Enhancement of Psychosocial Treatment With D-Cycloserine: Models, Moderators, and Future Directions

Molecular mechanisms underlying sex and treatment-dependent differences in an animal model of cue-exposure therapy for cocaine relapse prevention

Environmental enrichment combined with the glycine transporter-1 inhibitor Org24598 (EE+ORG) during cocaine-cue extinction (EXT) inhibited reacquisition of 1.0 mg/kg cocaine self-administration in male but not female rats in a previous investigation. In this investigation, we determined if this treatment benefit in males required EXT training and ascertained the molecular basis for the observed sex difference in treatment efficacy. Nine groups of male rats trained to self-administer 1.0 mg/kg cocaine or receiving yoked-saline underwent EXT or NoEXT with or without EE and/or ORG. Next, they underwent reacquisition of cocaine self-administration or were sacrificed for molecular analysis of 9 protein targets indicative of neuroplasticity in four brain regions. Two groups of female rats trained to self-administer 1.0 mg/kg cocaine also underwent EXT with or without EE + ORG and were sacrificed for molecular analysis, as above. EE + ORG facilitated the rate of EXT learning in both sexes, and importantly, the therapeutic benefit of EE + ORG for inhibiting cocaine relapse required EXT training. Males were more sensitive than females to neuroplasticity-inducing effects of EE + ORG, which prevented reductions in total GluA1 and PSD95 proteins selectively in basolateral amygdala of male rats trained to self-administer cocaine and receiving EXT. Females were deficient in expression of multiple protein targets, especially after EE + ORG. These included total GluA1 and PSD95 proteins in basolateral amygdala, and total TrkB protein in basolateral amygdala, dorsal hippocampus, and ventromedial prefrontal cortex. Together, these results support the clinical view that sex-specific pharmacological and behavioral treatment approaches may be needed during cue exposure therapy to inhibit cocaine relapse.

Using pre-treatment de novo threat conditioning outcomes to predict treatment response to DCS augmentation of exposure-based CBT

BACKGROUND

Over a decade and a half of research has resulted in inconsistent evidence for the efficacy of d-cycloserine (DCS), a partial glutamatergic N-methyl-D-aspartate agonist, for augmenting exposure-based cognitive behavioral therapy (CBT) for anxiety- and fear-based disorders. These variable findings have motivated the search for moderators of DCS augmentation efficacy.

METHODS

In this secondary analysis of a previous randomized clinical trial, we evaluated the value of de novo threat conditioning outcomes-degree of threat acquisition, extinction, and extinction retention-for predicting treatment response to exposure-based CBT for social anxiety disorder, applied with and without DCS augmentation in a sample of 59 outpatients.

RESULTS

We found that average differential skin conductance response (SCR) during extinction and extinction retention significantly moderated the prediction of clinical response to DCS: participants with poorer extinction and extinction retention showed relatively improved treatment response with DCS. No such effects were found for expectancy ratings, consistent with accounts of DCS selectively aiding lower-order but not higher-order extinction learning.

CONCLUSIONS

These findings provide support for extinction and extinction retention outcomes from threat conditioning as potential pre-treatment biomarkers for DCS augmentation benefits. Independent of DCS augmentation, the current study did not support threat conditioning outcomes as useful for predicting response to exposure-based CBT.

Acceptability of cognitive remediation for schizophrenia: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Acceptability is an important factor for predicting intervention use and potential treatment outcomes in psychosocial interventions. Cognitive remediation (CR) improves cognition and functioning in people with a diagnosis of schizophrenia, but its acceptability, and the impact of participants and treatment characteristics, remain to be investigated. Few studies provide a direct measure of acceptability, but treatment drop-out rates are often available and represent a valid surrogate.

METHOD

The systematic search conducted for the most comprehensive CR outcomes database for schizophrenia was updated in December 2020. Eligible studies were randomized clinical trials comparing CR with any other control condition in patients diagnosed with schizophrenia spectrum disorders and that also reported drop-out in treatment and control arms separately. Acceptability was measured as odd-ratios (OR) of drop-out.

RESULTS

Of 2119 identified reports, 151 studies, reporting 169 comparisons between CR and control interventions with 10 477 participants were included in the analyses. The overall rate of drop-out was 16.58% for CR programs and 15.21% for control conditions. In the meta-analysis, no difference emerged between CR interventions and controls [OR 1.10, 95% confidence interval (CI) 0.96-1.25, p = 0.177]. Factors improving acceptability were: inpatient only recruitment, participants with fewer years of education and lower premorbid IQ, the presence of all CR core elements, and the presence of techniques to transfer cognitive gains into real-world functioning.

CONCLUSIONS

CR for people diagnosed with schizophrenia is effective and has a good acceptability profile, similar to that of other evidence-based psychosocial interventions.

A Case for Translation From the Clinic to the Laboratory

Laboratory procedures have been used for decades as analogues for clinical processes with the goal of improving our understanding of psychological treatments for emotional disorders and identifying strategies to make treatments more effective. This research has often focused on translation from the laboratory to the clinic. Although this approach has notable successes, it has not been seamless. There are many examples of strategies that work in the laboratory that fail to lead to improved outcomes when applied clinically. One possible reason for this gap between experimental and clinical research is a failure to focus on translation from the clinic to the laboratory. Here, we discuss potential benefits of translation from the clinic to the laboratory and provide examples of how this might be implemented. We first consider two well-established laboratory analogues (extinction and cognitive reappraisal), identify critical aspects of the related clinical procedures (exposure and cognitive restructuring) that are missing from these analogues, and propose variations to better capture the clinical process. Second, we discuss two clinical procedures that have more recently been brought into the laboratory (eye-movement desensitization and reprocessing and imagery rescripting). We conclude by highlighting potential implications of this proposed shift in focus for translational research.

Structure, Function, and Pharmacology of Glutamate Receptor Ion Channels

Many physiologic effects of l-glutamate, the major excitatory neurotransmitter in the mammalian central nervous system, are mediated via signaling by ionotropic glutamate receptors (iGluRs). These ligand-gated ion channels are critical to brain function and are centrally implicated in numerous psychiatric and neurologic disorders. There are different classes of iGluRs with a variety of receptor subtypes in each class that play distinct roles in neuronal functions. The diversity in iGluR subtypes, with their unique functional properties and physiologic roles, has motivated a large number of studies. Our understanding of receptor subtypes has advanced considerably since the first iGluR subunit gene was cloned in 1989, and the research focus has expanded to encompass facets of biology that have been recently discovered and to exploit experimental paradigms made possible by technological advances. Here, we review insights from more than 3 decades of iGluR studies with an emphasis on the progress that has occurred in the past decade. We cover structure, function, pharmacology, roles in neurophysiology, and therapeutic implications for all classes of receptors assembled from the subunits encoded by the 18 ionotropic glutamate receptor genes. SIGNIFICANCE STATEMENT: Glutamate receptors play important roles in virtually all aspects of brain function and are either involved in mediating some clinical features of neurological disease or represent a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of this class of receptors will advance our understanding of many aspects of brain function at molecular, cellular, and system levels and provide new opportunities to treat patients.

