A psychophysiological investigation of the interplay between orienting and executive control during stimulus conflict: A heart rate variability study.

BACKGROUND: It has been hypothesized that resting state cardiac vagal activity (CVA) - an indicator of parasympathetic nervous system activity - is a specific psychophysiological marker of executive control function. Here, we propose an alternative hypothesis - that CVA is associated with early stage attention orientation, promoting the flexible uptake of new information, on which the later operation of such executive control functions depends. We therefore predicted that CVA would predict the interaction between orienting and executive control. This was tested using the revised version of the Attention Network Test (ANT-R) that was developed to distinguish between orienting and executive attention during a stimulus conflict task. METHODS: Healthy adults (N = 48) performed the ANT-R and their resting CVA was measured over a 5 min period using ECG recordings. RESULTS: Multiple regression analyses indicated that, when other factors were controlled for, CVA was more strongly associated with the interaction between the orienting and executive control terms than with either factor individually. CONCLUSION: Higher levels of CVA are specifically implicated in the modulation of executive control by intrinsic orientation operating at early stages of conflict detection. These initial findings of higher CVA on orienting attention in conflict detection need to be replicated in larger samples.

Can we rely on simulated patients' satisfaction with their consultation for assessing medical students' communication skills? A cross-sectional study.

BACKGROUND: In medical education, teaching methods offering intensive practice without high utilization of faculty resources are needed. We investigated whether simulated patients' (SPs') satisfaction with a consultation could predict professional observers' assessment of young doctors' communication skills. METHODS: This was a comparative cross-sectional study of 62 videotaped consultations in a general practice setting with young doctors who were finishing their internship. The SPs played a female patient who had observed blood when using the toilet, which had prompted a fear of cancer. Immediately afterwards, the SP rated her level of satisfaction with the consultation, and the scores were dichotomized into satisfaction or dissatisfaction. Professional observers viewed the videotapes and assessed the doctors' communication skills using the Arizona Communication Interview Rating Scale (ACIR). Their ratings of communication skills were dichotomized into acceptable versus unacceptable levels of competence. RESULTS: The SPs' satisfaction showed a predictive power of 0.74 for the observers' assessment of the young doctors and whether they reached an acceptable level of communication skills. The SPs' dissatisfaction had a predictive power of 0.71 for the observers' assessment of an unacceptable communication level. The two assessment methods differed in 26% of the consultations. When SPs felt relief about their cancer concern after the consultation, they assessed the doctors' skills as satisfactory independent of the observers' assessment. CONCLUSIONS: Accordance between the dichotomized SPs' satisfaction score and communication skills assessed by observers (using the ACIR) was in the acceptable range. These findings suggest that SPs' satisfaction scores may provide a reliable source for assessing communication skills in educational programs for medical trainees (students and young doctors). Awareness of the patient's concerns seems to be of vital importance to patient satisfaction.

The impact of cyclothymic temperament in adult ADHD.

BACKGROUND: Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder in children and adults. Many ADHD patients experience affective symptoms that resemble the cyclothymic temperament trait, which is suggested to be a part of the bipolar spectrum. However, the relationship between adult ADHD and cyclothymic temperament has never been systematically studied. METHODS: A sample of 586 clinically diagnosed Norwegian adult ADHD patients and 721 population derived controls responded to the 21-item cyclothymic subscale of the Temperament Evaluation of Memphis, Pisa, Paris and San Diego auto-questionnaire (TEMPS-A). Self-reported data on psychiatric symptoms, comorbidity, educational and occupational level, and known comorbidity in family members, including bipolar disorder, was also obtained. RESULTS: The mean TEMPS-A scores were 13.0 for patients and 4.6 for controls (p<0.001), and 71% of the patients compared to 13% of the controls were classified as having a cyclothymic temperament (TEMPS score ≥11 points). Among ADHD patients, cyclothymic temperament was strongly associated with more childhood and adult ADHD symptoms, lower educational and occupational achievements and increased psychiatric comorbidity, including bipolar disorder (10%). In addition, 49% screened positive on the Mood Disorder Questionnaire. LIMITATIONS: Although the cyclothymic TEMPS-A scale has been used in clinical settings in Norway for many years, it has not yet been officially validated. CONCLUSIONS: Cyclothymic temperament is highly prevalent in adults with ADHD, and this characterises a subgroup of more psychiatrically impaired individuals, possibly reflecting an underlying affective instability with a pathophysiology closer to the bipolar spectrum disorders.

