Are child and adolescent responses to placebo higher in major depression than in anxiety disorders? A systematic review of placebo-controlled trials

Systematic Review and Meta-Analysis of the Placebo Effect and its Correlates in Obsessive Compulsive Disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is a major mental health condition with a lifetime prevalence rate of 1.3% among adults. While placebo effects are well described for conditions such as depressive and anxiety disorders, they have not been systematically characterized in OCD.

OBJECTIVES

We aimed to determine the impact of placebos in improving different symptom domains in patients with OCD.

METHODS

We systematically searched PubMed, EMBASE, Scopus, Web of Science, Ovid, the Cochrane Library, and Google Scholar databases/search engine from inception to January 2021 for randomized controlled trials of treatments for OCD with a placebo arm. A modified Cohen's effect size (ES) was calculated using change in baseline to endpoint scores for different measurement scales within placebo arms to estimate placebo effects and to investigate their correlates by random-effects model meta-analyses.

RESULTS

Forty-nine clinical trials (placebo group n  =  1993), reporting 80 OCD specific (153 measures in general) were included in the analysis. Overall placebo ES (95% confidence interval [CI]) was 0.32 (0.22-0.41) on OCD symptoms, with substantial heterogeneity (I-square = 96.1%). Among secondary outcomes, general scales, ES: 0.27 (95%CI: 0.14-0.41), demonstrated higher ES than anxiety and depression scales, ES: 0.14 (95%CI: -0.4 to 0.32) and 0.05 (95%CI: -0.05 to 0.14), respectively. Clinician-rated scales, ES: 0.27(95%CI: 0.20-0.34), had a higher ES than self-reported scales, ES: 0.07 (95%CI: -0.08 to 0.22). More recent publication year, larger placebo group sample size, shorter follow-up duration, and younger age of participants were all associated with larger placebo ES. Egger's test reflected possible small-study effect publication bias (P  =  0.029).

CONCLUSION

Placebo effects are modest in OCD trials and are larger in clinician ratings, for younger patients, and early in the treatment course. These findings underscore the need for clinicians and scientists to be mindful of placebo effects when formulating treatments or research trials for OCD.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42019125979.

Placebo response in trials with patients with anxiety, obsessive-compulsive and stress disorders across the lifespan: a three-level meta-analysis

QUESTION

Randomised controlled trials assessing treatments for anxiety, obsessive-compulsive and stress-related disorders often present high placebo response rates in placebo groups. Understanding the placebo response is essential in accurately estimating the benefits of pharmacological agents; nevertheless, no studies have evaluated the placebo response across these disorders using a lifespan approach.

STUDY SELECTION AND ANALYSIS

We searched MEDLINE, PsycINFO, Embase, Cochrane, websites of regulatory agencies and international registers from inception to 9 September 2022. The primary outcome was the aggregate measure of internalising symptoms of participants in the placebo arms of randomised controlled trials designed to assess the efficacy of selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) in individuals diagnosed with anxiety, obsessive-compulsive or stress-related disorders. The secondary outcomes were placebo response and remission rates. Data were analysed through a three-level meta-analysis.

FINDINGS

We analysed 366 outcome measures from 135 studies (n=12 583). We found a large overall placebo response (standardised mean difference (SMD)=-1.11, 95% CI -1.22 to -1.00). The average response and remission rates in placebo groups were 37% and 24%, respectively. Larger placebo response was associated with a diagnosis of generalised anxiety disorder and post-traumatic stress disorder, when compared with panic, social anxiety and obsessive-compulsive disorder (SMD range, 0.40-0.49), and with absence of a placebo lead-in period (SMD=0.44, 95% CI 0.10 to 0.78). No significant differences were found in placebo response across age groups. We found substantial heterogeneity and moderate risk of bias.

CONCLUSIONS

Placebo response is substantial in SSRI and SNRI trials for anxiety, obsessive-compulsive and stress-related disorders. Clinicians and researchers should accurately interpret the benefits of pharmacological agents in contrast to placebo response.

PROSPERO REGISTRATION NUMBER

CRD42017069090.