GluN2D NMDA Receptors Gate Fear Extinction Learning and Interneuron Plasticity

The cerebellum is critically involved in the formation of associative fear memory and in subsequent extinction learning. Fear conditioning is associated with a long-term potentiation at both excitatory and inhibitory synapses onto Purkinje cells. We therefore tested whether fear conditioning unmasks novel forms of synaptic plasticity, which enable subsequent extinction learning to reset cerebellar circuitry. We found that fear learning enhanced GABA release from molecular layer interneurons and this was reversed after fear extinction learning. Importantly an extinction-like stimulation of parallel fibers after fear learning is sufficient to induce a lasting decrease in inhibitory transmission (I-LTD_stim) in the cerebellar cortex, a form of plasticity that is absent in naïve animals. While NMDA (N-methyl-D-aspartate) receptors are required for the formation and extinction of associative memory, the role of GluN2D, one of the four major NMDA receptor subunits, in learning and memory has not been determined. We found that fear conditioning elevates spontaneous GABA release in GluN2D KO as shown in WT mice. Deletion of GluN2D, however, abolished the I-LTD_stim induced by parallel fiber stimulation after learning. At the behavioral level, genetic deletion of GluN2D subunits did not affect associative learning and memory retention, but impaired subsequent fear extinction learning. D-cycloserine, a partial NMDA receptor (NMDAR) agonist, failed to rescue extinction learning in mutant mice. Our results identify GluN2D as a critical NMDAR subunit for extinction learning and reveal a form of GluN2D-dependent metaplasticity that is associated with extinction in the cerebellum.

Is glutamate associated with fear extinction and cognitive behavior therapy outcome in OCD? A pilot study

Cognitive behavioral therapy (CBT) including exposure and response prevention is a well-established treatment for obsessive-compulsive disorder (OCD) and is based on the principles of fear extinction. Fear extinction is linked to structural and functional variability in the ventromedial prefrontal cortex (vmPFC) and has been consistently associated with glutamate neurotransmission. The relationship between vmPFC glutamate and fear extinction and its effects on CBT outcome have not yet been explored in adults with OCD. We assessed glutamate levels in the vmPFC using 3T magnetic resonance spectroscopy, and fear extinction (learning and recall) using skin conductance responses during a 2-day experimental paradigm in OCD patients (n = 17) and in healthy controls (HC; n = 13). Obsessive-compulsive patients (n = 12) then received manualized CBT. Glutamate in the vmPFC was negatively associated with fear extinction recall and positively associated with CBT outcome (with higher glutamate levels predicting a better outcome) in OCD patients. Glutamate levels in the vmPFC in OCD patients were not significantly different from those in HC, and were not associated with OCD severity. Our results suggest that glutamate in the vmPFC is associated with fear extinction recall and CBT outcome in adult OCD patients.

Sex differences in the effects of a combined behavioral and pharmacological treatment strategy for cocaine relapse prevention in an animal model of cue exposure therapy

Brief interventions of environmental enrichment (EE) or the glycine transporter-1 inhibitor Org24598 administered with cocaine-cue extinction training were shown previously to inhibit reacquisition of cocaine self-administration in male rats trained to self-administer a moderate 0.3 mg/kg dose of cocaine. Determining how EE and Org24598 synergize in combination in an animal model of cue exposure therapy is novel. Important changes made in this investigation were increasing the cocaine training dose to 1.0 mg/kg and determining sex differences. Adult male and female rats self-administering 1.0 mg/kg cocaine for 35-40 daily sessions exhibited an addiction-like phenotype under a second-order schedule of cocaine delivery and cue presentation. Rats next underwent 6 weekly extinction training sessions for which treatments consisted of EE or NoEE and Vehicle or Org24598 (3.0 mg/kg in males; 3.0 or 7.5 mg/kg in females). Rats then were tested for reacquisition of cocaine self-administration for 15 daily sessions. In males, the combined EE +3.0 mg/kg Org24598 treatment facilitated extinction learning and inhibited reacquisition of cocaine self-administration to a greater extent than no treatment and to individual EE or 3.0 mg/kg Org24598 treatments. In females, EE +7.5 mg/kg Org24598 facilitated extinction learning, but did not inhibit reacquisition of cocaine self-administration. Thus, there were sex differences in the ability of EE + Org24598 administered in conjunction with extinction training to inhibit cocaine relapse in rats exhibiting an addiction-like phenotype. These findings suggest that this multimodal treatment approach might be a feasible option during cue exposure therapy in cocaine-dependent men, but not women.

(Neuro)therapeutic Approaches in the Field of Alcohol Use Disorders

Purpose of Review

Alcohol use disorder (AUD) is a burdening chronic condition that is characterized by high relapse rates despite severe negative consequences. There has been a recent emergence of interest in (neuro)therapeutic intervention strategies that largely involve the detrimental change in mechanisms linked to addiction disorders. Most prominently, the latter include habitual decision-making, cue-induced behavioral tendencies, as well as the amplifying effects of stressful events on drinking behavior. This article discusses these learning mechanisms and modification thereof as possible targets of (neuro)therapeutic interventions for AUD.

Recent Findings

Psychological therapies that target dysregulated neurocognitive processes underlying addictive behavior may hold promise as effective treatments for AUD.

Summary

Despite the progression in psychological and neuroscience research in the field of AUD, many behavioral interventions fail to systematically integrate and apply such findings into treatment development. Future research should focus on the targeted modification of the aforementioned processes.

D-cycloserine as adjunct to brief computerised CBT for spider fear: Effects on fear, behaviour, and cognitive biases

BACKGROUND AND OBJECTIVES

In anxiety disorders, cognitive behavioural therapy (CBT) improves information-processing biases such as implicit fear evaluations and avoidance tendencies, which predicts treatment response. Thus, these cognitive biases might constitute important treatment targets. This study investigated (i) whether information-processing biases could be changed following single-session computerised CBT for spider fear, and (ii) whether this effect could be augmented by administration of D-cycloserine (DCS).