Risk of depression in diabetes is highest for young persons using oral anti-diabetic agents.

AIMS: Previous studies report an increased risk of depression in patients with diabetes, but there is little knowledge about if or how the risk varies according to sex, groups of age and different type of treatments for the diabetes. We therefore aimed to investigate the risk of depression in different types of treatment for diabetes and in subgroups of age and sex. METHODS: Data on the Norwegian population from 20 years of age being prescribed antidepressants (n = 253 668) and anti-diabetic agents (n = 121 392) in 2006 was obtained from the National Register of Prescriptions and analysed in a cross-sectional design. RESULTS: Individuals using insulin in monotherapy (n = 29 611) had an age- and sex-adjusted odds ratio of 1.47 (95% CI 1.42-1.53) for receiving antidepressants. Corresponding odds ratios for individuals receiving oral anti-diabetic agents in monotherapy (n = 76 387) and for those who received both insulin and oral anti-diabetic agents (n = 15 394) were 1.44 (95% CI 1.41-1.47) and 1.82 (95% CI 1.80-1.97), respectively. No major differences in risk according to age were found for persons receiving insulin in monotherapy, while a marked and inverse association between age and risk of receiving antidepressants was found for those receiving oral anti-diabetic agents. Highest risk of antidepressant treatment [odds ratio 4.15 (95% CI 3.12-5.52)] was found for patients receiving both oral anti-diabetic agents and insulin at 30-39 years. The risk was equally increased among men and women. CONCLUSIONS: The risk of depression among patients with diabetes varies strongly according to age and type of treatment for diabetes.

Bipolar disorder risk alleles in adult ADHD patients.

Attention-deficit/hyperactivity disorder (ADHD) has an estimated prevalence of 3-5% in adults. Genome-wide association (GWA) studies have not been performed in adults with ADHD and studies in children have so far been inconclusive, possibly because of the small sample sizes. Larger GWA studies have been performed on bipolar disorder (BD) and BD symptoms, and several potential risk genes have been reported. ADHD and BD share many clinical features and comorbidity between these two disorders is common. We therefore wanted to examine whether the reported BD genetic variants in CACNA1C, ANK3, MYO5B, TSPAN8 and ZNF804A loci are associated with ADHD or with scores on the Mood Disorder Questionnaire (MDQ), a commonly used screening instrument for bipolar spectrum disorders. We studied 561 adult Norwegian ADHD patients and 711 controls from the general population. No significant associations or trends were found between any of the single nucleotide polymorphisms (SNPs) studied and ADHD [odds ratios (ORs) ≤ 1.05]. However, a weak association was found between rs1344706 in ZNF804A (OR = 1.25; P = 0.05) and MDQ. In conclusion, it seems unlikely that these six SNPs with strong evidence of association in BD GWA studies are shared risk variants between ADHD and BD.

A genome-wide association study of bipolar disorder and comorbid migraine.

Both migraine and bipolar affective disorder (BPAD) are complex phenotypes with significant genetic and nongenetic components. Epidemiological and clinical studies have showed a high degree of comorbidity between migraine and BPAD, and overlapping regions of linkage have been shown in numerous genome-wide linkage studies. To identify susceptibility factors for the BPAD/migraine phenotype, we conducted a genome-wide association study (GWAS) in 1001 cases with bipolar disorder collected through the NIMH Genetics Initiative for Bipolar Disorder and genotyped at 1 m single-nucleotide polymorphisms (SNPs) as part of the Genetic Association Information Network (GAIN). We compared BPAD patients without any headache (n = 699) with BPAD patients with doctor diagnosed migraine (n = 56). The strongest evidence for association was found for several SNPs in a 317-kb region encompassing the uncharacterized geneKIAA0564 {e.g. rs9566845 [OR = 4.98 (95% CI: 2.6-9.48), P = 7.7 × 10(-8)] and rs9566867 (P = 8.2 × 10(-8))}. Although the level of significance was significantly reduced when using the Fisher's exact test (as a result of the low count of cases with migraine), rs9566845 P = 1.4 × 10(-5) and rs9566867 P = 1.5 × 10(-5), this region remained the most prominent finding. Furthermore, marker rs9566845 was genotyped and found associated with migraine in an independent Norwegian sample of adult attention deficit hyperactivity disorder (ADHD) patients with and without comorbid migraine (n = 131 and n = 324, respectively), OR = 2.42 (1.18-4.97), P = 0.013. This is the first GWAS examining patients with bipolar disorder and comorbid migraine. These data suggest that genetic variants in the KIAA0564 gene region may predispose to migraine headaches in subgroups of patients with both BPAD and ADHD.

