stigma of patients with bipolar disorder (BD). In this study, a self-administered scale of self-stigmatising attitudes of patients with BD and schizophrenia was used to explore these attitudes, examine the potential differences between the two groups and study the factors that influence stigma within groups. METHODS: Self-stigma of 120 patients with schizophrenia and BD was assessed with the Self-stigma Questionnaire (SSQ) and the Stigma Inventory for Mental Illness (SIMI). Presence of clinical symptoms, overall functioning and level of self-esteem were also evaluated. RESULTS: Self-stigma is present in both groups but differs in its intensity. Patients with BD experience self-stigma in a lesser degree without affecting their social life or overall functioning. Patients with schizophrenia adopt more intense self-stigmatising attitudes leading to social exclusion and lower level of overall functioning. LIMITATIONS: The results are limited by the small sample size, whereas the inclusion of other questionnaires would broaden our insight to self-stigma. CONCLUSIONS: Self-stigma has a direct effect on overall functioning of patients with BD and schizophrenia tampering the clinical outcome of therapeutic interventions. Therefore, it should be incorporated in every treatment plan and be addressed as a clinical symptom of the mental illness.


Subject(s)
Bipolar Disorder/psychology , Schizophrenic Psychology , Social Stigma , Adult , Diagnostic and Statistical Manual of Mental Disorders , Empathy , Employment , Female , Humans , Male , Middle Aged , Self Concept , Social Behavior , Surveys and Questionnaires , Young Adult
2.
J Diabetes Res ; 2015: 354923, 2015.
Article in English | MEDLINE | ID: mdl-25722989

ABSTRACT

OBJECTIVE: This study investigates the association of homocysteine and cortisol with psychological factors in type 2 diabetic patients. METHOD: Homocysteine, cortisol, and psychological variables were analyzed from 131 diabetic patients. Psychological factors were assessed with the Eysenck Personality Questionnaire (EPQ), Hostility and Direction of Hostility Questionnaire (HDHQ), the Symptom Checklist 90-R (SCL 90-R), the Zung Self-Rating Depression Scale (ZDRS), and the Maudsley O-C Inventory Questionnaire (MOCI). Blood samples were taken by measuring homocysteine and cortisol in both subgroups during the initial phase of the study (T0). One year later (T1), the uncontrolled diabetic patients were reevaluated with the use of the same psychometric instruments and with an identical blood analysis. RESULTS: The relation of psychoticism and homocysteine is positive among controlled diabetic patients (P value = 0.006 < 0.05) and negative among uncontrolled ones (P value = 0.137). Higher values of cortisol correspond to lower scores on extraversion subscale (r(p) = -0.223, P value = 0.010). Controlled diabetic patients showed a statistically significant negative relationship between homocysteine and the act-out hostility subscale (r(sp) = -0.247, P = 0.023). There is a statistically significant relationship between homocysteine and somatization (r(sp) = -0.220, P = 0.043). CONCLUSIONS: These findings support the notion that homocysteine and cortisol are related to trait and state psychological factors in patients with diabetes mellitus type 2.


Subject(s)
Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/psychology , Homocysteine/blood , Hydrocortisone/blood , Psychotic Disorders/blood , Aged , Diabetes Mellitus, Type 2/complications , Female , Humans , Linear Models , Male , Middle Aged , Predictive Value of Tests , Psychiatric Status Rating Scales , Psychometrics , Psychopathology , Psychotic Disorders/complications , Surveys and Questionnaires
3.
Curr Diabetes Rev ; 9(6): 450-61, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24111620

ABSTRACT

Oxytocin (OXT) is a neurohypophysial hormone which is synthesized in the paraventricular and supraoptic nuclei of the hypothalamus. OXT is currently attracting considerable attention because it has been discovered that it regulates various functions of behavior especially in the context of social interactions. OXT is a key component in bone formation, glycemia, male sexuality, cardiac differentiation and pregnancy and thus it is important to be further explored. The authors review various aspects of gestational diabetes, including definition, screening, diagnostic procedures, complications, clinical evaluation, indications of delivery and neonatal aspects. Not only the relation among diabetes mellitus, oxytocin and neurophysiology concerning erectile dysfunction, but also the role of OXT in the activity of arginine and vasopressin is investigated. It is imperative to develop technological and experimental methods that will be able to reveal the oxytocin and its potential.


