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    <title>Tulen, J.H.M.</title>
    <link>http://repub.eur.nl/res/aut/313/</link>
    <description>List of Publications</description>
    <language>en</language>
    <image>
      <url>http://repub.eur.nl/static-eur/img/logo.png</url>
      <title>RePub, Erasmus University Rotterdam</title>
      <link>http://repub.eur.nl</link>
    </image>
    <item>
      <title>Sleep monitoring by actigraphy in short-stay ICU patients (Article)</title>
      <link>http://repub.eur.nl/res/pub/39637/</link>
      <pubDate>2013-04-01T00:00:00Z</pubDate>
      <description>Sleep deprivation is common in intensive care unit (ICU) patients. The criterion standard for sleep monitoring, polysomnography, is impractical in ICU. Actigraphy (a wrist watch indicating amount of sleep) proved to be a good alternative in non-ICU patients, but not in prolonged mechanically ventilated patients, probably due to ICU-acquired weakness. Short-stay ICU patients do not suffer from ICU-acquired weakness. However, the accuracy of actigraphy is unknown in these patients. Therefore, we compared actigraphy to polysomnography in short-stay ICU patients. Sleep measurements were conducted in 7 postcardiothoracic surgery patients. The sensitivity (percentage of actigraphy data that agreed with sleep determined using polysomnography) and specificity (percentage of actigraphy data that agreed with awake determined using polysomnography) were calculated. The result showed that actigraphy underestimated the amount of wake time and overestimated the amount of sleep. The median specificity for actigraphy was always less than 19% and sensitivity more than 94%. Therefore, actigraphy is not reliable for sleep monitoring in short-stay ICU patients. Copyright © 2013 Wolters Kluwer Health | Lippincott Williams and Wilkins.</description>
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      <title>Cardiac responses during picture viewing in young male patients with schizophrenia (Article)</title>
      <link>http://repub.eur.nl/res/pub/38445/</link>
      <pubDate>2012-12-03T00:00:00Z</pubDate>
      <description>Previous research investigating the emotion recognition ability in patients with schizophrenia has mainly focused on the recognition of facial expressions. To broaden our understanding of emotional processes in patients with schizophrenia, this study aimed to investigate whether these patients experience and process other emotionally evocative stimuli differently from healthy participants. To investigate this, we measured the cardiac and subjective responses of 33 male patients (9 with and 24 without antipsychotic medication) and 40 male control subjects to emotion-eliciting pictures. Cardiac responses were chosen as an outcome measure because previous research has indicated that these are linked with attentional and emotional processes and provide a more objective measure than self-report measures alone. The differences in cardiac responses between patients and controls were limited to medicated patients: only the medicated patients showed significantly decreased cardiac orienting responses compared with control subjects, regardless of picture contents. These results indicate that medicated patients directed less attention towards emotion-eliciting pictures than controls. Decreased attentional resources while processing emotional evocative stimuli could lead to incorrect appraisals of the environment and may have detrimental emotional and social consequences, contributing to chronic stress levels and an increased risk for cardiovascular disease. </description>
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      <title>Spot the red herring: Breastfeeding, fruitpurée, and infant autonomic functioning-the generation R study (Article)</title>
      <link>http://repub.eur.nl/res/pub/30922/</link>
      <pubDate>2011-10-01T00:00:00Z</pubDate>
      <description>Several studies have suggested that breastfeeding is related to infant autonomic functioning. The authors investigated whether this is a causal relation. In all, 444 mothers reported breastfeeding practices 2 mo postpartum. Infant autonomic functioning was assessed by heart rate variability at age 14 mo, after discontinuation of breastfeeding. The dose-dependent association between breastfeeding and infant autonomic functioning was tested with linear regression models adjusted for multiple confounders. The authors investigated the relation of fruitpurée consumption with infant autonomic functioning. Fruitpurée consumption has similar socioeconomic epiphenomena but is not related via the same causal mechanism to autonomic regulation as breastfeeding. Nonbreastfed infants had high sympathetic modulation [7.87 log (ms)/SD, 95% CI: 7.71-8.02], partially breastfed infants had intermediate sympathetic modulation [7.75 log (ms)/SD, 95% CI: 7.51-7.82], sympathetic modulation of exclusively breastfed infants was low [7.63 log (ms)/SD, 95% CI: 7.50-7.77]. However, this association could be explained by socioeconomic confounders. Furthermore, fruitpurée consumption was similarly associated with reduced infant sympathetic modulation. The association between breastfeeding practices and infant sympathetic modulation was accounted for by socioeconomic and environmental factors. We found a similar association between fruitpurée consumption and autonomic functioning, further suggesting that the association between breastfeeding and infant autonomic functioning is noncausal. Copyright </description>
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      <title>Effects of long-acting methylphenidate in adults with attention deficit hyperactivity disorder: A study with paired-pulse transcranial magnetic stimulation (Article)</title>
      <link>http://repub.eur.nl/res/pub/31017/</link>
      <pubDate>2011-09-01T00:00:00Z</pubDate>