Efficacy and Safety of Duloxetine in Children and Adolescents with Major Depressive Disorder in Japan: A Randomized Double-Blind Placebo-Controlled Clinical Trial Followed by an Open-Label Long-Term Extension Trial

Objective: The goal of this study was to evaluate the efficacy and safety of duloxetine in children and adolescents (9-17 years of age) with major depressive disorder (MDD) in Japan. Methods: This study consists of two clinical trials. First, a 6-week, randomized double-blind placebo-controlled clinical trial (RCT) was conducted. The primary endpoint of RCT was the change in Children's Depression Rating Scale-Revised (CDRS-R) total scores from baseline. Following RCT, an open-label long-term extension trial (OLE) was conducted to investigate the longer-term safety of duloxetine for ∼1 year. Results: In RCT, CDRS-R total score changes from baseline to 6 weeks after the start of administration (primary endpoint) were -21.03 in the duloxetine group (n = 74) and -22.42 in the placebo group (n = 74). No significant difference was observed in the primary endpoint between the groups (p = 0.5587). In addition, no significant difference was observed in secondary endpoints such as CDRS-R response rates. The proportion of patients with ≥1 treatment-emergent adverse event (TEAE) in RCT was significantly higher in the duloxetine group (78.7%) than in the placebo group (62.2%), and most were mild or moderate in severity. Changes in CDRS-R total scores during OLE, in consecutive patients from the duloxetine group in RCT (n = 63), or placebo group (n = 59) in RCT, and newly enrolled patients (n = 28), were -12.1, -11.3, and -17.8, respectively. The proportion of patients with ≥1 TEAE in OLE was 90.5%, 88.1%, and 89.3% in the respective groups, and most of them were mild or moderate in severity. Conclusions: Duloxetine did not show superiority to placebo in efficacy in children and adolescents with MDD in Japan. Overall reported TEAEs were consistent with the currently available duloxetine safety profile and no new safety finding was observed in the two clinical trials.

Influence of motivational placebo-related factors on the effects of exercise treatment in depressive adolescents

Recent meta-analyses reveal a moderate effect of physical activity (PA) in the treatment of adolescent depression. However, not only the underlying neurobiological mechanisms, also the influences of placebo-related motivational factors (beliefs and expectancies in sporting, enjoyment and prior sports experiences), are still unclear. Based on the data of our prior study "Mood Vibes", we hypothesized that placebo-inherent factors like positive prior sports experiences and motivational factors, (positive beliefs, expectancies, and enjoyment related to PA), would increase the effects of an add-on exercise-therapy in juvenile depression. From 64 included depressed adolescents, 41 underwent an intensive add-on PA-therapy. Motivational factors were assessed using sport-specific scales. The changes in depression scores under treatment were rated by self-rating scale (German "Childhood Depression Inventory", (DIKJ)). A mixed model for repeated measures (MMRM) was used to analyze the effects of the different motivational variates on DIKJ. While prior sports experiences had no impact, motivational factors showed a significant effect on PA-induced changes in DIKJ scores (p = 0.002). The demotivated participants improved less, whereas it was sufficient to be neutral towards sporting to benefit significantly more. Motivational placebo-related factors (beliefs, expectancies and enjoyment regarding PA) affected the outcomes of an exercise treatment in depressed adolescents. Yet, a neutral mindset was sufficient to profit more from PA. Prior sporting in the sense of positive conditioning and as a protective factor did not play a role. Knowledge about these influences could in a second step help to develop tailored therapies.

Meta-Analysis: Pediatric Placebo Response in Depression Trials Does Not Replicate in Anxiety and Obsessive-Compulsive Disorder Trials

Background: Placebo response has been identified as an important factor influencing the success of adult antidepressant trials, yet little research of placebo response has been conducted in pediatric populations. Understanding disorder-specific and transdiagnostic predictors of pediatric placebo response is important in designing successful child psychopharmacological trials. Methods: A PubMed search was conducted for all pediatric antidepressant randomized controlled trials treating depression, anxiety, or obsessive-compulsive disorder (OCD). A random-effects model was utilized to examine the magnitude of placebo symptom improvement using standardized mean difference (SMD) and placebo response rates. Stratified subgroup analysis was performed by diagnostic indication. Meta-regression was utilized to search possible correlates of placebo symptom improvement and placebo response rate. Results: Thirty antidepressant trials involving 2911 participants receiving placebo were included in this meta-analysis. Magnitude of placebo improvement and placebo response rates varied significantly across disorders; being greater in depression (SMD = 1.44, 95% confidence interval [CI]: 1.18 to 1.71) than anxiety disorders (SMD = 1.09, 95% CI: 0.77 to 1.41) and the lowest in OCD (SMD = 0.71, 95% CI: 0.32 to 1.12). Different predictors were associated with placebo response in different indications. Conclusions: Both the magnitude and predictors of placebo response in pediatric depression trials do not replicate across anxiety and OCD. Based on our results, across disorders, minimizing the number of sites might significantly reduce placebo improvement. In addition to these, we could potentially decrease the placebo response in depression trials by increasing the number of subjects enrolled per study site, minimizing the number of study visits and conducting the studies in the United States. Further research is needed into the predictors of placebo response in pediatric anxiety and OCD.

