A preliminary study of D-cycloserine augmentation of cognitive-behavioral therapy in pediatric obsessive-compulsive disorder

Pediatric Treatment-Resistant Obsessive Compulsive Disorder: Treatment Options and Challenges

Pediatric obsessive-compulsive disorder (OCD) is a chronic, potentially debilitating psychiatric condition. Although effective treatments exist, at least 10% of youth do not achieve remission despite receiving first-line treatments. This article reviews the extant, albeit limited, evidence supporting treatment approaches for youth with treatment-resistant OCD. A literature search for articles addressing pediatric treatment-resistant OCD was conducted through April 11, 2024. These results were augmented by searching for treatment-resistant OCD in adults; treatment strategies discovered for the adult population were then searched in the context of children and adolescents. In general, intensive treatment programs and antipsychotic augmentation of an antidepressant had the most substantial and consistent evidence base for treatment-resistant youth with OCD, although studies were limited and of relatively poor methodological quality (i.e., open trials, naturalistic studies). Several pharmacological approaches (clomipramine, antipsychotics [e.g., aripiprazole, risperidone], riluzole, ketamine, D-cycloserine, memantine, topiramate, N-acetylcysteine, ondansetron), largely based on supporting data among adults, have received varying levels of investigation and support. There is nascent support for how to treat pediatric treatment-resistant OCD. Future treatment studies need to consider how to manage the significant minority of youth who fail to benefit from first-line treatment approaches.

Efficacy of D-cycloserine augmented brief intensive cognitive-behavioural therapy for paediatric obsessive-compulsive disorder: A randomised clinical trial

OBJECTIVE

To examine the efficacy of weight-adjusted D-cycloserine (DCS) (35 or 70 mg) relative to placebo augmentation of intensive exposure therapy for youth with obsessive-compulsive disorder (OCD) in a double-blind, randomised controlled trial, and examine whether antidepressant medication or patient age moderated outcomes.

METHODS

Youth (n = 100, 7-17 years) with OCD were randomised in a 1:1 ratio to either DCS + exposure (n = 49) or placebo + exposure (n = 51). Assessments occurred posttreatment, 1 month later, and at 3 and 6 months. Pills were ingested immediately before sessions.

RESULTS

Significant improvements on all outcomes were observed at posttreatment, and to 6-month follow-up. Treatment arms did not differ across time, with no significant time-by-medication interactions on symptom severity (T1 to T2 estimate: 9.3, 95% confidence interval [CI]: -11.2 to -7.4, and estimate -10.7, 95% CI: -12.6 to -8.7), diagnostic severity (T1 to T2 estimate: -2.0, 95% CI: -2.4 to -1.5 and estimate -2.5, 95% CI: -3.0 to -2.0) or global functioning (T1 to T2 estimate: 13.8, 95% CI: 10.6 to 17.0, and estimate 16.6, 95% CI: 13.2 to 19.9). Neither antidepressants at baseline nor age moderated primary outcomes. There were significantly fewer responders/remitters at 1- and 6-month follow-up among youth in the DCS condition stabilised on SSRIs, relative to youth not taking SSRIs.

CONCLUSIONS

DCS augmented intensive exposure therapy did not result in overall additional benefits relative to placebo. Intensive exposure proved effective in reducing symptoms for the overall sample.

Systematic Review and Meta-analysis: An Empirical Approach to Defining Treatment Response and Remission in Pediatric Obsessive-Compulsive Disorder

OBJECTIVE

A lack of universal definitions for response and remission in pediatric obsessive-compulsive disorder (OCD) has hampered the comparability of results across trials. To address this problem, we conducted an individual participant data diagnostic test accuracy meta-analysis to evaluate the discriminative ability of the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) in determining response and remission. We also aimed to generate empirically derived cutoffs on the CY-BOCS for these outcomes.

METHOD

A systematic review of PubMed, PsycINFO, Embase and CENTRAL identified 5,401 references; 42 randomized controlled clinical trials were considered eligible, and 21 provided data for inclusion (N = 1,234). Scores of ≤2 in the Clinical Global Impressions Improvement and Severity scales were chosen to define response and remission, respectively. A 2-stage, random-effects meta-analysis model was established. The area under the curve (AUC) and the Youden Index were computed to indicate the discriminative ability of the CY-BOCS and to guide for the optimal cutoff, respectively.

RESULTS

The CY-BOCS had sufficient discriminative ability to determine response (AUC = 0.89) and remission (AUC = 0.92). The optimal cutoff for response was a ≥35% reduction from baseline to posttreatment (sensitivity = 83.9, 95% CI = 83.7-84.1; specificity = 81.7, 95% CI = 81.5-81.9). The optimal cutoff for remission was a posttreatment raw score of ≤12 (sensitivity = 82.0, 95% CI = 81.8-82.2; specificity = 84.6, 95% CI = 84.4-84.8).

CONCLUSION

Meta-analysis identified empirically optimal cutoffs on the CY-BOCS to determine response and remission in pediatric OCD randomized controlled clinical trials. Systematic adoption of standardized operational definitions for response and remission will improve comparability across trials for pediatric OCD.

Augmentation of Psychotherapy with Neurobiological Methods: Current State and Future Directions

BACKGROUND

Psychotherapy and pharmacotherapy are first-line treatments for mental disorders. Despite recent improvements, only approximately 50% of the patients reach sustained remission, indicating a need for novel developments. The main concept put forward in this systematic review and hypothesis article is the targeted co-administration of defined neurobiological interventions and specific psychotherapeutic techniques.

METHODS

We conducted a systematic literature search for randomized controlled trials comparing the efficacy of augmented psychotherapy to psychotherapy alone.

RESULTS

Thirty-five trials fulfilled the inclusion criteria. The majority (29 trials) used augmentation strategies such as D-cycloserine, yohimbine, or sleep to enhance the effects of exposure therapy for anxiety disorders. Fewer studies investigated noninvasive brain stimulation with the aim of improving cognitive control, psychedelic compounds with the aim of enhancing existentially oriented psychotherapy, and oxytocin to improve social communication during psychotherapy. Results demonstrate small augmentation effects for the enhancement of exposure therapy - however, some of the studies found negative results. Other methods are less thoroughly researched, and results are mixed.

CONCLUSIONS

This approach provides an open matrix for further research and has the potential to systematically guide future studies.

The effectiveness of exposure and response prevention combined with pharmacotherapy for obsessive-compulsive disorder: A systematic review and meta-analysis

OBJECTIVE

To systematically evaluate the effectiveness of exposure and response prevention (ERP) combined with medication on obsessive-compulsive disorder (OCD).

METHODS

PubMed, Web of Science, EBSCO, Cochrane, Embase, and Science Direct databases were searched to include randomized controlled trials of ERP combined with medication for OCD that met the criteria. The Yale Brown Obsessive Compulsive Scale was used as the primary outcome indicator, and Depression scales were used as secondary outcome indicators. An evaluation of bias risk was conducted to identify possible sources of bias based on methodological and clinical factors. Review Manager 5.3 and Stata 16.0 software was used to perform meta-analysis of the extracted data.