A genome-wide linkage study of bipolar disorder and co-morbid migraine: replication of migraine linkage on chromosome 4q24, and suggestion of an overlapping susceptibility region for both disorders on chromosome 20p11.

Migraine and Bipolar Disorder (BPAD) are clinically heterogeneous disorders of the brain with a significant, but complex, genetic component. Epidemiological and clinical studies have demonstrated a high degree of co-morbidity between migraine and BPAD. Several genome-wide linkage studies in BPAD and migraine have shown overlapping regions of linkage on chromosomes, and two functionally similar voltage-dependent calcium channels CACNA1A and CACNA1C have been identified in familial hemiplegic migraine and recently implicated in two whole genome BPAD association studies, respectively. We hypothesized that using migraine co-morbidity to look at subsets of BPAD families in a genetic linkage analysis would prove useful in identifying genetic susceptibility regions in both of these disorders. We used BPAD with co-morbid migraine as an alternative phenotype definition in a re-analysis of the NIMH Bipolar Genetics Initiative wave 4 data set. In this analysis we selected only those families in which at least two members were diagnosed with migraine by a doctor according to patients' reports. Nonparametric linkage analysis performed on 31 families segregating both BPAD and migraine identified a linkage signal on chromosome 4q24 for migraine (but not BPAD) with a peak LOD of 2.26. This region has previously been implicated in two independent migraine linkage studies. In addition we identified a locus on chromosome 20p11 with overlapping elevated LOD scores for both migraine (LOD=1.95) and BPAD (LOD=1.67) phenotypes. This region has previously been implicated in two BPAD linkage studies, and, interestingly, it harbors a known potassium dependant sodium/calcium exchanger gene, SLC24A3, that plays a critical role in neuronal calcium homeostasis. Our findings replicate a previously identified migraine linkage locus on chromosome 4 (not co-segregating with BPAD) in a sample of BPAD families with co-morbid migraine, and suggest a susceptibility locus on chromosome 20, harboring a gene for the migraine/BPAD phenotype. Together these data suggest that some genes may predispose to both bipolar disorder and migraine.

Meta-analysis of brain-derived neurotrophic factor p.Val66Met in adult ADHD in four European populations.

Attention-deficit hyperactivity disorder (ADHD) is a multifactorial, neurodevelopmental disorder that often persists into adolescence and adulthood and is characterized by inattention, hyperactivity and impulsiveness. Before the advent of the first genome-wide association studies in ADHD, genetic research had mainly focused on candidate genes related to the dopaminergic and serotoninergic systems, although several other genes had also been assessed. Pharmacological data, analysis of animal models and association studies suggest that Brain-Derived Neurotrophic Factor (BDNF) is also a strong candidate gene for ADHD. Several polymorphisms in BDNF have been reported and studied in psychiatric disorders but the most frequent is the p.Val66Met (rs6265G > A) single nucleotide polymorphism (SNP), with functional effects on the intracellular trafficking and secretion of the protein. To deal with the inconsistency raised among different case-control and family-based association studies regarding the p.Val66Met contribution to ADHD, we performed a meta-analysis of published as well as unpublished data from four different centers that are part of the International Multicentre Persistent ADHD CollaboraTion (IMpACT). A total of 1,445 adulthood ADHD patients and 2,247 sex-matched controls were available for the study. No association between the p.Val66Met polymorphism and ADHD was found in any of the four populations or in the pooled sample. The meta-analysis also showed that the overall gene effect for ADHD was not statistically significant when gender or comorbidity with mood disorders were considered. Despite the potential role of BDNF in ADHD, our data do not support the involvement of p.Val66Met in the pathogenesis of this neuropsychiatric disorder.