Talking to Children and Families about Chronic Pain: The Importance of Pain Education-An Introduction for Pediatricians and Other Health Care Providers

Chronic pain in children and adolescents is a common and debilitating health problem. This narrative review will give a brief overview on what pediatric chronic pain is and what treatment options there are for children and adolescents. The specific emphasis will be on pediatric chronic pain education and communication: this narrative review aims to show how important a good patient-health care provider relationship is-it builds the foundation for successful communication-and how this relationship can be established. In addition, we will present five steps that health care providers can perform to explain pediatric chronic pain to patients and their parents and what to keep in mind in their clinical routine. Our review is intended for pediatricians and other health care providers who treat pediatric patients with chronic pain but might feel uncertain on how to best communicate with them.

A Randomized, Double-Blind, Placebo-Controlled Trial of Vilazodone in Children and Adolescents with Major Depressive Disorder with Twenty-Six-Week Open-Label Follow-Up

Objective: To evaluate the efficacy and long-term safety of vilazodone in children and adolescent outpatients with major depressive disorder (MDD). Methods: Children and adolescents aged 7-17 years of age with MDD were randomized 2:2:1 to 8 weeks of double-blind placebo, vilazodone 15 or 30 mg/day or fluoxetine 20 mg/day, respectively. The primary and secondary efficacy outcomes, respectively, were change from baseline to week 8 in Children's Depression Rating Scale-Revised (CDRS-R) score total score and Clinical Global Impressions-Severity (CGI-S) score analyzed using a mixed model for repeated measurement approach. Patients who completed the 8-week randomized controlled trial (RCT), as well as new (de novo) patients, could participate in a 26-week, vilazodone-only, open-label extension (OLE) study. Results: The RCT enrolled 473 patients (60% female) with an average age of 13 years. Change in CDRS-R and CGI-S scores from baseline to week 8 did not differ between patients who received vilazodone and those randomized to placebo. The least-squares mean change from baseline in CDRS-R scores was similar for vilazodone and placebo (-20.7 vs. -20.3, p = 0.77; least-squares mean difference [LSMD] = -0.40). For fluoxetine, the LSMD versus placebo was -2.3 (p = 0.14). The OLE enrolled 330 patients (60% female) with an average age of 13-14 years. Overall, no new safety concerns were identified compared to what is known in adults. Conclusions: Similar improvements in depressive symptoms were observed in all arms. This study does not support the efficacy of vilazodone 15 or 30 mg/day for pediatric patients with MDD. No new or unexpected safety concerns were detected during the RCT or OLE studies.

Significant effect of information placebo on exercise test results in children with normal weight, overweight and obesity

AIM

The aim of the study was to examine the effect of information placebo on fitness test results in normal weight, overweight and obese children.

METHODS

Twenty-four pre-pubertal children with overweight or obesity and 24 age and maturity-matched normal weight children performed a progressive treadmill exercise test twice. Different types of information were randomly provided regarding a water drink consumed prior to testing; standard (water) vs deliberate positive (presumed energy drink, placebo) information.

RESULTS

Following the placebo drink, both groups demonstrated significantly higher peak heart rate (overweight 165.8 ± 16.7 vs 174.2 ± 14.8 bpm and normal weight 177.9 ± 13.6 vs 189.8 ± 12.2 bpm) and longer time to exhaustion (overweight 396.9 ± 161.9 vs 521.5 ± 182.5 seconds; normal weight: 700.1 ± 155.2 vs 893.3 ± 150.1 seconds). Despite longer exercise duration and higher peak heart rate, average and peak rate of perceived exertion were significantly lower after the placebo drink (overweight 14.1 ± 2.5 vs 12.5 ± 2.5; normal weight 12.1 ± 1.4 vs 10.7 ± 1.5), with significantly shorter recovery time (overweight 132.2 ± 28.5 vs 118.4 ± 31.6; normal weight: 106.7 ± 18.6 vs 96.7 ± 17.8 seconds).

CONCLUSION

Our results demonstrate a significant effect of information placebo on fitness test results that is unrelated to body weight. Children with obesity may enhance their physical activity levels and energy expenditure if properly encouraged.