RESULTS

A total of 21 studies with 1113 patients were included. Meta-analysis showed that ERP combined with medication therapy was significantly better than medication therapy alone including selective serotonin reuptake inhibitors, clomipramine and risperidone (MD = -6.60, 95% CI: -8.35 to -4.84, P < 0.00001), but D-cycloserine (DCS) drugs do not enhance the effect of ERP intervention in patients with OCD (MD = 0.15, 95% CI: -0.87 to 1.17, P = 0.77). There is more significant maintenance by combined treatment method of medication plus ERP than medication treatment alone during the follow-up period (MD = -7.14, 95% CI: -9.17 to -5.10, P < 0.00001). DCS drugs did not enhance the effect of ERP intervention on depression in patients with OCD (SMD = -0.08, 95% CI: -0.31 to 0.15, P = 0.50). ERP combined with drug improved patients' depression levels significantly better than providing drug alone (SMD = -0.40, 95% CI: -0.68 to -0.11, P = 0.006).

CONCLUSION

Patients with OCD have significant improvement in symptoms of obsessive-compulsive disorder and depression when ERP is combined with medication, however, not enough to prove that DCS can enhance ERP effectiveness.

Antiglutamatergic agents for obsessive-compulsive disorder: Where are we now and what are possible future prospects?

Recent data suggest that obsessive-compulsive disorder (OCD) is driven by an imbalance among the habit learning system and the goal-directed system. The frontostriatal loop termed cortico-striatal-thalamo-cortical (CSTC) circuitry loop is involved in habits and their dysfunction plays an important role in OCD. Glutamatergic neurotransmission is the principal neurotransmitter implicated in the CSTC model of OCD. Hyperactivity in the CSTC loop implies a high level of glutamate in the cortical-striatal pathways as well as a dysregulation of GABAergic transmission, and could represent the pathophysiology of OCD. Moreover, the dysregulation of glutamate levels can lead to neurotoxicity, acting as a neuronal excitotoxin. The hypothesis of a role of neurotoxicity in the pathophysiology of OCD clinically correlates to the importance of an early intervention for patients. Indeed, some studies have shown that a reduction of duration of untreated illness is related to an earlier onset of remission. Although robust data supporting a progression of such brain changes are not available so far, an early intervention could help interrupt damage from neurotoxicity. Moreover, agents targeting glutamate neurotransmission may represent promising therapeutical option in OCD patients.

Delayed Sleep Timing in Obsessive-Compulsive Disorder Is Associated With Diminished Response to Exposure and Ritual Prevention

Exposure and ritual prevention (ERP) and pharmacotherapy are typically associated with significant symptom reductions for individuals with obsessive-compulsive disorder (OCD). However, many patients are left with residual symptoms and other patients do not respond. There is increasing evidence that delays in sleep timing/circadian rhythms are associated with OCD but the potential effects of delays in sleep timing on ERP warrant attention. This paper presents data from 31 outpatients with OCD who participated in ERP. Results showed that delayed sleep timing was common and that individuals with delayed bedtimes benefited significantly less from treatment and were significantly more likely to be nonresponders compared to individuals with earlier bedtimes. Further, the effects of sleep timing remained statistically significant even after controlling for global sleep quality, negative affect, and several other variables. These findings add to a growing literature suggesting the utility of better understanding the role of disruptions in the timing of sleep in OCD.

Optimising Exposure for Children and Adolescents with Anxiety, OCD and PTSD: A Systematic Review

Cognitive behavioural therapy is an effective treatment for anxiety disorders in children and young people; however, many do not benefit. Behavioural exposure appears to be the critical ingredient in the treatment of anxiety disorders. Research with adults has identified innovative strategies to optimise exposure-based treatments, yet it is not clear how to optimise the effects of exposure for children and young people. This review was a preliminary exploration of the association between potential optimisation strategies and treatment procedures and outcomes for the treatment of child anxiety symptoms/disorders. We searched Psych-Info and Medline databases using a systematic search strategy and identified 29 articles. We found preliminary evidence that some specific strategies may enhance the effects of exposure, such as dropping safety behaviours, parents and therapists discouraging avoidance, and the use of homework. However, not one significant finding was replicated by another study for the same timepoint using the same methodology. To a large degree, this lack of replication reflects a limited number of studies combined with a lack of consistency across studies around conceptualisations, methodological approaches, and outcome measures making it difficult to make meaningful comparisons between studies and draw firm conclusions. Examination is needed of a wide range of theoretically-driven potential optimisation strategies using methodologically robust, preclinical studies with children and young people. Furthermore, the methods used in future research must enable comparisons across studies and explore developmental differences in the effects of particular optimisation strategies.

Optimizing behavior therapy for youth with Tourette's disorder

Tourette's Disorder (TD) is characterized by tics that cause distress and impairment. While treatment guidelines recommend behavior therapy as a first-line intervention, patients with TD may exhibit limited therapeutic response. Given the need to improve treatment outcomes, this study examined the efficacy of augmenting behavior therapy with D-cycloserine (DCS) to reduce tic severity in a placebo-controlled quick-win/fast-fail trial. Twenty youth with TD completed a baseline assessment to characterize tic severity, premonitory urges, medical history, and psychiatric comorbidity. Youth were randomly assigned to receive a single session of habit reversal training (HRT) augmented by either 50 mg of DCS or placebo. Two bothersome tics on the Hopkins Motor/Vocal Tic Scale (HM/VTS) were targeted for treatment during HRT. One week after the HRT session, youth completed a posttreatment assessment to evaluate change in the severity of bothersome tics. All assessments were completed by independent evaluators masked to treatment group. There was a Treatment Group by Time Interaction in favor of DCS-augmented HRT (p < 0.01), controlling for baseline tic severity, tic medication, and attention deficit hyperactivity disorder. Follow-up comparisons revealed small group differences at the treatment visit (d = 0.27), with the DCS group exhibiting slightly greater severity for targeted tics. There was a large group difference at posttreatment, in which the DCS group exhibited lower severity for targeted tics (d = 1.30, p < 0.001) relative to the placebo group. Findings demonstrate the preliminary enhancement of tic severity reductions by augmenting HRT with DCS compared with placebo augmentation.