METHODS

Spider-fearful individuals were randomized to receiving either 250 mg of DCS (n = 21) or placebo (n = 17). Three hours after drug administration, they received single-session computerized CBT, characterized by psychoeducation and exposure elements. Spider fear was assessed using self-report, behavioural, and information processing (Extrinsic Affective Simon Task & Approach Avoidance Task) measures at baseline (before drug administration), post-treatment, 1-day, and 1-month follow-up.

RESULTS

Linear mixed-effects analyses indicated significant improvements on self-report and behavioural spider fear indices following CBT, but not on cognitive bias measures. There was no evidence of an augmentation effect of DCS on any outcome. Cognitive bias measures at 1-day were not predictive of 1-month follow-up spider fear in adjusted linear regression analyses.

LIMITATIONS

Results might be biased by limited representativeness of the sample (high education and intelligence, largely Caucasian ethnicity, young age). The study was also only powered for detection of medium-sized DCS effects.

CONCLUSIONS

These findings do not provide evidence for information-processing biases relating to treatment outcome following computerised CBT for spider fear or augmentation with DCS.

D-Serine as the gatekeeper of NMDA receptor activity: implications for the pharmacologic management of anxiety disorders

Fear, anxiety, and trauma-related disorders, including post-traumatic stress disorder (PTSD), are quite common and debilitating, with an estimated lifetime prevalence of ~28% in Western populations. They are associated with excessive fear reactions, often including an inability to extinguish learned fear, increased avoidance behavior, as well as altered cognition and mood. There is an extensive literature demonstrating the importance of N-methyl-D-aspartate receptor (NMDAR) function in regulating these behaviors. NMDARs require the binding of a co-agonist, D-serine or glycine, at the glycine modulatory site (GMS) to function. D-serine is now garnering attention as the primary NMDAR co-agonist in limbic brain regions implicated in neuropsychiatric disorders. L-serine is synthesized by astrocytes, which is then transported to neurons for conversion to D-serine by serine racemase (SR), a model we term the 'serine shuttle.' The neuronally-released D-serine is what regulates NMDAR activity. Our review discusses how the systems that regulate the synaptic availability of D-serine, a critical gatekeeper of NMDAR-dependent activation, could be targeted to improve the pharmacologic management of anxiety-related disorders where the desired outcomes are the facilitation of fear extinction, as well as mood and cognitive enhancement.

Dose Timing of D-Cycloserine to Augment Exposure Therapy for Social Anxiety Disorder: A Randomized Clinical Trial

IMPORTANCE

Findings suggest that the efficacy of D-cycloserine (DCS) for enhancing exposure therapy may be strongest when administered after sessions marked by low fear at the conclusion of exposure practice. These findings have prompted investigation of DCS dosing tailored to results of exposure sessions.

OBJECTIVE

To compare tailored postsession DCS administration with presession DCS administration, postsession DCS administration, and placebo augmentation of exposure therapy for social anxiety disorder.

DESIGN, SETTING, AND PARTICIPANTS

This double-blind randomized clinical trial involved adults with social anxiety disorder enrolled at 3 US university centers. Symptom severity was assessed at baseline, weekly during treatment, and at 1-week and 3-month follow-up. Data analysis was performed from September 2019 to March 2020.

INTERVENTIONS

Participants completed a 5-session treatment and received pills commensurate with their condition assignment at sessions 2 through 5, which emphasized exposure practice.

MAIN OUTCOMES AND MEASURES

Symptom severity was evaluated by the Liebowitz Social Anxiety Scale and Social Phobic Disorders-Severity Form as administered by independent evaluators.

RESULTS

A total of 152 participants were enrolled (mean [SD] age, 29.24 [10.16] years; 84 men [55.26%]). Compared with placebo, presession and postsession conditions showed greater symptom improvement (b = -0.25; 95% CI, -0.37 to -0.13; P < .001; d = 1.07; and b = -0.20; 95% CI, -0.32 to -0.07; P = .002; d = 0.85) and lower symptom severity (b = -0.51; 95% CI, -0.81 to -0.21; P < .001; d = 0.76; and b = -0.49; 95% CI, -0.80 to -0.18; P = .002; d = 0.72) at 3-month follow-up. No differences were found between presession and postsession conditions. The tailored condition showed no advantage over placebo. Compared with the tailored condition, presession and postsession conditions evidenced greater decreases (b = -0.22; 95% CI, -0.34 to -0.10; P < .001; d = 0.94; and b = -0.17, 95% CI, -0.29 to -0.04; P = .008; d = 0.72) and lower symptom severity (b = -0.44, 95% CI, -0.73 to -0.14; P = .004; d = 0.64; and b = -0.41, 95% CI, -0.72 to -0.11; P = .008; d = 0.61) at 3-month follow-up.

CONCLUSIONS AND RELEVANCE

Administration of DCS enhanced exposure therapy for social anxiety disorder when given before or after the exposure session. However, the study failed to achieve the aim to develop a tailored clinical application.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02066792.

Steroid hormone secretion after stimulation of mineralocorticoid and NMDA receptors and cardiovascular risk in patients with depression

Major depressive disorder (MDD) is associated with altered mineralocorticoid receptor (MR) and glucocorticoid receptor function, and disturbed glutamatergic signaling. Both systems are closely intertwined and likely contribute not only to the pathophysiology of MDD, but also to the increased cardiovascular risk in MDD patients. Less is known about other steroid hormones, such as aldosterone and DHEA-S, and how they affect the glutamatergic system and cardiovascular disease risk in MDD. We examined salivary cortisol, aldosterone, and DHEA-S secretion after stimulation of MR and glutamatergic NMDA receptors in 116 unmedicated depressed patients, and 116 age- and sex-matched healthy controls. Patients (mean age = 34.7 years, SD = ±13.3; 78% women) and controls were randomized to four conditions: (a) control condition (placebo), (b) MR stimulation (0.4 mg fludrocortisone), (c) NMDA stimulation (250 mg D-cycloserine (DCS)), and (d) combined MR/NMDA stimulation (fludrocortisone + DCS). We additionally determined the cardiovascular risk profile in both groups. DCS had no effect on steroid hormone secretion, while cortisol secretion decreased in both fludrocortisone conditions across groups. Independent of condition, MDD patients showed (1) increased cortisol, increased aldosterone, and decreased DHEA-S concentrations, and (2) increased glucose levels and decreased high-density lipoprotein cholesterol levels compared with controls. Depressed patients show profound alterations in several steroid hormone systems that are associated both with MDD pathophysiology and increased cardiovascular risk. Prospective studies should examine whether modulating steroid hormone levels might reduce psychopathology and cardiovascular risk in depressed patients.