The Impact of Placebo Response Rates on Clinical Trial Outcome: A Systematic Review and Meta-Analysis of Antidepressants in Children and Adolescents with Major Depressive Disorder

Objective: The high placebo response rate may hamper the discovery of antidepressants in children and adolescents with major depressive disorder (MDD). The aim of the study was to clarify the relationship between the placebo response rate and clinical trial outcomes of the use of antidepressants in children and adolescents, and distinguish main factors responsible to placebo response rate. Methods: The PubMed and Cochrane Library databases were searched for double-blind randomized placebo-controlled trials of the new-generation antidepressants for the acute treatment of MDD in children and adolescents. The response rate differences (RDs) between placebo group and treatment group under different level of placebo response rate were pooled by random-effects meta-analysis. The classification thresholds for low, medium, and high placebo response rate were set at <40%, 40%-50%, and ≥50%, respectively. Predictors of placebo response rate were explored using meta-regression. Results: The analysis included 18 trials with 4365 participants. This study found that the lower the placebo response rate, the greater the efficacy differences between antidepressants and placebo. In the high, moderate, and low placebo response rate subgroups, the response RDs (95% CI) between antidepressants and placebo were 8 (1-14)%, 10 (2-17)%, and 21 (9-32)%, respectively. The meta-regression showed that the number of study sites was the factor most associated with placebo response rate, and that response rate increased 3% with every additional 10 study sites. Conclusions: The clinical outcome was related to the placebo response rates in the clinical trials of antidepressants in children and adolescents with MDD. The efficacy differences between antidepressants and placebo will be maximized when placebo response rates are reduced. The number of study sites was the factor most associated with the placebo response rates.

The Use of Opioids for Treatment of Pediatric Neuropathic Pain: A Literature Review

Pediatric neuropathic pain is caused by a spectrum of disorders that are generally challenging to treat. Many of the underlying altered neurological processes are being elucidated through mechanistic studies. Few randomized control trials have evaluated the use of opioids for the treatment of adult neuropathic pain conditions, and there have been none in pediatric populations. With sparse data to provide guidance and an incomplete understanding of the underlying mechanisms, the use of opioids remains unclear. Our clinical experience and typical risk versus benefit considerations suggest a limited, if any, role for using opioids to treat pediatric neuropathic pain. In this literature review, we review the available adult and pediatric data and provide general guidance on this subject matter.

Short- and Long-Term Antidepressant Clinical Trials for Major Depressive Disorder in Youth: Findings and Concerns

The diagnosis of major depressive disorder (MDD) in U.S. youth is increasing as is the rate of antidepressant medication (ADM) treatment for the disorder. Fluoxetine and escitalopram are FDA approved for the short term and maintenance treatment of MDD in youth. Placebo-controlled short-term ADM trials represent the basis for Food and Drug Administration (FDA) approval. Meta-analyses in 2007 and 2016 revealed that short-term ADM treatment of youth diagnosed with MDD resulted in no meaningful benefit for children and only marginal benefit for adolescents. Placebo substitution trials of ADM short-term responders represent the basis for FDA approval of ADM maintenance treatment. These ADM placebo substitution maintenance trials for youth with MDD are characterized by high dropout rates, a rapid withdrawal that often can follow the switch to placebo, and relapse rates that are not dissimilar from those in the natural course of the disorder. Without the evidence from problematic ADM placebo substitution trials, there is no acceptable support for the inclusion of ADM in maintenance treatment for MDD in youth.

The Short-Term Placebo Response in Children With Attention-Deficit Hyperactivity Disorder (ADHD)

To assess short-term placebo response in 6- to 13-year-old children with ADHD, children who were administered a double-blind placebo-methylphenidate trial, 1 week each, were included in the analysis. Conners' parents and Teacher Rating scales, the Aggregate Neurobehavioral Student Health and Educational Review inventory, and the Matching Familiar Figure Test were employed. A reduction of 30% or more in one or more of the teachers report subscales was observed in 18.8% of the participants. Attention test performance resulted in 58% of children exhibiting reduction in error rates and 36.2% exhibited longer latency period. Significant correlations between placebo response and methylphenidate response in all of the teachers report subscales were found. Base line severity, learning problem and emotional status were found associated with placebo response. Short-term placebo response should be accounted for in children with ADHD.

Inpatient psychiatric treatment is not always effective in adolescent sample

OBJECTIVE

Numerous studies confirm efficacy of psychiatric treatment as well as psychiatric placebo. The aim of the current study was the assessment of improvement rate and factors associated with treatment response in naturalistic group of adolescent inpatients.