      <description>Background: Methylphenidate improves attention deficits, hyperactivity and impulsivity in attention deficit hyperactivity disorder (ADHD). Recent investigations into motor cortex excitability with paired-pulse transcranial magnetic stimulation (ppTMS) technique have shown inhibition deficits in ADHD which correlate with clinical symptomatology. Therefore, we investigated the neurophysiological effects of long-acting methylphenidate (LA-Mph) with the ppTMS technique in adult patients with ADHD. Methods: Thirteen right-handed adult ADHD patients who were first diagnosed with ADHD were included in this ppTMS study. Measurements took place before and during treatment with LA-Mph (30-54 mg/day). Statistical analyses were performed to investigate treatment effects and correlations with clinical symptomatology. Results: LA-Mph significantly decreased the relative short intracortical motor inhibition (SICI) magnetically evoked potential (MEP) amplitude at 3-ms interstimulus interval (conditioned/unconditioned MEP amplitude: 0.83 ± 0.76 drug-free vs. 0.29 ± 0.19 with LA-Mph; p = 0.020). The relative intracortical facilitation MEP amplitude at 11 ms interstimulus interval (conditioned/unconditioned MEP amplitude: 1.51 ± 0.92 drug-free vs. 1.79 ± 0.95 with LA-Mph) was not significantly increased. The reduced relative SICI MEP amplitude with LA-Mph correlated significantly with the improvement of the psychopathological ADHD self-rating total scores (p = 0.046). Conclusion: These results show that in adult patients with ADHD, LA-Mph significantly improves motor disinhibition and might have differential stabilizing effects on motor hyperexcitability. Copyright </description>
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      <title>Cardiac and electrophysiological responses to valid and invalid feedback in a time-estimation task (Article)</title>
      <link>http://repub.eur.nl/res/pub/26658/</link>
      <pubDate>2011-07-13T00:00:00Z</pubDate>
      <description>This study investigated the cardiac and electrophysiological responses to feedback in a time-estimation task in which feedbackvalidity was manipulated. Participants across a wide age range had to produce 1 s intervals followed by positive and negative feedback that was valid or invalid (i.e., related or unrelated to the preceding time estimate). Performance results showed that they processed the information provided by the feedback. Negative feedback was associated with a transient cardiac slowing only when feedback was valid. Correct adjustments after valid negative feedback were associated with a more pronounced cardiac slowing. Validity did not affect the feedback-related negativity (FRN), except when remedial action was taken into account. The FRN and cardiac response to feedback decreased with advancing age, but performance did not. The current pattern of findings was interpreted to suggest that the FRN and cardiac response signal "alert" and that the cardiac response, but not the FRN, is implicated in the mechanisms invoked in remedial action. </description>
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      <title>Low autonomic arousal as vulnerability to externalising behaviour in infants with hostile mothers (Article)</title>
      <link>http://repub.eur.nl/res/pub/33717/</link>
      <pubDate>2011-01-30T00:00:00Z</pubDate>
      <description>Maternal psychopathology and the child's autonomic nervous system functioning are risk factors for aggressive behaviour later in life. While research has shown that maternal psychopathology already affects young children, less is known about the association between autonomic functioning and aggressive behaviour in young children. In addition, maternal psychopathology and autonomic nervous system functioning may interact to determine the risk of aggressive behaviour.In a sample of 375 infants and their mothers, maternal psychiatric symptoms were assessed with the Brief Symptom Inventory and toddler aggressive behaviour with the Child Behaviour Checklist. Infant heart rate was recorded at 14. months.Maternal psychiatric problems, including hostility and depression, were associated with toddler aggressive behaviour. Maternal psychiatric problems interacted with mean heart rate (P= 0.01) and HF variability (P= 0.03) in their effect on toddler aggressive behaviour.Mothers with high psychiatric problems, in particular, high hostility, were more likely to have toddlers with high aggressive behaviour. Moreover, in the presence of maternal risk factors, low autonomic arousal renders children particularly susceptible to aggressive behaviour. </description>
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      <title>Diurnal cortisol patterns of young male patients with schizophrenia (Article)</title>
      <link>http://repub.eur.nl/res/pub/21268/</link>
      <pubDate>2010-10-01T00:00:00Z</pubDate>
      <description>Aims: It has been suggested that schizophrenic patients are more vulnerable to stress than healthy persons, and that stressors can trigger a psychotic episode or worsen symptoms. The biological system often studied in relation to stress is the hypothalamic-pituitary-adrenal (HPA) axis, which controls the release of cortisol. We investigated whether the diurnal basal activity of the HPA axis differed between young male patients with schizophrenia and healthy controls. Methods: Twenty-seven male patients (mean age 22 ± 5 years) and 38 healthy male control subjects (mean age 22 ± 3 years) were included in the present study. Saliva was sampled at five time points during the day: directly after awakening, 30 min thereafter, and at 12.00 hours, 16.00 hours and 22.00 hours. Results: The cortisol concentration decreased significantly more during the day in the patient group thanin the control group. Patients also showed a significantly decreased area under the curve with respect to the increase, again indicating that the cortisol concentrations decreased more during the day in patients than in controls. Both the morning increase and the area under the curve with respect to the increase were significantly negatively correlated with negative symptom severity. Conclusions: Patients with schizophrenia showed a different daytime sensitivity of the HPA axis. Our findings further suggest that an increase in negative symptom severity is related to a decreased HPA axis sensitivity.</description>