Subject(s)
Arginine Vasopressin/metabolism , Brain Chemistry/drug effects , Diabetes Mellitus/metabolism , Hypothalamus/metabolism , Oxytocics/metabolism , Oxytocin/metabolism , Animals , Diabetes Mellitus/drug therapy , Diabetes Mellitus/physiopathology , Female , Gastric Emptying/drug effects , Humans , Labor, Obstetric/metabolism , Lactation/drug effects , Male , Oxytocics/administration & dosage , Oxytocin/administration & dosage , Pregnancy , Rats , Receptors, Cell Surface/drug effects , Receptors, Cell Surface/metabolism , Receptors, Oxytocin/metabolism , Social Behavior
4.
Exp Diabetes Res ; 2012: 560864, 2012.
Article in English | MEDLINE | ID: mdl-22997507

ABSTRACT

BACKGROUND: The aim of this study was to investigate the association of oxytocin with trait and state psychological factors in type 2 diabetic patients. METHODS: OXT and psychological variables were analyzed from 86 controlled diabetic patients (glycosylated haemoglobin A1c (HbA1c) < 7%) from 45 uncontrolled diabetic patients (HbA1c ≥ 7). Psychological characteristics were assessed with the Eysenck Personality Questionnaire (EPQ), while state psychological characteristics were measured with the Symptom Checklist 90-R (SCL 90-R). Blood samples were taken for measuring oxytocin in both subgroups during the initial phase of the study. One year later, the uncontrolled diabetic patients were reevaluated with the use of the same psychometric instruments. RESULTS: During the first evaluation of the uncontrolled diabetic patients, a statistically significant positive relationship between the levels of OXT and psychoticism in EPQ rating scale (P < 0.013) was observed. For controlled diabetic patients, a statistically significant negative relationship between oxytocin and somatization (P < 0.030), as well as obsessive-compulsive scores (P < 0.047) in SCL-90 rating scale, was observed. During the second assessment, the values of OXT decreased when the patients managed to control their metabolic profile. CONCLUSIONS: The OXT is in association with psychoticism, somatization, and obsessionality may be implicated in T2DM.


Subject(s)
Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/complications , Hyperglycemia/prevention & control , Obsessive-Compulsive Disorder/complications , Oxytocin/blood , Psychotic Disorders/complications , Somatoform Disorders/complications , Aged , Cross-Sectional Studies , Diabetes Mellitus, Type 2/psychology , Diabetes Mellitus, Type 2/therapy , Down-Regulation , Female , Glycated Hemoglobin/analysis , Greece , Hospitals, University , Humans , Male , Middle Aged , Obsessive-Compulsive Disorder/etiology , Outpatient Clinics, Hospital , Psychiatric Status Rating Scales , Psychotic Disorders/etiology , Somatoform Disorders/etiology
5.
Int J Psychiatry Clin Pract ; 15(4): 296-302, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22122004

ABSTRACT

OBJECTIVE: This retrospective study examined the demographic, clinical and pharmacological factors associated with aggressive behaviour after abrupt discontinuation of medication in schizophrenic patients. METHOD: The study reports on a survey of 402 schizophrenic patients, who had abruptly discontinued their medication and had been involuntarily hospitalized to Psychiatric Hospital of Attika. The survey utilized the Discontinuation-Emergent Signs and Symptoms Checklist (DESS) to assess the signs and symptoms that patients exhibited (Rosenbaum et al., Biol Psychiatry 1998;44:77), as well the Aggression Scale (Delgado-Escueta et al., New England J Med 1981;305:711) to estimate the aggressive behaviour. Demographic and clinical variables as well as variables related to pharmacological treatment have been also investigated. RESULTS: Analyses revealed that the presence of aggressive behaviour after abrupt drug discontinuation was associated positively with previous history of aggression, male gender , abrupt discontinuation of anticholinergics, delusions, nervousness or anxiety, elevated mood, irritability and negatively with negative symptoms. These predictors can correctly classify 76.3% of patients with aggressive behaviour and 64.0% of patients without aggressive behaviour. CONCLUSION: These findings suggest that abrupt discontinuation of medication in schizophrenic patients may lead to aggressive behaviour, being connected at least in the acute phase with particular demographic, clinical and pharmacological parameters.


