Generalised anxiety disorder: treatment options

The effect of apatinib on pharmacokinetic profile of buspirone both in vivo and in vitro

OBJECTIVE

In this study, we aimed to investigate the potential interaction of apatinib and buspirone and underlying mechanism.

METHODS

UPLC-MS/MS assay was applied to determine the concentrations of buspirone and its main metabolites (1-PP and 6-OH buspirone) after incubated with liver microsomes. Moreover, the connection of in vitro and in vivo was further determined. Sprague Dawley rats were randomly divided into two groups: group A (20 mg/kg buspirone) and group B (buspirone vs 40 mg/kg apatinib). Tail vein blood was collected and subjected to the UPLC-MS/MS detection.

KEY FINDINGS

Apatinib inhibited the generations of 1-PP and 6-OH buspirone dose-dependently with IC₅₀ of 1.76 and 2.23 μm in RLMs, and 1.51 and 1.48 μm in HLMs, respectively. There was a mixed mechanism underlying such an inhibition effect. In rat, AUC_{(0- t )} , AUC_(0-∞) , T_max and C_max of buspirone and 6-OH buspirone increased significantly while co-administering with apatinib, but V_z/F and CL_z/F decreased obviously while comparing group A with group B .

CONCLUSIONS

Apatinib suppresses the CYP450 based metabolism of buspirone in a mixed mechanism and boosted the blood exposure of prototype drug and 6-OH buspirone dramatically. Therefore, extra caution should be taken when combining apatinib with buspirone in clinic.

Efficacy and safety of Shu-gan-qing-re formula for generalized anxiety disorder: study protocol for a multi-center, prospective, double-blind, double-dummy, randomized controlled trial

Background

Generalized anxiety disorder (GAD) is a persistent and common mental disorder that entails significant impairments in role functioning and quality of life. Currently available effective interventions include psychological therapies, self-help approaches, and pharmacological treatments, which do not quite meet clinical needs, and the ideal anxiolytic is still being sought. Shu-gan-qing-re (SGQR) formula, a Chinese patent medicine, has been well received by patients with GAD in Chinese clinical practice for years. The present prospective, double-blind, double-dummy, randomized controlled trial is designed to investigate the efficacy and safety of SGQR formula for GAD.

Methods/design

A total of 200 eligible participants will be recruited from four hospitals in different parts of China. They will be randomly assigned to either the study group or the control group in a ratio of 1:1. Participants allocated to the study group will receive SGQR formula and buspirone placebo, while buspirone and SGQR placebo will be applied in the control group. Six scheduled visits will be conducted over the course of 8 weeks. Outcome measurements include Hamilton Anxiety Rating Scale (HAM-A), Hamilton Depression Rating Scale-17 (HAMD-17), Clinical Global Impression-Improvement Scale (CGI-I), Traditional Chinese Medicine Syndrome Scale for GAD, and pro-inflammatory cytokine tests: interleukin-1 beta (IL-1β), IL-6, and tumor necrosis factor-alpha. Adverse reactions will be evaluated by using the Treatment Emergent Symptom Scale (TESS). Safety outcomes and adverse events will also be recorded.

Discussion

The study will provide scientific and objective assessments for the efficacy and safety of SGQR formula for patients with GAD, hopefully offering clinicians an alternative approach to GAD.

Trial registration

Chinese Clinical Trial Registry, ID: ChiCTR-IPR-17013058. Registered on October 20, 2017.

Analysis of EEG dynamics in epileptic children during carbamazepine therapy

Background: The analysis of the dynamics of background EEG characteristics on the different stages of CBZtherapy is very important for revealing the possible early predictors of benefit/adverse effects of the treatment and optimizing the anti-epileptic therapy. Objective: Evaluate the carbamazepine (CBZ) effect on the dynamics of EEG pattern in epileptic children at different stages of CBZ-monotherapy. Methods: Forty-five children (aged 3-9) with partial epilepsy were investigated. The EEG was recorded at rest and during functional tests prior to CBZ administration and three and six months after the initiation of CBZtherapy. Epileptiform graphoelements and baseline EEG activities were analyzed. Results: Following three months of CBZ-therapy an absolute power value in the low frequency bands of EEG spectrum increased while an average frequency of alpha waves decreased. During rest, CBZ reduced density of spontaneous epileptiform graphoelements and generalized epileptiform bursts. Generalized paroxysmal bursts decreased under functional tests. The EEG pattern maintained the same characteristics for six months. Deterioration of EEG pattern and clinical signs was observed in four children. Conclusion: Elevation of indices of low frequency bands, especially in occipital and parietal regions, concomitant with reduction of epileptiform elements and seizure frequency three months after initiation of therapy suggests that CBZ in appropriate doses might be continued. Otherwise, the strategy of antiepileptic therapy should be revised.

Estimating the prevalence of depression associated with healthcare use in France using administrative databases

BACKGROUND

Quantitative indicators are needed in order to define priorities, plan policies and evaluate public health interventions in mental health. The aim of this study was to assess the contribution of a large and exhaustive French national administrative database to study and monitor treated depression by comparing the prevalence and characteristics of the population using significant healthcare resources for depression as identified by different estimation methods and sources and to discuss the advantages and drawbacks of these methods.

METHODS

This study included the French population covered by the main health insurance scheme in 2012 (Régime général, 86% of the insured French population). Data were extracted from the French health insurance claim database (SNIIRAM), which contains information on all reimbursements, including treatments and hospital stays in France. The following distinct sources of the SNIIRAM were used to select persons with depression: diagnoses of long-term or costly conditions, data from national hospital claims and data concerning all national health insurance reimbursements for drugs.

RESULTS

In 2012, we included 58,753,200 individuals covered by the main health insurance scheme; 271,275 individuals had full coverage for depression; 179,470 individuals had been admitted to a psychiatric hospital and 66,595 individuals admitted to a general hospital with a diagnosis of depression during a 2-year timeframe and 144,670 individuals had more than three reimbursements for antidepressants during the study year (with a history of hospitalisation for depression during the past 5 years). Only 16% of individuals were selected by more than one source.

CONCLUSIONS

We propose an algorithm that includes persons recently hospitalised for depression, or with a history of hospitalisation for depression and still taking antidepressants, or with full coverage for depression as a specific long-term or costly condition, yielding a prevalence estimate of 0.93% or 544,105 individuals. Changes in the case selection methodology have major consequences on the frequency count and characteristics of the selected population, and consequently on the conclusions that can be drawn from the data, emphasizing the importance of defining the characteristics of the target population before the study in order to produce relevant results.

Yokukansan Increases 5-HT1A Receptors in the Prefrontal Cortex and Enhances 5-HT1A Receptor Agonist-Induced Behavioral Responses in Socially Isolated Mice

The traditional Japanese medicine yokukansan has an anxiolytic effect, which occurs after repeated administration. In this study, to investigate the underlying mechanisms, we examined the effects of repeated yokukansan administration on serotonin 1A (5-HT_1A) receptor density and affinity and its expression at both mRNA and protein levels in the prefrontal cortex (PFC) of socially isolated mice. Moreover, we examined the effects of yokukansan on a 5-HT_1A receptor-mediated behavioral response. Male mice were subjected to social isolation stress for 6 weeks and simultaneously treated with yokukansan. Thereafter, the density and affinity of 5-HT_1A receptors were analyzed by a receptor-binding assay. Levels of 5-HT_1A receptor protein and mRNA were also measured. Furthermore, (±)-8-hydroxy-2-(dipropylamino)tetralin hydrobromide (8-OH-DPAT; a 5-HT_1A receptor agonist) was injected intraperitoneally, and rearing behavior was examined. Social isolation stress alone did not affect 5-HT_1A receptor density or affinity. However, yokukansan significantly increased receptor density and decreased affinity concomitant with unchanged protein and mRNA levels. Yokukansan also enhanced the 8-OH-DPAT-induced decrease in rearing behavior. These results suggest that yokukansan increases 5-HT_1A receptors in the PFC of socially isolated mice and enhances their function, which might underlie its anxiolytic effects.