Facilitative effects of environmental enrichment for cocaine relapse prevention are dependent on extinction training context and involve increased TrkB signaling in dorsal hippocampus and ventromedial prefrontal cortex

Cocaine-cue extinction training combined with brief interventions of environmental enrichment (EE) was shown previously to facilitate extinction and attenuate reacquisition of cocaine self-administration in rats. It is unknown whether or not the usefulness of this approach would be undermined if extinction training took place in a novel rather than familiar context. Drawing on previous studies involving pharmacological interventions, we hypothesized that the facilitative effects of EE for cocaine relapse prevention would be independent of the context used for extinction training. Rats trained to self-administer cocaine underwent cocaine-cue extinction training in either the familiar self-administration context or a novel context, with or without EE. Rats then were tested for reacquisition of cocaine self-administration in the familiar context. Target brain regions were lysed and probed for memory-related changes in receptors for glutamate and BDNF by western blotting. Contrary to our hypothesis, the facilitative effects of EE for cocaine relapse prevention were dependent on the context used for extinction training. While EE facilitated extinction regardless of context used, it inhibited cocaine relapse only after extinction training in the familiar context. EE was associated with increased GluA2 in nucleus accumbens, TrkB in dorsal hippocampus and activated TrkB in ventromedial prefrontal cortex. Of these, the changes in dorsal hippocampus and ventromedial prefrontal cortex mirrored outcomes of the cocaine relapse tests in that these changes were specific to rats receiving EE plus extinction training in the familiar context. These findings support a role for hippocampal-prefrontal BDNF-TrkB signaling in extinction-based relapse prevention strategies involving EE.

Enhancing panic and smoking reduction treatment with D-Cycloserine: A pilot randomized clinical trial

In this placebo-controlled randomized clinical trial, we examined the efficacy of 250 mg d-cycloserine (DCS) for enhancing the effects of cognitive behavior therapy targeting anxiety sensitivity reduction in the context of smoking cessation treatment among adults with a history of panic attacks. We hypothesized that DCS would enhance treatment of our mechanistic targets-anxiety sensitivity and panic and related symptoms-and result in greater smoking abstinence. A total of 53 smokers were randomized to a 7-week integrated treatment and received study medication (DCS or placebo) prior to sessions 3-5; these sessions emphasized interoceptive exposure practice. Nicotine replacement therapy was initiated at session 5 (quit date). We found that DCS augmentation led to greater reductions of one (anxiety sensitivity) of two of our mechanistic targets at early but not late assessments, and that engaging that target predicted better smoking outcomes. However, there was no evidence of group (DCS vs. placebo) differences in smoking cessation success at treatment endpoint or follow-up evaluations. Hence, although we found that DCS can enhance treatment targeting a smoking maintaining factor, additional strategies appear to be needed to significantly affect smoking outcomes.

The Efficacy of Modafinil as a Cognitive Enhancer: A Systematic Review and Meta-Analysis

BACKGROUND

Animal models and human studies have identified the potential of modafinil as a cognitive enhancing agent, independent of its effects on promoting wakefulness in sleep-deprived samples. Given that single-dose applications of other putative memory enhancers (eg, D-cycloserine, yohimbine, and methylene blue) have shown success in enhancing clinical outcomes for anxiety-related disorders, we conducted a meta-analytic review examining the potential for single-dose effects for modafinil on cognitive functioning in non-sleep-deprived adults.

METHODS

A total of 19 placebo-controlled trials that examined the effects of single-dose modafinil versus placebo on the cognitive domains of attention, executive functioning, memory, or processing speed were identified, allowing for the calculation of 67 cognitive domain-specific effect sizes.

RESULTS

The overall positive effect of modafinil over placebo across all cognitive domains was small and significant (g = 0.10; 95% confidence interval, 0.05-0.15; P < 0.001). No significant differences between cognitive domains were found. Likewise, no significant moderation was found for modafinil dose (100 mg vs 200 mg) or for the populations studied (psychiatric vs nonpsychiatric).

CONCLUSIONS

In conclusion, the available evidence indicates only limited potential for modafinil to act as a cognitive enhancer outside sleep-deprived populations.

Comparative Pro-cognitive and Neurochemical Profiles of Glycine Modulatory Site Agonists and Glycine Reuptake Inhibitors in the Rat: Potential Relevance to Cognitive Dysfunction and Its Management

Frontocortical NMDA receptors are pivotal in regulating cognition and mood, are hypofunctional in schizophrenia, and may contribute to autistic spectrum disorders. Despite extensive interest in agents potentiating activity at the co-agonist glycine modulatory site, few comparative functional studies exist. This study systematically compared the actions of the glycine reuptake inhibitors, sarcosine (40–200 mg/kg) and ORG24598 (0.63–5 mg/kg), the agonists, glycine (40–800 mg/kg), and D-serine (10–160 mg/kg) and the partial agonists, S18841 (2.5 mg/kg s.c.) and D-cycloserine (2.5–40 mg/kg) that all dose-dependently prevented scopolamine disruption of social recognition in adult rats. Over similar dose ranges, they also prevented a delay-induced impairment of novel object recognition (NOR). Glycine reuptake inhibitors specifically elevated glycine but not D-serine levels in rat prefrontal cortical (PFC) microdialysates, while glycine and D-serine markedly increased levels of glycine and D-serine, respectively. D-Cycloserine slightly elevated D-serine levels. Conversely, S18841 exerted no influence on glycine, D-serine, other amino acids, monamines, or acetylcholine. Reversal of NOR deficits by systemic S18841 was prevented by the NMDA receptor antagonist, CPP (20 mg/kg), and the glycine modulatory site antagonist, L701,324 (10 mg/kg). S18841 blocked deficits in NOR following microinjection into the PFC (2.5–10 μg/side) but not the striatum. Finally, in rats socially isolated from weaning (a neurodevelopmental model of schizophrenia), S18841 (2.5 and 10 mg/kg s.c.) reversed impairment of NOR and contextual fear-motivated learning without altering isolation-induced hyperactivity. In conclusion, despite contrasting neurochemical profiles, partial glycine site agonists and glycine reuptake inhibitors exhibit comparable pro-cognitive effects in rats of potential relevance to treatment of schizophrenia and other brain disorders where cognitive performance is impaired.

