Copeptin in CCK-4-induced panic in healthy man: Sexual dimorphisms in secretion pattern and panic response, but no correlation of copeptin with panic symptoms.

Copeptin, the C-terminal part of the hypothalamic arginine vaspopressin (AVP) precursor, closely mirrors the production of AVP and was proposed as an easily measured novel marker of the individual stress level in man. First data in male volunteers proposed copeptin as a potential endocrine surrogate marker of cholecystokinin-tetrapeptide (CCK-4)-induced panic. We tried to replicate these pilot data and to extend them to the other sex. 46 healthy human subjects (29 men, 17 women) were given an intravenous bolus of 50 µg CCK-4. Basal and stimulated plasma copeptin was measured and panic symptoms were assessed using the Acute Panic Inventory (API). Basal copeptin was significantly lower in women vs. men, while men showed a significantly higher CCK-4-induced increase of copeptin. In contrast, female subjects displayed a signifcantly higher increase of API ratings by CCK-4. No significant correlations of panic symptoms and copeptin release induced by CCK-4 could be found, neither in man, nor in women, nor in the total sample. A sexual dimorphism in copeptin secretion and in panic response was demonstrated. Prior unexpected findings of copeptin release as an objective read-out of panic could not be replicated. The role of the vasopressinergic system in panic anxiety needs further study in panic patients and in healthy man, using also other panic provocation paradigms.

Classical Risk Factors and Inflammatory Biomarkers: One of the Missing Biological Links between Cardiovascular Disease and Major Depressive Disorder.

BACKGROUND: Cardiovascular disorders (CVD) and major depressive disorder (MDD) are the most frequent diseases worldwide responsible for premature death and disability. Behavioral and immunological variables influence the pathophysiology of both disorders. We therefore determined frequency and severity of MDD in CVD and studied whether MDD without CVD or other somatic diseases influences classical and inflammatory biomarkers of cardiovascular risk. In addition, we investigated the influence of proinflammatory cytokines on antidepressant treatment outcome. METHODS: In a case-control design, 310 adults (MDD patients without CVD, CVD patients, and cardiologically and psychiatrically healthy matched controls) were investigated. MDD patients were recruited after admission in a psychiatric university hospital. Primary outcome criteria were clinical depression ratings (HAM-D scale), vital signs, classical cardiovascular risk factors and inflammatory biomarkers which were compared between MDD patients and healthy controls. RESULTS: We detected an enhanced cardiovascular risk in MDD. Untreated prehypertension and signs directing to a metabolic syndrome were detected in MDD. Significantly higher inflammatory biomarkers such as the high sensitivity C-reaktive protein (hsCRP) and proinflammatory acute phase cytokines interleukine-1ß (IL-1ß) and interleukine-6 (IL-6) underlined the higher cardiovascular risk in physically healthy MDD patients. Surprisingly, high inflammation markers before treatment were associated with better clinical outcome and faster remission. The rate of MDD in CVD patients was high. CONCLUSIONS: Patients suffering from MDD are at specific risk for CVD. Precise detection of cardiovascular risks in MDD beyond classical risk factors is warranted to allow effective prophylaxis and treatment of both conditions. Future studies of prophylactic interventions may help to provide a basis for prophylactic treatment of both MDD and CVD. In addition, the high risk for MDD in CVD patients was confirmed and underlines the requirement for clinical attention.

Benefit in liver transplantation: a survey among medical staff, patients, medical students and non-medical university staff and students.

BACKGROUND: The allocation of any scarce health care resource, especially a lifesaving resource, can create profound ethical and legal challenges. Liver transplant allocation currently is based upon urgency, a sickest-first approach, and does not utilize capacity to benefit. While urgency can be described reasonably well with the MELD system, benefit encompasses multiple dimensions of patients' well-being. Currently, the balance between both principles is ill-defined. METHODS: This survey with 502 participants examines how urgency and benefit are weighted by different stakeholders (medical staff, patients on the liver transplant list or already transplanted, medical students and non-medical university staff and students). RESULTS: Liver transplant patients favored the sickest-first allocation, although all other groups tended to favor benefit. Criteria of a successful transplantation were a minimum survival of at least 1 year and recovery of functional status to being ambulatory and capable of all self-care (ECOG 2). An individual delisting decision was accepted when the 1-year survival probability would fall below 50%. Benefit was found to be a critical variable that may also trigger the willingness to donate organs. CONCLUSIONS: The strong interest of stakeholder for successful liver transplants is inadequately translated into current allocation rules.