Genetic analyses of dopamine related genes in adult ADHD patients suggest an association with the DRD5-microsatellite repeat, but not with DRD4 or SLC6A3 VNTRs.

Attention deficit hyperactivity disorder (ADHD) is a common and highly heritable psychiatric disorder in children and adults. Recent meta-analyses have indicated an association between genes involved in dopaminergic signaling and childhood ADHD, but little is known about their possible role in adult ADHD. In this study of adults with ADHD, we evaluated the three most commonly studied ADHD candidate genetic polymorphisms; the dopamine receptor D4 (DRD4) exon 3 VNTR repeat, a microsatellite repeat 18.5 kb upstream of the DRD5 locus and the 3'UTR dopamine transporter SLC6A3 (DAT 1) VNTR. We examined 358 clinically diagnosed adult Norwegian ADHD patients (51% males) and 340 ethnically matched controls. We found a nominally significant overall association with adult ADHD for the DRD5 microsatellite marker (P = 0.04), and a trend toward increased risk associated with the 148-bp allele consistent with recent meta-analyses. The strongest overall association (P = 0.02) and increased risk for the 148-bp allele [odds ratio (OR) = 1.27 (95% CI: 1.00-1.61)] were seen in the inattentive and combined inattentive/hyperactive group as previously reported for childhood ADHD. No association was found for the DRD4 or SLC6A3 polymorphisms in this patient sample. In conclusion, our results among adults with a clinical diagnosis of ADHD support an association between ADHD and the DRD5 locus, but not the DRD4 or SLC6A3 loci. It is possible that the latter polymorphisms are associated with a transient form of ADHD with better long-term clinical outcome.

Migraine with and without aura: association with depression and anxiety disorder in a population-based study. The HUNT Study.

Some data indicate that migraine with aura (MA) is more strongly associated with anxiety disorder and depression than migraine without aura (MoA), but the evidence is not conclusive. In the Nord-Trøndelag Health study 1995-1997, a total of 49 205 (75% of the participants) subjects gave valid answers to both HADS (Hospital Anxiety and Depression Scale) and a validated headache questionnaire. Associations between anxiety disorder/depression and MA/MoA were evaluated by multiple logistic regression analysis. Depression (DEP) [odds ratio (OR) 1.7; 95% confidence interval (CI) 1.2, 2.6] and depression with comorbid anxiety disorder (COM) (OR 1.6; 95% CI 1.2, 2.1) were more likely in women having MA than in those with MoA. No stronger association was found for pure anxiety disorder (ANX) in MA vs. MoA (OR 0.9; 95% CI 0.7, 1.5). Among men, we found no difference in prevalence of depression and anxiety disorders between MA and MoA. This is a new finding that might have relevance for both research and clinical treatment.

The prevalence of migraine in patients with bipolar and unipolar affective disorders.

There is a well-known association between migraine and affective disorders, but the information is sparse concerning the prevalence of migraine in subgroups of the affective disorders. The present study was undertaken to investigate the prevalence of migraine in unipolar depressive, bipolar I and bipolar II disorders. Patients with major affective disorders (n = 62), consecutively admitted to an open psychiatric ward, were examined with a semi-structured interview based on DSM-IV diagnostic criteria, combined with separate criteria for affective temperaments. Diagnosis of unipolar and bipolar I disorders followed the DSM-IV criteria, while bipolar II disorder encompassed patients with either discrete hypomanic episodes or a cyclothymic temperament. Migraine was diagnosed according to IHS-criteria. Symptoms of migraine were found to be common in these patients, both in those with unipolar depression (46% prevalence of migraine) and in those with bipolar disorders (44% prevalence). Among the bipolar patients there was, however, a striking difference between the two diagnostic subgroups, with a prevalence of 77% in the bipolar II group compared with 14% in the bipolar I group (P = 0.001). These results support the contention that bipolar I and II are biologically separate disorders and point to the possibility of using the association of bipolar II disorder with migraine to study both the pathophysiology and the genetics of this affective disorder.

Clinical characteristics of patients with major affective disorders and comorbid migraine.