Effect of d-cycloserine on fear extinction training in adults with social anxiety disorder

Preclinical and clinical data have shown that D-cycloserine (DCS), a partial agonist at the N-methyl-d-aspartate receptor complex, augments the retention of fear extinction in animals and the therapeutic learning from exposure therapy in humans. However, studies with non-clinical human samples in de novo fear conditioning paradigms have demonstrated minimal to no benefit of DCS. The aim of this study was to evaluate the effects of DCS on the retention of extinction learning following de novo fear conditioning in a clinical sample. Eighty-one patients with social anxiety disorder were recruited and underwent a previously validated de novo fear conditioning and extinction paradigm over the course of three days. Of those, only 43 (53%) provided analyzable data. During conditioning on Day 1, participants viewed images of differently colored lamps, two of which were followed by with electric shock (CS+) and a third which was not (CS-). On Day 2, participants were randomly assigned to receive either 50 mg DCS or placebo, administered in a double-blind manner 1 hour prior to extinction training with a single CS+ in a distinct context. Day 3 consisted of tests of extinction recall and renewal. The primary outcome was skin conductance response to conditioned stimuli, and shock expectancy ratings were examined as a secondary outcome. Results showed greater skin conductance and expectancy ratings in response to the CS+ compared to CS- at the end of conditioning. As expected, this difference was no longer present at the end of extinction training, but returned at early recall and renewal phases on Day 3, showing evidence of return of fear. In contrast to hypotheses, DCS had no moderating influence on skin conductance response or expectancy of shock during recall or renewal phases. We did not find evidence of an effect of DCS on the retention of extinction learning in humans in this fear conditioning and extinction paradigm.

Novel pharmacological targets in drug development for the treatment of anxiety and anxiety-related disorders

Current medication for anxiety disorders is suboptimal in terms of efficiency and tolerability, highlighting the need for improved drug treatments. In this review an overview of drugs being studied in different phases of clinical trials for their potential in the treatment of fear-, anxiety- and trauma-related disorders is presented. One strategy followed in drug development is refining and improving compounds interacting with existing anxiolytic drug targets, such as serotonergic and prototypical GABAergic benzodiazepines. A more innovative approach involves the search for compounds with novel mechanisms of anxiolytic action using the growing knowledge base concerning the relevant neurocircuitries and neurobiological mechanisms underlying pathological fear and anxiety. The target systems evaluated in clinical trials include glutamate, endocannabinoid and neuropeptide systems, as well as ion channels and targets derived from phytochemicals. Examples of promising novel candidates currently in clinical development for generalised anxiety disorder, social anxiety disorder, panic disorder, obsessive compulsive disorder or post-traumatic stress disorder include ketamine, riluzole, xenon with one common pharmacological action of modulation of glutamatergic neurotransmission, as well as the neurosteroid aloradine. Finally, compounds such as D-cycloserine, MDMA, L-DOPA and cannabinoids have shown efficacy in enhancing fear-extinction learning in humans. They are thus investigated in clinical trials as an augmentative strategy for speeding up and enhancing the long-term effectiveness of exposure-based psychotherapy, which could render chronic anxiolytic drug treatment dispensable for many patients. These efforts are indicative of a rekindled interest and renewed optimism in the anxiety drug discovery field, after decades of relative stagnation.

Diagnosis and Management of Anxiety Disorders

PURPOSE OF REVIEW

This article provides a synopsis of the current understanding of the pathophysiology of anxiety disorders, the biological and environmental risk factors that contribute to their development and maintenance, a review of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria, and a practical approach to the treatment of anxiety disorders in adults.

RECENT FINDINGS

Despite the ubiquity of anxiety, the evidence is that most individuals with an anxiety disorder are not identified and do not receive guideline-level care. In part, this may be because of the manifold clinical presentations of anxiety disorders and clinicians' lack of confidence in accurately diagnosing and treating these conditions, especially in nonpsychiatric settings. Anxiety disorders represent the complex interplay between biological, psychological, temperamental, and environmental factors. Converging lines of evidence point to dysfunction in regulating activity in the "threat circuit" in the brain as a putative common pathophysiology underlying anxiety disorders. Evidence-based treatments for anxiety disorders, such as cognitive-behavioral therapy and antidepressant medications, have been shown to regulate activity in this circuit, which consists of reciprocal connections between the dorsomedial prefrontal cortex, insula, and amygdala.

SUMMARY

Anxiety disorders are the most common class of emotional disorders and a leading cause of disability worldwide. A variety of effective treatment strategies are available, which may exert their therapeutic benefits from top-down or bottom-up modulation of the dysfunctional brain activity associated with anxiety disorders.

L-DOPA improves extinction memory retrieval after successful fear extinction

RATIONALE

A promising strategy to prevent a return of fear after exposure-based therapy in anxiety disorders is to pharmacologically enhance the extinction memory consolidation presumed to occur after exposure. Accumulating evidence suggests that the effect of a number of pharmacological consolidation enhancers depends on a successful fear reduction during exposure. Here, we employed the dopamine precursor L-DOPA to clarify whether its documented potential to enhance extinction memory consolidation is dependent on successful fear extinction.

METHODS

In two double-blind, randomized and placebo-controlled experiments (experiment 1: N = 79, experiment 2: N = 32) comprising fear conditioning (day 1), extinction followed by administration of 150 mg L-DOPA or placebo (day 2) and a memory test (day 3) in healthy male adults, conditioned responses were assessed as differential skin conductance responses. We tested whether the effect of L-DOPA on conditioned responses at test depended on conditioned responses at the end of extinction in an experiment with a short (10 trials, experiment 1) and long (25 trials, experiment 2) extinction session.

RESULTS

In both experiments, the effect of L-DOPA was dependent on conditioned responses at the end of extinction. That is, post-extinction L-DOPA compared to placebo administration reduced conditioned responses at test only in participants showing a complete reduction of conditioned fear at the end of extinction.

CONCLUSION

The results support the potential use of L-DOPA as a pharmacological adjunct to exposure treatment, but point towards a common boundary condition for pharmacological consolidation enhancers: a successful reduction of fear in the exposure session.

Fibroblast growth factor-2 enhancement of extinction recall depends on the success of within-session extinction training in rats: a re-analysis

RATIONALE

One approach to improving exposure therapy for anxiety disorders has focused on developing pharmacological adjuncts to enhance extinction, but these efforts have produced modest success in clinical trials. Understanding the factors that predict the efficacy of adjuncts will help to develop personalized treatments for anxiety.

OBJECTIVES

We assessed whether individual differences in within-session extinction (fear reduction during extinction training) predict the extent to which the neurotrophin fibroblast growth factor-2 (FGF2) enhances extinction recall in rats.

METHODS

We re-analyzed data from five experiments that involved administering FGF2 immediately after extinction training; extinction recall was assessed the following day.