Tryptophan metabolism and immunogenetics in major depression: a role for interferon-γ gene.

The tryptophan metabolism and immune activation play a role in pathophysiology of major depressive disorders. The pro-inflammatory cytokine interferon-γ transcriptionally induces the indoleamine 2,3-dioxygenase enzyme that degrades the tryptophan and thus induces serotonin depletion. The polymorphism of certain cytokine genes was reported to be associated with major depression. We investigated the association between interferon-γ (IFNγ) gene CA repeat polymorphism, the profile of serotonin and tryptophan pathway metabolites and clinical parameters in 125 depressed patients and 93 healthy controls. Compared to controls, serum tryptophan and 5-hydroxyindoleacetic acid (5HIAA) concentrations in the patients were significantly lower and serum kynurenine concentrations were significantly higher at baseline (p<0.0001). The presence of IFNγ CA repeat allele 2 homozygous has significant association with higher kynurenine concentrations in controls (F=4.47, p=0.038) as well as in patients (F=3.79, p=0.045). The existence of interferon-γ CA repeat allele 2 (homo- or heterozygous) showed significant association with increase of tryptophan breakdown over time during the study period (F=6.0, p=0.019). The results indicated the association between IFNγ CA repeat allele 2, tryptophan metabolism and the effect of medication.

Benzodiazepines counteract rostral anterior cingulate cortex activation induced by cholecystokinin-tetrapeptide in humans.

BACKGROUND: Benzodiazepines modulate γ-aminobutyric acid type A (GABA(A)) receptors throughout the brain. However, it is not fully understood which brain regions within anxiety-related brain circuits are really responsible for their anxiolytic effects and how these regions interact. METHODS: We investigated whether the benzodiazepine alprazolam affects activity in distinct brain regions within anxiety-related circuits during an experimental anxiety paradigm by means of functional magnetic resonance imaging (fMRI). Panic symptoms were elicited by a bolus injection of the neuropeptide cholecystokinin-tetrapeptide (CCK-4) in 16 healthy male subjects in a double-blind, placebo-controlled design. Functional brain activation patterns were determined before and during the CCK-4-challenge without pretreatment and after treatment with either placebo or 1 mg alprazolam. RESULTS: The CCK-4 induced anxiety and elicited widely distributed activation patterns in anxiety-related brain circuits, especially in the rostral anterior cingulate cortex (rACC), which was attenuated after alprazolam treatment. In contrast to placebo, alprazolam abolished the activation of the rACC after challenge with CCK-4 (p<.005, corrected for multiple comparisons) and increased functional connectivity between the rACC and other anxiety-related brain regions such as amygdala and prefrontal cortex. Moreover, the reduction in the CCK-4 induced activation of the rACC correlated with the anxiolytic effect of alprazolam (r(p) = .52; p = .04). CONCLUSIONS: These findings put forward the rACC as a target for benzodiazepines and suggest that the CCK-4/fMRI paradigm might represent a human translational model for the investigation of anxiolytic drugs.

Major depressive disorder is associated with cardiovascular risk factors and low Omega-3 Index.

