Catecholamines, mood, and cardiovascular control

The research presented in this thesis addresses the above mentioned issue on the basis of four psychophysiological experiments. These experiments were aimed at separately manipulating concentrations of circulating adrenaline and noradrenaline by means of infusions of catecholamines, pharmacological interventions, or psychological (mental stress) challenges in healthy subjects, during studies of the effects on cardiovascular activity and subjective mood. In particular, the dynamics of the cardiovascular system were evaluated in relation to circulating noradrenaline and adrenaline by employing the method of spectral analysis of haemodynamic variables. In order to increase our understanding of the metabolism and renal excretion of catecholamines, special attention was paid to urinary catecholamine metabolites, in relation to altered plasma catecholamine concentrations. In the experiments presented in this thesis, plasma catecholamine concentrations were manipulated by means of pharmacological and psychological challenges. The subjects participating in the studies were healthy young male volunteers, recruited by means of advertisements. All volunteers were subjected to a medical, psychiatric and psychological screening to exclude abnormalities in physical and mental health. Careful attention was paid to the control of confounding factors such as posture, food intake, smoking, and drinking. Where appropriate, endocrine and metabolic parameters were monitored in order to control for the possible effects of our manipulations on these parameter

Sleep patterns in congenital dopamine beta-hydroxylase deficiency

Sleep patterns of two young female patients with congenital dopamine beta-hydroxylase deficiency are described. In this orthostatic syndrome central and peripheral noradrenergic failure occurs as a result of impaired beta-hydroxylation of dopamine. Consequently, the levels of dopamine and its metabolites are elevated. The relative importance of noradrenaline deficit in the face of dopamine excess for sleep-regulatory mechanisms can be inferred from the sleep pattern of these patients. No subjective sleep complaints were reported. The sleep patterns showed a high percentage of slow-wave sleep in both patients (29% and 34% of sleep period time) and a relatively low to normal percentage of REM sleep (18% and 21%). A normal cyclic REM sleep pattern was observed. Alpha-delta sleep occurred during light sleep (15% and 8%); consequently, the amount of stage 2 sleep was reduced. These results indicate that functional insufficiency of the noradrenergic system in two patients with dopamine beta-hydroxylase deficiency is not associated with profound changes in the (REM) sleep pattern. This supports a modulatory or permissive role for noradrenaline in REM sleep mechanisms

Emotional startle modulation in male patients with recent-onset schizophrenia

Patients with schizophrenia suffer from both cognitive as well as emotional disturbances, leading to reduced social functioning and quality of life. This study investigated the ongoing emotional states of medicated and antipsychotic-free patients and healthy controls using an emotional startle paradigm. During positive, neutral and negative emotional pictures, aversive acoustic startle stimuli were presented at 4 different probe latencies (300, 800, 1300 and 3800 ms) from picture onset. In both patients and controls, positive pictures, and more specifically erotic pictures, elicited significantly smaller eye blinks compared with startle stimuli presented during neutral and negative pictures. With regard to the subjective ratings, medicated patients rated erotic pictures significantly less pleasant and the adventure, nature, and household pictures as significantly more arousing than healthy control subjects. The present results indicate the need to further investigate emotional responding to specific picture contents, with specific focus on the sexual needs and expectations of schizophrenic patients, so as to eventually improve the quality of life in these patients

Dose-dependent effects of intravenous lorazepam on cardiovascular activity, plasma catecholamines and psychological function during rest and mental stress

Dose-dependent effects of intravenously administered lorazepam on psychophysiological activity during rest and mental stress were studied in order to examine differential responses to doses which may induce anxiolysis or sedation. In a double-blind randomized cross-over study, nine male volunteers participated in a placebo and a lorazepam session, during which the subjects repeatedly performed a 10-min version of the Stroop Color Word Test (CWT), with 10 min of rest between the CWTs. Lorazepam was administered before each rest period in increasing doses of 0.0, 0.06, 0.13, 0.25 and 0.5 mg (total cumulative dose: 0.94 mg). Heart rate showed a dose-dependent decrease during rest with an ED50 of 0.13 mg lorazepam, while lorazepam had no effect on the cardiovascular and plasma catecholamine response magnitudes to the CWT. Subjective fatigue and reaction time increased significantly after 0.94 mg lorazepam, while at the same dose vigor decreased; state anxiety after the CWT was not influenced by lorazepam. These data show differential effects of lorazepam on cardiovascular, biochemical and psychological function. While heart rate was suppressed at low doses during rest and reaction time and subjective fatigue increased at doses which induced sedation, state anxiety and physiological response patterns to the CWT were not influenced by lorazepam