The Psychopharmacology of Obsessive-Compulsive Disorder: A Preclinical Roadmap

This review evaluates current knowledge about obsessive-compulsive disorder (OCD), with the goal of providing a roadmap for future directions in research on the psychopharmacology of the disorder. It first addresses issues in the description and diagnosis of OCD, including the structure, measurement, and appropriate description of the disorder and issues of differential diagnosis. Current pharmacotherapies for OCD are then reviewed, including monotherapy with serotonin reuptake inhibitors and augmentation with antipsychotic medication and with psychologic treatment. Neuromodulatory therapies for OCD are also described, including psychosurgery, deep brain stimulation, and noninvasive brain stimulation. Psychotherapies for OCD are then reviewed, focusing on behavior therapy, including exposure and response prevention and cognitive therapy, and the efficacy of these interventions is discussed, touching on issues such as the timing of sessions, the adjunctive role of pharmacotherapy, and the underlying mechanisms. Next, current research on the neurobiology of OCD is examined, including work probing the role of various neurotransmitters and other endogenous processes and etiology as clues to the neurobiological fault that may underlie OCD. A new perspective on preclinical research is advanced, using the Research Domain Criteria to propose an adaptationist viewpoint that regards OCD as the dysfunction of a normal motivational system. A systems-design approach introduces the security motivation system (SMS) theory of OCD as a framework for research. Finally, a new perspective on psychopharmacological research for OCD is advanced, exploring three approaches: boosting infrastructure facilities of the brain, facilitating psychotherapeutic relearning, and targeting specific pathways of the SMS network to fix deficient SMS shut-down processes. SIGNIFICANCE STATEMENT: A significant proportion of patients with obsessive-compulsive disorder (OCD) do not achieve remission with current treatments, indicating the need for innovations in psychopharmacology for the disorder. OCD may be conceptualized as the dysfunction of a normal, special motivation system that evolved to manage the prospect of potential danger. This perspective, together with a wide-ranging review of the literature, suggests novel directions for psychopharmacological research, including boosting support systems of the brain, facilitating relearning that occurs in psychotherapy, and targeting specific pathways in the brain that provide deficient stopping processes in OCD.

Psychopharmacological Treatment of Obsessive-Compulsive Disorder (OCD)

Background:

Obsessive-compulsive disorder (OCD) is associated with affective and cognitive symptoms causing personal distress and reduced global functioning. These have considerable societal costs due to healthcare service utilization.

Objective:

Our aim was to assess the efficacy of pharmacological interventions in OCD and clinical guidelines, providing a comprehensive overview of this field.

Methods:

We searched the PubMed database for papers dealing with drug treatment of OCD, with a specific focus on clinical guidelines, treatments with antidepressants, antipsychotics, mood stabilizers, off-label medications, and pharmacogenomics.

Results:

Prolonged administration of selective serotonin reuptake inhibitors (SSRIs) is most effective. Better results can be obtained with a SSRI combined with cognitive behavioral therapy (CBT) or the similarly oriented exposure and response prevention (ERP). Refractory OCD could be treated with different strategies, including a switch to another SSRI or clomipramine, or augmentation with an atypical antipsychotic. The addition of medications other than antipsychotics or intravenous antidepressant administration needs further investigation, as the evidence is inconsistent. Pharmacogenomics and personalization of therapy could reduce treatment resistance.

Conclusions:

SSRI/clomipramine in combination with CBT/ERP is associated with the optimal response compared to each treatment alone or to other treatments. New strategies for refractory OCD are needed. The role of pharmacogenomics could become preponderant in the coming years.

Placebo Effect in Obsessive-Compulsive Disorder (OCD). Placebo Response and Placebo Responders in OCD: The Trend Over Time

BACKGROUND

Placebo response appears to be increasing in antidepressant, antipsychotic and various internal medicine trials. A similar trend has been reported for OCD during 1989-1999. Placebo response is generally considered as the extent to which placebo treatment is associated with core symptom improvement. In this analysis, we used Joinpoint regression to assess the time trend of both placebo response and placebo responder rates according to the year of publication with no time restriction in OCD drug trials.

METHODS

We included drug and/or psychotherapy trials vs. placebo from PubMed, Embase, CINAHL, and PsycINFO retrieved through the search (placebo OR sham) AND (obsessive* OR OCD). We included studies through investigator consensus. We then performed on data of included studies log-linear joinpoint segmented regression models using a p<0.05 cutoff.

RESULTS

We included 113 studies from 112 published papers. Placebo mean annual response rates in OCD studies significantly increased from 1991 to 2017 with an annual percent change (APC) of 0.66%, while placebo mean annual responder rates also significantly increased from 2010 to 2017, with an APC of 5.45%. Drug mean annual response rates in OCD studies significantly increased from 1987 to 2012 with an APC of 0.72%, while the corresponding responder rates did not show statistically significant APC changes between 1984 and 2017.

CONCLUSION

We observed a tendency for placebo to increase both measures of response in OCD clinical drug trials through the years that tend to approximate the responses shown by drugs. Changes in the type of study (moving from classical head to head comparisons to add-on studies in treatmentresistant populations) and countries involved in experimentation may partially account for some portion of these results. It appears that placebo effects are becoming more elusive and out of control.

The Glutamate and the Immune Systems: New Targets for the Pharmacological Treatment of OCD

BACKGROUND

In the last decades the pharmacological treatment of obsessivecompulsive disorder (OCD) has been significantly promoted by the effectiveness of selective serotonin (5-HT) reuptake inhibitors (SSRIs) and the subsequent development of the 5-HT hypothesis of OCD. However, since a large majority of patients (between 40% and 60 %) do not respond to SSRIs or strategies based on the modulation of the 5-HT system, it is now essential to search for other possible therapeutic targets.

AIMS

The aim of this paper was to review current literature through a PubMed and Google Scholar search of novel hypotheses and related compounds for the treatment of OCD, with a special focus on the glutammate and the immune systems.

DISCUSSION

The literature indicates that glutamate, the main excitatory neurotransmitter, might play an important role in the pathophysiology of OCD. In addition, a series of clinical studies also supports the potential efficacy of drugs modulating the glutamate system. The role of the immune system alterations in OCD in both children and adults needs to be more deeply elucidated. In children, a subtype of OCD has been widely described resulting from infections driven by group A streptococcus β-hemolitic and belonging to the so-called "pediatric autoimmune neuropsychiatric disorders associated with streptococcus" (PANDAS). In adults, available findings are meager and controversial, although interesting.

CONCLUSION

The glutamate and the immune systems represent two intriguing topics of research that hold promise for the development of open novel treatment strategies in OCD.

N-methyl-D-aspartate Partial Agonist Enhanced Intensive Cognitive-Behavioral Therapy of Panic Disorder in Adolescents

Panic disorder (PD) can result in significant functional impairment. Studies of cognitive behavioral therapy (CBT) for PD have demonstrated response rates ranging between 38 and 65%. D-cycloserine (DCS), a partial NMDA agonist, may enhance the effects of exposure-based therapy for PD in adults; however, no studies have examined its effect in adolescents with PD. This study examined the feasibility and acceptability of the use of DCS to augment intensive CBT for PD in adolescents. Twenty-four adolescents (ages 12-17) participated in this randomized, double-blinded, placebo-controlled trial, to compare CBT + DCS to CBT + placebo. The results demonstrated the feasibility and acceptability of the treatment to participants. No significant differences were found between the two groups, but both groups showed significant improvement. This is the first investigation of DCS in the treatment of PD in adolescents and it provides initial support for a more extensive study of DCS augmentation of CBT among adolescents with PD.

