Prescriptive variables for d-cycloserine augmentation of exposure therapy for posttraumatic stress disorder

Treatment Approaches for Posttraumatic Stress Disorder Derived From Basic Research on Fear Extinction

This brief review article will describe treatment approaches for posttraumatic stress disorder (PTSD) based on findings from basic research. The focus of this review will be fear conditioning and extinction models, which provide a translational model of PTSD that can help translate basic research in nonhuman animals through well-controlled trials confirming the efficacy of treatment approaches in humans with PTSD such as prolonged exposure therapy. Specific cognitive aspects of fear extinction processes, including consolidation and reconsolidation, are reviewed along with behavioral and pharmacological treatment strategies based on basic research in these areas including attempts to prevent the development of PTSD as well as the treatment of chronic PTSD. Pharmacological, behavioral, and device-based augmentation strategies of PTSD treatment based in basic science findings are reviewed, including those that disrupt noradrenergic receptor processes, medications that act on NMDA receptors, physical exercise, cannabinoids, estradiol, dexamethasone, yohimbine, losartan, dopamine, and MDMA, along with the evidence for their efficacy in human clinical samples. While fear extinction provides an exciting translational opportunity to improve PTSD based on basic science findings, we review limitations and challenges of the extant literature as well as future directions.

From Mouse to Man: N-Methyl-d-Aspartic Acid Receptor Activation as a Promising Pharmacotherapeutic Strategy for Autism Spectrum Disorders

The BALB/c mouse displays hypersensitivity to behavioral effects of MK-801 (dizocilpine), a noncompetitive N-methyl-d-aspartic acid (NMDA) receptor "open-channel" blocker, and shows both no preference for an enclosed stimulus mouse over an inanimate object and reduced social interaction with a freely behaving stimulus mouse. NMDA receptor agonist interventions improved measures of social preference and social interaction of the BALB/c mouse model of autism spectrum disorder (ASD). A "proof of principle/proof of concept" translational 10-week clinical trial with 8-week of active medication administration was conducted comparing 20 DSM-IV-TR-diagnosed older adolescent/young adult patients with ASD randomized to once-weekly pulsed administration (50 mg/d) versus daily administration of d-cycloserine (50 mg/d). The results showed that d-cycloserine, a partial glycine agonist, was well tolerated, the 2 dosing strategies did not differ, and improvement was noted on the "lethargy/social withdrawal" and "stereotypic behavior" subscales of the Aberrant Behavior Checklist. NMDA receptor activation contributes to the regulation of mTOR signaling, a pathologic point of convergence in several monogenic syndromic forms of ASD. Furthermore, both NMDA receptor hypofunction and imbalance between NMDA receptor activation mediated by GluN2B and GluN2A-containing NMDA receptors occur as "downstream" consequences of several genetically unrelated abnormalities associated with ASD. NMDA receptor-subtype selective "positive allosteric modulators (PAMs)" are particularly appealing medication candidates for future translational trials.

The glycine site of NMDA receptors: A target for cognitive enhancement in psychiatric disorders

Cognitive dysfunction is a principal determinant of functional impairment in major depressive disorder (MDD) and often persists during periods of euthymia. Abnormalities in the glutamate system, particularly in N-methyl-d-aspartate receptors (NMDARs) activity, have been shown to contribute to both mood and cognitive symptoms in MDD. The current narrative review aims to evaluate the potential pro-cognitive effects of targeting the glycine site of NMDARs in the treatment of psychiatric disorders, with a special focus on how these results may apply to MDD. Literature databases were searched from inception to May 2018 for relevant pre-clinical and clinical studies evaluating antidepressant and pro-cognitive effects of NMDAR glycine site modulators in both MDD and non-MDD samples. Six glycine site modulators with pro-cognitive and antidepressant properties were identified: d-serine (co-agonist), d-cycloserine (partial agonist), d-alanine (co-agonist), glycine (agonist), sarcosine (co-agonist) and rapastinel (partial agonist). Preclinical animal studies demonstrated improved neuroplasticity and pro-cognitive effects with these agents. Numerous proof-of-concept clinical trials demonstrated pro-cognitive and antidepressant effects trans-diagnostically (e.g., in healthy participants, MDD, schizophrenia, anxiety disorders, major neurocognitive disorders). The generalizability of these clinical studies was limited by the small sample sizes and the paucity of studies directly evaluating cognitive effects in MDD samples, as most clinical trials were in non-MDD samples. Taken together, preliminary results suggest that the glycine site of NMDARs is a promising target to ameliorate symptoms of depression and cognitive dysfunction. Additional rigorously designed clinical studies are required to determine the cognitive effects of these agents in MDD.