The present study was undertaken to examine the clinical characteristics of patients with major affective disorders and comorbid migraine. Patients (n = 102) with an index episode of either major depression or mania were interviewed with a semi-structured interview based partly on DSM-IV criteria and partly on Akiskal's criteria for affective temperaments. Compared to the patients without migraine (n = 49), the patients with comorbid migraine (n = 53) had a higher frequency of bipolar II disorder (43% vs. 10%), a lower frequency of bipolar I disorder (11% vs. 33%), an approximately equal frequency of unipolar depressive disorder (45% vs. 57%) and a higher frequency of affective temperaments (45% vs. 22%). The migraine patients also had a greater number of anxiety disorders (3.0 vs. 1.9) and a higher frequency of panic disorder and agoraphobia. Gender distribution, age, age at onset of first affective episode, number of previous episodes and symptoms during depressive episodes were similar in both groups. Based on these findings it is suggested that the presence of migraine may be used to delineate a distinct subgroup of the major affective disorders.

[Do antidepressive agents have analgesic effects?]. / Har antidepressiva analgetisk virkning?

Patients with chronic pain are often depressed, and antidepressants have been widely used in the treatment of these patients. Well controlled clinical studies have shown that antidepressants have analgesic effects, apparently independent of changes in mood, and in lower doses than used in the treatment of depression. Good results have been reported for several types of chronic pain, especially headache and facial pain, arthritis, fibromyalgia and neuralgias. In addition, antidepressants have also an indirect analgesic action by relieving a depressive condition associated with chronic pain.

Antinociceptive effects of serotonergic reuptake inhibitors in mice.

The antinociceptive effects of three predominantly serotonergic reuptake inhibitors, alaproclate, citalopram and clomipramine, were examined in mice using the hot-plate, formalin and substance P tests. The effects were compared with those of the noradrenergic reuptake inhibitor, desipramine. Different profiles in the three nociceptive tests were found for all four drugs, using doses of 10 and 40 mg/kg. The selective serotonergic reuptake inhibitor, alaproclate, seemed to have the least antinociceptive effects, and was the only drug that was ineffective in the hot-plate test. The other selective drug, citalopram, had a stronger effect than alaproclate in the substance P test, but in the formalin test, both drugs were approximately equally effective. Clomipramine differed from citalopram by being more effective in the formalin test. These findings thus indicate that selective inhibitors of the uptake of 5-HT have weaker antinociceptive effects than less selective drugs. Desipramine seemed to be no less effective than the serotonergic drugs and was the most potent drug in the hot-plate test.

Antinociceptive effects of (+/-)-, (+)- and (-)-nefopam in mice.

The antinociceptive activity of (+/-)-, (+)- and (-)-nefopam in mice has been examined using the hot-plate, formalin and tail-flick tests. Nefopam was administered by the intraperitoneal, intracerebroventricular (i.c.v.) and intrathecal (i.th.) routes. Intraperitoneal injection of (+/-)-nefopam (10-20 mg kg-1) had powerful analgesic effects in the hot-plate and formalin tests. In the tail-flick test it produced a weak, but significant elevation of the response latencies. In spinalized animals, however, the effect was abolished, indicating that nefopam prolonged the tail-flick latencies by activation of descending pain-modulating pathways. (+/-)-Nefopam (5-20 micrograms) elicited analgesia in the hot-plate test after i.c.v. or i.th. injection. These findings suggest that nefopam has both a spinal and a supraspinal site of action. (+)-Nefopam was significantly more potent than (-)-nefopam after both systemic and central administration.

Involvement of central serotonergic pathways in nefopam-induced antinociception.

The possible involvement of central serotonergic pathways in the mechanism of action of nefopam was investigated in male albino mice. Nefopam (15 mg/kg i.p.) did not alter the concentration of serotonin or its metabolite 5-hydroxyindole acetic acid in frontal cortex or spinal cord. Lesions of the ascending serotonergic pathways were made by systemic administration of p-chloroamphetamine (PCA). Serotonin depletion in all serotonergic systems was obtained by means of p-chlorophenylalanine (PCPA). Two different nociceptive assays were used, the formalin test and the increasing temperature hot plate test. PCPA pretreatment significantly reduced the effect of nefopam (15 mg/kg) in the formalin test. In contrast, nefopam-induced analgesia was not affected by PCA pretreatment, either in the formalin test or in the increasing temperature hot plate test. In conclusion, the data suggest that descending serotonergic pathways are involved in nefopam-induced antinociception.