A precision medicine approach to pharmacological adjuncts to extinction: a call to broaden research

There is a pressing need to improve treatments for anxiety. Although exposure-based therapy is currently the gold-standard treatment, many people either do not respond to this therapy or experience a relapse of symptoms after treatment has ceased. In recent years, there have been many novel pharmacological agents identified in preclinical research that have potential as adjuncts for exposure therapy, yet very few of these are regularly integrated into clinical practice. Unfortunately, the robust effects observed in the laboratory animal often do not translate to a clinical population. In this review, we discuss how age, sex, genetics, stress, medications, diet, alcohol, and the microbiome can vary across a clinical population and yet are rarely considered in drug development. While not an exhaustive list, we have focused on these factors because they have been shown to influence an individual's vulnerability to anxiety and alter the neurotransmitter systems often targeted by pharmacological adjuncts to therapy. We argue that for potential adjuncts to be successfully translated from the lab to the clinic empirical research must be broadened to consider how individual difference factors will influence drug efficacy.

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.

Learn to forget: Does post-exposure administration of d-cycloserine enhance fear extinction in agoraphobia?

The use of d-cycloserine (DCS) to augment exposure based therapy for anxiety disorders has shown mixed, although overall positive effects. Aim of the present study was to examine post-exposure administration of DCS in patients with agoraphobia with or without panic disorder. 73 patients with agoraphobia (with or without panic disorder) were treated with 12 sessions of cognitive behavioral therapy (CBT) including 3 exposures. Following successful exposure patients were given double blind either placebo or 50 mg of DCS. Primary outcome criterion was change in the Panic and Agoraphobia Scale (PAS) between CBT session t1, t4 (+∼2 months), t10 (+∼3 months) und t11 (+∼4 months). During the course of CBT the patients' symptomatology decreased significantly as measured by primary and secondary outcome criteria, however, without an additional benefit for DCS treated patients. Exploratory sub-group analyses for severely ill patients and patients with high anxiety and strong habituation during exposure showed that DCS administration was associated with increased improvement during the 1-month follow-up period (t10 - t11) with medium to large effect sizes (range in effect size η²_p from .06 to .25). Our study results are consistent with recent research on DCS, indicating a beneficial augmentative effect for sub-groups of anxiety patients. The lack of an overall DCS effect for the whole patient sample might be explained by a dual mechanism in fear conditioning and extinction with different cognitive processes being involved during exposure depending on the degree of anxiety experienced by the patient.

D-cycloserine-augmented one-session treatment of specific phobias in children and adolescents

BACKGROUND

D-Cycloserine has potential to enhance exposure therapy outcomes. The current study presents a preliminary randomized, placebo-controlled double-blind pilot trial of DCS-augmented one-session treatment (OST) for youth (7-14 years) with specific phobia. A secondary aim of this pilot study was to explore the effects of youth age and within-session fear reduction as potential moderators of DCS outcomes in order to generate hypotheses for a larger trial. It was hypothesized that DCS would be associated with greater improvements than placebo, that children (7-10 years) would have greater benefits than adolescents (11-14 years), and that DCS effects would be stronger for participants with the greater within-session fear reduction during the OST.

METHODS

Thirty-five children and adolescents were randomized to either OST combined with DCS (n = 17), or OST combined with placebo (PBO; n = 18) and assessed at 1 week, 1 month, and 3 month following treatment.

RESULTS

There were no significant pre- to post-treatment or follow-up benefits of DCS relative to placebo. Secondary analyses of age indicated that relative to PBO, DCS was associated with greater improvements for children (but not adolescents) on measures of severity at 1-month follow-up. Children in the DCS condition also showed significantly greater improvement to 1 month on global functioning relative to other groups. Conversely, adolescents had significant post-treatment benefits in the PBO condition on symptom severity measures relative to DCS, and adolescents in the DCS condition had significantly poorer functioning at 3 months relative to all other groups. Finally, there was a trend for within-session fear reduction to be associated with moderating effects of DCS, whereby greater reduction in fear was associated with greater functioning at one-month follow-up for children who received DCS, relative to PBO.

LIMITATIONS

The study sample was small and therefore conclusions are tentative and require replication.

CONCLUSIONS

Age and within-session fear reduction may be important moderators of DCS-augmented one-session exposure therapy, which requires testing in a fully powered randomized controlled trial.

New Directions in the Cognitive-Behavioral Treatment of OCD: Theory, Research, and Practice

The beneficial effects of cognitive-behavioral interventions (particularly exposure and response prevention) for OCD are among the most consistent research findings in the mental health literature. Nevertheless, even after an adequate trial, many individuals experience residual symptoms, and others never receive adequate treatment due to limited access. These and other issues have prompted clinicians and researchers to search for ways to improve the conceptual and practical aspects of existing treatment approaches, as well as look for augmentation strategies. In the present article, we review a number of recent developments and new directions in the psychological treatment of OCD, including (a) the application of inhibitory learning approaches to exposure therapy, (b) the development of acceptance-based approaches, (c) involvement of caregivers (partners and parents) in treatment, (d) pharmacological cognitive enhancement of exposure therapy, and (e) the use of technology to disseminate effective treatment. We focus on both the conceptual/scientific and practical aspects of these topics so that clinicians and researchers alike can assess their relative merits and disadvantages.

Implications of the Research Domain Criteria project for childhood anxiety and its disorders

Anxiety disorders are among the most prevalent psychiatric disorders in youth; however, progress in treatment for childhood anxiety has stalled over the past decade. The National Institute of Mental Health (NIMH) Research Domain Criteria (RDoC) project represents a shift toward a dimensional and interdisciplinary approach to psychiatric disorders; this shift can reframe developmental psychopathology for childhood anxiety and facilitate novel advances in its classification and treatment. Here we highlight constructs in the Systems for Social Processes and the Negative Valence System domains of RDoC, as they relate to childhood anxiety disorders. Childhood anxiety relates to both RDoC domains. In terms of social processes, through natural reliance on parents to reduce children's fear, attachment represents one particular social process, which plays a central role in anxiety among youth. In terms of negative valence, considerable research links threat conditioning to pediatric anxiety. Finally, fronto-amygdala circuitry relates to all three entities, as it has been shown to underly both attachment processes and threat learning, while it also has been consistently implicated in anxiety disorders across development. Through integrative and translational approaches, RDoC provides unique opportunities and simultaneous challenges for advancing the understanding and treatment of childhood anxiety disorders.

Pharmacotherapy for obsessive—compulsive disorder

We present a narrative review of evidence-based treatment for obsessive–compulsive disorder (OCD), covering first-line pharmacological treatment, augmentation strategies, approaches for treatment-refractory OCD and the management of OCD in special populations (children and adolescents, pregnant and breast-feeding women, and elderly people).

Obsessive–compulsive disorder in young people

Obsessive–compulsive disorder (OCD) is one of the most debilitating psychiatric conditions in young people. In DSM-5 it is no longer characterised as an anxiety disorder, but instead is part of a group of ‘obsessive–compulsive and related disorders'. In the past 10 years, cognitive—behavioural therapy (CBT) has become well established as the first-choice treatment. This article explains some of the elements of CBT and describes new directions in research which might improve interventions.