Controlled release effervescent buccal discs of buspirone hydrochloride: in vitro and in vivo evaluation studies

In the present study controlled release effervescent buccal discs of buspirone hydrochloride (BS) were designed using HPMC as rate controlling and bioadhesive polymer by direct compression method. Sodium bicarbonate and citric acid were used in varying amounts as effervescence forming agents. Carbon dioxide evolved due to reaction of sodium bicarbonate and citric acid was explored for its potential as buccal permeation enhancer. The designed buccal discs were evaluated for physical characteristics and in vitro drug release studies. Bioadhesive behavior of designed buccal discs was assessed using texture analyzer. In vivo animal studies were performed in rabbits to study bioavailability of BS in the designed buccal discs and to establish permeation enhancement ability of carbon dioxide. It was observed that effervescent buccal discs have faster drug release compared to non-effervescent buccal discs in vitro and effervescent buccal discs demonstrated significant increase in bioavailability of drug when compared to non-effervescent formulation. Hence, effervescent buccal discs can be used as an alternative to improve the drug permeation resulting in better bioavailability. However, the amount of acid and base used for generation of carbon dioxide should be selected with care as this may damage the integrity of bioadhesive dosage form.

Effect of HPMC and mannitol on drug release and bioadhesion behavior of buccal discs of buspirone hydrochloride: In-vitro and in-vivo pharmacokinetic studies

Delivery of orally compromised therapeutic drug molecules to the systemic circulation via buccal route has gained a significant interest in recent past. Bioadhesive polymers play a major role in designing such buccal dosage forms, as they help in adhesion of designed delivery system to mucosal membrane and also prolong release of drug from delivery system. In the present study, HPMC (release retarding polymer) and mannitol (diluent and pore former) were used to prepare bioadhesive and controlled release buccal discs of buspirone hydrochloride (BS) by direct compression method. Compatibility of BS with various excipients used during the study was assessed using DSC and FTIR techniques. Effect of mannitol and HPMC on drug release and bioadhesive strength was studied using a 3² factorial design. The drug release rate from delivery system decreased with increasing levels of HPMC in formulations. However, bioadhesive strength of formulations increased with increasing proportion of HPMC in buccal discs. Increased levels of mannitol resulted in faster rate of drug release and rapid in vitro uptake of water due to the formation of channels in the matrix. Pharmacokinetic studies of designed bioadhesive buccal discs in rabbits demonstrated a 10-fold increase in bioavailability in comparison with oral bioavailability of buspirone reported.

Strategies for managing symptoms of anxiety

The purpose of this article is to summarize strategies for effectively managing the symptoms of anxiety. The distinction between the cognitive, physiological and behavioral components of fear and anxiety is explained and various treatment targets are outlined. Empirically-supported strategies that are effective in alleviating common symptoms of anxiety are reviewed. These include various forms of psychosocial intervention (i.e., cognitive and behavioral therapies), pharmacotherapy, in addition combined treatment approaches. Expert consensus guidelines, prognostic factors, patient preferences and accessibility issues are discussed with regard to treatment selection in addition to emerging challenges in the field and future research directions.

The age of anxiety: role of animal models of anxiolytic action in drug discovery

Anxiety disorders are common, serious and a growing health problem worldwide. However, the causative factors, aetiology and underlying mechanisms of anxiety disorders, as for most psychiatric disorders, remain relatively poorly understood. Animal models are an important aid in giving insight into the aetiology, neurobiology and, ultimately, the therapy of human anxiety disorders. The approach, however, is challenged with a number of complexities. In particular, the heterogeneous nature of anxiety disorders in humans coupled with the associated multifaceted and descriptive diagnostic criteria, creates challenges in both animal modelling and in clinical research. In this paper, we describe some of the more widely used approaches for assessing the anxiolytic activity of known and potential therapeutic agents. These include ethological, conflict-based, hyponeophagia, vocalization-based, physiological and cognitive-based paradigms. Developments in the characterization of translational models are also summarized, as are the challenges facing researchers in their drug discovery efforts in developing new anxiolytic drugs, not least the ever-shifting clinical conceptualization of anxiety disorders. In conclusion, to date, although animal models of anxiety have relatively good validity, anxiolytic drugs with novel mechanisms have been slow to emerge. It is clear that a better alignment of the interactions between basic and clinical scientists is needed if this is to change.

Contextual conditioning in rats as an animal model for generalized anxiety disorder

Animal models of psychiatric disorders are important translational tools for exploring new treatment options and gaining more insight into the disease. Thus far, there is no systematically validated animal model for generalized anxiety disorder (GAD), a severely impairing and difficult-to-treat disease. In this review, we propose contextual conditioning (CC) as an animal model for GAD. We argue that this model has sufficient face validity (there are several symptom similarities), predictive validity (it responds to clinically effective treatments), and construct validity (the underlying mechanisms are comparable). Although the refinement and validation of an animal model is a never-ending process, we want to give a concise overview of the currently available evidence. We suggest that the CC model might be a valuable preclinical tool to enhance the development of new treatment strategies and our understanding of GAD.

Aripiprazole: a clinical review of its use for the treatment of anxiety disorders and anxiety as a comorbidity in mental illness

BACKGROUND

Although anxiety disorders are common, optimal treatment is elusive. More than half of anxiety patients treated with an adequate course of antidepressants fail to fully improve: treatment resistance, residual symptoms, and recurrence/relapse remain a challenge. Recently, atypical antipsychotics have been considered for treatment-resistant anxiety disorders. This review will explore the available data for the role of aripiprazole in the treatment of anxiety.

METHODS

PubMed and conference abstracts were searched for randomized, double-blind studies that investigated the efficacy of aripiprazole in anxiety; its efficacy in bipolar disorder and depression was also explored for comparison.

RESULTS

A number of studies have shown atypical antipsychotics to be effective in anxiety, and currently available data suggest that aripiprazole augmentation in patients with anxiety disorders is likely as effective as other atypical antipsychotic drugs. Although there have been no randomized, controlled trials, aripiprazole has been found to be effective in treating anxiety disorders in two open-label trials. This combined with the larger data base demonstrating its utility in bipolar disorder and depression, its safety profile and its unique mechanism of action, make aripiprazole for anxiety an intriguing avenue of exploration.

LIMITATIONS

Data from large randomized, controlled trials on the use of atypical antipsychotics for anxiety in general, and aripiprazole in particular, are currently lacking.

CONCLUSION

The results of open-label trials of aripiprazole in anxiety provide enough support to warrant its further study. This, combined with a larger data base demonstrating its utility in bipolar disorder and depression, its safety profile and its unique mechanism of action, make aripiprazole for anxiety an intriguing avenue of exploration.

Anxiolytic effect of music exposure on BDNFMet/Met transgenic mice

Brain-derived neurotrophic factor (BDNF) has been reported to play important roles in the modulation of anxiety, mood stabilizers, and pathophysiology of affective disorders. Recently, a single nucleotide polymorphism (SNP) in the BDNF gene (Val66Met) has been found to be associated with depression and anxiety disorders. The humanized BDNF(Met/Met) knock-in transgenic mice exhibited increased anxiety-related behaviors that were unresponsive to serotonin reuptake inhibitors, fluoxetine. Music is known to be able to elicit emotional changes, including anxiolytic effects. In this study, we found that music treatment could significantly decrease anxiety state in BDNF(Met/Met) mice, but not in BDNF(+/)(-), mice compared with white noise exposure in open field and elevated plus maze test. Moreover, in contrast to white noise exposure, BDNF expression levels in the prefrontal cortex (PFC), amygdala and hippocampus were significantly increased in music-exposed adult BDNF(Met/Met) mice. However, music treatment could not upregulate BDNF levels in the PFC, amygdala, and hippocampus in BDNF(+/)(-) mice, which suggests the essential role of BDNF in the anxiolytic effect of music. Together, our results imply that music may provide an effective therapeutic intervention for anxiety disorders in humans with this genetic BDNF(Met) variant.

