Transcranial magnetic stimulation in a finger-tapping task separates motor from timing mechanisms and induces frequency doubling.

We study the interplay between motor programs and their timing in the brain by using precise pulses of transcranial magnetic stimulation (TMS) applied to the primary motor cortex. The movement of the finger performing a tapping task is periodically perturbed in synchronization with a metronome. TMS perturbation can profoundly affect both the finger trajectory and its kinematics, but the tapping accuracy itself is surprisingly not affected.

Transcranial Magnetic Stimulation at M1 disrupts cognitive networks in schizophrenia.

Transcranial Magnetic Stimulation (TMS) is rapidly gaining acceptance as a non-invasive probe into brain functionality. We utilize TMS to study the connectivity of a simple motor network in patients of schizophrenia (N=19), and in healthy control subjects (N=9). TMS was used in an externally paced finger tapping task, perturbing the internal network oscillations invoked by the finger motion as it keeps pace with a metronome.

State and trait related predictors of serum cortisol to DHEA(S) molar ratios and hormone concentrations in schizophrenia patients.

Objective: In previous studies we have demonstrated high serum molar ratios of cortisol to dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) [together abbreviated DHEA(S)], and the value of both cortisol/DHEA(S) molar ratios for prediction of responsivity to antipsychotic treatment in schizophrenia patients. The present study aimed to examine the contribution of anxiety, and severity of symptoms to the prediction of serum cortisol, DHEA(S) levels and two molar ratios across three examinations.

Method: Serum concentrations of cortisol and DHEA(S)were examined in 43 schizophrenia inpatients and in 20 age matched healthy controls at baseline, and after 2 and 4 weeks.

Cost effectiveness, safety, and satisfaction with video telepsychiatry versus face-to-face care in ambulatory settings.

Videoconference telepsychiatry provides an alternative for the psychiatric treatment of mental health patients who reside in remote communities. The objective of this study was to compare institutional ambulatory and hospitalization costs, treatment adherence, patient and physician satisfaction, and treatment safety between mental healthcare via videoconferencing and care provided in person. Data collected for 1 year of telepsychiatry treatment was compared to that of the preceding year and a matched comparison group.

Serotonin transporter characteristics in lymphocytes and platelets of male aggressive schizophrenia patients compared to non-aggressive schizophrenia patients.

A large body of literature indicates that disturbances of central serotonin (5-HT) function play an important role in aggressive behavior. Results from open-label and placebo-controlled trials as well as the reported inverse relationship between 5-HT function and aggression in human subjects, suggest that reduced 5-HT activity is associated with aggressive behavior. The activity of the 5-HT transporter (5-HTT), as determined by [(3)H]5-HT uptake to blood lymphocytes, was measured in 20 currently aggressive and 20 non-aggressive male schizophrenia patients.

Improving the accuracy of the diagnosis of schizophrenia by means of virtual reality.

Objective: The authors' goal was to improve the diagnosis of schizophrenia by using virtual reality technology to build a complex, multimodal environment in which cognitive functions can be studied (and measured) in parallel.

Method: The authors studied sensory integration within working memory by means of computer navigation through a virtual maze. The simulated journey consisted of a series of rooms, each of which included three doors.

Characterization of the serotonin transporter in lymphocytes and platelets of schizophrenia patients treated with atypical or typical antipsychotics compared to healthy individuals.

A rapidly growing body of data suggests that abnormalities in serotonergic function might be involved in the pathophysiology of schizophrenia and that serotonergic mechanisms play a role in the therapeutic effects of antipsychotics. The activity of the serotonin transporter (5-HTT), as determined by [(3)H]5-HT uptake to blood lymphocytes, was measured in 38 medicated schizophrenia patients (15 of them treated with typical antipsychotics and 23 treated with atypical antipsychotics) and 15 healthy control subjects. In addition, the pharmacodynamic characteristics of platelet 5-HTT were assessed by [(3)H]citalopram binding.

A double-blind, cross-over comparison of the effects of amantadine or placebo on visuomotor and cognitive function in medicated schizophrenia patients.

The present study aimed to test the hypothesis that dopamine agonists may enhance cognitive function. The effect of amantadine on neuropsychological function in medicated schizophrenia patients was investigated. The study comprised an add-on, double-blind, placebo-controlled, cross-over 6-week trial.

Rating of textual associations in organized and nonorganized sentences for the assessment of semantic networks in schizophrenia.

Background: Collins and Quillian ( Acta Psychol 1970;33:304-314) proposed that semantic representations in the human brain could have a "networklike" theoretical construct. Thought disorders in schizophrenia have been described as disturbances in the spread of activation within semantic networks. Semantic networks are typically evaluated indirectly via reaction times of priming tasks.

Cortisol/dehydroepiandrosterone ratio and responses to antipsychotic treatment in schizophrenia.

Dehydroepiandrosterone (DHEA) or their sulfate conjugate (DHEAS) (together abbreviated DHEA(S)) exert multiple effects in the central nervous system, and may be involved in the pathophysiological processes in schizophrenia. This prospective study aimed to investigate whether serum cortisol/DHEA(S) molar ratios are associated with response to antipsychotic treatment during the exacerbation of schizophrenia. Serum DHEA(S) and cortisol were determined at baseline, and 2 and 4 weeks later for 43 medicated schizophrenia inpatients with acute exacerbation.

Schizophrenia patients with a history of severe violence differ from nonviolent schizophrenia patients in perception of emotions but not cognitive function.

Background: Impaired processing of emotions may relate to violent behavior in schizophrenia patients. We compared emotional function in schizophrenia patients with and without a history of severe violent behavior.