Can Cognitive Behavioral Therapy for Anxiety and Depression Be Improved with Pharmacotherapy? A Meta-analysis

The present meta-analysis examined controlled trials of pharmacologic augmentation of cognitive-behavioral therapy (CBT) for patients with anxiety or depressive disorders. The additive effect of medications was small for both anxiety and depressive disorders at posttreatment, and there was no additive benefit after medications were discontinued. A small body of evidence suggested that antidepressant medications are an efficacious second-line treatment for patients failing to respond to CBT alone. In anxiety disorders, novel agents thought to potentiate the biological mechanisms of CBT showed small effects at posttreatment; after discontinuation, some of these agents were associated with an increasing effect.

No Effects of D-Cycloserine Enhancement in Exposure With Response Prevention Therapy in Panic Disorder With Agoraphobia: A Double-Blind, Randomized Controlled Trial

PURPOSE/BACKGROUND

D-cycloserine (DCS) is a partial N-methyl-D-aspartate receptor agonist that potentially augments response to exposure therapy in anxiety disorders by enhancing extinction learning. This randomized, double-blinded, placebo-controlled augmentation trial examined (1) the effectiveness of adding 125 mg of DCS to exposure therapy (before or directly after the first 6 treatment sessions) in patients with panic disorder with agoraphobia and (2) the effectiveness of DCS augmentation preceding exposure relative to DCS augmentation directly postexposure.

METHODS/PROCEDURES

Fifty-seven patients were allocated to 1 of 3 medication conditions (placebo and pre-exposure and postexposure DCS) as an addition to 6 exposure sessions within a 12-session exposure and response prevention protocol. The primary outcome measure was the mean score on the "alone" subscale of the Mobility Inventory (MI).

FINDINGS/RESULTS

No differences were found in treatment outcome between DCS and placebo, administered either pre-exposure or postexposure therapy, although at 3-month follow-up, the DCS postexposure group compared with DCS pre-exposure, exhibited greater symptom reduction on the MI-alone subscale. Ancillary analyses in specific subgroups (responders vs nonresponders, early vs late responders, severely vs mildly affected patients) did not reveal any between-group DCS versus placebo differences. Finally, the study did not find an effect of DCS relative to placebo to be specific for successful exposure sessions.

IMPLICATIONS/CONCLUSIONS

This study does not find an effect of augmentation with DCS in patients with severe panic disorder and agoraphobia administered either pretreatment or directly posttreatment sessions. Moreover, no preferential effects are revealed in specific subgroups nor in successful exposure sessions. Yet, a small effect of DCS administration postexposure therapy cannot be ruled out, given the relatively small sample size of this study.

Assessment and Treatment of Anxiety Among Children and Adolescents

Among children and adolescents, anxiety disorders are common psychiatric disorders that confer risk of comorbid psychiatric disorders and social and academic impairment. This review focuses on the assessment and treatment of anxiety disorders among children and adolescents, with attention to separation anxiety disorder, social phobia disorder (social anxiety disorder), panic disorder, and generalized anxiety disorder. Comprehensive assessment of child and adolescent anxiety disorders benefits from a multimethod approach to evaluation and diagnosis, including semistructured interviews; child and informant questionnaires; collateral information from parents, teachers, pediatricians, and school psychologists; and behavioral observations. Because anxiety symptoms can include avoidance behaviors, somatic complaints, social difficulties, and sleep disturbances, consideration of a differential diagnosis is important. Among the available psychosocial interventions, cognitive-behavioral therapy (CBT) and exposure-based therapies have emerged as the most well-established treatment approaches for addressing anxiety disorders among children and adolescents. Pharmacologically, selective serotonin reuptake inhibitors (SSRIs) have been established to be safe and efficacious for the treatment of pediatric anxiety and are considered the medications of choice for this population. Research indicates that CBT plus SSRI medication is the most effective treatment of anxiety for youths ages seven to 17, compared with either CBT or medication alone. Medication monotherapy and CBT monotherapy have also been demonstrated to be effective treatments.

D-cycloserine augmentation of behavior therapy for anxiety and obsessive-compulsive disorders: A meta-analysis

OBJECTIVE

The present meta-analysis investigates whether the antibiotic D-cycloserine (DCS), a partial agonist at the glutamatergic N-methyl-D-aspartate receptor, can augment the effect of behavior therapy in humans with anxiety and obsessive-compulsive disorders.

METHOD

A keyword-based computer search was conducted using common electronic databases. Only studies investigating the effect of DCS in humans with anxiety and obsessive-compulsive disorders were included, resulting in 23 studies with a combined sample size of 1314 patients. Effect sizes were coded as Hedges' g and SMCC, the latter also incorporating differences in pre-treatment values. Bayesian multilevel meta-analysis was applied to take dependencies of effect sizes obtained from the same study into account.

RESULTS

While previous meta-analyses found small to moderate improvements, the current results including the most recent research indicate that the overall effect of DCS is very small and almost indistinguishable from zero (g = -0.12, CI = [-0.27, 0.02]; SMCC = -0.10, CI = [-0.29, 0.07]). Slightly larger effects were found for social anxious patients. Further, study quality and year of publication were relevant moderators, with higher quality / more recent studies reported smaller effects of DCS.

CONCLUSIONS

These findings raise the question of the usefulness of DCS as an augmentation of exposure therapy for anxiety and obsessive-compulsive disorders. At least, it seems to be less promising than initially thought. The fact that study quality was inversely related to the reported effect sizes underlines the importance of high quality primary research in order to avoid over-estimation of treatment effects in clinical psychology.

The Efficacy of Augment of D-Cycloserine and Cognitive-behavioral Therapy on Adolescent with one Type of Anxiety Disorders: A Double-blind Randomized Controlled Trial

Background:

This study was designed to investigating the effect of combining D-cycloserine (DCS) and cognitive-behavioral therapy (CBT) on adolescent with at least one type of anxiety disorders.

Materials and Methods:

The present study was conducted as a double-blind randomized controlled trial on 36 adolescent with anxiety disorders. Patients were assessed in two groups. In addition to 4 sessions of weekly CBT in both groups; case group, received a 50-mg DCS capsules, control group, received Placebo daily for a month. Patients received DCS capsules or placebo 1 h before sessions of CBT. Age, sex, kind of anxiety disorders “screen for child anxiety related disorders (SCARED)” and “cognitive abilities test (CATS)” scores were evaluated and compared between groups.

Results:

The mean age of the studied patients (29 females (80.6%) and 7 males (19.4%)) was 14.1 ± 1.8 years. The most frequent anxiety disorder among the study population was generalized social disorder (GAD) (77.7%). Age, sex and the frequency of anxiety disorders were not statistically significant between the study groups (P > 0.05). The mean score of “SCARED” and “CATS” at before starting the treatment, after treatment and three month after the treatment were not statistically significant between groups (P > 0.05). Also, decrease in values of “SCARED” and “CATS” during the evaluation time periods was not statistically significant between groups (P > 0.05).

Conclusions:

Findings of this study showed that there has been no difference in symptoms improvement in adolescent with anxiety disorder who received treatment protocol including 4 sessions of CBT, weekly, together with 50 mgs of DCS compared to the patients of the control group.