OBJECTIVE: Cardiovascular disease (CVD) and major depressive disorder (MDD) are frequent worldwide and have a high comorbidity rate. Omega-3 fatty acids have been suggested as disease modulators for both CVD and MDD. Therefore, we studied whether polyunsaturated fatty acids and the Omega-3 Index may represent markers for assessment of the cardiovascular risk in somatically healthy patients suffering from MDD. METHOD: We conducted a case-control study from July 2004 to December 2007 in 166 adults (86 inpatients with MDD but without CVD from the Department of Psychiatry and Psychotherapy and 80 age- and sex-matched healthy controls from an outpatient clinic of the Division of Preventive Cardiology, Ludwig Maximilian University of Munich, Germany). Information gathered at baseline included MDD diagnosis according to DSM-IV criteria, depression ratings, conventional cardiovascular risk factors, and fatty acid and interleukin-6 determinations. Fatty acid composition was analyzed according to the HS-Omega-3 Index methodology. During the study, patients received no supplementation with omega-3 fatty acids. The main inclusion criteria were the diagnosis of MDD according to DSM-IV and a 17-item Hamilton Depression Rating Scale (HDRS-17) score of at least 17. Treatment response and remission were defined using the HDRS-17. RESULTS: Several conventional risk factors such as high triglyceride (mean, 152 mg/dL vs 100 mg/dL; P < .001) and fasting glucose (mean, 96 mg/dL vs 87 mg/dL; P = .005) values as well as greater waist circumference (mean, 97 cm vs 87 cm; P = .019) and higher body mass index (calculated as kg/m(2); mean, 26 vs 24; P = .011) were more prevalent in MDD patients in comparison with controls. The Omega-3 Index (mean, 3.9% vs 5.1%; P < .001) and individual omega-3 fatty acids were significantly lower in MDD patients. An Omega-3 Index < 4% was associated with high concentrations of the proinflammatory cytokine interleukin-6 (χ(2) = 7.8, P = .02). CONCLUSIONS: Conventional cardiovascular risk factors, the Omega-3 Index, and interleukin-6 levels indicated an elevated cardiovascular risk profile in MDD patients currently free of CVD. Our results support the employment of strategies to reduce the cardiovascular risk in still cardiovascularly healthy MDD patients by targeting conventional risk factors and the Omega-3 Index.

Glyoxalase-I mRNA expression and CCK-4 induced panic attacks.

RATIONALE: There is evidence that the anti-glycation enzyme glyoxalase-1 (GLO1) may play a role in anxiety-related behaviour. However, discordant findings between GLO1 expression and anxiety-related behaviour have been observed in animal models. Because no data are available on the relation between GLO1 mRNA expression and human anxiety so far, we investigated the expression of GLO1 mRNA in peripheral blood cells in relation to cholecystokinin-tetrapeptide (CCK-4) induced panic anxiety in healthy subjects as an established model of human anxiety in healthy volunteers. METHODS: Twenty-three healthy subjects underwent challenge with CCK-4. GLO1 mRNA expression was assessed by quantitative real-time polymerase chain reaction prior to CCK-4 injection. Baseline anxiety was assessed with the State-Trait-Anxiety-Inventory (STAI) and panic response was measured with the Panic Symptom Scale (PSS). RESULTS: CCK-4 elicited a marked anxiety response accompanied by a significant increase in heart rate. GLO1 mRNA expression did not correlate with state or trait anxiety nor with severity of CCK-4 induced anxiety. CONCLUSIONS: The lack of correlation between GLO1 mRNA expression and CCK-4 induced panic severity suggests that GLO1 is not involved into the acute panic response to CCK-4 in healthy volunteers. Therefore, further studies are needed to clarify the involvement of GLO1 in anxiety disorders at baseline and in anxiety challenge paradigms to resolve the apparent contradictions of preclinical studies concerning the relationship between GLO1 expression and anxiety.

Agomelatine: The evidence for its place in the treatment of depression.

INTRODUCTION: Depressive disorders are among the main causes of disability due to disease. In spite of recent progress in the pharmacotherapy of depression, there is still a high nonresponse rate of approximately 30% to the first antidepressant treatment. Furthermore, the latency of several weeks until sufficient clinical improvement and the risk of side effects remain unresolved problems. Therefore, there is still further need for the development of new antidepressants. In the last years a variety of melatonin receptor agonists have been synthesized and evaluated for the treatment of sleep disorders. Animal studies suggested that agomelatine (S-20098), a synthetic melatonergic MT(1) and MT(2) receptor agonist with serotonin receptor antagonistic properties, may have additional activating properties and may represent a new approach in the treatment of depression. AIMS: Clinical trials that have demonstrated efficacy and safety of agomelatine for the treatment of depression are reviewed. EVIDENCE REVIEW: In clinical trials, including phase III studies, superior efficacy compared to placebo and good efficacy compared to standard antidepressants was shown for agomelatine for the acute treatment of major depression. In all studies published so far agomelatine was safe and the overall tolerability profile was superior to selective serotonin reuptake inhibitors or selective serotonin and norepinephrine reuptake inhibitors. PLACE IN THERAPY: Agomelatine may represent a novel perspective in the treatment of acute depression. The improvement of sleep disturbances, the tolerability in terms of sexual side effects, and the lack of withdrawal symptoms after abrupt discontinuation of treatment may represent important clinical benefits compared to established antidepressants.