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      <title>Reduced autonomic flexibility as a predictor for future anxiety in girls from the general population: The TRAILS study (Article)</title>
      <link>http://repub.eur.nl/res/pub/23065/</link>
      <pubDate>2010-09-01T00:00:00Z</pubDate>
      <description>The present study investigated whether autonomic flexibility predicted future anxiety levels in adolescent boys and girls. This study is part of the TRacking Adolescents' Individual Lives Survey (TRAILS), a prospective cohort study of Dutch adolescents. The current study included a subsample of 965 individuals. Measures of autonomic flexibility, i.e., heart rate (HR) and respiratory sinus arrhythmia (RSA), were determined during the first assessment wave (T1: participants 10–12 years old). Self-reported anxiety was assessed at the first and second assessment wave (T2: participants 12–14 years old). Possible gender differences and cooccurring depressive problems were examined. In girls, low RSA predicted anxiety levels 2 years later. In boys, no associations between HR and RSA and future anxiety were found. We conclude that in adolescent girls from the general population, signs of reduced autonomic flexibility (i.e., low RSA) predict future anxiety levels. Since the effect size was small, at this point, RSA reactivity alone cannot be used to identify individuals
at risk for anxiety, but should be regarded as one factor within a large group of risk factors. However, if the present findings are replicated in clinical studies, intervention programmes – in the future – aimed at normalising autonomic functioning may be helpful.</description>
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      <title>The association of the dopamine transporter gene and the dopamine receptor 2 gene with delirium, a meta-analysis (Article)</title>
      <link>http://repub.eur.nl/res/pub/18682/</link>
      <pubDate>2010-03-01T00:00:00Z</pubDate>
      <description>Delirium is the most common neuropsychiatric syndrome in elderly ill patients. Previously, associations between delirium and the dopamine transporter gene (solute carrier family 6, member 3 (SLC6A3)) and dopamine receptor 2 gene (DRD2) were found. The aim of this study was to validate whether markers of the SLC6A3 and DRD2 genes are were associated with delirium in independent populations. Six European populations collected DNA of older delirious patients. Associations were determined per population and results were combined in a meta-analysis. In total 820 medical inpatients, 185 cardiac surgery patients, 134 non-cardiac surgery patients and 502 population-based elderly subjects were included. Mean age was 82 years (SD 7.5 years), 598 (36%) were male, 665 (41%) had pre-existing cognitive impairment, and 558 (34%) experienced delirium. The SLC6A3 rs393795 homozygous AA genotype was more frequent in patients without delirium in all populations. The meta-analysis showed an Odds Ratio (OR) for delirium of 0.4 (95% confidence interval (C.I.) 0.2-0.6, P=0.0003) for subjects with AA genotype compared to the AG and GG genotypes. SLC6A3 marker rs1042098 showed no association with delirium. In meta-analysis the DRD2 rs6276 homozygous GG genotype showed an OR of 0.8 for delirium (95% C.I. 0.6-1.1, P=0.24). When subjects were stratified for cognitive status the rs6276 GG genotype showed ORs of 0.6 (95% C.I. 0.4-1.0, P=0.06) and 0.8 (95% C.I. 0.5-1.5, P=0.51) for delirium in patients with and without cognitive impairment, respectively. In independent cohorts, a variation in the SLC6A3 gene and possibly the DRD2 gene were found to protect for delirium.</description>
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      <title>CBT for childhood anxiety disorders: differential changes in selective attention between treatment responders and non-responders (Article)</title>
      <link>http://repub.eur.nl/res/pub/23072/</link>
      <pubDate>2010-02-01T00:00:00Z</pubDate>
      <description>Abstract
BACKGROUND: This study examined whether treatment response to stepped-care cognitive-behavioural treatment (CBT) is associated with changes in threat-related selective attention and its specific components in a large clinical sample of anxiety-disordered children.
METHODS: Ninety-one children with an anxiety disorder were included in the present study. Children received a standardized stepped-care CBT. Three treatment response groups were distinguished: initial responders (anxiety disorder free after phase one: child-focused CBT), secondary responders (anxiety disorder free after phase two: child-parent-focused CBT), and treatment non-responders. Treatment response was determined using a semi-structured clinical interview. Children performed a pictorial dot-probe task before and after stepped-care CBT (i.e., before phase one and after phase two CBT).
RESULTS: Changes in selective attention to severely threatening pictures, but not to mildly threatening pictures, were significantly associated with treatment success. At pre-treatment assessment, initial responders selectively attended away from severely threatening pictures, whereas secondary responders selectively attended toward severely threatening pictures. After stepped-care CBT, initial and secondary responders did not show any selectivity in the attentional processing of severely threatening pictures. Treatment non-responders did not show any changes in selective attention due to CBT.