Buspirone-induced changes in the serotonergic and non-serotonergic cells in the dorsal raphe nucleus of rats

Buspirone, a 5-HT (5-hydroxytryptamine, serotonin)(1A) partial agonist, is being used as an anxiolytic drug. The mechanism of action is explained by an effect on the 5-HT system. The main source of 5-HT in the forebrain is the dorsal raphe nucleus (DRN). However, there are also other populations of non-5-HT neurons in the DRN. Here, we investigated the effect of acute and chronic buspirone treatments on the 5-HT and non-5-HT cells, the neuronal nitric oxide synthase (nNOS) and tyrosine hydroxylase (TH) cells, in the DRN. Rats received either an acute or chronic administration of buspirone or saline. Hereafter, the brains were processed for 5-HT, nNOS, and TH immunohistochemistry. We found that acute and chronic buspirone treatments significantly lowered the mean optical density of nNOS in the DRN as compared to controls. Meanwhile only the chronic buspirone treatment reduced the mean density of 5-HT and TH immunoreactivity but not the acute buspirone as compared to saline treated animals. Our findings suggest that buspirone treatment affects not only the intracellular content of 5-HT but also nNOS and TH. Therefore, the cellular effect of buspirone is more complex than thought.

Acute administration of leptin produces anxiolytic-like effects: a comparison with fluoxetine

RATIONALE

Our previous studies in rats have shown that the adipocyte-derived hormone leptin induces antidepressant-like effects with a behavioral profile similar to selective serotonin reuptake inhibitor (SSRI) antidepressants. Acute SSRI treatment causes paradoxical anxiogenic responses, although chronic treatment has therapeutic effects on anxiety. However, the role of leptin in anxiety remains to be established.

OBJECTIVES

The scope of this study was to investigate the acute effects of leptin on anxiety-related behaviors in comparison with the SSRI antidepressant fluoxetine.

MATERIALS AND METHODS

Adult male C57BL/6J mice received intraperitoneal injection of leptin or fluoxetine. Thirty minutes after injection, mice were subjected to the tail suspension test (TST) and forced swim test (FST) for evaluating antidepressant activity. Anxiety-like behavior was assessed in the elevated plus maze (EPM), social interaction, and open field tests 30 min following drug treatment.

RESULTS

While leptin and fluoxetine showed similar antidepressant-like behavioral effects in the TST and FST, they differed in the behavioral assays for anxiety. Open arm exploration in the EPM was increased by leptin but decreased by fluoxetine. Analysis of social interaction revealed that distinct social behavioral components were modulated by leptin and fluoxetine. The total time of active social behaviors was increased by leptin but reduced by fluoxetine. In addition, self-grooming, a non-social behavior, was suppressed by leptin treatment. Neither leptin nor fluoxetine produced significant effects in the open field test.

CONCLUSIONS

In contrast to anxiogenic-like effects induced by acute fluoxetine, leptin elicits anxiolytic-like effects after acute administration. These results suggest that leptin has both antidepressant-like and anxiolytic-like properties.

Aripiprazole for the treatment of schizophrenia with co-occurring social anxiety: an open-label cross-taper study

OBJECTIVES

Co-occurring social anxiety in patients with schizophrenia is common and often severe. Pharmacologic agents with serotonin receptor 1A agonist properties such as aripiprazole are believed to be effective anxiolytic drugs. This open-label study tested the hypothesis that a switchover to aripiprazole would reduce the severity of social anxiety in patients, who have schizophrenia with co-occurring social anxiety, treated with neuroleptic medications.

STUDY DESIGN

Eligible consenting outpatients meeting the criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, for schizophrenia or schizoaffective disorder with co-occurring social anxiety symptoms completed baseline assessments, after which their neuroleptic medication was gradually cross-titrated over to a maximum of 30 mg of aripiprazole orally per day. Patients who completed the 2-month short-term study had the option to continue for 10 more months in the extension phase of the study. Complete baseline assessments were performed after 1, 2, 4, 6, 9, and 12 months. The study hypothesized that a switchover to aripiprazole would significantly improve social anxiety symptoms and quality of life ratings in the short term and that treatment continuation would help maintain and strengthen those effects, as assessed on the Liebowitz Social Anxiety and Sheehan Disability scales and on preselected specific global items of the Lehman Quality of Life Interview.

RESULTS

Sixteen patients were enrolled in the short-term study, and 10 of them entered the extension phase study. Last observation carried forward analysis showed significant improvements from baseline to the end of month 2 and from baseline to the end of month 12 in social anxiety scores (Liebowitz Social Anxiety Scale total, avoidance, and anxiety), social disability scores (Sheehan Disability Scale total, work, social life, and family), and in the Lehman Quality of Life Interview overall function, average life in general, and emotional well-being scores and psychosis (Positive and Negative Syndrome Scale total) scores.

CONCLUSIONS

These findings suggest that the switchover to aripiprazole effectively improved social anxiety, psychosis, and quality of life in patients with schizophrenia who were treated with neuroleptic medications. These improvements occurred within the first 8 weeks of treatment and persisted when treatment was continued for up to 1 year. Further studies are warranted to replicate these findings in controlled trials.

Differences in medication adherence and healthcare resource utilization patterns: older versus newer antidepressant agents in patients with depression and/or anxiety disorders

BACKGROUND

Given the number of antidepressants available and their rising costs, healthcare payers have initiated restrictive reimbursement policies for newer antidepressants, without consideration for differences in their effectiveness or tolerability.

OBJECTIVE

The objective of this study was to comprehensively compare medication adherence rates and associated healthcare utilization costs for patients using later-generation versus earlier-generation antidepressants in a managed care setting. Antidepressants launched after 2002 were deemed third-generation antidepressants, while antidepressants available prior to 2002 were deemed first-generation (TCAs and MAOIs) and second-generation (serotonin and noradrenaline [norepinephrine]-dopamine reuptake inhibitors).

STUDY DESIGN

Retrospective database analysis using medical and pharmacy data from over 75 managed care plans covering 55 million lives.

SETTING/PATIENTS

All patients receiving an antidepressant between 1 January 2002 and 30 September 2004 were identified. The index date for patients was the date of their first antidepressant prescription within this time period. Patients had to (i) have a diagnosis of depression or anxiety disorder, or depression and anxiety disorder within 6 months prior to or 30 days after their index prescription; (ii) be at least 18 years of age, without having taken antidepressant therapy for 6 months prior to their index date; and (iii) be continuously eligible for 6 months prior to their index date and during their 6-month follow-up period. Patients were excluded if they had a diagnosis of psychosis-related disease, Alzheimer's or Parkinson's disease, or were initiated on psychosis-related medications. INTERVENTION/MAIN OUTCOME MEASURE: Patients meeting selection criteria were followed for 6 months to assess rates of antidepressant adherence, therapy change rates and medical healthcare costs.

STUDY POPULATION

A total of 266 665 patients met the study criteria. Approximately 66% were female, with a mean age of 39 years. About 63% had a diagnosis of depression, 31% had an anxiety disorder diagnosis and 6% had diagnoses for both an anxiety disorder and depression. Therapy change: Therapy change within 6 months occurred in 18% of patients receiving third-generation agents compared with 21% and 40% for second- and first-generation agents, respectively. The odds of a therapy change were significantly lower with third-generation antidepressants compared with both older agent cohorts. Adherence: Of patients receiving third-generation antidepressants, 33.6% were adherent compared with 29.3% and 12.4% of patients receiving second- and first-generation antidepressants, respectively. Newer agents also had better adherence rates across all diagnostic cohorts. After adjusting for baseline differences, the odds of being adherent to therapy were significantly lower for those taking second- and first-generation agents versus newer antidepressants. Among the newer agents, the proportion of patients adherent to their therapy was: venlafaxine extended release 38%, paroxetine controlled release (CR) 35%, escitalopram 34%, duloxetine 32% and bupropion extended release (XL) 31%. Healthcare utilization: Of the patients taking older antidepressants, 13% (second generation) and 21% (first generation) were hospitalized at least once for any reason compared with 12% of patients taking newer agents. Overall, the odds of all-cause hospitalization within 6 months of therapy initiation were significantly higher for patients taking older antidepressants. Among the newer agents, hospitalization rates ranged from 15.9% for duloxetine to 12.5% for paroxetine CR and bupropion XL. The unadjusted 6-month total medical costs (not including pharmacy costs) per patient were $US 3514 for second-generation, $US 5744 for first-generation and $US 3284 for newer antidepressants. After controlling for baseline differences, patients receiving second- and first-generation antidepressants incurred 12% and 44% higher costs, respectively. The unadjusted 6-month medical costs for the newer agents ranged from $US 2715 for paroxetine CR to $US 6042 for duloxetine.