Influence of age on effectiveness and tolerability of electroconvulsive therapy.

OBJECTIVES: The effectiveness of electroconvulsive therapy (ECT) in pharmacotherapy-resistant major depressive disorder and schizophrenia has been shown for all age groups. Nevertheless, age-specific adverse effects such as greater cognitive impairment and higher somatic risks due to medical comorbidities and concomitant medication may be limiting factors in geriatric patients. METHODS: We retrospectively evaluated 4457 treatments in 380 patients to investigate the influence of age on ECT outcome, safety, and adverse effects. Clinical variables, treatment modalities, and neurophysiological parameters were analyzed. For modeling the influence of age on these variables of interest, linear and logistic regression models were performed. RESULTS: The mean (SD) age of our patients was 51.2 (15) years; 30% were older than 60 years. Diagnoses were major depressive disorder in 74.4% and schizophrenia in 25.6%. We found a considerable clinical improvement in all age groups. A higher severity of disease at admission corresponded to a better clinical response. Analyzing treatment modalities of elderly patients older than 60 years, no significant differences in need and number of concomitant psychotropic medications were seen, but significant differences were seen in medical co-medication. Ictal and postictal neurophysiological parameters were only in part predictive for clinical outcome, but age had a significant influence on most of them. Transient cardiovascular adverse effects and cognitive disturbances were more frequent in the elderly. In most cases, there was no need for any specific treatment. CONCLUSIONS: Our data confirm previous studies indicating the good effectiveness of ECT irrespective of age. We also found an excellent tolerability profile in the elderly in our patient sample. There was no mortality, and only transient and no life-threatening adverse events occurred.

Mirtazapine does not influence tetrahydrodeoxycorticosterone levels in depressed patients.

BACKGROUND: Among the neuroactive steroids, 3alpha,5alpha-tetrahydrodeoxycorticosterone (3alpha,5alpha-THDOC) is at least in part produced in the adrenal gland and is therefore under the control of the hypothalamic-pituitary-adrenocortical (HPA) system. The antidepressant mirtazapine has been shown to attenuate HPA axis activity and to increase the concentrations of 3alpha-reduced metabolites of progesterone in depressed patients. In the present study, the impact of mirtazapine on 3alpha,5alpha-THDOC levels was investigated in relation to clinical response in depressed patients. METHOD: A total of 23 drug-free inpatients suffering from a major depressive episode (DSM-IV criteria) underwent 5-week treatment with mirtazapine (45 mg/day). Plasma samples were taken weekly at 08:00 h and were quantified for 3alpha,5alpha-THDOC levels. RESULTS: 3alpha,5alpha-THDOC levels were not correlated with demographic and clinical parameters such as age and severity of depression. Moreover, 5-week treatment with mirtazapine did not influence the 3alpha,5alpha-THDOC in the depressed patients, neither in responders nor in non-responders. CONCLUSION: Putative increasing effects of mirtazapine on 3alpha-reduced neuroactive steroids such as 3alpha,5alpha-THDOC which may be mediated via an impact on the neurosteroidogenic enzyme 3alpha-hydroxysteroid dehydrogenase seem to be counterbalanced by the mirtazapine-induced inhibition of ACTH secretion which directly influences the 3alpha,5alpha-THDOC release of the adrenal cortex.

Severe dependency on zolpidem in a patient with multiple sclerosis suffering from paraspasticity.