CONCLUSIONS: Initial and secondary treatment responders showed a reduction of their predisposition to selectively attend away or toward severely threatening pictures, respectively. Treatment non-responders did not show any changes in selective attention. The pictorial dot-probe task can be considered a potentially valuable tool in assigning children to appropriate treatment formats as well as for monitoring changes in selective attention during the course of CBT.</description>
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      <title>Genome-wide linkage analysis in a Dutch multigenerational family with attention deficit hyperactivity disorder (Article)</title>
      <link>http://repub.eur.nl/res/pub/23079/</link>
      <pubDate>2010-02-01T00:00:00Z</pubDate>
      <description>Abstract:  Attention deficit hyperactivity disorder (ADHD) is a common neuropsychiatric disorder. Genetics has an important role in the aetiology of this disease. In this study, we describe the clinical findings in a Dutch family with eight patients suffering from ADHD, in whom five had at least one other psychiatric disorder. We performed a genome-wide (parametric and nonparametric) affected-only linkage analysis. Two genomic regions on chromosomes 7 and 14 showed an excess of allele sharing among the definitely affected members of the family with suggestive LOD scores (2.1 and 2.08). Nonparametric linkage analyses (NPL) yielded a maxNPL of 2.92 (P=0.001) for marker D7S502 and a maxNPL score of 2.56 (P=0.003) for marker D14S275. We confirmed that all patients share the same haplotype in each region of 7p15.1-q31.33 and 14q11.2-q22.3. Interestingly, both loci have been reported before in Dutch (affected sib pairs) and German (extended families) ADHD linkage studies. Hopefully, the genome-wide association studies in ADHD will help to highlight specific polymorphisms and genes within the broad areas detected by our, as well as other, linkage studies.</description>
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      <title>Cardiovascular variability during treatment with haloperidol, olanzapine or risperidone in recent-onset schizophrenia (Article)</title>
      <link>http://repub.eur.nl/res/pub/22567/</link>
      <pubDate>2009-08-01T00:00:00Z</pubDate>
      <description>This study aimed to investigate the effects of treatment with haloperidol, olanzapine and risperidone on cardiovascular variability in patients with recent-onset schizophrenia by means of spectral analysis. Unmedicated patients (n = 18) had a higher mean heart rate and a tendency for a lower high-frequency power of heart rate variability than healthy control subjects (n = 57), indicating a decreased cardiac vagal control in unmedicated patients with schizophrenia. Patients treated with haloperidol (n = 10) showed significantly lower low-frequency power of heart rate and systolic blood pressure variability compared with olanzapine-treated patients, suggesting that haloperidol attenuated sympathetic functioning. On the contrary, olanzapine-treated patients (n = 10) showed the highest power in the low-frequency range of heart rate and systolic blood pressure variability, suggesting an increased sympathetic cardiac functioning. No significant effects of risperidone (n = 13) were found. None of the antipsychotic agents differed in their parasympathetic cardiovascular effects. We conclude that young, unmedicated patients with schizophrenia differed from controls in their parasympathetic functioning, but the antipsychotic agents haloperidol, risperidone and olanzapine induced only minor cardiovascular side effects</description>
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      <title>Maternal Psychopathology Influences Infant Heart Rate Variability: Generation R Study (Article)</title>
      <link>http://repub.eur.nl/res/pub/21980/</link>
      <pubDate>2009-04-01T00:00:00Z</pubDate>
      <description>Abstract

OBJECTIVE: To assess the determinants of heart rate (HR) and heart rate variability (HRV) in children. The autonomic nervous system as measured by HR and HRV is considered a biological marker of psychopathology in children.

METHODS: We examined the relationship of maternal psychopathology with infant HR and HRV. HR was recorded at 14 months in 528 infants. The high-frequency component of HRV was used as an indicator of cardiac vagal modulation. The presence of a lifetime maternal psychiatric diagnosis was assessed with the Composite International Diagnostic Interview. Presence of maternal psychiatric symptoms during pregnancy and 2 months after birth was assessed, using the Brief Symptom Inventory.

RESULTS: A maternal history of a psychiatric disorder was associated with a 0.24-standard deviation (SD) higher mean HR in the infant (beta = 0.24, 95% Confidence Interval (CI) = 0.03, 0.4, p = .025) and a 0.14-SD lower high-frequency power (beta = -0.14, 95% CI = -0.6, -0.03, p = .003). Likewise, postnatal maternal anxiety and depression symptoms were associated with infant mean HR. A 1-point increase in the mean anxiety symptom score was associated with 0.14-SD higher mean HR in the infant (beta = 0.14, 95% CI = 0.05, 0.2, p = .004), and a 1-point increase in mean depression score with a 0.11-SD increase (beta = 0.11, 95% CI = 0.01, 0.2, p = .025). No significant associations of prenatal maternal affective symptoms with infants autonomic functioning were found.