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 enhanced extinction of cocaine-induced conditioned place preference is attenuated in serotonin transporter knockout rats

d-Cycloserine (DCS), a partial NMDA receptor agonist, has been proposed as a cognitive enhancer to facilitate the extinction of drug-related memories. However, it is unknown whether there are individual differences in the efficacy of DCS. Here, we set out to investigate the influence of serotonin transporter (5-HTT) genotype on DCS treatment outcome and the underlying neural mechanism. To that end, we first determined the mRNA levels of several NMDA receptor subunits and observed a reduction in NR1/NR2C receptors in the ventromedial prefrontal cortex and nucleus accumbens of 5-HTT^-/- compared with 5-HTT^+/+ rats. Based on this finding, we hypothesized a lower sensitivity to DCS in the 5-HTT^-/- rats. To test this, rats were trained in a cocaine-induced conditioned place preference (CPP) paradigm. A significant extinction of CPP was observed in 5-HTT^+/+ rats receiving 1 mg/kg i.v. DCS, while a similar effect was found in the 5-HTT^-/- rats only after 5 mg/kg. Following CPP, we tested if DCS were able to reduce FosB/∆FosB protein expression, a molecular switch for cocaine-seeking behaviour. We observed an overall lower number of FosB/∆FosB positive cells in 5-HTT^-/- ventromedial prefrontal cortex and amygdala and an overall effect of DCS treatment on the number of positive cells in the nucleus accumbens. In conclusion, in this study, we show that the dosing of DCS to facilitate the extinction of cocaine-seeking behaviour is, at least partially, determined by 5-HTT genotype.

Intensive prolonged exposure therapy for chronic PTSD patients following multiple trauma and multiple treatment attempts

Background: Suboptimal response and high dropout rates leave room for improvement of trauma-focused treatment (TFT) effectiveness in ameliorating posttraumatic stress disorder (PTSD) symptoms. Objective: To explore the effectiveness and safety of intensive prolonged exposure (iPE) targeting chronic PTSD patients with a likely diagnosis of ICD-11 Complex PTSD following multiple interpersonal trauma and a history of multiple treatment attempts. Method: Participants (N = 73) received iPE in 12 × 90-minute sessions over four days (intensive phase) followed by four weekly 90-minute booster prolonged exposure (PE) sessions (booster phase). The primary outcomes, clinician-rated severity of PTSD symptoms, and diagnostic status (Clinician-Administered PTSD Scale; CAPS-IV) were assessed at baseline, post-treatment, and at three and six months. Treatment response trajectories were identified and predictors of these trajectories explored. Results: Mixed model repeated measures analysis of CAPS-IV scores showed a baseline-to-posttreatment decrease in PTSD symptom severity (p < .001) that persisted during the three- and six-month follow-ups with large effect sizes (Cohen's d > 1.2); 71% of the participants responded. None of the participants dropped out during the intensive phase and only 5% during the booster phase. Adverse events were extremely low and only a minority showed symptom exacerbation. Cluster analysis demonstrated four treatment response trajectories: Fast responders (13%), Slow responders (26%), Partial responders (32%), and Non-responders (29%). Living condition and between-session fear habituation were found to predict outcome. Participants living alone were more likely to belong to the Partial responders than to the Non-responders cluster, and participants showing more between-session fear habituation were more likely to belong to the Fast responders than to the Non-responders cluster. Conclusions: The results of this open study suggest that iPE can be effective in PTSD patients with multiple interpersonal trauma and after multiple previous treatment attempts. In addition, in this chronic PTSD population iPE was safe.