Zolpidem, a non-benzodiazepine hypnotic, acts selectively via the alpha(1)-subunit of GABA(A) receptors at therapeutic doses. It is therefore thought to lack both benzodiazepine properties such as anxiolysis, anticonvulsion, muscle relaxation, and side effects such as dependency. We report a case of severe dependency of zolpidem taken because of percieved myorelaxation in a patient with multiple sclerosis and paraspasticity. The observations in the patient described here suggest that zolpidem looses alpha1-receptor selectivity at higher doses, thereby leading to the same risks and benefits such as benzodiazepines. This should be taken into account by doctors when prescribing higher doses. Zolpidem may improve symptoms of spasticity in high doses via affection of GABA alpha2-receptor and alpha3-receptor subunits.

The influence of anaesthetic medication on safety, tolerability and clinical effectiveness of electroconvulsive therapy.

BACKGROUND: Electroconvulsive therapy (ECT) is still considered the most effective biological treatment strategy in psychiatric disorders. However, the clinical efficacy of ECT may be affected by stimulus variables and the concomitant use of psychopharmacological medication. Furthermore, most anaesthetics have anticonvulsant properties and therefore might additionally influence the efficacy of ECT. METHOD: In order to explore whether different anaesthetics might alter the effectiveness or safety of ECT we retrospectively analyzed 5482 ECT treatments in 455 patients. Anaesthetics were chosen according to clinical reasons and comprised thiopental, methohexital, propofol and etomidate. RESULTS: Seizure duration was significantly affected by the anaesthetic medication with longest seizure activity during thiopental anaesthesia. In addition, postictal suppression, a further prospective parameter of ECT effectiveness, was significantly higher during propofol and thiopental anaesthesia. The clinical effectiveness was significantly better during propofol and thiopental anaesthesia. In contrast, the overall safety did not differ between the anaesthetic groups. CONCLUSION: Our study supports the hypothesis that inducting anaesthetic agents have a different impact on seizure duration, ictal and postictal electrophysiological indices and clinical efficacy of ECT. Compared to thiopental, which has been established as a standard anaesthetic during ECT, also the modern anaesthetic propofol is a suitable inducting agent.

Hypothalamic-pituitary-adrenocortical system dysregulation and new treatment strategies in depression.

According to the corticoid receptor hypothesis of depression, hyperactivity of the hypothalamic-pituitary-adrenocortical (HPA) system is one of the major pathophysiological factors for the development of depression and opens a broad range of new antidepressant treatment options that are related to direct interventions in HPA system regulation in depressed patients. These new therapy strategies include inhibition of hypothalamic corticotropin-releasing hormone (CRH) release, antagonism at CRH1 receptors, antagonism at vasopressin V1b receptors, inhibition of cortisol synthesis, antiglucocorticoid treatment with dehydroepiandrosterone and treatment with glucocorticoid receptor antagonists. Although preclinical data support the view that CRH1 receptor antagonists are useful in the treatment of depression, currently no controlled studies are available that demonstrate clinical efficacy in depressed patients. The use of the antiglucocorticoid neuroactive steroid dehydroepiandrosterone, the cortisol synthesis inhibitor metyrapone and the glucocorticoid receptor antagonist mifepristone in depression has been demonstrated in some small, double-blind, placebo-controlled studies. However, three recently completed Phase III trials failed to significantly separate mifepristone from placebo in depression. Thus, it is unclear at present to what extent new, clinically effective antidepressant therapies can be developed based on the corticoid receptor hypothesis of depression.

Changes in CCK-4 induced panic after treatment with the GABA-reuptake inhibitor tiagabine are associated with an increase in 3alpha,5alpha-tetrahydrodeoxycorticosterone concentrations.