CONCLUSION: Maternal lifetime psychiatric diagnosis and postnatal psychiatric symptoms are associated with infant autonomic functioning, namely, higher mean HR and lower vagal modulation.</description>
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      <title>Screening methods for delirium: Early diagnosis by means of objective quantification of motor activity patterns using wrist-actigraphy (Article)</title>
      <link>http://repub.eur.nl/res/pub/18232/</link>
      <pubDate>2009-03-01T00:00:00Z</pubDate>
      <description>Delirium after cardiac surgery is a risk factor for adverse outcome and even death. Disturbance of motor activity is a core feature of delirium, but hypoactive delirium often remains unrecognized. We explored wrist-actigraphy as a tool to objectively quantify postoperative recovery of 24-h rest-activity patterns to improve the early recognition of delirium after surgery. Motor activity was recorded by wristactigraphy after cardiac surgery in 88 patients over 65 years of age. Patients were assessed daily by using the CAM-ICU. Our final analyses were based on 32 non-delirious patients and 38 patients who were delirious on the first day after surgery. The delirious patients showed lower mean activity levels during the first postoperative night (P&lt;0.05), reduced restlessness during the first day (P&lt;0.05), and a lower mean activity of the 5 h with lowest activity within the first 24 h (P=0.01), as compared to the non-delirious patients. Already at a very early stage after cardiac surgery, a difference in motor activity was observed between patients with and without a delirium. As an unobtrusive method, actigraphy has the potential to be a screening method that may lead to early diagnosis and treatment of delirium.</description>
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      <title>Disturbed circadian motor activity patterns in postcardiotomy delirium (Article)</title>
      <link>http://repub.eur.nl/res/pub/14958/</link>
      <pubDate>2009-02-01T00:00:00Z</pubDate>
      <description>Aims: More than 20% of patients of 65 years or older may develop a delirium after cardiac surgery. Patients with delirium frequently show a disturbed 24-hr motor activity pattern, but objective and quantitative data are scarce. Our aim was to quantify motor activity patterns in elderly patients with or without a postcardiotomy delirium after elective cardiac surgery. Methods: Wrist-actigraphy was used to quantify 24-hr motor activity patterns for a 5-day period following cardiac surgery in 79 patients of 65 years or older. Clinical state was monitored daily by means of the Confusion Assessment Method-Intensive Care Unit and the Delirium Rating Scale-Revised 98. Results: The activity Amplitude, and the daytime Activity/minute and Restlessness index were significantly higher and the daytime number of Immobility minutes significantly lower for the patients without delirium or with short delirium episodes, as compared to patients with a sustained delirium (&gt;3 days). Conclusions: Actigraphy proves to be a valuable instrument for evaluating motor activity patterns in relation to clinical state in patients with a postcardiotomy delirium.</description>
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      <title>Threat-Related Selective Attention Predicts Treatment Success in Childhood Anxiety Disorders (Article)</title>
      <link>http://repub.eur.nl/res/pub/22572/</link>
      <pubDate>2009-02-01T00:00:00Z</pubDate>
      <description>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.</description>
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      <title>Long sleep duration is associated with serum cholesterol in the elderly: The rotterdam study (Article)</title>
      <link>http://repub.eur.nl/res/pub/28849/</link>
      <pubDate>2008-11-01T00:00:00Z</pubDate>
      <description>Objective: Epidemiological studies have repeatedly found increased mortality associated with both habitual short and long sleep duration. The mechanisms behind these associations are unclear. We investigated whether objectively measured sleep duration, time in bed, and sleep fragmentation were associated with total cholesterol and high density lipoprotein (HDL) cholesterol in community-dwelling elderly. Methods: This cross-sectional study was conducted among 768 participants of the Rotterdam Study, aged 57 to 97 years. Sleep parameters were assessed with actigraphy, a validated method that infers wakefulness and sleep from arm movement. Cholesterol levels in serum were determined in fasting blood samples. All regression analyses were adjusted for age, gender, body mass index, smoking, depressive symptoms, and heart failure. Results: Sleep duration was positively associated with total cholesterol level: β = 0.11 (95% confidence interval = 0.03 0.18) mmol/l per hour of sleep. Persons who slept longer, and spent more time in bed, also had a higher total/HDL cholesterol ratio. A less fragmented sleep was also associated with higher total cholesterol. Some of these associations showed significant interactions with age. The association between time in bed and total/HDL ratio was mainly driven by persons aged &lt; 65, whereas the relationship between sleep fragmentation and total cholesterol level was most prominent in persons aged ≥70. Conclusions: A longer sleep duration was related to higher total cholesterol level and a higher total/HDL cholesterol ratio. Two separate mechanisms, a longer time in bed and sleep fragmentation, seem to explain these associations in different age categories. Copyright </description>
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      <title>Disagreement between subjective and actigraphic measures of sleep duration in a population-based study of elderly persons (Article)</title>
      <link>http://repub.eur.nl/res/pub/29871/</link>
      <pubDate>2008-09-01T00:00:00Z</pubDate>
      <description>Sleep duration is an important concept in epidemiological studies. It characterizes a night's sleep or a person's sleep pattern, and is associated with numerous health outcomes. In most large studies, sleep duration is assessed with questionnaires or sleep diaries. As an alternative, actigraphy may be used, as it objectively measures sleep parameters and is feasible in large studies. However, actigraphy and sleep diaries may not measure exactly the same phenomenon. Our study aims to determine disagreement between actigraphic and diary estimates of sleep duration, and to investigate possible determinants of this disagreement. This investigation was embedded in the population-based Rotterdam Study. The study population consisted of 969 community-dwelling participants aged 57-97 years. Participants wore an actigraph and kept a sleep diary for, on average, six consecutive nights. Both measures were used to determine total sleep time (TST). In 34% of the participants, the estimated TST in the sleep diaries deviated more than 1 h from actigraphically measured TST. The level of disagreement between diary and actigraphic measures decreased with subjective and actigraphic measures of sleep quality, and increased with male gender, poor cognitive function and functional disability. Actigraphically measured poor sleep was often accompanied by longer subjective estimates of TST, whereas subjectively poor sleepers tended to report shorter TST in their diaries than was measured with actigraphy. We recommend, whenever possible, to use multiple measures of sleep duration, to perform analyses with both, and to examine the consistency of the results over assessment methods. </description>