CONCLUSION

The results of this study provide essential information for healthcare decision makers about the potential advantages of newer generation antidepressants versus older generation antidepressants, as well as the differences between the specific newer agents, with respect to improved rates of adherence and therapy change, reduced hospitalizations and healthcare costs.

Genetic approaches to modeling anxiety in animals

Anxiety disorders are a growing health problem world-wide. However, the causative factors, etiology, and underlying mechanisms of anxiety disorders, as for most psychiatric disorders, remain relatively poorly understood. The current status of clinical research indicates that anxiety traits and anxiety disorder in man have a genetic component, and therefore genetic modeling in animals is a logical approach to gain a greater insight into their neurobiology. However, it is also clear that the nature of these genetic contributions is highly complex. Moreover, the success of this approach is largely contingent upon the utility of available behavioral paradigms for modeling anxiety-related behaviors in mice. Animal genetic models provide a unique and comprehensive methodological tool to aid discovery into the etiology, neurobiology, and ultimately, the therapy of human anxiety disorders. The approach, however, is challenged with a number of complexities. In particular, the heterogeneous nature of anxiety disorders in man coupled with the associated multifaceted and descriptive diagnostic criteria, create challenges in both animal modeling and in clinical research. In this article, we describe some of the powerful modem genetic techniques that are uniquely amenable to the laboratory mouse and thus provide a strategy for approaching some of these challenges. Moreover, we focus on recent advances which have highlighted the relative contribution of genetic modeling in animals to the understanding of underlying neurobiology and genetic basis of anxiety disorders.

In vivo characterization and dynamic receptor occupancy imaging of TPA023B, an alpha 2/alpha 3/alpha 5 subtype selective gamma-aminobutyric acid-a partial agonist

BACKGROUND

A novel, high-affinity (.7-2.0 nmol) compound that selectively activates the alpha2, alpha 3, and alpha 5 (but not alpha1) gamma-aminobutyric acid-A (GABA(A)) receptor subtypes, TPA023B (2',6-difluoro-5'-[3-(1-hydroxy-1-methylethyl) imidazo[1,2-b][1,2,4]triazin-7-yl][1,1'-biphenyl]-2-carbonitrile) was pharmacologically characterized and studied by means of positron emission tomography (PET) to determine dynamic occupancies of the benzodiazepine binding site of human brain GABA(A) receptors after a single oral dose.

METHODS

Four healthy male volunteers were studied in a double-blind, randomized placebo-controlled study of which three were given a single dose of 1.5 mg TPA023B and the fourth received placebo. The time course of GABA(A) receptor occupancy was determined with multiple dynamic [(11)C]flumazenil PET studies at pre-dose baseline and 5 and 24 hours after dose. Arterial sampling and full kinetic modeling with a two-compartment model was used to calculate parametric maps of receptor availability (distribution volume V(T)) and of occupancy.

RESULTS

The GABA(A) receptor occupancy as determined from [(11)C]flumazenil V(T) values in all brain regions was reduced homogeneously, on average by 52.5 +/- 1.2% after 5 hours and 46.4 +/- 6.0% after 24 hours. No serious adverse events were encountered in humans.

CONCLUSIONS

Single oral doses of 1.5 mg of TPA023B correspond to average receptor occupancies in neocortical regions of 52% and 46% after 5 and 24 hours, respectively. Provided suitable ligands and quantification methods are available for the appropriate target, quantitative PET offers a unique tool for dynamic in vivo measurement of relevant on-site receptor occupancy.

Buspirone induced acute and chronic changes of neural activation in the periaqueductal gray of rats

5-HT(1A) modulation within the midbrain periaqueductal gray (PAG) is closely associated with anxiety- or panic-like behavior. Several findings have demonstrated that the properties of buspirone (a 5-HT(1A) partial agonist) would function as either anxiolytic or panicolytic in both clinical and laboratory animal research. In this study, we have investigated the neuronal activity occurring within the different regions of the PAG induced by buspirone treatment. Twenty-eight albino Wistar rats (350-400 g) were injected with either acute or chronic saline/buspirone (each, n=7), respectively. Our results show that buspirone treatment reduced locomotor activity, body weight and fecal boli, particularly in the chronic buspirone group. Two-way ANOVA revealed a significant decrease of c-Fos-immunoreactive (ir) cells expression in all regions of the rostral PAG after both acute and chronic buspirone (acute buspirone (AB) and chronic buspirone (CB), respectively) treatment. However, no effects on c-Fos-ir were detected in the caudal lateral periaqueductal gray (lPAG) and ventrolateral periaqueductal gray (vlPAG) in both the AB and CB groups, and in the dorsolateral periaqueductal gray (dlPAG) of the CB group. Interestingly, c-Fos-ir cells in the dorsomedial periaqueductal gray (dmPAG) column were reduced consistently in both the rostral and caudal PAG in both AB and CB groups. Besides, in all regions the number of c-Fos-ir cells was higher in the AB than in the CB group with exception of the rostral lPAG. In conclusion, the main anxiolytic effect of buspirone was specifically localized in all regions of the rostral PAG and in the caudal dmPAG. However, the caudal dlPAG, lPAG and vlPAG were found to be ineffective to buspirone treatment, probably due to their distinctive function in mediating higher level of anxiety in defensive behavior. This indicates that the longitudinal anatomical structure of the PAG possesses a different level of receptor sensitivity of 5-HT(1A) in the pathophysiology of anxiety and panic disorder.

6-Hydroxybuspirone Is a Major Active Metabolite of Buspirone: Assessment of Pharmacokinetics and 5-Hydroxytryptamine1AReceptor Occupancy in Rats

The pharmacokinetics and in vivo potency of 6-hydroxybuspirone (6-OH-buspirone), a major metabolite of buspirone, were investigated. The plasma clearance (47.3 +/- 3.5 ml/min/kg), volume of distribution (2.6 +/- 0.3 l/kg), and half-life (1.2 +/- 0.2 h) of 6-OH-buspirone in rats were similar to those for buspirone. Bioavailability was higher for 6-OH-buspirone (19%) compared with that for buspirone (1.4%). After intravenous infusions to steady-state levels in plasma, 6-OH-buspirone and buspirone increased 5-hydroxytryptamine (HT)(1A) receptor occupancy in a concentration-dependent manner with EC(50) values of 1.0 +/- 0.3 and 0.38 +/- 0.06 microM in the dorsal raphe and 4.0 +/- 0.6 and 1.5 +/- 0.3 microM in the hippocampus, respectively. Both compounds appeared to be approximately 4-fold more potent in occupying presynaptic 5-HT(1A) receptors in the dorsal raphe than the postsynaptic receptors in the hippocampus. Oral dosing of buspirone in rats resulted in exposures (area under the concentration-time profile) of 6-OH-buspirone and 1-(2-pyrimidinyl)-piperazine (1-PP), another major metabolite of buspirone, that were approximately 12 (6-OH-buspirone)- and 49 (1-PP)-fold higher than the exposure of the parent compound. As a whole, these preclinical data suggest that 6-OH-buspirone probably contributes to the clinical efficacy of buspirone as an anxiolytic agent.