Subject(s)
Aggression/psychology , Psychotropic Drugs/administration & dosage , Schizophrenia/drug therapy , Adult , Age Factors , Female , Humans , Male , Middle Aged , Retrospective Studies , Schizophrenic Psychology , Sex Factors
6.
In Vivo ; 24(5): 803-10, 2010.
Article in English | MEDLINE | ID: mdl-20952755

ABSTRACT

OBJECTIVE: A significant proportion of breast cancer patients experience psychiatric morbidity. The present study compared the psychopathological profile (depression, anxiety and general psychopathology) of Greek women with breast cancer with a group of healthy controls. MATERIALS AND METHODS: Patients (n=109) were recruited from a specialized oncology breast cancer department and healthy controls (n=71) from a breast outpatient clinic. General psychopathology was assessed by the SCL-90-R. The Montgomery-Asberg Depression Rating Scale (MADRS) and the Spielberger State-Trait Anxiety Inventory (STAI) were used for assessing depression and anxiety. Demographics and clinical characteristics were also recorded. Data were modeled using multiple regression analysis. RESULTS: The mean age was 54.7±18.1 years for the control group and 51.2±9.5 years for the patient group (p=0.288). Mean scores on SCL-90-R, MADRS and STAI were significantly higher in the cancer group compared to controls (p<0.05). Multiple regression analysis revealed that breast cancer was independently and positively associated with all psychological measures (p<0.05). Regression coefficients ranged from 0.19 (SCL-90-R, psychotism) to 0.33 (MADRS). Lower anger/aggressiveness and anxiety were found in highly educated women; divorced/widowed women scored higher on obsessionality and MADRS compared to married women. Psychiatric treatment was associated with higher scores on somatization, depression, phobic anxiety and general psychopathology. CONCLUSION: Anxiety, depression, and overall psychopathology are more frequent in breast cancer patients compared to controls. Disease makes a larger independent contribution to all psychopathological measures than any other investigated variable. Therefore, breast cancer patients should be closely followed up in order to identify and timely treat any mental health problems that may arise.


Subject(s)
Anxiety/epidemiology , Breast Neoplasms/epidemiology , Breast Neoplasms/psychology , Depression/epidemiology , Adult , Aged , Anxiety/diagnosis , Cross-Sectional Studies , Depression/diagnosis , Female , Humans , Linear Models , Middle Aged , Morbidity , Risk Factors
7.
Ann Rheum Dis ; 68(1): 40-6, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18276740

ABSTRACT

OBJECTIVES: Previous evidence suggests the role of psychological stress in triggering the onset of autoimmunity. We aimed to investigate whether stress following major and minor life events could precede the onset of primary Sjögren's syndrome (pSS). The role of coping strategies and social support, as compensating buffering mechanisms, was also explored. METHODS: 47 patients with pSS were compared with two control groups: 35 patients with lymphoma (disease controls, DC) and 120 healthy controls (HC) with disease onset within the previous year. All subjects completed questionnaires assessing the occurrence of major and minor stressful events, coping strategies and social support prior to disease onset. Data analysis was performed by univariate and multivariate logistic regression models. RESULTS: A higher number of patients with pSS reported the occurrence of negative stressful life events prior to disease onset compared with patients with lymphoma and HC, while the number and impact of daily hassles did not differ between the three groups. Coping strategies were defective and the overall social support was lower in patients with pSS compared with DC and HC groups. In the multivariate model, pSS status was associated with maladaptive coping and lower overall social support relative to DC and HC, as well as with an increased number of negative stressful life events compared with HC but not DC. CONCLUSIONS: Prior to disease onset, patients with pSS experience high psychological stress following major negative life events, without developing satisfactory adaptive coping strategies to confront their stressful life changes. Lack of social support may contribute to the relative risk of disease development.