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      <title>Actigraphic sleep duration and fragmentation are related to obesity in the elderly: The Rotterdam Study (Article)</title>
      <link>http://repub.eur.nl/res/pub/29687/</link>
      <pubDate>2008-07-01T00:00:00Z</pubDate>
      <description>Objective: The epidemiological evidence for the association between sleep duration and obesity in the elderly is inconsistent and has not been investigated with objective measures. Furthermore, the role of sleep fragmentation in this relationship is unknown. Our aim was to investigate the association of sleep measures with body mass index (BMI) and obesity in a normal elderly population. Design: Cross-sectional study. Subjects: A total of 983 community-dwelling elderly (mean age 68.4±6.9 years, range, 57-97). Measurements: Weight and height were measured, and sleep duration and fragmentation were assessed with on average six nights of actigraphy. Results: A quadratic model adequately described the association between continuous measures of sleep duration and BMI. Actigraphic sleep duration had a significant U-shaped relationship with BMI (β of quadratic term=0.30, 95% confidence interval (CI): 0.08, 0.52). Both short sleepers (&lt;5 h: OR, 2.76 (95% CI: 1.38, 5.49), 5 to &lt;6 h: OR, 1.97 (95% CI: 1.26, 3.08)) and long sleepers (≥8 h: OR, 2.93 (95% CI: 1.39, 6.16)) were more likely to be obese, compared to participants who slept 7 to &lt;8 h. BMI increased with 0.59 kg m-2per standard deviation of sleep fragmentation (95% CI: 0.34, 0.84). After adjustment for sleep fragmentation, the association between short sleep and obesity was no longer significant. Exclusion of participants with probable sleep apnea only marginally changed these associations. Self-reported habitual sleep duration was not associated with BMI or obesity. Conclusions: Sleep duration, as measured with actigraphy, had a U-shaped relationship with BMI and obesity in an elderly population. A highly fragmented sleep is associated with a higher BMI and a higher risk of obesity, and may explain why short sleep is related to obesity. To preclude bias that can be introduced by self-report measures of sleep duration, using multiple measures of sleep parameters is recommended in future research. </description>
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      <title>Associations between HPA axis functioning and level of anxiety in children and adolescents with an anxiety disorder (Article)</title>
      <link>http://repub.eur.nl/res/pub/30154/</link>
      <pubDate>2008-03-11T00:00:00Z</pubDate>
      <description>The hypothalamus-pituitary-adrenal (HPA) axis becomes active in response to stress. Hence, increased levels of anxiety in children and adolescents may be associated with changes in HPA-axis functioning. The aim of this study was to test if level of anxiety or specific anxiety disorders were associated with basal HPA axis activity in children and adolescents with an anxiety disorder. In 99 8- to 16-year-olds with an anxiety disorder, basal cortisol levels were assessed. It was tested if (1) cortisol levels correlated with the level of self-reported anxiety and (2) if cortisol levels were different for individuals with different anxiety disorders. In girls, low levels of anxiety were associated with a stronger rise in early morning cortisol concentrations. In both boys and girls, harm avoidance predicted low cortisol concentrations after awakening. Separation anxiety and physical anxiety symptoms predicted cortisol concentrations at noon. Differences between individuals with different anxiety disorders were not found. More research is needed regarding mechanisms that explain the associations that were found, and to investigate if treatment may influence HPA axis functioning in children and adolescents with an anxiety disorder. </description>
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      <title>The effect of antipsychotic medication on facial affect recognition in schizophrenia: A review (Article)</title>
      <link>http://repub.eur.nl/res/pub/19715/</link>
      <pubDate>2008-01-01T00:00:00Z</pubDate>
      <description>Patients with schizophrenia suffer from impairments in facial affect recognition and social functioning. Since antipsychotic medication affects different areas in the brain, they may also affect target areas involved in emotional processing mechanisms. In this article, we review the findings of the effect of antipsychotic medication on facial affect recognition in schizophrenia. We searched PubMed for articles in English with the keywords schizophrenia, facial, affect, emotion, antipsychotic and medication, published till January 2008. Eight relevant articles were found describing original studies. No substantial improvements in facial affect recognition were found after treatment with either typical or atypical antipsychotic drugs. Facial affect recognition was not related to neuropsychological functioning, and it was unclear whether improvement of symptom severity was related to performance on the facial affect recognition tasks. It is recommended that future research should focus on measuring social skills and social functioning more directly, and by investigating the effects of additional behavioural treatments on facial affect recognition and social functioning relative to treatment with antipsychotic medication alone.</description>
    </item> <item>
      <title>Sleep duration and hypertension are not associated in the elderly (Article)</title>
      <link>http://repub.eur.nl/res/pub/35744/</link>
      <pubDate>2007-09-01T00:00:00Z</pubDate>
      <description>Several large studies have shown that both short and long average sleep durations increase the risk of hypertension in adults. We investigated whether sleep duration is also associated with hypertension in the elderly. This cross-sectional study was conducted in 5058 participants of the population-based Rotterdam Study, aged 58 to 98 years. Blood pressure was measured at the research center. Hypertension was defined as a systolic blood pressure of ≥160 mm Hg and/or a diastolic blood pressure of ≥100 mm Hg or current use of antihypertensive medication. In all of the participants, sleep duration was assessed by self-report. In a subsample of 975 subjects, it was additionally measured with actigraphy, a validated method that infers wakefulness and sleep from the presence or absence of limb movement. After adjustment for age and gender and additionally for body mass index, smoking, depressive symptoms, sleep medication use, diabetes mellitus, myocardial infarction, and stroke, none of the odds ratios (varying from 0.54; 95% CI: 0.27 to 1.08; to 1.19; 95% CI: 0.89 to 1.58) reflected a significant association between sleep duration and hypertension, whether measured by self-report or actigraphy. This study strongly suggests that sleep duration is not associated with hypertension in the elderly. </description>