An empirical review of potential mediators and mechanisms of prolonged exposure therapy

Prolonged exposure (PE) is an empirically-supported treatment for posttraumatic stress disorder (PTSD), but the precise mechanism(s) by which PE promotes symptom change are not well established. Understanding how PE works is critical to improving clinical outcomes, advancing dissemination efforts, and enhancing transdiagnostic models of psychopathology. However, mechanisms research conducted in clinical treatment settings is complex, and findings may be difficult to interpret without appropriate context. This is the first review of potential mechanisms of PE to provide such context, by rigorously evaluating empirical findings in line with essential criteria for effective research on mechanisms (or mediators). We begin by describing six putative mechanisms identified by emotional processing theory and contemporary models of fear extinction, before thoroughly reviewing empirical findings from clinical research on PE and similar PTSD treatments. We provide a detailed description of each study and mechanism test, as well as ratings of strength of evidence and quality of evaluation based on a novel rating scheme. We highlight variables with strong evidence (belief change and between-session habituation), intermediate evidence (inhibitory learning and emotional engagement), and minimal support (narrative organization and within-session habituation). After discussing limitations of the extant literature and this review, we summarize specific challenges for research on PE mechanisms and highlight directions for future study based on clinical and research implications.

Emotional Modulation of Learning and Memory: Pharmacological Implications

Memory consolidation involves the process by which newly acquired information becomes stored in a long-lasting fashion. Evidence acquired over the past several decades, especially from studies using post-training drug administration, indicates that emotional arousal during the consolidation period influences and enhances the strength of the memory and that multiple different chemical signaling systems participate in this process. The mechanisms underlying the emotional influences on memory involve the release of stress hormones and activation of the basolateral amygdala, which work together to modulate memory consolidation. Moreover, work suggests that this amygdala-based memory modulation occurs with numerous types of learning and involves interactions with many different brain regions to alter consolidation. Additionally, studies suggest that emotional arousal and amygdala activity in particular influence synaptic plasticity and associated proteins in downstream brain regions. This review considers the historical understanding for memory modulation and cellular consolidation processes and examines several research areas currently using this foundational knowledge to develop therapeutic treatments.

What good are positive emotions for treatment? Trait positive emotionality predicts response to Cognitive Behavioral Therapy for anxiety

OBJECTIVE

Cognitive behavioral therapy (CBT) is empirically supported for the treatment of anxiety disorders; however, not all individuals achieve recovery following CBT. Positive emotions serve a number of functions that theoretically should facilitate response to CBT - they promote flexible patterns of information processing and assimilation of new information, encourage approach-oriented behavior, and speed physiological recovery from negative emotions. We conducted a secondary analysis of an existing clinical trial dataset to test the a priori hypothesis that individual differences in trait positive emotions would predict CBT response for anxiety.

METHOD

Participants meeting diagnostic criteria for panic disorder (n = 28) or generalized anxiety disorder (n = 31) completed 10 weekly individual CBT sessions. Trait positive emotionality was assessed at pre-treatment, and severity of anxiety symptoms and associated impairment was assessed throughout treatment.

RESULTS

Participants who reported a greater propensity to experience positive emotions at pre-treatment displayed the largest reduction in anxiety symptoms as well as fewer symptoms following treatment. Positive emotions remained a robust predictor of change in symptoms when controlling for baseline depression severity.

CONCLUSIONS

Initial evidence supports the predictive value of trait positive emotions as a prognostic indicator for CBT outcome in a GAD and PD sample.