Medication use in a female orofacial pain population

OBJECTIVE

This study compared, both quantitatively and qualitatively, the self-reported medication usage between an adult female orofacial pain population and a comparison group.

STUDY DESIGN

Eighty-seven subjects from both an orofacial pain center (OPC) and undergraduate dental clinic (UDC) completed a standardized medical history questionnaire. Both groups had a similar distribution with regard to age. The number of medications and medication categories were compared between the two groups. Statistical analysis used the Student t-test, Fisher's exact tests, Pearson's chi2 tests, and calculated odds ratios.

RESULTS

The number of pain and non-pain medications, and the number of medication categories endorsed by OPC subjects was significantly higher compared with the UDC group.

CONCLUSION

Adult female orofacial pain subjects report greater overall and higher rate of medication use, which was not limited to only the analgesic/narcotic categories, than the comparison group.

The corticotropin-releasing factor receptor: a novel target for the treatment of depression and anxiety-related disorders

The treatment of mood disorders has been the subject of intense study for more than half a century and has resulted in the discovery and availability of a number of compounds that have seen tremendous success in the management of major depression and anxiety-related disorders. In spite of this success, these drugs have not provided a complete therapeutic solution for all patients and this has revitalised the need for a greater understanding of the underlying molecular mechanisms and targets involved in these disorders. Elucidation of these novel targets will enable the development of a better class of compounds which could benefit a greater majority of the patient population and be devoid of the current side effect liabilities. Towards that end, this review examines, in detail, the prospect of one such target, the corticotropin-releasing factor system, as having an enhanced therapeutic profile with the potential of a broader range of efficacy with reduced side effect liabilities.

Pregabalin: in the treatment of generalised anxiety disorder

Pregabalin, the pharmacologically active S-enantiomer of 3-aminomethyl-5-methyl-hexanoic acid, is a structural analogue of GABA, although it is not active at GABA receptors, nor does it acutely alter GABA uptake or degradation.black triangle Pregabalin binds with high affinity to the alpha2-delta subunit protein of voltage-gated calcium channels in CNS tissues and acts as a presynaptic modulator of the excessive release, in hyperexcited neurons, of various excitatory neurotransmitters. Binding of pregabalin to the alpha2-delta subunit appears necessary for its demonstrable anxiolytic, analgesic and anticonvulsant activities in animal models.black triangle Oral pregabalin, typically at dosages of 300-600 mg/day, was superior to placebo and similar to lorazepam 6 mg/day, alprazolam 1.5 mg/day and venlafaxine 75 mg/day in improving anxiety and depressive symptoms in patients with moderate-to-severe generalised anxiety disorder (GAD). Pregabalin had a rapid onset of anxiolytic activity relative to alprazolam and venlafaxine, which was evident after 1 week. Additionally, pregabalin (initial dosage 450 mg/day) was effective for the prevention of relapse of GAD over 34 weeks. Pregabalin was well tolerated during dosage escalation to fixed dosages (maximum 600 mg/day) over 7 days. Dizziness and somnolence, usually of mild to moderate severity, were the most common adverse events.black triangle The drug was not associated with a clinically significant medication withdrawal syndrome during a 1-week taper following 4 or 6 weeks' double-blind treatment.

Multi-target strategies for the improved treatment of depressive states: Conceptual foundations and neuronal substrates, drug discovery and therapeutic application

Major depression is a debilitating and recurrent disorder with a substantial lifetime risk and a high social cost. Depressed patients generally display co-morbid symptoms, and depression frequently accompanies other serious disorders. Currently available drugs display limited efficacy and a pronounced delay to onset of action, and all provoke distressing side effects. Cloning of the human genome has fuelled expectations that symptomatic treatment may soon become more rapid and effective, and that depressive states may ultimately be "prevented" or "cured". In pursuing these objectives, in particular for genome-derived, non-monoaminergic targets, "specificity" of drug actions is often emphasized. That is, priority is afforded to agents that interact exclusively with a single site hypothesized as critically involved in the pathogenesis and/or control of depression. Certain highly selective drugs may prove effective, and they remain indispensable in the experimental (and clinical) evaluation of the significance of novel mechanisms. However, by analogy to other multifactorial disorders, "multi-target" agents may be better adapted to the improved treatment of depressive states. Support for this contention is garnered from a broad palette of observations, ranging from mechanisms of action of adjunctive drug combinations and electroconvulsive therapy to "network theory" analysis of the etiology and management of depressive states. The review also outlines opportunities to be exploited, and challenges to be addressed, in the discovery and characterization of drugs recognizing multiple targets. Finally, a diversity of multi-target strategies is proposed for the more efficacious and rapid control of core and co-morbid symptoms of depression, together with improved tolerance relative to currently available agents.

METABOLISM AND DISPOSITION OF A POTENT AND SELECTIVE GABA-Aα2/3 RECEPTOR AGONIST IN HEALTHY MALE VOLUNTEERS

[14C]7-(1,1-Dimethylethyl)-6-(2-ethyl-2H-1,2,4-triazol-3-ylmethoxy)-3-(2-fluorophenyl)-1,2,4-triazolo[4,3-b]pyridazine ([14C]-TPA023; 99 microCi/dose) was administered to five young, healthy, fasted male subjects as a single oral dose (3.0 mg) in solution (propylene glycol/water, 10:90 v/v). The parent compound was rapidly absorbed (plasma Tmax approximately 2 h), exhibited an apparent terminal half-life of 6.7 h, and accounted for approximately 53% of the total radioactivity in plasma. After 7 days of collection, the mean total recovery of radioactivity in the excreta was 82.6%, with 53.2% and 29.4% in urine and feces, respectively. Radiochromatographic analysis of the excreta revealed that TPA023 was metabolized extensively, and only trace amounts of unchanged parent were recovered. Radiochromatograms of urine and feces showed that TPA023 underwent metabolism via three pathways (t-butyl hydroxylation, N-deethylation, and direct N-glucuronidation). The products of t-butyl hydroxylation and N-deethylation, together with their corresponding secondary metabolites, accounted for the majority of the radioactivity in the excreta. In addition, approximately 10.3% of the dose was recovered in urine as the triazolo-pyridazine N1-glucuronide of TPA023. The t-butyl hydroxy and N-desethyl metabolites of TPA023, the TPA023 N1-glucuronide, and the triazolo-pyridazine N1-glucuronide of N-desethyl TPA023 were present in plasma. In healthy male subjects, therefore, TPA023 is well absorbed and is metabolized extensively (t-butyl hydroxylation and N-deethylation > glucuronidation), and the metabolites are excreted in urine and feces.

Norepinephrine transporter-deficient mice respond to anxiety producing and fearful environments with bradycardia and hypotension

The study of anxiety and fear involves complex interrelationships between psychiatry and the autonomic nervous system. Altered noradrenergic signaling is linked to certain types of depression and anxiety disorders, and treatment often includes specific transporter blockade. The norepinephrine transporter is crucial in limiting catecholaminergic signaling. Norepinephrine transporter-deficient mice have increased circulating catecholamines and elevated heart rate and blood pressure. We hypothesized, therefore, that reduced norepinephrine clearance would heighten the autonomic cardiovascular response to anxiety and fear. In separate experiments, norepinephrine transporter-deficient (norepinephrine transporter-/-) mice underwent tactile startle and trace fear conditioning to measure hemodynamic responses. A dramatic tachycardia was observed in norepinephrine transporter-/- mice compared with controls following both airpuff or footshock stimuli, and pressure changes were also greater. Interestingly, in contrast to normally elevated home cage levels in norepinephrine transporter-deficient mice, prestimulus heart rate and blood pressure were actually higher in norepinephrine transporter+/+ animals throughout behavioral testing. Upon placement in the behavioral chamber, norepinephrine transporter-deficient mice demonstrated a notable bradycardia and depressor effect that was more pronounced in females. Power spectral analysis indicated an increase in low frequency oscillations of heart rate variability; in mice, suggesting increased parasympathetic tone. Finally, norepinephrine transporter-/- mice exhibited sexual dimorphism in freeze behavior, which was greatest in females. Therefore, while reduced catecholamine clearance amplifies immediate cardiovascular responses to anxiety- or fear-inducing stimuli in norepinephrine transporter-/- mice, norepinephrine transporter deficiency apparently prevents protracted hemodynamic escalation in a fearful environment. Conceivably, chronic norepinephrine transporter blockade with transporter-specific drugs might attenuate recognition of autonomic and somatic distress signals in individuals with anxiety disorders, possibly lessening their behavioral reactivity, and reducing the cardiovascular risk factors associated with persistent emotional arousal.