A Meta-Analysis of D-Cycloserine in Exposure-Based Treatment: Moderators of Treatment Efficacy, Response, and Diagnostic Remission

OBJECTIVE

This meta-analysis examined treatment efficacy, treatment response, and diagnostic remission effect sizes and moderators of D-cycloserine-augmented exposure treatment in randomized controlled trials (RCTs) of individuals with anxiety disorders, obsessive-compulsive disorder (OCD), and posttraumatic stress disorder (PTSD).

DATA SOURCES AND STUDY SELECTION

The terms D-cycloserine AND randomized controlled trial were used to search the PubMed (1965-May 2015), PsycINFO, and Scopus databases for randomized placebo-controlled trials of D-cycloserine-augmented exposure therapy for anxiety disorders, OCD, and PTSD.

DATA EXTRACTION

Clinical variables and effect sizes were extracted from 20 RCTs (957 participants). A random-effects model calculated the effect sizes for treatment efficacy, treatment response, and diagnostic remission using standardized rating scales. Subgroup analyses and meta-regression were used to examine potential moderators.

RESULTS

A small, nonsignificant benefit of D-cycloserine augmentation compared to placebo augmentation was identified across treatment efficacy (g = 0.15), response (risk ratio [RR] = 1.08), and remission (RR = 1.109), with a moderately significant effect (P = .03) for anxiety disorders specifically (g = 0.33). At initial follow-up assessments, a small, nonsignificant effect size of D-cycloserine augmentation compared to placebo was found for treatment efficacy (g = 0.21), response (RR = 1.06), and remission (RR = 1.12). Specific treatment moderators (eg, comorbidity, medication status, gender, publication year) were found across conditions for both acute treatment and initial follow-up assessments.

CONCLUSIONS

D-Cycloserine does not universally enhance treatment outcomes but demonstrates promise for anxiety disorders. Distinct treatment moderators may account for discrepant findings across RCTs and disorders. Future trials may be strengthened by accounting for identified moderators in their design, with ongoing research needed on the mechanisms of D-cycloserine to tailor treatment protocols and maximize its benefit.

Glutamate-Modulating Drugs as a Potential Therapeutic Strategy in Obsessive-Compulsive Disorder

OBJECTIVE

Obsessive-compulsive disorder (OCD) is a mental disease commonly associated with severe distress and impairment of social functioning. Serotonin reuptake inhibitors and/or cognitive behavioural therapy are the therapy of choice, however up to 40% of patients do not respond to treatment. Glutamatergic signalling has also been implicated in OCD. The aim of the current study was to review the clinical evidence for therapeutic utility of glutamate-modulating drugs as an augmentation or monotherapy in OCD patients.

METHODS

We conducted a search of the MEDLINE database for clinical studies evaluating the effect of glutamate-modulating drugs in OCD.

RESULTS

Memantine is the compound most consistently showing a positive effect as an augmentation therapy in OCD. Anti-convulsant drugs (lamotrigine, topiramate) and riluzole may also provide therapeutic benefit to some OCD patients. Finally, ketamine may be of interest due to its potential for a rapid onset of action.

CONCLUSION

Further randomized placebo-controlled trials in larger study populations are necessary in order to draw definitive conclusions on the utility of glutamate-modulating drugs in OCD. Furthermore, genetic and epigenetic factors, clinical symptoms and subtypes predicting treatment response to glutamate-modulating drugs need to be investigated systematically.

d-cycloserine addition to exposure sessions in the treatment of patients with obsessive-compulsive disorder

BACKGROUND

Preliminary studies have shown that the addition of the partial NMDA-agonist d-cycloserine (DCS) might be promising in enhancing the results of exposure therapy in obsessive-compulsive disorder (OCD). We examined the effect of DCS addition to exposure therapy in a somewhat larger sample of OCD patients with special attention to subgroups, because of the heterogeneity of OCD.

METHODS

A randomized, double-blind, placebo controlled trial was conducted in 39 patients with OCD. Patients received 6 guided exposure sessions, once a week. One hour before each session 125mg DCS or placebo was administered.

RESULTS

Scores on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) declined more in the DCS group than in the placebo group, but the difference did not reach statistical significance (P=0.076, partial η²=0.13). Response percentages also did not differ between the DCS and the placebo group (37% and 15% respectively). In the 'cleaning/contamination' subgroup a significant effect was found in favour of DCS (P=0.033, partial η²=0.297).

CONCLUSIONS

The results of this study did not support the application of DCS to exposure therapy in OCD. Some specific aspects need further investigation: efficacy of DCS in a larger 'cleaning/contamination' (sub-)group, DCS addition only after successful sessions, interaction with antidepressants.

Plasticity-augmented psychotherapy for refractory depressive and anxiety disorders

Psychotherapy and pharmacotherapy have been the mainstays of treatment for depression and anxiety disorders during the last century. However, treatment response has not improved in the last few decades, with only half of all patients responding satisfactorily to typical antidepressants. To fulfill the needs of the remaining patients, new treatments with better efficacy are in demand. The addition of psychotherapy to antidepressant treatment has been shown to be superior to pharmacotherapy alone. However, the time costs of psychotherapy limit its use for clinicians and patients. Advancements in neuroscience have contributed to an improved understanding of the pathogenesis of depressive and anxiety disorders. In particular, recent advances in the field of fear conditioning have provided valuable insight into the treatment of refractory depressive and anxiety disorders. In this review, we studied the reconsolidation-updating paradigm and the concept of epigenetic modification, which has been shown to permanently attenuate remote fear memory. This has implications for drug-augmented, e.g. antidepressant and valproic acid, psychotherapy. Future research on more sophisticated psychotherapy techniques will increase the desirability of this treatment modality for both clinicians and patients.

Efficacy of Augmentation of Cognitive Behavior Therapy With Weight-Adjusted d-Cycloserine vs Placebo in Pediatric Obsessive-Compulsive Disorder: A Randomized Clinical Trial

IMPORTANCE

Cognitive behavior therapy (CBT) among youth with obsessive-compulsive disorder (OCD) is effective, but many patients remain symptomatic after intervention. d-cycloserine, a partial agonist at the N-methyl-d-aspartate receptor in the amygdala, has been associated with enhanced CBT outcome for OCD among adults but requires evaluation among youth.

OBJECTIVES

To examine the relative efficacy of weight-adjusted d-cycloserine (25 or 50 mg) vs placebo augmentation of CBT for youth with OCD and to assess if concomitant antidepressant medication moderated effects.

DESIGN, SETTING, AND PARTICIPANTS

In a placebo-controlled randomized clinical trial, 142 youths (age range, 7-17 years) enrolled between June 1, 2011, and January 30, 2015, at 2 academic health science centers (University of South Florida and Massachusetts General Hospital) with a primary diagnosis of OCD were randomized in a double-blind fashion to d-cycloserine plus CBT or placebo plus CBT. Intent-to-treat analysis was performed.

