The role of dopamine in inhibitory control in smokers and non-smokers: a pharmacological fMRI study.

Contemporary theoretical models of substance dependence posit that deficits in inhibitory control play an important role in substance dependence. The neural network underlying inhibitory control and its association with substance dependence have been widely investigated. However, the pharmacology of inhibitory control is still insufficiently clear.

Brain activation associated with attentional bias in smokers is modulated by a dopamine antagonist.

Attentional bias in substance-dependent individuals is the tendency to automatically direct the attention to substance-related cues in the environment. Attentional bias is known to be associated with clinical measures such as relapse or successful quitting in smokers. It has been suggested that attentional bias emerges as a consequence of dopaminergic activity evoked by substance-related cues.

Effects of dopaminergic modulation on electrophysiological brain response to affective stimuli.

Introduction: Several theoretical accounts of the role of dopamine suggest that dopamine has an influence on the processing of affective stimuli. There is some indirect evidence for this from studies showing an association between the treatment with dopaminergic agents and self-reported affect.

Materials And Methods: We addressed this issue directly by examining the electrophysiological correlates of affective picture processing during a single-dose treatment with a dopamine D2 agonist (bromocriptine), a dopamine D2 antagonist (haloperidol), and a placebo.

Nitric oxide and neopterin in bipolar affective disorder.

Background: There is an increasing interest in the role of nitric oxide (NO) and pterines in the pathophysiology of neuropsychiatric disorders. The results so far show an inconsistent pattern.

Methods: In the present study, neopterin and a measure of NO synthesis in plasma of symptomatic and euthymic bipolar affective patients were compared to those of patients with a major depression and healthy controls.

Bipolar mania and plasma amino acids: increased levels of glycine.

Previous studies have suggested that the N-methyl-d-aspartate (NMDA) glutamate receptor complex is implicated in the pathophysiology of several neuropsychiatric disorders. Especially the glycine coagonist site of this receptor has been proposed as a therapeutic target. It has been hypothesized that the NMDA receptor and the serotonergic system, which function is compromised in affective disorders, are functionally coupled.

Mefloquine increases the risk of serious psychiatric events during travel abroad: a nationwide case-control study in the Netherlands.

Background: Psychiatric events during travel abroad account for a large percentage of medical repatriations arranged by insurance companies. Several risk factors have been proposed for such events, one of these being use of mefloquine. We investigated the risk of psychiatric events during use of mefloquine.

Plasma amino acids and sports injuries.

The aim of this study was to explore the relationship between changes in plasma amino acids and the incidence of sports injuries during a soccer season. Fourteen plasma amino acids were assayed at monthly intervals in 12 young soccer players during a whole soccer season. Based on the number and severity of injuries the soccer players were divided into an injury-prone and a non-injury-prone group.

Effects of imipramine, fluvoxamine and depressive mood on autonomic cardiac functioning in major depressive disorder.

Objective: Diminished HR variability is considered to be associated with depression and the increased risk of cardiovascular disease. The pharmacological effects of antidepressants and depressive mood itself may contribute to alterations in autonomic cardiac functioning, but a limited amount of data is available. We studied the effects of two different types of antidepressant treatments (imipramine and fluvoxamine), in addition to the effect of depressive mood, on the cardiovascular system in depressed patients.

Effect of light therapy on biopterin, neopterin and tryptophan in patients with seasonal affective disorder.

The serotonergic system is believed to play a key role in the pathophysiology of seasonal affective disorder (SAD). Tetrahydrobiopterin is an essential cofactor in the hydroxylation of tryptophan and, therefore, in the synthesis of serotonin, while neopterin is known as a marker of cell-mediated immune activity. The present study was designed to measure levels of biopterin, neopterin and tryptophan in plasma of 19 depressed patients with a history of SAD, before and after light therapy as well as in a control group.

Motor activity and autonomic cardiac functioning in major depressive disorder.

Background: The daily pattern of motor activity and the autonomic cardiovascular regulation were studied in major depression to quantify changes in psychomotor function and autonomic cardiac functioning. Additionally, relationships between motor activity parameters, cardiovascular measures and specific clinical features were examined.

Methods: Wrist-actigraphy was used to monitor 24-h motor activity for 67 unmedicated (unipolar) depressed inpatients and 64 control subjects.

The acute transient polymorphic psychosis: a biochemical subtype of the cycloid psychosis.

Background: The pathogenesis of atypical psychoses, in particularly those characterized by polymorphic psychopathology, is hypothesized to be related to disturbances in amino acid metabolism.

Objective: In the present study, the role of the amino acid serine was investigated in patients with acute transient polymorphic psychosis.

Methods: Patients were loaded with serine and with the amino acids glycine and alanine as controls and subsequently evaluated for the development of psychopathological symptoms.

24-Hour motor activity after treatment with imipramine or fluvoxamine in major depressive disorder.

Psychomotor dysfunction in depression is related to alterations in the 24-h pattern of motor activity. After antidepressant treatment the diurnal pattern may be changed due to improvement of clinical state or pharmacological actions. The purpose of this study was to evaluate in 52 depressed in-patients the effects of imipramine (tricyclic antidepressant) and fluvoxamine (SSRI) on the 24-h motor activity.

Catatonia: the rise and fall of an intriguing psychopathological dimension.

