D-Cycloserine Augmentation of Cognitive-Behavioral Therapy: Directions for Pilot Research in Pediatric Obsessive-Compulsive Disorder

Successful pharmacotherapy for the treatment of severe feeding aversion with mechanistic insights from cross-species neuronal remodeling

Pediatric feeding disorders affect up to 5% of children, causing severe food intake problems that can result in serious medical and developmental outcomes. Behavioral intervention (BI) is effective in extinguishing feeding aversions, and also expert-dependent, time/labor-intensive and not well understood at a neurobiological level. Here we first conducted a double-blind, placebo-controlled trial comparing BI with BI plus d-cycloserine (DCS). DCS is a partial N-methyl-d-aspartate (NMDA) receptor agonist shown to augment extinction therapies in multiple anxiety disorders. We examined whether DCS enhanced extinction of feeding aversion in 15 children with avoidant/restrictive food intake disorder (ages 20-58 months). After five treatment days, BI improved feeding by 37%. By contrast, BI+DCS improved feeding by 76%. To gain insight into possible mechanisms of successful intervention, we next tested the neurobiological consequences of DCS in a murine model of feeding aversion and avoidance. In mice with conditioned food aversion, DCS enhanced avoidance extinction across a broad dose range. Confocal fluorescence microscopy and three-dimensional neuronal reconstruction indicated that DCS enlarged dendritic spine heads-the primary sites of excitatory plasticity in the brain-within the orbitofrontal prefrontal cortex, a sensory-cognition integration hub. DCS also increased phosphorylation of the plasticity-associated extracellular signal-regulated kinase 1/2. In summary, DCS successfully augments the extinction of food aversion in children and mice, an effect that may involve plasticity in the orbitofrontal cortex. These results warrant a larger-scale efficacy study of DCS for the treatment of pediatric feeding disorders and further investigations of neural mechanisms.

Factors Associated With Parental Consent to use D-Cycloserine for Child Anxiety

This study examined factors influencing parent willingness to use D-Cycloserine (DCS) for treating child anxiety. N = 222 parents were given information about using DCS to treat anxiety. They were then asked to rate their willingness to allow their child to take DCS/antibiotics for mild anxiety, severe anxiety, or an infection. The associations between willingness to use DCS and parental trait anxiety, demographics, as well as specific concerns regarding the medication, were examined. Parents could also provide written responses regarding their attitudes to DCS, which were analysed for themes. Parents reported concerns regarding potential side-effects from DCS. More severe anxiety was associated with more willingness to consent; however, parents were more willing to use antibiotics to treat an infection than DCS to treat their child's anxiety. The degree of perceived benefit from DCS was most strongly associated with parents’ willingness to use it. Overall, parents expressed mixed views, reporting they would consider using DCS to treat their child; however, they had significant concerns about it. Results suggest providing parents with information explaining how DCS works, its risks and potential benefits may increase its acceptability.

Does D-cycloserine enhance exposure therapy for anxiety disorders in humans? A meta-analysis

The treatment of anxiety is on the edge of a new era of combinations of pharmacologic and psychosocial interventions. A new wave of translational research has focused on the use of pharmacological agents as psychotherapy adjuvants using neurobiological insights into the mechanism of the action of certain psychological treatments such as exposure therapy. Recently, d-cycloserine (DCS) an antibiotic used to treat tuberculosis has been applied to enhance exposure-based treatment for anxiety and has proved to be a promising, but as yet unproven intervention. The present study aimed to evaluate the efficacy of DCS in the enhancement of exposure therapy in anxiety disorders. A systematic review/meta-analysis was conducted. Electronic searches were conducted in the databases ISI-Web of Science, Pubmed and PsycINFO. We included only randomized, double-blind, placebo-controlled trials with humans, focusing on the role of DCS in enhancing the action of exposure therapy for anxiety disorders. We identified 328 references, 13 studies were included in our final sample: 4 on obsessive-compulsive disorder, 2 on panic disorder, 2 on social anxiety disorder, 2 on posttraumatic stress disorder, one on acrophobia, and 2 on snake phobia. The results of the present meta-analysis show that DCS enhances exposure therapy in the treatment of anxiety disorders (Cohen d =  −0.34; CI: −0.54 to −0.14), facilitating the specific process of extinction of fear. DCS seems to be effective when administered at a time close to the exposure therapy, at low doses and a limited number of times. DCS emerges as a potential new therapeutic approach for patients with refractory anxiety disorders that are unresponsive to the conventional treatments available. When administered correctly, DCS is a promising strategy for augmentation of CBT and could reduce health care costs, drop-out rates and bring faster relief to patients.

Advances in the treatment of pediatric obsessive-compulsive d-cycloserine with exposure and response prevention

Exposure-based cognitive-behavioral therapy and serotonin reuptake inhibitor medications are efficacious treatment options for the management of pediatric obsessive-compulsive disorder. Despite established efficacy, many youths receiving either therapy remain symptomatic after acute treatment. Regardless of the rationale for persistent symptoms, a clear need emerges for treatment options that restore functioning efficiently to symptomatic youths. One innovative approach builds upon the identified role of NMDA receptors in the fear extinction process. Instead of breaking existing connections during fear extinction, new associations develop that eventually predominate over prior associations. Recent investigations have explored augmenting exposure-based cognitive-behavioral therapy with the NMDA partial agonist d-cycloserine, with preliminary results demonstrating expedited treatment gains and moderately larger effects above exposure and response prevention therapy alone. A large randomized clinical trial is underway to evaluate the efficacy and efficiency of this therapeutic combination in pediatric obsessive-compulsive disorder. Results from this trial may translate into improved management practices.