INTERVENTIONS

Patients were randomly assigned in a 1:1 ratio to either 10 sessions of d-cycloserine plus CBT or placebo plus CBT. d-cycloserine (25 or 50 mg) or placebo was taken 1 hour before sessions 4 through 10.

MAIN OUTCOMES AND MEASURES

Children's Yale-Brown Obsessive Compulsive Scale at randomization, biweekly, midtreatment, and posttreatment. Secondary outcomes included the Clinical Global Impressions-Severity or Clinical Global Impressions-Improvement, remission status, Children's Depression Rating Scale, Multidimensional Anxiety Scale for Children, and Children's Obsessive-Compulsive Impact Scale-Parent Version.

RESULTS

The study cohort comprised 142 participants. Their mean (SD) age was 12.7 (2.9) years, and 53.5% (76 of 142) were female. A mixed-effects model using all available data indicated significant declines in the Children's Yale-Brown Obsessive Compulsive Scale total score and Clinical Global Impressions-Severity. No significant interaction between treatment group and changes in the Children's Yale-Brown Obsessive Compulsive Scale and Clinical Global Impressions-Severity indicated that the d-cycloserine plus CBT group and the placebo plus CBT group declined at similar rates per assessment point on the Children's Yale-Brown Obsessive Compulsive Scale total score (estimate, -2.31, 95% CI, -2.79 to -1.83 and estimate, -2.03, 95% CI, -2.47 to -1.58, respectively) and Clinical Global Impressions-Severity (estimate, -0.29, 95% CI, -0.35 to -0.22 and estimate, -0.23, 95% CI, -0.29 to -0.17, respectively). No group differences in secondary outcomes were present. Antidepressant medication use at baseline did not moderate changes for either group.

CONCLUSIONS AND RELEVANCE

d-cycloserine augmentation of CBT did not confer additional benefit relative to placebo among youth with OCD. Other augmentation approaches should be examined to enhance outcome.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00864123.

Impaired fear extinction in adolescent rodents: Behavioural and neural analyses

Despite adolescence being a developmental window of vulnerability, up until very recently there were surprisingly few studies on fear extinction during this period. Here we summarise the recent work in this area, focusing on the unique behavioural and neural characteristics of fear extinction in adolescent rodents, and humans where relevant. A prominent hypothesis posits that anxiety disorders peak during late childhood/adolescence due to the non-linear maturation of the fear inhibition neural circuitry. We discuss evidence that impaired extinction retention in adolescence is due to subregions of the medial prefrontal cortex and amygdala mediating fear inhibition being underactive while other subregions that mediate fear expression are overactive. We also review work on various interventions and surprising circumstances which enhance fear extinction in adolescence. This latter work revealed that the neural correlates of extinction in adolescence are different to that in younger and older animals even when extinction retention is not impaired. This growing body of work highlights that adolescence is a unique period of development for fear inhibition.

Molecular mechanisms of D-cycloserine in facilitating fear extinction: insights from RNAseq

D-cycloserine (DCS) has been shown to be effective in facilitating fear extinction in animal and human studies, however the precise mechanisms whereby the co-administration of DCS and behavioural fear extinction reduce fear are still unclear. This study investigated the molecular mechanisms of intrahippocampally administered D-cycloserine in facilitating fear extinction in a contextual fear conditioning animal model. Male Sprague Dawley rats (n = 120) were grouped into four experimental groups (n = 30) based on fear conditioning and intrahippocampal administration of either DCS or saline. The light/dark avoidance test was used to differentiate maladapted (MA) (anxious) from well-adapted (WA) (not anxious) subgroups. RNA extracted from the left dorsal hippocampus was used for RNA sequencing and gene expression data was compared between six fear-conditioned + saline MA (FEAR + SALINE MA) and six fear-conditioned + DCS WA (FEAR + DCS WA) animals. Of the 424 significantly downregulated and 25 significantly upregulated genes identified in the FEAR + DCS WA group compared to the FEAR + SALINE MA group, 121 downregulated and nine upregulated genes were predicted to be relevant to fear conditioning and anxiety and stress-related disorders. The majority of downregulated genes transcribed immune, proinflammatory and oxidative stress systems molecules. These molecules mediate neuroinflammation and cause neuronal damage. DCS also regulated genes involved in learning and memory processes, and genes associated with anxiety, stress-related disorders and co-occurring diseases (e.g., cardiovascular diseases, digestive system diseases and nervous system diseases). Identifying the molecular underpinnings of DCS-mediated fear extinction brings us closer to understanding the process of fear extinction.

EFFECTS OF HOMEWORK COMPLIANCE ON COGNITIVE-BEHAVIORAL THERAPY WITH D-CYCLOSERINE AUGMENTATION FOR CHILDREN WITH OBSESSIVE COMPULSIVE DISORDER

BACKGROUND

The present study examined the effects of homework compliance on outcome from cognitive behavioral therapy (CBT) for children with obsessive-compulsive disorder (OCD) and the extent to which these effects differ as a function of augmentation of CBT with D-cycloserine (DCS).

METHODS

Twenty-seven youth with OCD were randomized to either 50 mg DCS or placebo (PBO) administered immediately after each of 10 CBT sessions, primarily consisting of exposure and ritual prevention (ERP). Independent evaluators assessed OCD severity using the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) at the start of each session. Compliance with between-session ERP assignments was also assessed at the start of each session using the Patient ERP Adherence Scale (PEAS).

RESULTS

Greater homework compliance between the previous session and the current session was related to lower CY-BOCS at the current session. However, the relation between homework compliance and CY-BOCS varied by treatment condition. Higher homework compliance was related to lower CY-BOCS for participants in the DCS condition, but not for participants in the PBO condition. Furthermore, participants receiving DCS were estimated to have significantly lower CY-BOCS than those given PBO among those with the highest levels of homework compliance.

CONCLUSIONS

DCS may more effectively facilitate the effects of CBT for youth with OCD when patients are compliant with prescribed homework. Theoretical and clinical implications are discussed.

Glutamatergic agents for OCD and related disorders

Pharmacotherapy remains inadequate for many patients with OCD; there is an urgent need for alternative pharmacological strategies. Convergent evidence suggests imbalance in glutamate, the brain's primary excitatory neurotransmitter, in some patients. This has motivated interest in glutamate modulators in patients who are unresponsive to standard pharmacotherapeutic approaches. While no glutamate modulator can be considered proven as an efficacious treatment of OCD, promising suggestions of benefit have been reported for memantine and riluzole. The evidence is thinner for N-acetylcysteine, but this agent's low cost and benign side effect profile make it a reasonable consideration in certain patients. Intriguing research on D-cycloserine and ketamine suggest potential benefit as well. It is notable that these agents all work by different, and in some cases opposite, mechanisms; this suggests that we have much to learn about the role of glutamate dysregulation in the etiology of OCD, and of glutamate modulators in its treatment.