Efficacy of the 5-HT1A agonist, buspirone hydrochloride, in migraineurs with anxiety: a randomized, prospective, parallel group, double-blind, placebo-controlled study

OBJECTIVE

To examine the efficacy of buspirone, a 5-HT1A agonist, for migraine combined with anxiety disorder.

BACKGROUND

Modulation of the 5-hydroxytryptamine (5-HT) system is used for the neuropharmacology of migraine treatment; however, the involvement of the 5-HT1A system in migraine is not fully understood.

METHODS

Seventy-four outpatients aged 20 to 70 years (mean, 46.4; SD, 12.8) were analyzed. All subjects were diagnosed to have migraine according to the International Headache Society criteria and anxiety disorder according to DSM-IV. Subjects were randomly assigned to treatment with either buspirone (10 mg/day) or placebo for 6 weeks. Efficacy variables included changes in headache frequency, headache intensity, Hamilton Anxiety Rating Scale (HAM-A), Headache Self-Efficacy Scale (HMSE), and Headache Disability Inventory (HDI). The correlation between the headache improvement and the anxiolytic effect was analyzed.

RESULTS

Headache frequency showed a 43.3% reduction in the buspirone-treated group, but by only 10.3% in the placebo group. HAM-A and HDI were also significantly more lowered in buspirone-treated patients than in placebo-treated patients. However, headache intensity and HMSE score were unchanged. Correlation analysis of the relation between headache frequency reduction and HAM-A improvement, revealed no significant association.

CONCLUSIONS

In this study, buspirone showed a prophylactic effect in migraine with anxiety disorder, which was not secondary to its anxiolytic effect. This suggests that the agonistic action for 5-HT1A can be directly effective in migraine prophylaxis. However, more long-term study is warranted before concluding the efficacy.

The ascent of mouse: advances in modelling human depression and anxiety

Psychiatry has proven to be among the least penetrable clinical disciplines for the development of satisfactory in vivo model systems for evaluating novel treatment approaches. However, mood and anxiety disorders remain poorly understood and inadequately treated. With the explosion in the use of genetically modified mice, enormous research efforts have been focused on developing mouse models of psychiatric disorders. The success of this approach is largely contingent on the usefulness of available behavioural models of depression- and anxiety-related behaviours in mice. Here, we assess the current status of research into developing appropriate tests for assessing such behaviours.

[Patients with epilepsy and anxiety disorders. Diagnosis and treatment]

Up to 50-60% of patients with epilepsy may develop psychiatric complications, in particular depression, anxiety, and psychotic disorders. Although this comorbidity has received a great deal of attention in recent years, the anxiety spectrum of psychiatric disturbances in epilepsy patients has not been extensively studied, although this comorbidity has a significant effect on the medical management and quality of life. The etiology is multifactorial, including neurobiological and shared pathophysiological mechanisms as well as psychosocial and iatrogenic factors (e.g., influence of antiepileptic drugs, epilepsy surgery). Despite the high prevalence of comorbid anxiety in epilepsy, very little is known about optimal treatment strategies. This article reviews the complex interrelationships between anxiety disorders and epilepsy from a clinical point of view. The evaluation of anxiety relative to ictal, peri-ictal, and postictal states is described, and medical treatment options for anxiety disorders in patients with epilepsy are discussed, illustrating that their treatment extends far beyond seizure control.

The pharmacology of DMP696 and DMP904, non-peptidergic CRF1 receptor antagonists

CRF(1) antagonists DMP696 and DMP904 were designed as drug development candidates for the treatment of anxiety and depression. Both compounds display nanomolar affinity for human CRF(1) receptors, and exhibit >1000-fold selectivity for CRF(1) over CRF(2) receptors and over a broad panel of other proteins. DMP696 and DMP904 block CRF-stimulated adenylyl cyclase activity in cortical homogenates and cell-lines expressing CRF(1) receptors. Both compounds inhibit CRF-stimulated ACTH release from rat pituitary corticotropes. Binding and functional studies indicate that DMP696 and DMP904 behave as noncompetitive full antagonists. DMP696 and DMP904 exhibit anxiolytic-like efficacy in several rat anxiety models. In the defensive withdrawal test, both compounds reduce exit latency with lowest effective doses of 3 and 1 mg/kg, respectively. The anxiolytic-like effect is maintained over 14 days of repeated dosing. In the context of a novel environment used in this test, DMP696 and DMP904 reverse mild stress-induced increases in plasma CORT secretion but at doses 3-4-fold greater than those required for anxiolyticlike efficacy. DMP696 and DMP904 are ineffective in three depression models including the learned helplessness paradigm at doses up to 30 mg/kg. At lowest anxiolytic-like doses, DMP696 and DMP904 occupy >50% CRF(1) receptors in the brain. The in vivo IC(50) values (plasma concentrations required for occupying 50% CRF(1) receptors) estimated based upon free, but not total, plasma concentrations are an excellent correlation with the in vitro IC(50) values. Neither compound produces sedation, ataxia, chlordiazepoxide-like subjective effects or adverse effects on cognition at doses 10-fold higher than anxiolytic-like doses. Neither compound produces physiologically significant changes in cardiovascular, respiratory, gastrointestinal or renal functions at anxiolytic-like doses. DMP696 and DMP904 have favorable pharmacokinetic profiles with good oral bioavailabilities. The overall pharmacological properties suggest that both compounds may be effective anxiolytics with low behavioral side effect liabilities.

Psychotropic drug epidemiology: the road travelled, the road ahead

Psychotropic drug epidemiology is a discipline developed to study the use and the effects of drugs in large numbers of individuals. It describes how drugs are prescribed and utilized, investigates reasons underlying prescriptions, and monitors outcomes and variables which may affect these outcomes. In this article the main purposes, study designs and limitations of current pharmacoepidemiological approaches are reviewed with the aim of assessing whether this discipline can constitute a permanent link between the experimental world of clinical trials and the real world of everyday prescribing. We support the notion that evidence generated in clinical practice, by means of pharmacoepidemiological studies, should increasingly be used to develop and suggest innovative research hypotheses to be subsequently tested in pragmatic experimental studies.

Effects of CRF1 receptor antagonists and benzodiazepines in the Morris water maze and delayed non-matching to position tests

RATIONALE

Benzodiazepines continue to be widely used for the treatment of anxiety, but it is well known that benzodiazepines have undesirable side effects, including sedation, ataxia, cognitive deficits and the risk of addiction and abuse. CRF(1) receptor antagonists are being developed as potential novel anxiolytics, but while CRF(1) receptor antagonists seem to have a better side-effect profile than benzodiazepines with respect to sedation and ataxia, the effects of CRF(1) receptor antagonists on cognitive function have not been well characterized. It is somewhat surprising that the potential cognitive effects of CRF(1) receptor antagonists have not been more fully characterized since there is some evidence to suggest that these compounds may impair cognitive function.

OBJECTIVE

The Morris water maze and the delayed non-matching to position test are sensitive tests of a range of cognitive functions, including spatial learning, attention and short-term memory, so the objective of the present experiments was to assess the effects of benzodiazepines and CRF(1) receptor antagonists in these tests.