Predicting trauma-focused treatment outcome in psychosis

OBJECTIVE

Although TF treatments are effective in patients with psychosis, it is unknown whether specific psychosis-related obstacles limit the effects, and what determines good outcome.

METHODS

Baseline posttraumatic stress disorder (PTSD) symptom severity and seven psychosis-specific variables were tested as predictors in patients with a psychotic disorder and PTSD (n=108), who received eight sessions of TF treatment (Prolonged Exposure, or Eye Movement Desensitization and Reprocessing therapy) in a single-blind randomized controlled trial. Multiple regression analyses were performed.

RESULTS

Baseline PTSD symptom severity was significantly associated with posttreatment PTSD symptom severity, explaining 11.4% of the variance. Additionally, more severe PTSD at baseline was also significantly associated with greater PTSD symptom improvement during treatment. After correction for baseline PTSD symptom severity, the model with the seven baseline variables did not significantly explain the variance in posttreatment PTSD outcome. Within this non-significant model, the presence of auditory verbal hallucinations contributed uniquely to posttreatment outcome but explained little variance (5.4%). Treatment completers and dropouts showed no significant difference on any of the psychosis-related variables.

CONCLUSIONS

Given the low predictive utility of baseline psychosis-related factors, we conclude that there is no evidence-based reason to exclude patients with psychotic disorders from TF treatments. Also, we speculate that patients with psychosis and severe baseline PTSD might derive more benefit if given more than eight sessions. Trial registration current controlled-trials.com | Identifier: ISRCTN79584912 | http://www.isrctn.com/ISRCTN79584912.

The key role of extinction learning in anxiety disorders: behavioral strategies to enhance exposure-based treatments

PURPOSE OF REVIEW

Extinction learning is a major mechanism for fear reduction by means of exposure. Current research targets innovative strategies to enhance fear extinction and thereby optimize exposure-based treatments for anxiety disorders. This selective review updates novel behavioral strategies that may provide cutting-edge clinical implications.

RECENT FINDINGS

Recent studies provide further support for two types of enhancement strategies. Procedural enhancement strategies implemented during extinction training translate to how exposure exercises may be conducted to optimize fear extinction. These strategies mostly focus on a maximized violation of dysfunctional threat expectancies and on reducing context and stimulus specificity of extinction learning. Flanking enhancement strategies target periods before and after extinction training and inform optimal preparation and post-processing of exposure exercises. These flanking strategies focus on the enhancement of learning in general, memory (re-)consolidation, and memory retrieval.

SUMMARY

Behavioral strategies to enhance fear extinction may provide powerful clinical applications to further maximize the efficacy of exposure-based interventions. However, future replications, mechanistic examinations, and translational studies are warranted to verify long-term effects and naturalistic utility. Future directions also comprise the interplay of optimized fear extinction with (avoidance) behavior and motivational antecedents of exposure.

Psychosocial predictors of treatment outcome for trauma-affected refugees

BACKGROUND

The effects of treatment in trials with trauma-affected refugees vary considerably not only between studies but also between patients within a single study. However, we know little about why some patients benefit more from treatment, as few studies have analysed predictors of treatment outcome.

OBJECTIVE

The objective of the study was to examine possible psychosocial predictors of treatment outcome for trauma-affected refugees.

METHOD

The participants were 195 adult refugees with posttraumatic stress disorder (PTSD) who were enrolled in a 6- to 7-month treatment programme at the Competence Centre for Transcultural Psychiatry (CTP), Denmark. The CTP Predictor Index used in the study included 15 different possible outcome predictors concerning the patients' past, chronicity of mental health problems, pain, treatment motivation, prerequisites for engaging in psychotherapy, and social situation. The primary outcome measure was PTSD symptoms measured on the Harvard Trauma Questionnaire (HTQ). Other outcome measures included the Hopkins Symptom Check List-25, the WHO-5 Well-being Index, Sheehan Disability Scale, Hamilton Depression and Anxiety Scales, the somatisation scale of the Symptoms Checklist-90, Global Assessment of Functioning scales, and pain rated on visual analogue scales. The relations between treatment outcomes and the total score as well as subscores of the CTP Predictor Index were analysed.