RESULTS

Regression analyses revealed that fear responses at the end, but not the start, of extinction training predicted extinction recall in FGF2- but not vehicle-treated rats. Comparisons between FGF2- and vehicle-treated rats that exhibited better or worse extinction recall (determined by a median split in freezing during extinction recall) confirmed that FGF2-treated rats exhibiting better extinction recall had significantly lower freezing at the end of extinction training relative to FGF2-treated rats exhibiting poorer extinction recall. In contrast, vehicle-treated rats did not differ in within-session extinction based on their performance at extinction recall. Finally, even when classified as having poorer extinction recall, FGF2-treated rats had stronger extinction recall than vehicle-treated rats.

CONCLUSIONS

These results suggest that FGF2 may be most effective amongst rats that exhibit the lowest fear responses at the end of extinction training. Furthermore, FGF2 does not appear to exacerbate fear in rats that exhibit minimal fear reduction during extinction training.

N-Methyl D-aspartate receptor subunit signaling in fear extinction

N-Methyl D-aspartate receptors (NMDAR) are central mediators of glutamate actions underlying learning and memory processes including those required for extinction of fear and fear-related behaviors. Consistent with this view, in animal models, antagonists of NMDAR typically impair fear extinction, whereas partial agonists have facilitating effects. Promoting NMDAR function has thus been recognized as a promising strategy towards reduction of fear symptoms in patients suffering from anxiety disorders and post-traumatic disorder (PTSD). Nevertheless, application of these drugs in clinical trials has proved of limited utility. Here we summarize recent advances in our knowledge of NMDAR pharmacology relevant for fear extinction, focusing on molecular, cellular, and circuit aspects of NMDAR function as they relate to fear extinction at the level of behavior and cognition. We also discuss how these advances from animal models might help to understand and overcome the limitations of existing approaches in human anxiety disorders and how novel, more specific, and personalized approaches might help advance future therapeutic strategies.

Effects of post-exposure naps on exposure therapy for social anxiety

Exposure therapy for social anxiety disorder (SAD) utilizes fear extinction, a memory process enhanced by sleep. We investigated whether naps following exposure sessions might improve symptoms and biomarkers in response to social stress in adults undergoing 5-week exposure-based group SAD therapy. Thirty-two participants aged 18-39 (18 females) with SAD were randomized. Before and after treatment, participants completed the Liebowitz Social Anxiety Scale (LSAS) and underwent a Trier Social Stress Test with psychophysiological monitoring (mpTSST) that included skin conductance (SCL), electromyographic (EMG) and electrocardiographic recording, and an auditory startle procedure while anticipating the social stressor. At sessions 3 and 4, exposure was followed by either a 120-min polysomnographically monitored sleep opportunity (Nap, N = 17) or wakefulness (Wake, N = 15). Primary hypotheses about SAD symptom change (LSAS) and EMG blink-startle response failed to differ with naps, despite significant symptom improvement (LSAS) with therapy. Some secondary biomarkers, however, provided preliminary support for enhanced extinction learning with naps, with trend-level Time (pre-, post-treatment) × Arm interactions and significant reduction from pre- to post treatment in the Nap arm alone for mpTSST SCL and salivary cortisol rise. Because of the small sample size and limited sleep duration, additional well-powered studies with more robust sleep interventions are indicated.

D-Cycloserine augmentation of cognitive behavior therapy for pediatric OCD: Predictors and moderators of outcome

BACKGROUND

Over half of children receiving cognitive behavioral therapy (CBT) for obsessive compulsive disorder (OCD) do not fully remit. To improve response rates and enhance extinction learning, d-cycloserine (DCS) has been examined as an augmenting agent of CBT. To direct children with OCD towards treatments with the highest likelihood of success, the current study evaluated the conditions under which DCS augmentation works best (i.e., moderators) and the baseline characteristics associated with outcome, irrespective of treatment type (i.e., predictors).

METHODS

Data came from a two-site randomized controlled trial (N = 142) in which children received either DCS + CBT (n = 70) or placebo + CBT.

RESULTS

No baseline variables moderated the effects of DCS augmentation on CBT outcome. However, several predictor variables were associated with a decreased likelihood of achieving remission status, including higher family accommodation scores, higher impairment scores, higher depression scores, and higher externalizing scores. Furthermore, better insight at pre-treatment was associated with more improvement longitudinally on a clinician-rated summary measure of illness severity.

LIMITATIONS

The current study did not examine all variables that had previously been shown to moderate or predict treatment outcome (e.g., family history of OCD or cognitive profile).

CONCLUSIONS

The absence of significant moderators suggests that baseline factors cannot yet be used to determine who benefits most from DCS. To maximize treatment benefits for children presenting with identified predictors of worse treatment outcome, clinicians might need to adapt existing CBT protocols and administer additional interventions that address patients' specific problem areas.

A placebo-controlled randomized trial of D-cycloserine augmentation of cue exposure therapy for smoking cessation

Recent studies underscore the importance of studying d-cycloserine (DCS) augmentation under conditions of adequate cue exposure treatment (CET) and protection from reconditioning experiences. In this randomized trial, we evaluated the efficacy of DCS for augmenting CET for smoking cessation under these conditions. Sixty-two smokers attained at least 18 hours abstinence following 4 weeks of smoking cessation treatment and were randomly assigned to receive a single dose of DCS (n=30) or placebo (n=32) prior to each of two sessions of CET. Mechanistic outcomes were self-reported cravings and physiologic reactivity to smoking cues. The primary clinical outcome was 6-week, biochemically-verified, continuous tobacco abstinence. DCS, relative to placebo, augmentation of CET resulted in lower self-reported craving to smoking pictorial and in vivo cues (d = 0.8 to 1.21) in a relevant subsample of participants who were reactive to cues and free from smoking-related reconditioning experiences. Select craving outcomes were correlated with smoking abstinence, and DCS augmentation was associated with a trend toward a higher continuous abstinence rate (33% vs. 13% for placebo augmentation). DCS augmentation of CET can significantly reduce cue-induced craving, supporting the therapeutic potential of DCS augmentation when applied under appropriate conditions for adequate extinction learning.