Background: For at least 125 years the discussion about the clinical relevance of catatonic symptoms in psychiatry continues. It started from the original description by Kahlbaum and was revived by modern factor analytical studies, that identified the catatonic dimension in about 10% of newly admitted patients.

Objective: Over a period of 2 years, four patients with an acute episodic psychosis and prominent catatonic symptoms were examined.

Effect of personality dimensions on the diurnal pattern of motor activity.

The effects of personality dimensions, age, and gender on 24-hour motor activity patterns were studied in 101 healthy subjects between 20-70 years. We measured motor activity by wrist-actigraphy and personality dimensions by the Tridimensional Personality Questionnaire (TPQ) of Cloninger. Random Regression Models were used to estimate the effects of personality dimensions, age, and gender on the diurnal pattern of motor activity.

Pharmacokinetics of the beta-carboline norharman in man.

In healthy subjects, pharmacokinetics were characterised using single oral and sublingual administrations of the beta-carboline norharman. For this purpose, norharman levels in blood plasma were measured up to 90-105 min after both routes of administration. Dose proportionality of three different single oral doses of norharman (7, 65 and 110 microg/kg) administered as 0.

Effect of electroconvulsive therapy on biopterin and large neutral amino acids in severe, medication-resistant depression.

Biopterin, neopterin and the large neutral amino acids (LNAA), i.e. phenylalanine, tyrosine, tryptophan, isoleucine, leucine and valine were measured in plasma of 20 severely depressed inpatients before and after a course of electroconvulsive therapy (ECT).

The acute effects of norharman on cocaine self-administration and sensorimotor function in male Wistar rats.

The purpose of the present study was to determine the acute effects of the beta-carboline norharman on cocaine dependence. Male Wistar rats were allowed to self-administer cocaine for 3 h for seven sessions. A single injection of norharman (0.

Tryptophan: a precursor for the endogenous synthesis of norharman in man.

We investigated whether in healthy subjects L-tryptophan may serve as a precursor for the endogenous synthesis of the beta-carboline norharman. For this purpose subjects, smokers as well as non-smokers, received 0 or 1.2 g of an oral dose of tryptophan.

Prescribing patterns in patients using new antidepressants.

Aims: To study possible selective prescribing ('channelling') we compared characteristics of patients using the SSRI sertraline with patients using longer available SSRIs.

Methods: An observational cohort study in 1251 patients being prescribed an SSRI.

Results: In contrast to other studies, we found no evidence for channeling of sertraline.

Towards an objective quantitative assessment of daily functioning in migraine: a feasibility study.

Migraine is a chronic disabling disorder, with migraine episodes significantly reducing quality of life and leading to impaired functioning (physically, socially, emotionally) both at home and at work. We explored whether ambulatory accelerometry can be used as an objective method to quantify the behavioral aspects of migraine-related disability. Four body mounted uni-axial piezo-resistive accelerometers were used to quantify the time spent in different body postures (lying, sitting, standing), physical activities (walking, cycling) and a general index of body motility during eight migraine attacks and subsequent recovery periods of six patients in their habitual environment.

Is delirium after cardiac surgery related to plasma amino acids and physical condition?

The authors studied interrelationships between plasma levels of amino acids, physical condition (as apparent from cortisol, albumin, and thyroid hormone concentrations), and postoperative delirium in 296 patients undergoing elective cardiac surgery. Both plasma tryptophan (Trp) and ratio of Trp to the other large neutral amino acids (oLNAA) were reduced in delirious patients compared with control patients. The lower availability of Trp for the brain in delirious patients may lead to decreased serotonergic function.

Personality traits and psychological reactions to mental stress of female migraine patients.

The purpose of this study was (i) to compare a range of stress-related personality traits, including defense and coping mechanisms, of migraine patients (n = 23) with those of tension headache patients (n = 18) and dermatologically afflicted, but otherwise healthy, controls (n = 22), and (ii) to compare their state anxiety and other moods before, during, and after the presentation of a psychological stressor (mental arithmetic). For all three groups, mental arithmetic induced a significant increase in state anxiety and mood disturbance, followed by a subsequent decrease during recovery. Migraine patients were not found to have a higher disposition for anxiety, depression, or rigidity than tension headache patients or controls.

Incidence of and preoperative predictors for delirium after cardiac surgery.

Incidence of and preoperative predictors for postoperative delirium were studied in 296 patients (age 26-83 years, mean age 63 years) undergoing elective cardiac surgery. Delirium occurred in 40 (13.5%) patients.

Stress and self-injurious behavior; hormonal and serotonergic parameters in mentally retarded subjects.

Self-injurious behavior (SIB) and stereotyped behavior (SB) are major challenges for professionals in the field of mental retardation. From animal experiments it has become obvious that these behavioral disturbances are not purposeless but may emerge secondary to restrictive environment and may serve de-arousing objectives. In mentally retarded subjects, several hypotheses have been formulated concerning the pathogenesis of SIB, particularly about the involvement of serotonin and beta-endorphin, which are supported by beneficial treatment effects of the opiate antagonist naltrexone and serotonin modulating compounds, respectively.

Atypical psychoses.

The European psychiatric literature is rich in descriptions and studies of atypical psychotic disorders. Most of these are finally deemed to be varieties of the affective or schizophrenic disorders, which in turn are regarded to be typical. The acute polymorphic psychotic disorder according to the ICD-10, and the periodic catatonia of Gjessing, although hardly recognized and acknowledged, are good candidates to be considered as separate psychotic disease entities.