    </item> <item>
      <title>Subjective and physiological responses to emotion-eliciting pictures in male schizophrenic patients (Article)</title>
      <link>http://repub.eur.nl/res/pub/35799/</link>
      <pubDate>2007-05-01T00:00:00Z</pubDate>
      <description>Several studies have shown that schizophrenic patients have difficulties in their ability to recognize emotional facial expressions, whereas other research indicated that they subjectively report the same emotional experience as healthy controls. The purpose of this study was to investigate whether the physiological responses that accompany emotions differ between schizophrenic patients and controls, which would suggest a different basic emotional processing mechanism in these patients. We presented 40 emotion-eliciting pictures to male patients (n = 26) and controls (n = 21), while measuring heart rate (HR), breathing rate (BR), skin conductance response (SCR) and systolic blood pressure (SBP). Each subject rated each picture for its degree of valence and arousal. Mixed-effects regression models were used to investigate the relationships between the subjective ratings and the physiological responses. In both groups, BR and SCR increased with increasing arousal ratings, suggesting sympathetic activation. The SBP of both groups increased with increases in both the valence and the arousal ratings. However, whereas the patients' HR first decreased with decreasing pleasure ratings and subsequently increased with higher arousal and valence ratings, the HR in the control group was influenced by a complex interaction between valence and arousal ratings. Thus, the schizophrenic patients showed similar relationships between subjective ratings and SCR, BR, and SBP, but a different relationship between subjective ratings and HR compared with the healthy controls. </description>
    </item> <item>
      <title>Autonomic reactivity in clinically referred children attention-deficit/ hyperactivity disorder versus anxiety disorder (Article)</title>
      <link>http://repub.eur.nl/res/pub/36686/</link>
      <pubDate>2007-03-01T00:00:00Z</pubDate>
      <description>This study examined whether children with attention-deficit/hyperactivity disorder (ADHD) have lower autonomic nervous system (ANS) activity and show less stress reactivity than children with an anxiety disorder. It also explored whether such a difference was accounted for by comorbid oppositional defiant disorder (ODD) or conduct disorder (CD) in some of the ADHD children. Forty-three referred children performed a stress task, during which skin conductance (SCL) and heart rate (HR) levels were measured. Results showed that the ADHD group had similar SCL responses as the anxiety disorder group, but showed less HR reactivity immediately after the stress task. The ADHD with ODD/CD group had a slightly higher HR level than the pure ADHD group, but showed similar SCL and HR reactivity and recovery. It was concluded that ADHD children have less HR reactivity immediately after stress than children with an anxiety disorder, which was not accounted for by comorbid ODD/CD symptoms, and which may be related to a stronger parasympathetic than sympathetic activation. </description>
    </item> <item>
      <title>Spectral analysis of heart rate and blood pressure variability in primary Sjogren's syndrome (Article)</title>
      <link>http://repub.eur.nl/res/pub/8507/</link>
      <pubDate>2002-01-01T00:00:00Z</pubDate>
      <description>BACKGROUND: Autonomic dysfunction has been described in primary Sjogren's
      syndrome (SS). OBJECTIVE: To investigate the circulatory autonomic
      regulation in patients with primary SS by power spectral analysis of heart
      rate and blood pressure variability. METHODS: Forty three (42 female)
      patients with primary SS, mean age 52 years (range 23-80), with a mean
      disease duration of eight years (range 1-30) and 30 (15 female) healthy
      controls, mean age 43 years (range 21-68) were studied. In each patient
      blood pressure, heart rate, and respiration were measured continuously
      during supine rest and orthostatic challenge (60 degrees head-up tilt).
      Power spectral analysis was performed to determine possible differences in
      short term sympathetic and parasympathetic autonomic regulation between
      patients and controls. Furthermore, spectral parameters were studied in
      relation to illness severity and disease duration of the patients with
      primary SS. RESULTS: After controlling for differences in age, heart rate
      variability of the mid-frequency band and the variation coefficient of
      systolic blood pressure were significantly lower in patients with primary
      SS than in controls during supine rest. During 60 degrees tilt patients
      with primary SS showed a significantly higher mean heart rate, mean
      systolic blood pressure, and variation coefficient of diastolic blood
      pressure, and a significantly lower baroreflex index than controls. After
      controlling for age, no differences were found either in heart rate
      variability, blood pressure results, and baroreflex sensitivity during
      supine rest and tilt between the subgroups divided according to disease
      duration, Schirmer test results, or between the subgroups with different
      fatigue scores. No differences were found in spectral data between the
      groups with and without positive antinuclear antibody serology.
      CONCLUSION: For the group no differences in sympathetic and
      parasympathetic cardiac control were seen between patients with primary SS
      and controls, as assessed by spectral techniques, although some
      cardiovascular differences were found, particularly during orthostatic
      challenge.</description>
    </item> <item>
      <title>Quantitative study of spontaneous eye blinks and eye tics in Gilles de la Tourette's syndrome (Article)</title>
      <link>http://repub.eur.nl/res/pub/9197/</link>
      <pubDate>1999-01-01T00:00:00Z</pubDate>
      <description>Spontaneous eye blink rate and frequency of eye tics were studied in nine
          Tourette patients during periods of rest, conversation, and video
          watching. In comparison with controls, the Tourette patients showed a
          significantly higher blink rate during rest and video watching.