RESULTS

Overall, the total score of the CTP Predictor Index was significantly correlated to pre- to post treatment score changes on the majority of the ratings mentioned above. While employment status was the only single item significantly correlated to HTQ-score changes, a number of single items from the CTP Predictor Index correlated significantly with changes in depression and anxiety symptoms, but the size of the correlation coefficients were modest.

CONCLUSIONS

The total score of the CTP Predictor Index correlated significantly with outcomes on most of the rating scales, but correlations were modest in size, possibly due to the number of different factors influencing treatment outcome.

Exposing therapists to trauma-focused treatment in psychosis: effects on credibility, expected burden, and harm expectancies

BACKGROUND

Despite robust empirical support for the efficacy of trauma-focused treatments, the dissemination proves difficult, especially in relation to patients with comorbid psychosis. Many therapists endorse negative beliefs about the credibility, burden, and harm of such treatment.

OBJECTIVE

This feasibility study explores the impact of specialized training on therapists' beliefs about trauma-focused treatment within a randomized controlled trial.

METHOD

Therapist-rated (n=16) credibility, expected burden, and harm expectancies of trauma-focused treatment were assessed at baseline, post-theoretical training, post-technical training, post-supervised practical training, and at 2-year follow-up. Credibility and burden beliefs of therapists concerning the treatment of every specific patient in the trial were also assessed.

RESULTS

Over time, therapist-rated credibility of trauma-focused treatment showed a significant increase, whereas therapists' expected burden and harm expectancies decreased significantly. In treating posttraumatic stress disorder (PTSD) in patients with psychotic disorders (n=79), pre-treatment symptom severity was not associated with therapist-rated credibility or expected burden of that specific treatment. Treatment outcome had no influence on patient-specific credibility or burden expectancies of therapists.

CONCLUSIONS

These findings support the notion that specialized training, including practical training with supervision, has long-term positive effects on therapists' credibility, burden, and harm beliefs concerning trauma-focused 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.

Extinction learning as a moderator of d-cycloserine efficacy for enhancing exposure therapy in posttraumatic stress disorder

Augmentation of exposure therapy with d-cycloserine (DCS) has proven efficacious across anxiety disorders, although results in PTSD have been mixed. Work in animals and anxiety-disordered patients suggest that the potentiating effects of DCS are dependent on the level of extinction learning during extinction training and exposure treatment, respectively. The aim of the current study was to replicate and extend previous work by examining the association between the degree of extinction learning and DCS efficacy in our randomized clinical trial on DCS (50 mg) versus placebo enhancement of exposure therapy in a chronic mixed-trauma PTSD sample (N=67; de Kleine, Hendriks, Kusters, Broekman, & van Minnen, 2012). The decline in subjective units of distress ratings collected during and across the exposure sessions were evaluated as indices of extinction learning. First, we examined whether extinction learning during an exposure session moderated DCS effects on self-reported PTSD symptoms at the next session. Second, we examined whether averaged extinction learning over the course of treatment interacted with group assignment to predict change over time and post treatment outcome. We did not find evidence that DCS effects were moderated by the degree of extinction learning, although, extinction learning was related to outcome regardless of group assignment. In PTSD, not one extinction-learning index has been consistently linked to DCS enhanced exposure treatment outcome. More (experimental) work needs to been done to unravel the complex interplay between extinction learning and DCS enhancement, especially in PTSD patients.