There is evidence that gamma-amino-butyric acid type A (GABA(A))-receptor modulating neuroactive steroids play a role in the pathophysiology of panic disorder. Antidepressant treatment has been suggested to stabilize the concentrations of neuroactive steroids. In this pilot study we investigated neuroactive steroid concentrations during GABAergic treatment, which might represent an alternative anxiolytic pharmacotherapeutic strategy. Neuroactive steroid concentrations were determined in 10 healthy subjects treated with tiagabine. To evaluate the anxiolytic effects of tiagabine a cholecystokinin-tetrapeptide (CCK-4) challenge was performed before and after treatment. Treatment with tiagabine led to a significant increase in 3alpha,5alpha-tetrahydrodeoxycorticosterone (3alpha,5alpha-THDOC) from 0.49 to 1.42 nmol/l (Z=-2.80, p=.005), which was significantly correlated with a decrease of panic symptoms in the CCK-4 challenge. Thus, it might be hypothesized that the anxiolytic effects of GABAergic treatment might in part be mediated by their influence on 3alpha,5alpha-THDOC concentrations.

Translocator protein (18 kD) as target for anxiolytics without benzodiazepine-like side effects.

Most antianxiety drugs (anxiolytics) work by modulating neurotransmitters in the brain. Benzodiazepines are fast and effective anxiolytic drugs; however, their long-term use is limited by the development of tolerance and withdrawal symptoms. Ligands of the translocator protein [18 kilodaltons (kD)] may promote the synthesis of endogenous neurosteroids, which also exert anxiolytic effects in animal models. Here, we found that the translocator protein (18 kD) ligand XBD173 enhanced gamma-aminobutyric acid-mediated neurotransmission and counteracted induced panic attacks in rodents in the absence of sedation and tolerance development. XBD173 also exerted antipanic activity in humans and, in contrast to benzodiazepines, did not cause sedation or withdrawal symptoms. Thus, translocator protein (18 kD) ligands are promising candidates for fast-acting anxiolytic drugs with less severe side effects than benzodiazepines.

The combined dexamethasone/CRH Test (DEX/CRH test) and prediction of acute treatment response in major depression.

BACKGROUND: In this study the predictive value of the combined dexamethasone/CRH test (DEX/CRH test) for acute antidepressant response was investigated. METHODOLOGY/PRINCIPAL FINDINGS: In 114 depressed inpatients suffering from unipolar or bipolar depression (sample 1) the DEX/CRH test was performed at admission and shortly before discharge. During their stay in the hospital patients received different antidepressant treatment regimens. At admission, the rate of nonsuppression (basal cortisol levels >75.3 nmol/l) was 24.6% and was not related to the later therapeutic response. Moreover, 45 out of 114 (39.5%) patients showed an enhancement of HPA axis function at discharge in spite of clinical improvement. In a second sample, 40 depressed patients were treated either with reboxetine or mirtazapine for 5 weeks. The DEX/CRH test was performed before, after 1 week, and after 5 weeks of pharmacotherapy. Attenuation of HPA axis activity after 1 week was associated with a more pronounced alleviation of depressive symptoms after 5-week mirtazapine treatment, whereas downregulation of HPA system activity after 5 weeks was related to clinical response to reboxetine. However, early improvement of HPA axis dysregulation was not necessarily followed by a beneficial treatment outcome. CONCLUSIONS/SIGNIFICANCE: Taken together, performance of a single DEX/CRH test does not predict the therapeutic response. The best predictor for response seems to be an early attenuation of HPA axis activity within 1 or 2 weeks. However, early improvement of HPA system dysfunction is not a sufficient condition for a favourable response. Since a substantial part of depressive patients display a persistence of HPA axis hyperactivity at discharge, downregulation of HPA system function is not a necessary condition for acute clinical improvement either. Our data underline the importance of HPA axis dysregulation for treatment outcome in major depression, although restoration of HPA system dysfunction seems to be neither a necessary nor a sufficient determinant for acute treatment response.

Impact of loudness dependency of auditory evoked potentials on the panic response to CCK-4.