METHODS

Eighty two consecutive adolescent inpatients were recruited. Each patient at the admission and discharge was assessed with brief psychiatric rating scale (BPRS), eating attitude test (EAT-26), clinical global impression scale (CGI-S) and children global assessment scale (CGAS). Individual and family history was assessed by semi-structured interview. Patients, who improved in at least two interviewer-based scales (IMP, n = 67) were compared to the rest (N-IMP, n = 15). For statistical analysis STATISTICA package was used.

RESULTS

The main difference between groups was ICD-10 diagnosis distribution: in the IMP group more anxiety-related disorders (F4), in the N-IMP group more personality disorders (F6). Other differences include history of paediatric hospitalisations and surgery (more in the N-IMP group). Most of the analysed factors did not differ between groups.

CONCLUSIONS

The inpatient treatment seems to be most effective in severe mental states and in anxiety-related disorders and least effective in personality disorders. Due to limited inpatient treatment efficacy we believe outpatients services are crucial in adolescent psychiatry.

Anticipatory Effects on Perceived Pain: Associations With Development and Anxiety

OBJECTIVE

Naturalistic studies suggest that expectation of adverse experiences such as pain exerts particularly strong effects on anxious youth. In healthy adults, expectation influences the experience of pain. The current study uses experimental methods to compare the effects of expectation on pain among adults, healthy youth, and youth with an anxiety disorder.

METHODS

Twenty-three healthy adults, 20 healthy youth, and 20 youth with an anxiety disorder underwent procedures in which auditory cues were paired with noxious thermal stimulation. Through instructed conditioning, one cue predicted low-pain stimulation and the other predicted high-pain stimulation. At test, each cue was additionally followed by a single temperature calibrated to elicit medium pain ratings. We compared cue-based expectancy effects on pain across the three groups, based on cue effects on pain elicited on medium heat trials.

RESULTS

Across all groups, as expected, participants reported greater pain with increasing heat intensity (β = 2.29, t(41) = 29.94, p < .001). Across all groups, the critical medium temperature trials were rated as more painful in the high- relative to low-expectancy condition (β = 1.72, t(41) = 10.48, p < .001). However, no evidence of between-group differences or continuous associations with age or anxiety was observed.

CONCLUSIONS

All participants showed strong effects of expectancy on pain. No influences of development or anxiety arose. Complex factors may influence associations among anxiety, development, and pain reports in naturalistic studies. Such factors may be identified using experiments that employ more complex, yet controlled manipulations of expectancy or assess neural correlates of expectancy.

Efficacy and Safety of Selective Serotonin Reuptake Inhibitors, Serotonin-Norepinephrine Reuptake Inhibitors, and Placebo for Common Psychiatric Disorders Among Children and Adolescents: A Systematic Review and Meta-analysis

Importance

Depressive disorders (DDs), anxiety disorders (ADs), obsessive-compulsive disorder (OCD), and posttraumatic stress disorder (PTSD) are common mental disorders in children and adolescents.

Objective

To examine the relative efficacy and safety of selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and placebo for the treatment of DD, AD, OCD, and PTSD in children and adolescents.

Data Sources

PubMed, EMBASE, PsycINFO, Web of Science, and Cochrane Database from inception through August 7, 2016.

Study Selection

Published and unpublished randomized clinical trials of SSRIs or SNRIs in youths with DD, AD, OCD, or PTSD were included. Trials using other antidepressants (eg, tricyclic antidepressants, monoamine oxidase inhibitors) were excluded.

Data Extraction and Synthesis

Effect sizes, calculated as standardized mean differences (Hedges g) and risk ratios (RRs) for adverse events, were assessed in a random-effects model.

Main Outcomes and Measures

Primary outcomes, as defined by authors on preintervention and postintervention data, mean change data, and adverse event data, were extracted independently by multiple observers following PRISMA guidelines.