NMDA receptor activation regulates sociability by its effect on mTOR signaling activity

Tuberous Sclerosis Complex is one example of a syndromic form of autism spectrum disorder associated with disinhibited activity of mTORC1 in neurons (e.g., cerebellar Purkinje cells). mTORC1 is a complex protein possessing serine/threonine kinase activity and a key downstream molecule in a signaling cascade beginning at the cell surface with the transduction of neurotransmitters (e.g., glutamate and acetylcholine) and nerve growth factors (e.g., Brain-Derived Neurotrophic Factor). Interestingly, the severity of the intellectual disability in Tuberous Sclerosis Complex may relate more to this metabolic disturbance (i.e., overactivity of mTOR signaling) than the density of cortical tubers. Several recent reports showed that rapamycin, an inhibitor of mTORC1, improved sociability and other symptoms in mouse models of Tuberous Sclerosis Complex and autism spectrum disorder, consistent with mTORC1 overactivity playing an important pathogenic role. NMDA receptor activation may also dampen mTORC1 activity by at least two possible mechanisms: regulating intraneuronal accumulation of arginine and the phosphorylation status of a specific extracellular signal regulating kinase (i.e., ERK1/2), both of which are "drivers" of mTORC1 activity. Conceivably, the prosocial effects of targeting the NMDA receptor with agonists in mouse models of autism spectrum disorders result from their ability to dampen mTORC1 activity in neurons. Strategies for dampening mTORC1 overactivity by NMDA receptor activation may be preferred to its direct inhibition in chronic neurodevelopmental disorders, such as autism spectrum disorders.

Augmentation of cognitive and behavioural therapies (CBT) with d-cycloserine for anxiety and related disorders

BACKGROUND

A significant number of patients who suffer with anxiety and related disorders (that is post-traumatic stress disorder (PTSD), social anxiety disorder (SAnD), panic disorder with or without agoraphobia (PD), specific phobia (SPh) and obsessive compulsive disorder (OCD)) fail to respond optimally to first-line treatment with medication or cognitive and behavioural therapies. The addition of d-cycloserine (DCS) to cognitive and behavioural therapies may improve treatment response by impacting the glutamatergic system. This systematic review aimed to investigate the effects of adding DCS to cognitive and behavioural therapies by synthesising data from relevant randomised controlled trials and following the guidelines recommended by Cochrane.

OBJECTIVES

To assess the effect of DCS augmentation of cognitive and behavioural therapies compared to placebo augmentation of cognitive and behavioural therapies in the treatment of anxiety and related disorders. Additionally, to assess the efficacy and tolerability of DCS across different anxiety and related disorders.

SEARCH METHODS

This review fully incorporates studies identified from a search of the Cochrane Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR) to 12 March 2015. This register includes relevant randomised controlled trials (RCTs) from: the Cochrane Library (all years), EMBASE (1974 to date), MEDLINE (1950 to date), PsycINFO (1967 to date), the World Health Organization's trials portal (ICTRP) and ClinicalTrials.gov . Reference lists from previous meta-analyses and reports of RCTs were also checked. No restrictions were placed on language, setting, date or publication status.

SELECTION CRITERIA

All RCTs of DCS augmentation of cognitive and behavioural therapies versus placebo augmentation of cognitive and behavioural therapies for anxiety and related disorders were included.

DATA COLLECTION AND ANALYSIS

Two authors (RO and TA) independently assessed RCTs for eligibility and inclusion, extracted outcomes and risk of bias data and entered these into a customised extraction form. Investigators were contacted to obtain missing data. In addition, data entry and analysis were performed by two review authors (KSW and HB).