Subject(s)
Adaptation, Psychological , Life Change Events , Models, Psychological , Sjogren's Syndrome/psychology , Stress, Psychological/immunology , Case-Control Studies , Female , Humans , Male , Middle Aged , Multivariate Analysis , Retrospective Studies , Social Support
8.
J Affect Disord ; 99(1-3): 107-15, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17011042

ABSTRACT

BACKGROUND: Although maternity blues have been studied in many countries worldwide the factors that influence the occurrence of this clinical entity are not well understood. The purpose of this study was to investigate the prevalence, time course and symptomatology of maternity blues in a Greek urban environment as well as the relation of maternity blues with certain clinical and sociodemographic factors. METHOD: A study of a sample of 402 women that were recruited during the first day after delivery. Each woman completed the Kennerley's Blues Questionnaire on a daily basis for the first 3 days of puerpartum. Clinical and sociodemographic data were obtained through questionnaires and personal interview. RESULTS: 179 (44.5%) women experienced severe maternity blues during the first 3 days after delivery. Delivery by caesarian section (P=0.006), stressful events during pregnancy (P=0.02), depressive feelings the last month prior to delivery (P=0.002), anxiety on the day of delivery (P=0.001) and hypochondriasis (P=0.001) were the factors that were found to relate significantly to maternity blues. CONCLUSION: The women's emotional condition prior and after delivery, delivery via caesarotomy, as well as fears concerning somatic health had strong impact on the occurrence of maternity blues.


Subject(s)
Depression, Postpartum/epidemiology , Urban Population/statistics & numerical data , Adult , Anxiety/diagnosis , Anxiety/epidemiology , Anxiety/psychology , Cesarean Section/psychology , Cross-Cultural Comparison , Cross-Sectional Studies , Depression/diagnosis , Depression/epidemiology , Depression/psychology , Depression, Postpartum/diagnosis , Depression, Postpartum/psychology , Female , Greece , Humans , Hypochondriasis/diagnosis , Hypochondriasis/epidemiology , Hypochondriasis/psychology , Incidence , Life Change Events , Personality Assessment , Personality Inventory , Pregnancy , Pregnancy, Unwanted/psychology , Risk Factors , Socioeconomic Factors , Statistics as Topic
10.
Soc Psychiatry Psychiatr Epidemiol ; 40(5): 417-24, 2005 May.
Article in English | MEDLINE | ID: mdl-15902413

ABSTRACT

BACKGROUND: This article presents a study of the Occupational Abilities and Performance Scale (OAPS), developed for administration to schizophrenic patients. The reliability and validity of the OAPS has been evaluated. METHOD: A total of 174 schizophrenic patients who participated in the Psychosocial and Vocational Rehabilitation Unit (PVRU) of the University Mental Health Research Institute (UMHRI) in Athens were assessed. The OAPS is conducted at entry and after 18 months, when the client has completed training. RESULTS: The results of the reliability analysis showed very good internal consistency, with high split-half reliability as well as test-retest reliability and inter-rater agreement. The scale was also found to have good predictive validity, as well as concurrent validity. Finally, factor analysis with principal components extraction method was performed in order to assess the construct validity of the scale. CONCLUSIONS: The results of factor analysis supported the conclusion of good reliability and validity of the OAPS and revealed the existence of five components, each correlated with a set of the original items.


Subject(s)
Aptitude , Employee Performance Appraisal/statistics & numerical data , Psychological Tests/statistics & numerical data , Rehabilitation, Vocational , Schizophrenia/rehabilitation , Adult , Combined Modality Therapy , Employment , Factor Analysis, Statistical , Female , Follow-Up Studies , Greece , Humans , Male , Psychometrics/statistics & numerical data , Reproducibility of Results , Treatment Outcome
11.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 3994-7, 2005.
Article in English | MEDLINE | ID: mdl-17281107

ABSTRACT

In the present study an attempt was made to focus in the differences between Obsessive-Compulsive Disorder (OCD) patients and healthy controls, as reflected by the P600 component of event-related potential (ERP) signals, to locate brain areas that may be related to Working Memory (WM) deficits. Neuropsychological research has yielded contradicting results regarding WM in OCD. Eighteen patients with OCD symptomatology and 20 normal controls (age and sex matched) were subjected to a computerized version of the digit span Wechsler test. EEG activity was recorded from 15 scalp electrodes (leads). A dedicated computer software was developed to read the ERP signals and to calculate features related to the ERP P600 component (500-800 ms). Nineteen features were generated, from each ERP-signal and each lead, and were employed in the design of the Probabilistic Neural Network (PNN) classifier. Highest single-lead precision (86.8%) was found at the Fp2 and C6 leads. When the output from all single-lead PNN classifiers fed a Majority Vote Engine (MVE), the system classified correctly all subjects, providing a powerful classification scheme. Findings indicated that OCD patients differed from normal controls at the prefrontal and temporo-central brain regions.