Changes in nociception after acute and chronic administration of zimelidine: different effects in the formalin test and the substance P behavioural assay.

The selective inhibitor of the reuptake of 5-hydroxytryptamine (5-HT), zimelidine, was administered intraperitoneally to mice (10 mg/kg) and nociceptive sensitivity was evaluated using the formalin test (20 microliters of 1% formalin, injected subcutaneously) and the assay for substance P (5 ng administered intrathecally). Zimelidine increased the behavioural response to formalin, but reduced the response to substance P. These effects of zimelidine seemed to be unchanged after chronic treatment (2 X 10 mg/kg for 14 days). It is suggested that zimelidine produces a central antinociceptive effect, but elicits a peripheral hyperalgesia, which predominates in the formalin test.

Increased sensitivity to intrathecal substance P following chronic administration of zimelidine.

The behavioural response to intrathecal substance P (SP) was evaluated following acute and chronic administration of the selective serotonin reuptake inhibitor zimelidine. A single dose of zimelidine (10 mg/kg) attenuated the response to SP by approximately 40%, in agreement with previous findings that acute administration of zimelidine reduces nociceptive behaviour. Twenty-four hours following the withdrawal of long-term treatment with zimelidine (10 mg/kg X 2 daily for 14 days) the behavioural response to SP was increased by 116%. This may indicate the development of supersensitivity to SP, or may reflect an increased responsiveness to noxious stimuli due to reduced serotonergic inhibition.

Development of tolerance to the antinociceptive effect of metergoline.

Metergoline given IP reduced the response to noxious stimulation in the mouse formalin test. Tolerance to this effect developed after a chronic treatment schedule consisting of ten daily injections of 5 mg/kg. Twenty four hours after the last injection a test dose of metergoline (2.5 mg/kg) reduced the licking time in the formalin test by 28% in the chronic metergoline group, compared to 68% reduction in the vehicle-treated animals. In addition, the antinociceptive effect of the 5-hydroxytryptamine releasing compound p-chloramphetamine (PCA) was reduced following chronic treatment with metergoline. The reduced effect of PCA may have been caused by down-regulation of 5-HT2 receptors. However, this finding is also compatible with the contention that metergoline may act as an agonist at postsynaptic serotonergic receptors.

Effects of the putative 5-HT1A receptor agonist 8-OH-2-(di-n-propylamino)tetralin on nociceptive sensitivity in mice.

The ability of 8-OH-2-(di-n-propylamino)tetralin (8-OH-DPAT) to alter nociceptive sensitivity in mice was studied using the tail-flick, hot-plate and formalin tests. Subcutaneous (SC) administration of 8-OH-DPAT (0.63-1.0 mg/kg) dose-dependently increased the temperature at which hindpaw lick occurred in a hot-plate test using slowly rising temperature and increased the latencies to hindpaw lick, but reduced the latencies to jump in a conventional hot-plate test. Intracerebroventricular (ICV) injections (0.25-1.0 microgram) produced similar results in the conventional hot plate test. Following intrathecal (ITH) injections (0.25-1.0 microgram), however, the latencies to hindpaw lick were elevated without any change in jump latencies. In the formalin test a low systemic dose of 8-OH-DPAT (0.063 mg/kg) elicited hyperalgesia, while hypoalgesia was found after a high dose (1.0 mg/kg). ICV injection of 1.0 microgram produced hypoalgesia in the formalin test while the same dose injected ITH was without effect. 8-OH-DPAT did not alter tail-flick latencies, either by SC, ICV or ITH administration. Previous studies have shown that 8-OH-DPAT stimulates central serotonergic receptors, and shows selectivity for the 5-HT1A recognition site. The present findings indicate an involvement of 5-HT1A receptors in the processing of nociceptive information both at spinal and supraspinal sites. However, stimulation of 5-HT1A receptors does not seem to affect spinal, nociceptive reflexes.