The Japanese Male-Female Wage Differentials Revisited

Contains fulltext : 139890.pdf (publisher's version ) (Open Access)Aims: Abnormal physiological stress reactivity is increasingly investigated as a vulnerability marker for various physical and psychological health problems. However, studies are inconsistent in taking into account potential covariates that may influence the developing stress system. We systematically tested determinants (individual, developmental, environmental and substance use-related) of physiological and perceived physiological stress reactivity. We also examined the relation between physiological and perceived physiological stress reactivity. Method: In a stratified sample of 363 children (7–12 years) and 344 adolescents (13–20 years) from the general population, we examined cortisol, heart rate, respiratory sinus arrhythmia and perceived physiological stress reactivity to a psychosocial stress procedure. Results: Using multivariate linear regression models, we found that individual, developmental, environmental and substance use-related factors were related to each of the stress response indices. These determinant factors were different for each of the stress reactivity indices, and different in children versus adolescents. Perceived physiological stress reactivity predicted cortisol reactivity in adolescents only. All other relations between perceived physiological and physiological stress reactivity were not significant. Conclusions: As physiological stress variables are often examined as vulnerability markers for the development of health problems, we maintain that it is essential that future studies take into consideration factors that may account for found relations. Our study provides an overview and indication of which variables should be considered in the investigation of the relation between physiological stress indices and illness.13 p

Threat-Related Selective Attention Predicts Treatment Success in Childhood Anxiety Disorders

Abstract OBJECTIVE: The present study examined whether threat-related selective attention was predictive of treatment success in children with anxiety disorders and whether age moderated this association. Specific components of selective attention were examined in treatment responders and nonresponders. METHOD: Participants consisted of 131 children with anxiety disorders (aged 8-16 years), who received standardized cognitive-behavioral therapy. At pretreatment, a pictorial dot-probe task was administered to assess selective attention. Both at pretreatment and posttreatment, diagnostic status of the children was evaluated with a semistructured clinical interview (the Anxiety Disorders Interview Schedule for Children). RESULTS: Selective attention for severely threatening pictures at pretreatment assessment was predictive of treatment success. Examination of the specific components of selective attention revealed that nonresponders showed difficulties to disengage their attention away from severe threat. Treatment responders showed a tendency not to engage their attention toward severe threat. Age was not associated with selective attention and treatment success. CONCLUSIONS: Threat-related selective attention is a significant predictor of treatment success in children with anxiety disorders. Clinically anxious children with difficulties disengaging their attention away from severe threat profit less from cognitive-behavioral therapy. For these children, additional training focused on learning to disengage attention away from anxiety-arousing stimuli may be beneficial

Urbanicity, biological stress system functioning and mental health in adolescents

Growing up in an urban area has been associated with an increased chance of mental health problems in adults, but less is known about this association in adolescents. We examined whether current urbanicity was associated with mental health problems directly and indirectly via biological stress system functioning. Participants (n = 323) were adolescents from the Dutch general population. Measures included home and laboratory assessments of autonomic nervous system and hypothalamic-pituitary-adrenal axis functioning, neighborhood-level urbanicity and socioeconomic status, and mother- and adolescent self-reported mental health problems. Structural equation models showed that urbanicity was not associated with mental health problems directly. Urbanicity was associated with acute autonomic nervous system and hypothalamic-pituitary-adrenal axis reactivity such that adolescents who lived in more urban areas showed blunted biological stress reactivity. Furthermore, there was some evidence for an indirect effect of urbanicity on mother-reported behavioral problems via acute autonomic nervous system reactivity. Urbanicity was not associated with overall autonomic nervous system and hypothalamic-pituitary-adrenal axis reactivity or basal hypothalamic-pituitary-adrenal axis functioning. Although we observed some evidence for associations between urbanicity, biological stress reactivity and mental health problems, most of the tested associations were not statistically significant. Measures of long-term biological stress system functioning may be more relevant to the study of broader environmental factors such as urbanicity