An Overview of Translationally Informed Treatments for Posttraumatic Stress Disorder: Animal Models of Pavlovian Fear Conditioning to Human Clinical Trials

Posttraumatic stress disorder manifests after exposure to a traumatic event and is characterized by avoidance/numbing, intrusive symptoms and flashbacks, mood and cognitive disruptions, and hyperarousal/reactivity symptoms. These symptoms reflect dysregulation of the fear system likely caused by poor fear inhibition/extinction, increased generalization, and/or enhanced consolidation or acquisition of fear. These phenotypes can be modeled in animal subjects using Pavlovian fear conditioning, allowing investigation of the underlying neurobiology of normative and pathological fear. Preclinical studies reveal a number of neurotransmitter systems and circuits critical for aversive learning and memory that have informed the development of therapies used in human clinical trials. In this review, we discuss the evidence for a number of established and emerging pharmacotherapies and device-based treatments for posttraumatic stress disorder that have been developed via a bench to bedside translational model.

D-cycloserine enhances generalization of fear extinction in children

BACKGROUND

For exposure therapy to be successful, it is essential that fear extinction learning extends beyond the treatment setting. D-cycloserine (DCS) may facilitate treatment gains by increasing generalization of extinction learning, however, its effects have not been tested in children. We examined whether DCS enhanced generalization of fear extinction learning across different stimuli and contexts among children with specific phobias.

METHODS

The study was a double-blind placebo-controlled randomized controlled trial among dog or spider phobic children aged 6-14. Participants ingested either 50 mg of DCS (n = 18) or placebo (n = 17) before receiving a single prolonged exposure session to their feared stimulus. Return of fear was examined 1 week later to a different stimulus (a different dog or spider), presented in both the original treatment context and an alternate context. Avoidance and fear were measured with Behavior Approach Tests (BATs), where the child was asked to increase proximity to the stimulus while reporting their fear level.

RESULTS

There were no differences in BAT performance between groups during the exposure session or when a new stimulus was later presented in the treatment context. However, when the new stimulus was presented in a different context, relative to placebo, the DCS group showed less avoidance (P = .03) and less increase in fear (P = .04) with moderate effect sizes.

CONCLUSIONS

DCS enabled children to better retain their fear extinction learning. This new learning generalized to different stimuli and contexts.

Efficacy of Glutamate Modulators in Tic Suppression: A Double-Blind, Randomized Control Trial of D-serine and Riluzole in Tourette Syndrome

BACKGROUND

It has been hypothesized that glutamatergic transmission may be altered in Tourette syndrome. In this study, we explored the efficacy of a glutamate agonist (D-serine) and antagonist (riluzole) as tic-suppressing agents in children with Tourette syndrome.

METHODS

We performed a parallel three-arm, 8-week, double-blind, randomized placebo-controlled treatment study in children with Tourette syndrome. Each child received 6 weeks of treatment with D-serine (maximum dose 30 mg/kg/day), riluzole (maximum dose 200 mg/day), or placebo, followed by a 2-week taper. The primary outcome measure was effective tic suppression as determined by the differences in the Yale Global Tic Severity Scale score; specifically, the total tic score and the combined score (total tic score + global impairment) between treatment arms after 6 weeks of treatment. Mann-Whitney U tests were performed to analyze differences between each group and the placebo group.

RESULTS

Twenty-four patients (males = 21, ages 9-18) enrolled in the study; one patient dropped out before completion. Combined Yale Global Tic Severity Scale score and total tic scores improved in all groups. The 6-week mean percent improvement of the riluzole (n = 10), D-serine (n = 9), and placebo (n = 5) groups in the combined Yale Global Tic Severity Scale score were 43.7, 39.5, and 30.2 and for total tic scores were 38.0, 25.0, and 34.0, respectively. There were no significant differences in Yale Global Tic Severity Scale score or total tic score, respectively, between the riluzole and placebo (P = 0.35, 0.85) or D-serine and placebo (P = 0.50, 0.69) groups.

CONCLUSION

Tics diminished by comparable percentages in the riluzole, D-serine, and placebo groups. These preliminary data suggest that D-serine and riluzole are not effective in tic suppression.

Cognitive-behavioral therapy for pediatric obsessive-compulsive disorder: Empirical review and clinical recommendations

The efficacy of cognitive-behavioral therapy (CBT) for pediatric obsessive-compulsive disorder (OCD) has been the subject of much study over the past fifteen years. Building on a foundation of case studies and open clinical trials, the literature now contains many methodologically sound studies that have compared full CBT protocols to waitlist controls, pill placebo, psychosocial comparison conditions, active medication, combined treatments, and brief CBT. This review is part of a series commissioned by The Canadian Institute for Obsessive Compulsive Disorders (CIOCD) in an effort to publish in one place what is known about the efficacy of treatments for OCD. A total of fourteen studies were identified; collectively their findings support the efficacy of CBT for youth with OCD. CBT protocols that emphasized either strictly behavioral or cognitive conceptualizations have each been found efficacious relative to waitlist controls. Efforts to enhance CBT׳s efficacy and reach have been undertaken. These trials provide guidance regarding next steps to be taken to maximize efficacy and treatment availability. Findings from studies in community clinics suggest that significant treatment benefits can be realized and are not reported only from within academic contexts. These findings bode well for broader dissemination efforts. Recommendations for future research directions are provided.

D-cycloserine augmentation in behavioral therapy for obsessive-compulsive disorder: a meta-analysis

OBJECTIVE

To evaluate the overall effect of D-cycloserine (DCS) augmentation on exposure and response prevention (ERP) therapy for obsessive-compulsive disorder (OCD).

METHODS

Clinical studies on the effect of DCS augmentation on ERP therapy for OCD compared to placebo were included for meta analysis. The primary outcome was the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Meta-analyses were performed with a random-effect model or a fixed-effect model using the Cochrane Review Manager (RevMan, version 5.2) to calculate the odds ratio and the mean difference, with their corresponding 95% confidence intervals.

RESULTS

A total of six studies was included in the current meta-analyses, and their data were extracted. Among them, four were for analyses of DCS and Y-BOCS at midtreatment, six for analysis at posttreatment, and four at 3-month follow-up. Besides, three of the six eligible studies were included in the meta-analysis of the DCS and Clinical Global Impression-Severity Scale at posttreatment, and three in the meta-analysis of DCS and proportions of treatment responders and of subjects attaining clinical remission status criteria at posttreatment. Our meta-analyses do not reveal a significant effect of DCS augmentation in ERP therapy for OCD patients, except when measured at midtreatment. Compared to the placebo group, DCS augmentation did show a trend toward significantly lower/decreased Y-BOCS; when measured at posttreatment and in the subpopulation of DCS taken before some of the ERP sessions, DCS augmentation showed a trend toward significantly lower/decreased Y-BOCS.

CONCLUSION

Our result suggested that with the careful optimization of DCS-augmented ERP therapy by fine-tuning timing and dosing of DCS administration and number and frequency of ERP sessions, DCS may enhance the efficacy of ERP therapy in reducing the symptomatic severity of OCD patients, especially at early stage of the treatment; therefore, DCS augmentation could possibly reduce treatment cost, reduce treatment drop and refusal rate, and help to improve access to the limited number of experienced therapists.