In session extinction and outcome in Virtual Reality Exposure Therapy for PTSD

Recent research emphasizes emotional engagement and between-session extinction, but no longer within-session extinction, as the primary mechanisms underlying exposure therapy for the treatment of PTSD. No previous studies have examined change in subjective units of distress (SUDS) in virtual reality exposure (VRE) for PTSD despite its potential facilitation of engagement (see McLay et al., 2012; Reger & Gahm, 2008). Using in session data from Rothbaum et al. (2014) we examined patterns of within- and between-session SUDS change in veterans receiving VRE for PTSD augmented by d-cycloserine, alprazolam, or placebo. The number of treatment sessions significantly predicted SUDS rating (t = -7.74, p < 0.001). Time in session continued to serve as a significant predictor of SUDS (t = 13.44, p < 0.001). Specifically, engagement increased within session and then reduction (extinction/habituation) was apparent across sessions. Treatment group was a predictor of SUDS rating within treatment sessions (t = 2.26, p < 0.05) but not across sessions, such that participants receiving medication experienced greater increases in SUDS within-session than those receiving placebo. Responder status was a predictor of SUDS reduction across treatment sessions (t = -4.43, p < 0.001) but did not produce an overall or within-session effect on SUDS. Thus, medications impact within-session SUDS changes but do not impact between-session reductions in SUDS- the change most consistently and closely related to magnitude of therapeutic change and responder status.

Investigating d-cycloserine as a potential pharmacological enhancer of an emotional bias learning procedure

The partial N-methyl-D-aspartate receptor agonist d-cycloserine may enhance psychological therapies. However, its exact mechanism of action is still being investigated. Cognitive bias modification techniques allow isolation of cognitive processes and thus investigation of how they may be affected by d-cycloserine. We used a cognitive bias modification paradigm targeting appraisals of a stressful event, Cognitive Bias Modification-Appraisal, to investigate whether d-cycloserine enhanced the modification of appraisal, and whether it caused greater reduction in indices of psychopathology. Participants received either 250 mg of d-cycloserine ( n=19) or placebo ( n=19). As a stressor task, participants recalled a negative life event, followed by positive Cognitive Bias Modification-Appraisal training. Before and after Cognitive Bias Modification-Appraisal, appraisals and indices of psychopathology related to the stressor were assessed. Cognitive Bias Modification-Appraisal successfully modified appraisals, but d-cycloserine did not affect appraisals post-training. There were no post-training group differences in frequency of intrusions. Interestingly, d-cycloserine led to a greater reduction in distress and impact on state mood from recalling the event, and lower distress post-training was associated with fewer intrusions. Therefore, d-cycloserine may affect emotional reactivity to recalling a negative event when combined with induction of a positive appraisal style, but via a mechanism other than enhanced learning of the appraisal style.

Memory creation and modification: Enhancing the treatment of psychological disorders

Modification of the ongoing influence of maladaptive cognitive, emotional, and behavioral patterns is a fundamental feature of many psychological treatments. Accordingly, a clear understanding of the nature of memory adaptation and accommodation to therapeutic learning becomes an important issue for (1) understanding the impact of clinical interventions, and (2) considering innovations in treatment strategies. In this article, we consider advances in the conceptualization of memory processes and memory modification research relative to clinical treatment. We review basic research on the formation of memories, the way in which new learning is integrated within memory structures, and strategies to influence the nature and degree to which new learning is integrated. We then discuss cognitive/behavioral and pharmacological strategies for influencing memory formation in relation to disorder prevention or treatment. Our goal is to foster awareness of current strategies for enhancing therapeutic learning and to encourage research on potential new avenues for memory enhancement in service of the treatment of mental health disorders. (PsycINFO Database Record

Identification of AICP as a GluN2C-Selective N-Methyl-d-Aspartate Receptor Superagonist at the GluN1 Glycine Site

N-methyl-d-aspartate (NMDA)-type ionotropic glutamate receptors mediate excitatory neurotransmission in the central nervous system and are critically involved in brain function. NMDA receptors are also implicated in psychiatric and neurological disorders and have received considerable attention as therapeutic targets. In this regard, administration of d-cycloserine (DCS), which is a glycine site NMDA receptor agonist, can enhance extinction of conditioned fear responses. The intriguing behavioral effects of DCS have been linked to its unique pharmacological profile among NMDA receptor subtypes (GluN1/2A-D), in which DCS is a superagonist at GluN2C-containing receptors compared with glycine and a partial agonist at GluN2B-containing receptors. Here, we identify (R)-2-amino-3-(4-(2-ethylphenyl)-1H-indole-2-carboxamido)propanoic acid (AICP) as a glycine site agonist with unique GluN2-dependent differences in agonist efficacy at recombinant NMDA receptor subtypes. AICP is a full agonist at GluN1/2A (100% response compared with glycine), a partial agonist at GluN1/2B and GluN1/2D (10% and 27%, respectively), and a highly efficacious superagonist at GluN1/2C receptors (353%). Furthermore, AICP potencies are enhanced compared with DCS with EC₅₀ values in the low nanomolar range (1.7 nM at GluN1/2C). We show that GluN1/2C superagonism of AICP and DCS is mediated by overlapping but distinct mechanisms and that AICP selectively enhances responses from recombinant GluN1/2C receptors in the presence of physiological glycine concentrations. This functional selectivity of AICP for GluN2C-containing NMDA receptors is more pronounced compared with DCS, suggesting that AICP can be a useful tool compound for uncovering the roles of GluN2C subunits in neuronal circuit function and in the development of new therapeutic strategies.

Aripiprazole Facilitates Extinction of Conditioned Fear in Adolescent Rats

Anxiety disorders are the most common type of mental disorder during adolescence, which is at least partly due to the resistance to extinction exhibited at this age. The dopaminergic system is known to be dysregulated during adolescence; therefore, we aimed to facilitate extinction in adolescent rats using the dopamine receptor 2 partial agonist aripiprazole (Abilify™), and examine the behavioral and neural outcomes. Adolescent rats were conditioned to fear a tone. The next day, rats received extinction 30 min after a systemic injection of either 5 mg/kg aripiprazole or vehicle, and then were tested the following day. For the immunohistochemistry experiment, naïve and "no extinction" conditions were added and rats were perfused either on the extinction day or test day. To assess the activation of neurons receiving dopaminergic input, c-Fos, and dopamine- and cAMP-regulated neuronal phosphoprotein (DARPP-32) labeled neurons were quantified in the amygdala and the medial prefrontal cortex (mPFC). Systemic treatment with aripiprazole at the time of extinction significantly reduced freezing at test the next day. This effect was not observed in rats that were fear conditioned but did not receive any extinction. Aripiprazole's facilitation of extinction was accompanied by increased activation of neurons in the mPFC. Taken together, aripiprazole represents a novel pharmacological adjunct to exposure therapy worthy of further examination. The effect of aripiprazole is related to enhanced activation of mPFC neurons receiving dopaminergic innervation.