12.
J Psychopharmacol ; 18(2): 277-80, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15260918

ABSTRACT

Transdermal fentanyl is an opioid analgesic that is effective on chronic pain, and which appears to be advantageous due to several factors such as ease of administration, the relatively stable serum concentration and long dose intervals. Nevertheless, the danger of abuse and dependence exists among patients who are prescribed fentanyl patches. We present a case of transdermal fentanyl abuse, where the administration route of the drug was changed. Our patient, who had no history of substance abuse and who suffered from chronic nonmalignant pain, used the fentanyl transdermal patches as oral transmucosal medication, raising the dose by ten-fold. This abuse of the drug was only for analgesic purposes without seeking anxiolysis and/or euphoria. After treatment and progressive reduction of fentanyl, the patient remains in good condition, and is currently taking the initial dose of the drug transdermally, without having experienced any withdrawal symptoms.


Subject(s)
Administration, Cutaneous , Administration, Oral , Fentanyl/adverse effects , Fentanyl/therapeutic use , Substance-Related Disorders/etiology , Adult , Chronic Disease , Depressive Disorder/complications , Depressive Disorder/diagnosis , Depressive Disorder/drug therapy , Drug Administration Schedule , Drug Therapy, Combination , Dysthymic Disorder/complications , Dysthymic Disorder/diagnosis , Female , Fentanyl/administration & dosage , Fluoxetine/therapeutic use , Greece , Humans , Mouth Mucosa/drug effects , Pain/complications , Pain/diagnosis , Pain/drug therapy , Pica/complications , Polychondritis, Relapsing/complications , Polychondritis, Relapsing/diagnosis , Polychondritis, Relapsing/drug therapy , Self Administration/methods
13.
Comput Methods Programs Biomed ; 75(1): 11-22, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15158043

ABSTRACT

A computer-based classification system has been designed capable of distinguishing patients with depression from normal controls by event-related potential (ERP) signals using the P600 component. Clinical material comprised 25 patients with depression and an equal number of gender and aged-matched healthy controls. All subjects were evaluated by a computerized version of the digit span Wechsler test. EEG activity was recorded and digitized from 15 scalp electrodes (leads). Seventeen features related to the shape of the waveform were generated and were employed in the design of an optimum support vector machine (SVM) classifier at each lead. The outcomes of those SVM classifiers were selected by a majority-vote engine (MVE), which assigned each subject to either the normal or depressive classes. MVE classification accuracy was 94% when using all leads and 92% or 82% when using only the right or left scalp leads, respectively. These findings support the hypothesis that depression is associated with dysfunction of right hemisphere mechanisms mediating the processing of information that assigns a specific response to a specific stimulus, as those mechanisms are reflected by the P600 component of ERPs. Our method may aid the further understanding of the neurophysiology underlying depression, due to its potentiality to integrate theories of depression and psychophysiology.


Subject(s)
Depression/diagnosis , Diagnosis, Computer-Assisted/statistics & numerical data , Evoked Potentials , Case-Control Studies , Depression/physiopathology , Female , Greece , Humans , Male
14.
Article in English | MEDLINE | ID: mdl-17271608

ABSTRACT

The analysis of the P600 component of Event-related Potentials (ERPs) has attracted attention due to its relation to covert cognitive mechanisms, in connection to memory processes. The component may often be low-amplitude, compared to other components such as the P300. Independent component analysis (ICA) techniques have been successfully applied in ERP processing, in the framework of blind source separation (BSS) for unmixing recorded potentials into a sum of temporally independent and spatially fixed components. In the present work ICA was used for reconstructing averaged ERPs in the time window of the P600 component, selecting a subset of independent components' projections to the original electrode recording positions. The selection is based on two empirical criteria, selecting the projection that reconstructs a P600 nearest temporally to the original P600, or selecting the projection combination - up to a preselected maximum number of combined projections providing maximum reconstructed P600 amplitude. The techniques are tested on ERPs recorded from healthy subjects and psychiatric patients, notably improving the differentiation of the two groups, based on either the amplitude or the latency of the reconstructed P600 component, in comparison to results achieved using the original ERPs.