MAIN RESULTS

Twenty-one published RCTs, with 788 participants in outpatient settings, were included in the review. Sixteen studies had an age range of 18 to 75 years, while four investigated paediatric populations aged 8 to 17 years and one included children, adolescents and adults. The 21 RCTs investigated OCD (number of RCTs (N) = 6), PTSD (N = 5), SAnD (N = 5), SPh (N = 3) and PD (N = 2). Most information from the studies was rated as having either low risk or unclear risk of bias.There was no evidence of a difference between DCS augmentation of cognitive and behavioural therapies and placebo augmentation of cognitive and behavioural therapies for the treatment of anxiety and related disorders in adults at the endpoint (treatment responders, N = 9, risk ratio (RR) 1.10; 95% confidence interval (CI) 0.89 to 1.34; number of participants (n) = 449; low quality evidence) and between 1 and 12 months follow-up (N = 7, RR 1.08; 95% CI 0.90 to 1.31; n = 383). DCS augmentation of cognitive and behavioural therapies was not superior to placebo augmentation of cognitive and behavioural therapies for children and adolescents, both at the endpoint (N = 4, RR 1.01; 95% CI 0.78 to 1.31; n = 121; low quality evidence) and between 3 and 12 months follow-up (N = 3, RR 0.86; 95% CI 0.67 to 1.09; n = 91).There was no evidence of a difference in treatment acceptability for DCS augmentation of cognitive and behavioural therapies compared with placebo augmentation of cognitive and behavioural therapies in adults (N = 16, RR 0.88; 95% CI 0.61 to 1.25; n = 740), nor in children and adolescents (N = 4, RR 0.90; 95% CI 0.17 to 4.69; n = 131). These conclusions were based on moderate quality evidence for adults, and very low quality evidence for children and adolescents. Although the observed difference was small, it is noteworthy that there was a high efficacy of exposure-based therapies alone in the included trials. Due to the limited number of studies, subgroup analysis of moderating factors for clinical and methodological effect could not take place.

AUTHORS' CONCLUSIONS

This review found no evidence of a difference between DCS augmentation of cognitive and behavioural therapies and placebo augmentation of cognitive and behavioural therapies for treating anxiety and related disorders in children, adolescents and adults. These findings are based on low quality evidence from heterogenous studies with small sample sizes and incomplete data for clinical response, which precludes us from drawing conclusions on the use of DCS augmentation of cognitive and behavioural therapies at this stage. Given there is some promising preliminary data from individual studies, further research is necessary to assess DCS compared with placebo augmentation of cognitive and behavioural therapies, and determine mechanisms of action as well as magnitude of effect in anxiety and related disorders.

Stress: perspectives on its impact on cognition and pharmacological treatment

Stress in life is unavoidable, affecting everyone on a daily basis. Psychological stress in mammals triggers a rapidly organized response for survival, but it may also cause a variety of behavioral disorders and damage cognitive function. Stress is associated with biases in cognitive processing; some of the most enduring memories are formed by traumatic events. Our understanding of how cognition is shaped by stress is still relatively primitive; however, evidence is rapidly accumulating that the 'mature' brain has a great capacity for plasticity and that there are numerous ways through which pharmacological therapeutics could rescue cognitive function and regain cognitive balance. In this review, we discuss recent advances in our understanding of the interplay between stress and cognitive processes and potential therapeutic approaches to stress-related behavioral and cognitive disorders.

The impact of alcohol use severity on anxiety treatment outcomes in a large effectiveness trial in primary care

OBJECTIVE

The presence of anxiety disorders is associated with poorer alcohol use disorder treatment outcomes, but little is known about the impact of alcohol use problems on anxiety disorder treatment outcomes despite their high comorbidity. The current study examined the impact of alcohol use symptom severity on anxiety disorder treatment outcomes in a multi-site primary care effectiveness study of anxiety disorder treatment.

METHOD

Data came from the Coordinated Anxiety Learning and Management (CALM) effectiveness trial. Participants (N=1004) were randomized to an evidence-based anxiety intervention (including cognitive behavioral therapy and medications) or usual care in primary care. Participants completed measures of alcohol use, anxiety, and depression at baseline, 6-, 12-, and 18-month follow-up periods. Patients with alcohol dependence were excluded.

RESULTS

There were no significant moderating (Treatment Group × Alcohol Use Severity) interactions. The majority of analyses revealed no predictive effects of alcohol use severity on outcome; however, alcohol problems at baseline were associated with somewhat higher anxiety and depression symptoms at the 18-month follow-up.