          Conversation induced a significant increase in blink rate in the control
          group, but not in the Tourette patients, whereas video watching
          significantly increased blink rate in both groups. The frequency of eye
          tics showed a significant decrease during conversation and increased
          significantly during video watching in Tourette patients. In five
          patients, a significant positive correlation between blink rate and eye
          tic frequency was found, whereas one patient showed a significant negative
          correlation. Our results show that, even though some of our patients were
          on neuroleptic treatment, blink rate was about twofold to threefold
          increased versus healthy controls, suggesting increased central
          dopaminergic activity. Furthermore, these first quantitative data
          illustrate task specific effects on eye tic frequency and the complexity
          of their relation with eye blinks.</description>
    </item> <item>
      <title>Parasympathetic failure does not contribute to ocular dryness in primary Sjogren's syndrome (Article)</title>
      <link>http://repub.eur.nl/res/pub/9200/</link>
      <pubDate>1999-01-01T00:00:00Z</pubDate>
      <description>OBJECTIVE: To investigate the sympathetic and parasympathetic
      cardiovascular function in primary Sjogren's syndrome (SS) and to
      investigate the possible relation with ocular dryness. METHODS: 41 (40
      women) patients with primary SS, mean age 50 years (range 20-80) with a
      mean disease duration of eight years (range 1-30), were studied. In each
      patient direct arterial blood pressure (BP), heart rate (HR) and
      respiration were measured continuously for two hours. The function of the
      autonomic circulatory regulation was evaluated by measuring the heart rate
      response to deep breathing (6 cycles/min) and by means of the Valsalva
      manoeuvre and the responses of BP, HR and plasma noradrenaline
      (norepinephrine) concentrations to a 10 minute 60 degree head up tilt
      test. Pupillography was done to evaluate ocular autonomic function.
      RESULTS: The HR-Valsalva ratio was abnormal in 24% of the patients, and
      the HR variability during forced respiration was abnormal in 56% of the
      patients. The HR responses to both the Valsalva manoeuvre and deep
      breathing, as indicators of parasympathetic function, were abnormally low
      in 6 of 41 (15%) patients. In only two patients the decrease in systolic
      BP in response to the head up tilt test, as indicator of sympathetic
      function, was more than 20 mm Hg. However, increment of plasma
      noradrenaline concentration during head up tilt test and the overshoot of
      BP in phase IV of the Valsalva manoeuvre, as indicators of sympathetic
      function, were normal in both patients. Thus, no evidence for sympathetic
      dysfunction was found, whereas evidence for parasympathetic failure
      occurred sometimes. Autonomic pupillary function in patients with primary
      SS and healthy controls, as well as the Schirmer test in patients with or
      without evidence for parasympathetic dysfunction as based on the results
      of the Valsalva and deep breathing tests, were not significantly
      different. CONCLUSION: Parasympathetic, but not sympathetic dysfunction
      seems to occur in a subgroup of primary SS. Results show that this does
      not necessarily contribute to the typical ocular dryness in this
      condition.</description>
    </item> <item>
      <title>Fatigue in primary Sjogren's syndrome (Article)</title>
      <link>http://repub.eur.nl/res/pub/8900/</link>
      <pubDate>1998-01-01T00:00:00Z</pubDate>
      <description>OBJECTIVE: To assess fatigue in relation to depression, blood pressure,
          and plasma catecholamines in patients with primary Sjogren's syndrome
          (SS), in comparison with healthy controls and patients with rheumatoid
          arthritis. METHODS: For the assessment of fatigue the Multidimensional
          Fatigue Inventory (MFI) was used, a 20 item questionnaire, covering the
          following dimensions: general fatigue, physical fatigue, mental fatigue,
          reduced motivation, and reduced activity. Furthermore, the Zung depression
          scale was used to quantify aspects of depression. Forty nine female
          primary SS patients, 44 female patients with rheumatoid arthritis (RA),
          and 32 healthy women filled in both questionnaires. In addition, supine
          values of blood pressure and plasma catecholamines were measured in the
          patients with primary SS. RESULTS: Primary SS patients were more fatigued
          compared with the healthy controls on all the five dimensions of the MFI.
          When the analyses were repeated using depression as a covariate, group
          differences disappeared for the dimensions of reduced motivation and
          mental fatigue. In the primary SS patients, significant positive
          correlations between depression and the dimensions of reduced motivation
          and mental fatigue were found. Comparing patients with primary SS with
          those with RA, using depression as covariate, no statistically significant
          differences were found between these groups. No relation between fatigue
          and blood pressure was found, but a negative correlation was observed
          between the general fatigue subscale of the MFI and plasma noradrenaline.
          CONCLUSION: Patients with primary SS report more fatigue than healthy
          controls on all the dimensions of the MFI and when controlling for
          depression significant differences remain on the dimensions of general
          fatigue, physical fatigue, and reduced activity. The negative correlations
          between levels of noradrenaline and general fatigue in patients with
          primary SS may imply the involvement of the autonomic nervous system in
          chronic fatigue.</description>
    </item> <item>
      <title>Catecholamines, mood, and cardiovascular control (Doctoral Thesis)</title>
      <link>http://repub.eur.nl/res/pub/39429/</link>
      <pubDate>1993-06-02T00:00:00Z</pubDate>
      <description>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
parameters</description>
    </item>
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