15.
J Neurol Neurosurg Psychiatry ; 74(9): 1231-5, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12933924

ABSTRACT

BACKGROUND: Recently, the P600 component of event related potentials, a waveform that is conceived to be generated and/or modulated by basal ganglia and cingulate area has been considered an index of the completion of any synchronised operation after target detection, having much in common with working memory operation. Moreover, dysfunction of these brain structures as well as working memory deficits have been implicated in the pathophysiology of multiple sclerosis. The aim of this study was to investigate the patterns of P600 elicited during a working memory test in multiple sclerosis patients compared with healthy controls. METHODS: Twenty two definite, chronic progressive multiple sclerosis patients, with recent exacerbation of their illness, and 20 normal subjects matched for age, sex, and educational level, were studied with a computerised version of the digit span test of Wechsler batteries. Auditory P600 were measured during the anticipatory period of this test. RESULTS: The patient group, as compared with healthy controls, showed significantly reduced latencies of P600 at left frontal areas and reduced P600 amplitudes at left temporoparietal region. Moreover, memory performance of patients was significantly more impaired when compared with healthy controls. CONCLUSIONS: These findings may indicate that multiple sclerosis is associated with abnormal features of the completion of synchronised operation after target detection, as they are reflected by P600 amplitudes and latencies. Dysfunction of this mechanism may contribute to the identification of basic cognitive processes that could account for the cognitive deficits in multiple sclerosis.


Subject(s)
Cognition Disorders/etiology , Evoked Potentials, Auditory , Memory Disorders/etiology , Multiple Sclerosis/complications , Multiple Sclerosis/psychology , Adult , Cognition Disorders/physiopathology , Female , Frontal Lobe/pathology , Humans , Male , Memory Disorders/physiopathology , Mental Processes , Middle Aged , Reaction Time
16.
Psychol Med ; 33(3): 555-61, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12701676

ABSTRACT

BACKGROUND: Transsexualism is thought to be related to cortical processes reflecting a complex mosaic of biological, psychological and social/cultural information. Since the P300 component of event-related potentials is considered as an index of attentional processes, the present study focuses on auditory P300 elicited during a short memory test in male to female (MF) transsexuals, compared with that in healthy controls. METHOD: The P300 component was evaluated during the anticipatory period of a short memory test in 13 MF transsexuals who had a gender reassignment operation, at least 3 years previously (mean time 17-6 years, range 3-31 years) and 26 healthy subjects (11 males and 15 females) matched for age and educational level. RESULTS: MF transsexuals exhibited significant reduction of P300 amplitude in the left frontal and temporoparietal areas in comparison to the control group. Furthermore, the group of transsexuals showed a significant delay of P300 latency in comparison to the controls, at the central frontal region. CONCLUSIONS: These findings point to significant psychophysiological alterations of distributed cortical circuits in MF transsexuals. These alterations may be critically related to the biological substrate of MF transsexualism.


Subject(s)
Attention/physiology , Event-Related Potentials, P300/physiology , Transsexualism/psychology , Female , Humans , Male , Memory, Short-Term , Middle Aged , Psychophysiology , Reaction Time
17.
Neuroreport ; 12(13): 2801-6, 2001 Sep 17.
Article in English | MEDLINE | ID: mdl-11588580

ABSTRACT

Deficits of working memory (WM) are recognized as an important pathological feature in schizophrenia. Since the P600 component of event related potentials has been hypothesized that represents aspects of second-pass parsing processes of information processing, and is related to WM, the present study focuses on P600 elicited during a WM test in drug-naive first-episode schizophrenics (FES) compared to healthy controls. We examined 16 drug-naive first-episode schizophrenic patients and 23 healthy controls matched for age and sex. Compared with controls schizophrenic patients showed reduced P600 amplitude on left temporoparietal region and increased P600 amplitude on left occipital region. With regard to the latency, the patients exhibited significantly prolongation on right temporoparietal region. The obtained pattern of differences classified correctly 89.20% of patients. Memory performance of patients was also significantly impaired relative to controls. Our results suggest that second-pass parsing process of information processing, as indexed by P600, elicited during a WM test, is impaired in FES. Moreover, these findings lend support to the view that the auditory WM in schizophrenia involves or affects a circuitry including temporoparietal and occipital brain areas.