Method: Tests of identification and differentiation of facial emotions were performed to compare 35 patients with chronic schizophrenia or schizoaffective disorder (DSM-IV criteria) and a history of severe violent behavior with 35 non-violent schizophrenia patients and 46 healthy controls.

Animal-assisted therapy ameliorates anhedonia in schizophrenia patients. A controlled pilot study.

Background: Anhedonia, a component of the negative symptom dimension and a core phenomenon in schizophrenia, is associated with poor social functioning and is resistant to treatment. We tested the hypothesis that animal-assisted therapy (AAT) may improve anhedonia.

Objective: To compare the effect of psychosocial treatment sessions in which a dog was an active participant (AAT) with comparable sessions without a dog, using a controlled protocol.

Elevation of the cortisol/dehydroepiandrosterone ratio in schizophrenia patients.

Dehydroepiandrosterone (DHEA) and its sulfate derivative DHEA-S are neurosteroids, produced in the brain, and neuroactive steroids, produced in the adrenals and affecting the brain. We compared the ratios of serum cortisol/DHEA or DHEA-S in schizophrenia patients with normal subjects, and determined the correlation of these ratios with psychopathology and distress. Early morning plasma concentrations of DHEA, DHEA-S, and cortisol were determined by radioimmunassay in 40 medicated schizophrenia inpatients, and 15 healthy subjects with similar age and sex distribution.

Interpersonal distance in schizophrenic patients: relationship to negative syndrome.

Background: Personal space is the area individuals maintain around themselves into which others cannot intrude without arousing discomfort.

Objective: We tested the hypotheses that psychological distancing of patients with schizophrenia would be a characteristic of 1) diagnosis and/or 2) syndrome.

Methods: For this aim, 30 schizophrenic and 30 age matching normal males established comfortable interpersonal distances for 20 word-stimuli representing family members, significant others, self-images, emotionally neutral and threatening surroundings.

Somatosensory evoked potentials during a rubber-hand illusion in schizophrenia.

The rubber-hand illusion (RHI), an illusion in which tactile sensations are referred to a synthetic alien limb, is enhanced in schizophrenia patients. Somatosensory evoked responses of the illusion were compared between schizophrenia patients and normal control subjects. Schizophrenia patients had significant alterations in long latency evoked responses during the illusion.

Decreased platelet peripheral-type benzodiazepine receptors in persistently violent schizophrenia patients.

Peripheral-type benzodiazepine receptors (PBR) have been shown to be sensitive to stressful conditions. This study aimed to explore a possible association of platelets PBR binding with aggressive behavior and homicidal history in schizophrenia patients. The authors compared [(3)H] PK 11195 binding to platelet membrane among 11 currently aggressive schizophrenia patients, 15 schizophrenia patients with homicidal history, 14 nonaggressive schizophrenia patients, and 15 healthy volunteers.

Fluvoxamine augmentation of olanzapine in chronic schizophrenia: pharmacokinetic interactions and clinical effects.

Olanzapine is a substrate of the cytochrome P450 enzyme (CYP) 1A2. In this study, pharmacokinetic interactions and clinical effects of adding the CYP1A2 inhibitor fluvoxamine to steady-state olanzapine was examined in patients suffering from schizophrenia. Eight patients had been treated for at least 3 months with 10 to 20 mg/day olanzapine.

An association of CAG repeats at the KCNN3 locus with symptom dimensions of schizophrenia.

Background: In 1999 Cardno et al reported that long CAG repeats in the calcium-activated potassium channel gene hSKCa3/KCNN3 are associated with higher negative symptom dimension scores in schizophrenia patients. There has been no attempt to replicate the results. In this study, we investigated whether a symptom polymorphism of schizophrenia is associated with both the CAG repeat numbers and the difference in allele sizes.

Assessing psychological distress in psychiatric patients: validation of the Talbieh Brief Distress Inventory.

The present study examined the psychometric properties of the Talbieh Brief Distress Inventory (TBDI), a 24-item self-report instrument used to measure psychological distress, for use in psychiatric patients. A case-control and partly longitudinal design was used to test the TBDI among 431 psychiatric outpatients and inpatients and 197 gender- and age-matched nonpatients. All respondents were interviewed using the ICD-10 Symptom Checklist, and patients additionally with psychopathology rating scales.

Angiotensin converting enzyme gene insertion/deletion polymorphism: case-control association studies in schizophrenia, major affective disorder, and tardive dyskinesia and a family-based association study in schizophrenia.

Angiotensin converting enzyme (ACE) is a candidate gene for psychiatric disorders. We examined the frequency of a functional insertion/deletion (I/D) polymorphism in the 16th intron of the ACE gene (located on chromosome 17q23) in groups of patients with schizophrenia (n = 104 and 113), major depression (n = 55), and bipolar disorder (n = 87) compared to healthy control subjects (n = 87). There was no evidence for allelic or genotypic association of the polymorphism with any of the disorders or with tardive dyskinesia (TD) in patients with schizophrenia.

A computerized patient information system in a psychiatric hospital.

The authors describe a computerized patient information system at a psychiatric hospital in Israel. The system is a fully implemented work instrument that promotes clinical safety and cost containment. It allows interactive online consultations, clinical cross-checking, the production of computerized reports and schedules, fast response to laboratory results, and safer drug administration, all of which help improve the quality of care.

Schizophrenic patients who smoke have a faster finger tapping rate than non-smokers.

The increased rate of smoking in schizophrenia patients remains unexplained and may reflect attempts at self-treatment. The effect sought from smoking may be related to nicotine's stimulating action. We tested this hypothesis by examining the relationship between smoking status and finger tapping rate, a measure of central processing, in schizophrenia patients treated with atypical antipsychotics.