Pharmacotherapy of social anxiety disorder

Reduced Consolidation, Reinstatement, and Renewal of Conditioned Fear Memory by Repetitive Treatment of Radix Polygalae in Mice

The therapeutic goal for the treatment of posttraumatic stress disorder (PTSD) is to promote extinction and to prevent the relapse of fearful memories. Research has identified pharmacological treatments that may regulate the formation and extinction of fear memories, but not many reagents that block the relapse of extinguished fear are known. Radix Polygalae (RP) is an Asian herb used for sedation, and its ingredients have anxiolytic and antidepressant properties. As various neurological effects have been identified, we tested whether RP affects the relapse of fear. Freezing in response to a conditioned context and cues was used to measure the effects of RP in mice. In cohort 1 (n = 30), consolidation, extinction, and reinstatement were tested during the course of 18 days of treatment. In cohort 2 (n = 30), consolidation, extinction, and renewal were tested during 10 days of treatment. The consolidation, extinction, reinstatement, and possibly the renewal of context-induced freezing were inhibited due to the administration of RP in animal subjects. However, the effects of RP on the freezing responses of subjects elicited by conditioned auditory cues were less obvious. Because it effectively suppresses the consolidation of fear memories, RP may be used for primary and secondary prevention of symptoms in PTSD patients. Additionally, because it effectively suppresses the reinstatement and renewal of fear memories, RP may be applied for the prevention of fear relapse in PTSD patients who have undergone exposure therapy.

Multi-target therapeutics for neuropsychiatric and neurodegenerative disorders

Historically, neuropsychiatric and neurodegenerative disease treatments focused on the 'magic bullet' concept; however multi-targeted strategies are increasingly attractive gauging from the escalating research in this area. Because these diseases are typically co-morbid, multi-targeted drugs capable of interacting with multiple targets will expand treatment to the co-morbid disease condition. Despite their theoretical efficacy, there are significant impediments to clinical success (e.g., difficulty titrating individual aspects of the drug and inconclusive pathophysiological mechanisms). The new and revised diagnostic frameworks along with studies detailing the endophenotypic characteristics of the diseases promise to provide the foundation for the circumvention of these impediments. This review serves to evaluate the various marketed and nonmarketed multi-targeted drugs with particular emphasis on their design strategy.

5-HT(1A) [corrected] receptors in mood and anxiety: recent insights into autoreceptor versus heteroreceptor function

RATIONALE

Serotonin (5-HT) neurotransmission is intimately linked to anxiety and depression and a diverse body of evidence supports the involvement of the main inhibitory serotonergic receptor, the serotonin-1A (5-HT(1A)) subtype, in both disorders.

OBJECTIVES

In this review, we examine the function of 5-HT(1A) receptor subpopulations and re-interpret our understanding of their role in mental illness in light of new data, separating both spatial (autoreceptor versus heteroreceptor) and the temporal (developmental versus adult) roles of the endogenous 5-HT(1A) receptors, emphasizing their distinct actions in mediating anxiety and depression-like behaviors.

RESULTS

It is difficult to unambiguously distinguish the effects of different populations of the 5-HT(1A) receptors with traditional genetic animal models and pharmacological approaches. However, with the advent of novel genetic systems and subpopulation-selective pharmacological agents, direct evidence for the distinct roles of these populations in governing emotion-related behavior is emerging.

CONCLUSIONS

There is strong and growing evidence for a functional dissociation between auto- and heteroreceptor populations in mediating anxiety and depressive-like behaviors, respectively. Furthermore, while it is well established that 5-HT(1A) receptors act developmentally to establish normal anxiety-like behaviors, the developmental role of 5-HT(1A) heteroreceptors is less clear, and the specific mechanisms underlying the developmental role of each subpopulation are likely to be key elements determining mood control in adult subjects.

50 years of hurdles and hope in anxiolytic drug discovery

Anxiety disorders are the most prevalent group of psychiatric diseases, and have high personal and societal costs. The search for novel pharmacological treatments for these conditions is driven by the growing medical need to improve on the effectiveness and the side effect profile of existing drugs. A huge volume of data has been generated by anxiolytic drug discovery studies, which has led to the progression of numerous new molecules into clinical trials. However, the clinical outcome of these efforts has been disappointing, as promising results with novel agents in rodent studies have very rarely translated into effectiveness in humans. Here, we analyse the major trends from preclinical studies over the past 50 years conducted in the search for new drugs beyond those that target the prototypical anxiety-associated GABA (γ-aminobutyric acid)-benzodiazepine system, which have focused most intensively on the serotonin, neuropeptide, glutamate and endocannabinoid systems. We highlight various key issues that may have hampered progress in the field, and offer recommendations for how anxiolytic drug discovery can be more effective in the future.

Pharmacotherapy of anxiety disorders: a critical review

Given the enormous contribution of anxiety disorders to the burden of disease, it is key to optimize their prevention and treatment. In this critical review we assess advances in the pharmacotherapy of anxiety disorders, as well as remaining challenges, in recent decades, the field has seen rigorous clinical trial methods to quantify the efficacy and safety of serendipitously discovered agents, more focused development of medications with selective mechanisms of action, and the gradual translation of insights from laboratory research into proof-of-principle clinical trials. On the positive side, a considerable database of studies shows efficacy and relative tolerability of the selective serotonin reuptake inhibitors in the major anxiety disorders, and secondary analyses of such datasets have informed questions such as optimal definition of response and remission, optimal dose and duration, and comparative efficacy of different agents. Significant challenges in the field include barriers to appropriate diagnosis and treatment of anxiety disorders, failure of a significant proportion of patients to respond to first-line pharmacotherapy agents, and a limited database of efficacy or effectiveness studies to guide treatment in such cases.