CONCLUSIONS

These data indicate that patients with alcohol problems in primary care can be effectively treated for anxiety disorders. Baseline alcohol problems were associated with some poorer long-term outcomes, but this was evident across CALM and usual care. These findings provide preliminary evidence that there may be no need to postpone treatment of anxiety disorders until alcohol problems are addressed, at least among those who have mild to moderate alcohol problems. Replication with more severe alcohol use disorders is needed.

Social cognition

Social cognition is a major problem underlying deficiencies in interpersonal relationships in several psychiatric populations. And yet there is currently no gold standard for pharmacological treatment of psychiatric illness that directly targets these social cognitive areas. This chapter serves to illustrate some of the most innovative attempts at pharmacological modulation of social cognition in psychiatric illnesses including schizophrenia, borderline personality disorder, autism spectrum disorders, antisocial personality disorder and psychopathy, social anxiety disorder, and posttraumatic stress disorder. Pharmacological modulation includes studies administering oxytocin, ecstasy (MDMA), modafinil, methylphenidate, and D-cycloserine. Furthermore, some background on social cognition research in healthy individuals, which could be helpful in developing future treatments, is provided as well as the potential for each drug as a long-term treatment option.

D-cycloserine augmentation of cognitive behavioral therapy for anxiety disorders: an update

Although cognitive behavioral therapy (CBT) is a generally effective treatment for treating anxiety disorders, there is clearly still room for further improvements. Recent advances in neuroscience of extinction learning led to novel clinical strategies to augment exposure-based treatments with d-cycloserine (DCS), a partial agonist at the glycine recognition site of the glutamatergic N-methyl-D-aspartate receptor. This review provides an update on the current knowledge of DCS as an augmentation strategy of CBT for anxiety disorders. The adequacy of the CBT to be augmented, the dose of DCS, and the timing and duration of augmentation efforts all appear to be important moderating variables. Moreover, there is evidence that DCS may also augment fear memory reconsolidation if the fear level remains high after the exposure. Future studies need to examine whether DCS can augment CBT when administered after exposure in order to develop a tailored administration strategy to maximize its clinical utility.

On the Road to Translation for PTSD Treatment: Theoretical and Practical Considerations of the Use of Human Models of Conditioned Fear for Drug Development

The use of quantitative, laboratory-based measures of threat in humans for proof-of-concept studies and target development for novel drug discovery has grown tremendously in the last 2 decades. In particular, in the field of posttraumatic stress disorder (PTSD), human models of fear conditioning have been critical in shaping our theoretical understanding of fear processes and importantly, validating findings from animal models of the neural substrates and signaling pathways required for these complex processes. Here, we will review the use of laboratory-based measures of fear processes in humans including cued and contextual conditioning, generalization, extinction, reconsolidation, and reinstatement to develop novel drug treatments for PTSD. We will primarily focus on recent advances in using behavioral and physiological measures of fear, discussing their sensitivity as biobehavioral markers of PTSD symptoms, their response to known and novel PTSD treatments, and in the case of d-cycloserine, how well these findings have translated to outcomes in clinical trials. We will highlight some gaps in the literature and needs for future research, discuss benefits and limitations of these outcome measures in designing proof-of-concept trials, and offer practical guidelines on design and interpretation when using these fear models for drug discovery.

Pharmacotherapy in the aftermath of trauma; opportunities in the 'golden hours'

Several lines of research have demonstrated that memories for fearful events become transiently labile upon re-exposure. Activation of molecular mechanisms is required in order to maintain retrieved information. This process is called reconsolidation. Targeting reconsolidation - as in exposure-based psychotherapy - offers therefore a potentially interesting tool to manipulate fear memories, and subsequently to treat disorders such as post-traumatic stress disorder (PTSD). In this paper we discuss the evidence for reconsolidation in rodents and humans and highlight recent studies in which clinical research on normal and abnormal fear extinction reduction of the expression of fear was obtained by targeting the process of reconsolidation. We conclude that reconsolidation presents an interesting opportunity to modify or alter fear and fear-related memories. More clinical research on normal and abnormal fear extinction is required.