Subject(s)
Antipsychotic Agents/pharmacology , Cerebral Cortex/physiopathology , Evoked Potentials/physiology , Memory Disorders/etiology , Memory, Short-Term/physiology , Reaction Time/physiology , Schizophrenia/complications , Acoustic Stimulation , Adult , Age of Onset , Cerebral Cortex/pathology , Chronic Disease , Electroencephalography , Female , Hospitalization , Humans , Male , Memory Disorders/pathology , Memory Disorders/physiopathology , Neuropsychological Tests , Predictive Value of Tests , Schizophrenia/pathology , Schizophrenia/physiopathology , Statistical Distributions
18.
Neuroreport ; 12(8): 1773-8, 2001 Jun 13.
Article in English | MEDLINE | ID: mdl-11409757

ABSTRACT

The P600 component of event-related potentials, believed to be generated by anterior cingulate gyrus and basal ganglia, is considered as an index of aspects of second-pass parsing processes of information processing, having much in common with working memory (WM) systems. Moreover, dysfunction of these brain structures as well as WM deficits have been implicated in the pathophysiology of opioid addicts. The present study is focused on P600 elicited during a WM test in twenty heroin addicts with prolonged abstinence compared with an equal number of healthy controls. The results showed significantly prolonged latencies at right hemisphere, specifically at Fp2 abduction. Moreover, memory performance of patients did not differ from that of normal controls. These findings may indicate that abstinent heroin addicts manifest abnormal aspects of second-pass parsing processes as are reflected by the P600 latencies, elicited during a WM test. Additionally, the P600 might serve as a valuable investigative tool for a more comprehensive understanding of the neurobiological substrate of drug abuse.


Subject(s)
Brain/physiology , Heroin Dependence/psychology , Heroin/adverse effects , Memory/physiology , Substance Withdrawal Syndrome/psychology , Adult , Evoked Potentials/physiology , Female , Humans , Male , Reference Values , Time Factors
19.
IEEE Trans Inf Technol Biomed ; 4(3): 238-46, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11026594

ABSTRACT

Long latency evoked potentials (EP's) are electrical potentials related to brain information processing mechanisms. In this paper, three-layered neurophysiologically based artificial neural network model is presented whose neurons obey to Dale's law. The first two layers of the network can memorize and recall sparsely coded patterns, oscillating at biologically plausible frequencies. Excitatory low-pass filtering synapses, from the second to the third layer, create evoked current dipoles, when the network retrieves memories related to stimuli. Based on psychophysiological indications, simulated intracranial dipoles are straightforwardly transformed into long latency EP components such as N100 and P300 that match laboratory-measured scalp EP's.


Subject(s)
Evoked Potentials , Neural Networks, Computer , Biomedical Engineering , Humans , Models, Neurological , Nerve Net/physiology
20.
Eur Neuropsychopharmacol ; 10(5): 385-7, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10974610

ABSTRACT

Clozapine and risperidone have been implicated in the development of obsessive-compulsive symptoms. We present three cases in which olanzapine caused a significant exacerbation of obsessive-compulsive symptoms in schizophrenia (two cases) and obsessive-compulsive disorder (one case).


Subject(s)
Antipsychotic Agents/adverse effects , Obsessive-Compulsive Disorder/chemically induced , Pirenzepine/analogs & derivatives , Pirenzepine/adverse effects , Schizophrenia/drug therapy , Adult , Benzodiazepines , Female , Humans , Male , Obsessive-Compulsive Disorder/psychology , Olanzapine , Schizophrenia/complications
SELECTION OF CITATIONS
SEARCH DETAIL