RESULTS

The benzodiazepines chlordiazepoxide and alprazolam disrupted performance in the Morris water maze and delayed non-matching to position at doses close to their therapeutic, anxiolytic doses. In contrast, the CRF(1) receptor antagonists DMP-904 and DMP-696 produced little or no impairment in the Morris water maze or delayed non-matching to position test even at doses 10-fold higher than were necessary to produce anxiolytic effects.

CONCLUSIONS

The results of the present experiments suggest that, with respect to their effects on cognitive functions, CRF(1) receptor antagonists seem to have a wider therapeutic index than benzodiazepines.

CYTOCHROME P450 3A-MEDIATED METABOLISM OF BUSPIRONE IN HUMAN LIVER MICROSOMES

This study was carried out to determine the metabolic pathways of buspirone and cytochrome P450 (P450) isoform(s) responsible for buspirone metabolism in human liver microsomes (HLMs). Buspirone mainly underwent N-dealkylation to 1-pyrimidinylpiperazine (1-PP), N-oxidation on the piperazine ring to buspirone N-oxide (Bu N-oxide), and hydroxylation to 3'-hydroxybuspirone (3'-OH-Bu), 5-hydroxybuspirone (5-OH-Bu), and 6'-hydroxybuspirone (6'-OH-Bu) in HLMs. The apparent K(m) values for buspirone metabolite formation in pooled HLMs were 8.7 (1-PP), 34.0 (Bu N-oxide), 4.3 (3'-OH-Bu), 11.4/514 (5-OH-Bu), and 8.8 microM (6'-OH-Bu). CYP3A inhibitor ketoconazole (1 microM) completely inhibited the formation of all major metabolites in HLMs (0-16% of control), whereas the chemical inhibitor selective to other P450 isoforms had little or no inhibitory effect. Recombinant CYP3A4, CYP3A5, and CYP2D6 exhibited buspirone oxidation activities among nine P450 isoforms tested. The overall metabolism rate of 5 microM buspirone by CYP3A4 was 18-fold greater than that by CYP2D6 and 35-fold greater than that by CYP3A5. In a panel of HLMs from 16 donors, buspirone metabolism correlated well CYP3A activity (r2 = 0.85-0.96, rho < 0.0005), but not the activities of other P450 isoforms. The metabolism rates of buspirone in CYP2D6 poor-metabolizer genotype HLMs were comparable to those in pooled HLMs. Taken together, these data suggest that CYP3A, mostly likely CYP3A4, is primarily responsible for the metabolism of buspirone in HLMs.

Aripiprazole as an augmentor of selective serotonin reuptake inhibitors in depression and anxiety disorder patients

More than half of anxiety and depression patients treated with an adequate course of antidepressants fail to fully improve. We retrospectively examined whether treatment-resistant depression and anxiety disorder patients responded to and tolerated augmentation with the atypical antipsychotic, aripiprazole. We report on patients with depression and anxiety disorders, including panic disorder, generalized anxiety disorder, social anxiety and post-traumatic stress disorder, who had an incomplete response to a variety of selective serotonin reuptake inhibitors (SSRIs) and who received augmentation with aripiprazole. The primary outcome measure was the Clinical Global Impression of Improvement (CGI-I). In the intent-to-treat analysis, the mean+/-SD CGI-S was 3.8+/-1.3 at endpoint. Fifty-nine percent of subjects received CGI-I ratings of 1 or 2, 'much improved' or 'very much improved,' in terms of their depression and anxiety symptoms at the end of 12 weeks. Several patients showed an early (weeks 1-5), as well as sustained, response to augmentation with doses of aripiprazole between 15 and 30 mg/day. The results suggest that aripiprazole may be effective as an augmentation for patients with persistent depressive and anxiety disorders despite initial SSRI treatment. Because this is a retrospective case review, further prospective studies are required to confirm these findings.

Stressor controllability and learned helplessness: The roles of the dorsal raphe nucleus, serotonin, and corticotropin-releasing factor

The term 'learned helplessness' refers to a constellation of behavioral changes that follow exposure to stressors that are not controllable by means of behavioral responses, but that fail to occur if the stressor is controllable. This paper discusses the nature of learned helplessness, as well as the role of the dorsal raphe nucleus, serotonin, and corticotropin-releasing hormone in mediating the behavioral effects of uncontrollable stressors. Recent research indicates that (a) uncontrollable stressors sensitize serotonergic neurons in the dorsal raphe, and that a corticotropin-releasing factor-related ligand, acting at the Type II receptor, is essential to this sensitization process, and (b) the consequent exaggerated release of serotonin in response to subsequent input is at least in part responsible for the behavioral changes that occur. Finally, implications for the general role of corticotropin-releasing hormone in stress-related phenomena and for the learned helplessness paradigm as an animal model of either depression or anxiety are discussed.

Are we going to increase the use of antidepressants up to that of benzodiazepines?

OBJECTIVE

The present study compared recent trends in benzodiazepine and antidepressant consumption in Italy and projected their global sales in the future. We investigated whether the increasing use of antidepressants is associated with a progressive reduction in benzodiazepine use.

METHODS

Data concerning actual quantities of benzodiazepines and antidepressants dispensed in Italy from 1995 to June 2003 were obtained from IMS Health. For each agent, the number of defined daily doses (DDDs) per 1000 inhabitants per day and the annual expenditure in Euros was calculated.

RESULTS

During the 9-year period, benzodiazepine consumption remained substantially stable, accounting for 50 DDDs/1000 per day in 2003. In the same period, antidepressant consumption dramatically rose, from 9 DDDs/1000 per day in 1995 to 26 DDDs/1000 per day in 2003, an increase of nearly three times. While the use of tricyclic antidepressants declined by one-third and that of other older agents remained substantially stable, the use of selective serotonin-reuptake inhibitors and newer agents (venlafaxine, mirtazapine, reboxetine) increased by 623%. Global consumption of antidepressants was projected to increase still further, and, in 2007, the total sales of antidepressants were projected to be similar to the total sales of benzodiazepines. The value of benzodiazepine sales increased from 322 million to 565 million Euros, an increase of 43%; similarly, the value of antidepressant sales increased from 186 million to 569 million Euros, an increase of 67%.

CONCLUSIONS

In Italy, the consumption of benzodiazepines was not affected by the increased prescribing of selective serotonin-reuptake inhibitors and newer antidepressants.

Autoradiographic distribution of serotonin transporters and receptor subtypes in human brain

Several neurochemical in vitro and in vivo imaging studies have been aimed at characterizing the localization of serotonin receptors and transporters in the human brain. In this study, a detailed comparison of the distribution of a number of 5-HT receptor subtypes and the 5-HT transporter was carried out in vitro using human postmortem brain tissue. Anatomically adjacent whole hemisphere sections were incubated with specific radioligands for the 5-HT(1A), 5-HT(1B), 5-HT(2A), 5-HT(4) receptors and the 5-HT transporter. The autoradiograms revealed different laminar and regional distribution patterns in the isocortex, where 5-HT(1A) and 5-HT(4) receptor binding showed highest densities in superficial layers and 5-HT(2A) receptor binding was most abundant in middle layers. In cortical regions, 5-HT transporters were concentrated to several limbic lobe structures (posterior uncus, entorhinal, cingulate, insular and temporal polar regions). 5-HT(1A) receptor densities were also high in limbic cortical regions (hippocampus, posterior entorhinal cortex, and subcallosal area) compared to the isocortex. Subregionally different distribution patterns were observed in the basal ganglia with a trend toward higher levels in ventral striatal (5-HT(1B) receptors) and pallidal (5-HT transporters and 5-HT(1B) receptors) regions. The localization in regions belonging to limbic cortico-striato-pallido-thalamic circuits is in line with the documented role of 5-HT in modulation of mood and emotion, and the suggested involvement of this system in pathophysiology of various psychiatric disorders. The qualitative and quantitative information reported in this study might provide important complements to in vivo neuroimaging studies of the 5-HT system.