Morbid Anxiety: Identification and Treatment

Due to their prevalence, chronicity, and poorly understood pathophysiology, anxiety disorders remain an important public health problem. Despite clear diagnostic guidelines and the availability of excellent evidence-based treatments, most anxiety patients remain underrecognized and inadequately treated. This clinical synthesis highlights changes to anxiety disorder diagnosis that became effective with DSM-5. The article also provides some clinical perspective on clarifying differential diagnostic problems and building an alliance with the anxious patient. The quality and strength of the evidence base for current anxiolytic medications options (selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, benzodiazepines, and other agents), antianxiety psychotherapies (cognitive-behavioral therapy and brief dynamic therapies), and combination treatments are discussed. A brief update on newer treatment strategies, such as cognitive enhancement, complementary therapies, and neuromodulation, is included. Future directions for anxiety nosology and treatment are summarized, including the National Institute of Mental Health Research Domain Criteria initiative and the promising role of personalized medicine.

Pharmacological Augmentation of Psychosocial and Remediation Training Efforts in Schizophrenia

Pharmacological approaches to cognitive enhancement have received considerable attention but have not had considerable success in improving their cognitive and functional targets. Other intervention strategies, such as cognitive remediation therapy (CRT), have been shown to enhance cognitive performance but have not been found to improve functional outcomes without additional psychosocial interventions. Recently, several studies have attempted to enhance the effects of CRT by adding pharmacological interventions to the CRT treatments. In addition, as CRT has been shown to synergistically improve the effects of psychosocial interventions, the combination of pharmacological therapies aimed at cognition and psychosocial interventions may itself provide a promising strategy for improving functional outcomes. This review and commentary examines the current state of interventions combining CRT and psychosocial treatments with pharmacological augmentation. Our focus is on the specific level of effect of the pharmacological intervention, which could be enhancing motivation, training efficiency, or the consolidation of therapeutic gains. Different pharmacological strategies (e.g., stimulants, plasticity-inducing agents, or attentional or alertness enhancers) may have the potential to lead to different types of gains when combined with CRT or psychosocial interventions. The relative potential of these different mechanisms for immediate and durable effects is considered.

Extinction learning in childhood anxiety disorders, obsessive compulsive disorder and post-traumatic stress disorder: implications for treatment

INTRODUCTION

Threat conditioning and extinction play an important role in anxiety disorders, obsessive compulsive disorder (OCD), and post-traumatic stress disorder (PTSD). Although these conditions commonly affect children, threat conditioning and extinction have been primarily studied in adults. However, differences in phenomenology and neural architecture prohibit the generalization of adult findings to youth.

AREAS COVERED

A comprehensive literature search using PubMed and PsycInfo was conducted to identify studies that have used differential conditioning tasks to examine threat acquisition and extinction in youth. The information obtained from this review helps to clarify the influence of these processes on the etiology and treatment of youth with OCD, PTSD and other anxiety disorders. Thirty studies of threat conditioning and extinction were identified Expert commentary: Youth with anxiety disorders, OCD, and PTSD have largely comparable threat acquisition relative to unaffected controls, with some distinctions noted for youth with PTSD or youth who have suffered maltreatment. However, impaired extinction was consistently observed across youth with these disorders and appears to be consistent with deficiencies in inhibitory learning. Incorporating strategies to improve inhibitory learning may improve extinction learning within extinction-based treatments like cognitive behavioral therapy (CBT). Strategies to improve inhibitory learning in CBT are discussed.

RANDOMIZED TRIAL OF D-CYCLOSERINE ENHANCEMENT OF COGNITIVE-BEHAVIORAL THERAPY FOR PANIC DISORDER

BACKGROUND

Initial studies have provided a mixed perspective of the efficacy of d-cycloserine (DCS) for augmenting the efficacy of exposure-based cognitive behavioral therapy (CBT) for panic disorder. In this multicenter trial, we examine the magnitude of DCS augmentation effects for an ultra-brief program of CBT.

METHODS

We conducted a double-blind, controlled trial at three treatment sites, randomizing 180 adults with a primary diagnosis of panic disorder to five sessions of treatment, with study pill (50 mg DCS or matching placebo) administered 1 hr prior to the final three sessions. Two booster sessions were subsequently provided, and outcome was assessed at posttreatment and 1-month, 2-month, and 6-month follow-up assessments. The primary outcome was the degree of reduction in the Panic Disorder Severity Scale. Additional analyses examined the role of severity and current antidepressant or benzodiazepine use as moderators of DCS augmentation effects.

RESULTS

DCS augmentation resulted in significant benefit only early in the trial, with no beneficial effects of DCS augmentation evident at follow-up evaluations. We did not find that baseline severity or antidepressant or benzodiazepine use moderated DCS efficacy, but benzodiazepine use was associated with lower efficacy of CBT regardless of augmentation condition.

CONCLUSIONS

Consistent with other recent multicenter trials, the benefit of DCS was less than indicated by pilot study and reflected an acceleration of treatment response evident at treatment endpoint, but no advantage in response over follow-up evaluation. Our results did not support severity or concomitant medication moderators observed in previous trials of DCS augmentation.

The Role of Psychotropic Medications in the Management of Anorexia Nervosa: Rationale, Evidence and Future Prospects

Anorexia nervosa (AN) is a severe psychiatric disorder without approved medication intervention. Every class of psychoactive medication has been tried to improve treatment outcome; however, randomized controlled trials have been ambiguous at best and across studies have not shown robust improvements in weight gain and recovery. Here we review the available literature on pharmacological interventions since AN came to greater public recognition in the 1960s, including a critical review of why those trials may not have been successful. We further provide a neurobiological background for the disorder and discuss how cognition, learning, and emotion-regulating circuits could become treatment targets in the future. Making every effort to develop effective pharmacological treatment options for AN is imperative as it continues to be a complex psychiatric disorder with high disease burden and mortality.

Enhancing panic and smoking reduction treatment with d-cycloserine: Study protocol for a randomized controlled trial

There has been relatively little attention focused on treatment strategies for smokers with panic attacks despite their increased risk of relapse. Panic and Smoking Reduction Treatment (PSRT) integrates standard smoking cessation treatment with an exposure-based intervention targeting the mechanisms underlying panic-smoking relations. Building upon emerging evidence supporting the efficacy of d-cycloserine (DCS) for augmenting exposure-based therapy, we are conducting an initial test of the efficacy of DCS for enhancing PSRT outcomes. Utilizing a randomized, double-blind trial comparing PSRT+DCS to PSRT+placebo, we will obtain initial effect sizes for short-term and long-term smoking cessation outcomes and perform an initial test of putative mechanisms.