RATIONALE: Experimental panic induction with cholecystokinin-tetrapeptide (CCK-4) has been established as a model to study the pathophysiology of panic disorder. In line with the serotonin (5-HT)-hypothesis of panic disorder it has been suggested that the panicogenic effects of CCK-4 are mediated in part through the 5-HT system. The analysis of the loudness dependency of the auditory evoked potentials (LDAEP) is a valid non-invasive indicator of central serotonergic activity. METHODS: We investigated the correlation between LDAEP and behavioral, cardiovascular and neuroendocrine panic responses to CCK-4in 77 healthy volunteers and explored whether differences in LDAEP paralleled subjective panic severity. Behavioral panic responses were measured with the panic symptom scale (PSS). Heart rate and ACTH/cortisol plasma concentrations were assessed concomitantly. RESULTS: LDAEP did not differ between panickers and nonpanickers. Furthermore, LDAEP did not correlate with the behavioral panic response. However, a significant positive correlation between LDAEP and CCK-4 induced HPA-axis activation, which was uniform in panickers and nonpanickers, could be detected. CONCLUSIONS: The psychological effects of CCK-4 rather are mediated by neurotransmitters others than the endogenous 5-HT system. However, the extent of the neuroendocrine activation related to the CCK-4 panic provocation was correlated with the LDAEP, thereby suggesting that central 5-HT mechanisms are involved in the HPA-axis activation during this challenge paradigm.

Functional neuroanatomy of CCK-4-induced panic attacks in healthy volunteers.

Experimental panic induction with cholecystokinin tetrapeptide (CCK-4) is considered as a suitable model to investigate the pathophysiology of panic attacks. While only a few studies investigated the brain activation patterns following CCK-4, no data are available on the putative involvement of the amygdala in the CCK-4 elicited anxiety response. We studied the functional correlates of CCK-4-induced anxiety in healthy volunteers by means of functional magnetic resonance imaging (fMRI) and region of interest (ROI) analysis of the amygdala. Sixteen healthy volunteers underwent challenge with CCK-4 compared with placebo in a single-blind design. Functional brain activation patterns were determined for the CCK-4-challenge, the placebo response and anticipatory anxiety (AA). CCK-4-induced anxiety was accompanied by a strong and robust activation (random effects analysis, P < 0.00001, uncorrected for multiple testing) in the ventral anterior cingulate cortex (ACC), middle and superior frontal gyrus, precuneus, middle and superior temporal gyrus, occipital lobe, sublobar areas, cerebellum, and brainstem. In contrast, random effects group analysis for placebo and AA using the same level of significance generated no significant results. Using a more liberal level of significance, activations could be observed in some brain regions such as the dorsal part of the ACC during AA (random effects analysis, P < 0.005). Overall functional responses did not differ between panickers and nonpanickers. Only 5 of 11 subjects showed strong amygdala activation. However, ROI analysis pointed towards higher scores in fear items in these subjects. In conclusion, while overall brain activation patterns are not related to the subjective anxiety response to CCK-4, amygdala activation may be involved in the subjective perception of CCK-4-induced fear.

Effects of mirtazapine on dehydroepiandrosterone-sulfate and cortisol plasma concentrations in depressed patients.

BACKGROUND: Among the neuroactive steroids, dehydroepiandrosterone sulfate (DHEA-S) is at least in part produced in the adrenal gland and is therefore under the control of the hypothalamic-pituitary-adrenocortical (HPA)-system. In the present study, the impact of mirtazapine on DHEA-S and cortisol (COR) levels was investigated in relation to clinical response in depressed patients. METHODS: A total of 23 inpatients suffering from a major depressive episode (DSM-IV criteria) underwent 5-week treatment with mirtazapine (45 mg/day). Plasma samples were taken weekly at 0800 h and quantified for COR and DHEA-S levels. RESULTS: Mirtazapine significantly reduced both COR and DHEA-S concentrations, but had no impact on the COR/DHEA-S ratio. The percentage decrease of DHEA-S, but not that of COR was significantly and positively correlated with the percentage reduction in the sum score of the Hamilton Depression Rating Scale at week 5, suggesting a relationship between DHEA-S reduction and clinical efficacy of mirtazapine. There was a significant positive correlation between the decline in COR and DHEA-S levels. CONCLUSIONS: Apparently, the decrease in COR and DHEA-S concentrations conjointly reflects an attenuating impact of mirtazapine on HPA axis activity, thereby decreasing the adrenal secretion of COR and DHEA-S.