The effect of social factors on the anxiolytic efficacy of buspirone in male rats, male mice, and men

Earlier findings suggest that housing conditions in laboratory animals and life events in humans influence the efficacy of anxiolytic drugs. Here we report on the impact of social isolation on buspirone efficacy in male mice and rats as assessed by the elevated plus-maze. In addition, the impact of social support on buspirone efficacy was assessed in male patients. When administered 30 min before testing and irrespective of housing conditions, buspirone significantly suppressed locomotor activity both in mice (6 mg/kg) and rats (10 mg/kg) and, as such, other behavioral changes observed at this time point must be seen as behaviorally nonselective. However, these locomotor disruptive effects of buspirone were not evident in either species at longer injection-test intervals (2 and 4 h). When given 2 h prior to testing, a low (3 mg/kg) but not high (10 mg/kg) dose of buspirone increased the frequency of open arm exploration in rats (but not mice) irrespective of housing conditions. At the longest injection-test interval used (4 h), buspirone increased the duration of open arm exploration in individually housed, but not group-housed, rats. Similar, though somewhat less robust, effects were observed in male mice at this time. In a double-blind placebo-controlled study with male patients, chronic buspirone treatment (3 x 10 mg daily for 6 weeks) produced a highly significant reduction in scores on the Hamilton Rating Scale for Anxiety (HAM-A). Multiple regression analysis of social support received by patients indicated that the support of nonrelatives (but not of family or other relatives) was a strong positive predictor of buspirone efficacy. Taken together, our data support the hypothesis that social conditions affect the anxiolytic efficacy of buspirone. Results are discussed in relation to differences in the social organization of the three species investigated.

The safety of SSRIs in generalised anxiety disorder: any reason to be anxious?

Generalised anxiety disorder (GAD) significantly impacts upon quality of life and has a chronic and persistent nature. GAD requires pharmacological therapies that are well-tolerated, lessen the mitigating effects of common comorbidities and do not pose a high risk for dependency or abuse. Selective serotonin and serotonin-noradrenaline re-uptake inhibitors have become more viable treatments for GAD than the traditionally used benzodiazepines due to greater efficacy and a more tolerable adverse event profile. Among these newer-generation antidepressants, only paroxetine and venlafaxine are currently FDA-approved for the treatment of GAD. Paroxetine was approved after three double-blind, placebo-controlled studies demonstrated its superior efficacy compared to placebo for short-term treatment of GAD. Venlafaxine was approved for both short- and long-term treatment of GAD after demonstrating efficacy in 8-week and 6-month double-blind, placebo-controlled trials. For both paroxetine and venlafaxine, the safety and tolerability profiles during treatment of GAD are consistent with those demonstrated during the short- and long-term treatment of patients with major depressive disorder.

Venlafaxine: A 2003 update

BACKGROUND

venlafaxine has been available for use as an antidepressant in the United States for a decade.

OBJECTIVE

Comprehensive reviews of venlafaxine have been published elsewhere; thus, this update focuses on newer issues of treatment remission in depression, treatment-resistant depression, and extended-release venlafaxine for generalized anxiety disorder (GAD).

METHODS

Relevant clinical literature from 1993 through 2003 was identified from database searches of MEDLINE and International Pharmaceutical Abstracts, and from manual searches of reference lists of the identified papers. Search terms included venlafaxine extended-release, venlafaxine XR, treatment-resistant depression, depressive disorders, anxiety disorders, generalized anxiety disorder, and antidepressive agents second generation.

RESULTS

With its dual action of serotonin and noradrenergic reuptake inhibition, venlafaxine has been shown to be superior in efficacy to selective serotonin reuptake inhibitors for severe major depressive disorder, treatment-resistant depression, and depressive symptom remission. Its demonstrated efficacy for both short- and long-term treatment of GAD has led to its use for obsessive-compulsive disorder and chronic pain syndromes, although inadequate clinical literature currently exists to support these latter 2 uses. In the past decade, no new or unexpected adverse events have been identified with venlafaxine therapy, except a possibly greater risk of fatal overdose compared with other serotonergic drugs, suggesting the need for caution in patients with suicidal ideation. Because venlafaxine is a potent serotonin agonist, caution must also be exercised to prevent the possibility of serotonin syndrome when used with other serotonin agonists, and its dose should be tapered very gradually to minimize the risk of a serotonin withdrawal reaction.

CONCLUSION

Venlafaxine has emerged as a successful post-SSRI-era antidepressant with an expanded range of uses since it was first marketed.

The neurobiology and control of anxious states

Fear is an adaptive component of the acute "stress" response to potentially-dangerous (external and internal) stimuli which threaten to perturb homeostasis. However, when disproportional in intensity, chronic and/or irreversible, or not associated with any genuine risk, it may be symptomatic of a debilitating anxious state: for example, social phobia, panic attacks or generalized anxiety disorder. In view of the importance of guaranteeing an appropriate emotional response to aversive events, it is not surprising that a diversity of mechanisms are involved in the induction and inhibition of anxious states. Apart from conventional neurotransmitters, such as monoamines, gamma-amino-butyric acid (GABA) and glutamate, many other modulators have been implicated, including: adenosine, cannabinoids, numerous neuropeptides, hormones, neurotrophins, cytokines and several cellular mediators. Accordingly, though benzodiazepines (which reinforce transmission at GABA(A) receptors), serotonin (5-HT)(1A) receptor agonists and 5-HT reuptake inhibitors are currently the principle drugs employed in the management of anxiety disorders, there is considerable scope for the development of alternative therapies. In addition to cellular, anatomical and neurochemical strategies, behavioral models are indispensable for the characterization of anxious states and their modulation. Amongst diverse paradigms, conflict procedures--in which subjects experience opposing impulses of desire and fear--are of especial conceptual and therapeutic pertinence. For example, in the Vogel Conflict Test (VCT), the ability of drugs to release punishment-suppressed drinking behavior is evaluated. In reviewing the neurobiology of anxious states, the present article focuses in particular upon: the multifarious and complex roles of individual modulators, often as a function of the specific receptor type and neuronal substrate involved in their actions; novel targets for the management of anxiety disorders; the influence of neurotransmitters and other agents upon performance in the VCT; data acquired from complementary pharmacological and genetic strategies and, finally, several open questions likely to orientate future experimental- and clinical-research. In view of the recent proliferation of mechanisms implicated in the pathogenesis, modulation and, potentially, treatment of anxiety disorders, this is an opportune moment to survey their functional and pathophysiological significance, and to assess their influence upon performance in the VCT and other models of potential anxiolytic properties.

Is there a rationale for prescription of benzodiazepines in the elderly? Review of the literature

Benzodiazepines (BZDs) constitute the most widely used symptomatic treatment of insomnia and anxiety. Many of these drugs are associated with adverse effects, such as daytime sedation and dependence with continued use. There is a concern about the rationale for and extent of benzodiazepine (BZD) use in the elderly. The sedation due to BZD use is a main risk factor for falls and other accidents. Impaired cognitive function with continuous use appears to be a major side effect. There is a general awareness that BZD use is inappropriate in many patients, and therefore discontinuation should be recommended whenever possible. Moreover, long-term use of these drugs should be actively discouraged. Although no unanimous recommendations concerning the optimal duration of the withdrawal process exist, BZDs may easily be withdrawn during a short period in most patients who are habituated to a low dose, if an initial phase with dose reduction and psychological support are provided. Alternative approaches involve sleep hygiene guidelines, behavioural treatment and psychotherapy tailored to the needs of the individual patient.

Treating depression comorbid with anxiety--results of an open, practice-oriented study with St John's wort WS 5572 and valerian extract in high doses

Depressive disorders in comorbidity with anxiety disorders represent an frequently diagnostic and therapeutic problem. The studies quoted here prove that the symptoms associated with anxiety that severely afflict patients can be clearly improved more quickly with a combination therapy of St John's wort extract and valerian extract than with St John's wort monotherapy. The combination therapy was well tolerated, no significant side-effects occurred. Further studies are necessary to compare the combination treatment with other forms of therapy (serotonin- and noradrenalin re-uptake inhibitors).