Results

Thirty-six trials were eligible, including 6778 participants (3484 [51.4%] female; mean [SD] age, 12.9 [5.1] years); 17 studies for DD, 10 for AD, 8 for OCD, and 1 for PTSD. Analysis showed that SSRIs and SNRIs were significantly more beneficial compared with placebo, yielding a small effect size (g = 0.32; 95% CI, 0.25-0.40; P < .001). Anxiety disorder (g = 0.56; 95% CI, 0.40-0.72; P < .001) showed significantly larger between-group effect sizes than DD (g = 0.20; 95% CI, 0.13-0.27; P < .001). This difference was driven primarily by the placebo response: patients with DD exhibited significantly larger placebo responses (g = 1.57; 95% CI, 1.36-1.78; P < .001) compared with those with AD (g = 1.03; 95% CI, 0.84-1.21; P < .001). The SSRIs produced a relatively large effect size for ADs (g = 0.71; 95% CI, 0.45-0.97; P < .001). Compared with participants receiving placebo, patients receiving an antidepressant reported significantly more treatment-emergent adverse events (RR, 1.07; 95% CI, 1.01-1.12; P = .01 or RR, 1.49; 95% CI, 1.22-1.82; P < .001, depending on the reporting method), severe adverse events (RR, 1.76; 95% CI, 1.34-2.32; P < .001), and study discontinuation due to adverse events (RR, 1.79; 95% CI, 1.38-2.32; P < .001).

Conclusions and Relevance

Compared with placebo, SSRIs and SNRIs are more beneficial than placebo in children and adolescents; however, the benefit is small and disorder specific, yielding a larger drug-placebo difference for AD than for other conditions. Response to placebo is large, especially in DD. Severe adverse events are significantly more common with SSRIs and SNRIs than placebo.

Drug versus placebo randomized controlled trials in neonates: A review of ClinicalTrials.gov registry

BACKGROUND

Despite specific initiatives and identified needs, most neonatal drugs are still used off-label, with variable dosage administrations and schedules. In high risk preterm and term neonates, drug evaluation is challenging and randomized controlled trials (RCT) are difficult to conduct and even more is the use of a placebo, required in the absence of a reference validated drug to be used as comparator.

METHODS

We analyzed the complete ClinicalTrials.gov registry 1) to describe neonatal RCT involving a placebo, 2) to report on the medical context and ethical aspects of placebo use.

RESULTS

Placebo versus drug RCT (n = 146), either prevention trials (n = 57, 39%) or therapeutic interventions (n = 89, 61%), represent more than a third of neonatal trials registered in the National Institute of Health clinical trial database (USA) since 1999. They mainly concerned preterm infants, evaluating complications of prematurity. Most trials were conducted in the USA, were single centered, and funded by non-profit organizations. For the three top drug trials evaluating steroids (n = 13, 9.6%), erythropoietin (EPO, n = 10, 6.8%) and nitric oxide (NO, n = 9, 6.2%), the objectives of the trial and follow-up were analyzed in more details.

CONCLUSION

Although a matter of debate, the use of placebo should be promoted in neonates to evaluate a potential new treatment, in the absence of reference drug. Analysis of the trials evaluating steroids showed that long-term follow-up of exposed patients, although required by international guidelines, is frequently missing and should be planned to collect additional information and optimize drug evaluation in these high-risk patients.

Evidence-based treatments for youths with severely dysregulated mood: a qualitative systematic review of trials for SMD and DMDD

The aim of this literature review was to examine the evidence for psychotherapeutic and pharmacological treatments in subjects with severely dysregulated mood and to identify potential areas for improvements in research designs. A literature search was conducted using several databases for published (PubMed, PsycINFO) and ongoing (clinical trial registries) studies conducted in youths who met NIMH's criteria for Severe Mood Dysregulation (SMD) or the DSM-5 diagnosis of Disruptive Mood Dysregulation Disorder (DMDD). Eight completed studies were identified: three randomized trials, four open pilot studies and one case report. Seven ongoing studies were found in trial registries. The available evidence suggests potential efficacy of psychotherapies which have previously been developed for internalizing and externalizing disorders. The two main pharmacological strategies tested are, first, a monotherapy of psychostimulant or atypical antipsychotic such as risperidone, already used in the treatment of severe irritability in youths with developmental disorders; and second, the use of a serotonergic antidepressant as an add-on therapy in youths treated with psychostimulant. Ongoing studies will further clarify the effectiveness of psychotherapeutic interventions for DMDD individuals and whether they should be given alone or in conjunction with other treatments. The short duration of the trials for a chronic disorder, the low number of studies, the lack of placebo or active comparator arm, and restrictive inclusion criteria in most of the controlled trials dramatically limit the interpretation of the results. Finally, future research should be conducted across multiple sites, with standardized procedures to measure DMDD symptoms reduction, and include a run-in period to limit placebo effect.

Is the perceived placebo effect comparable between adults and children? A meta-regression analysis

BACKGROUND

A potential larger perceived placebo effect in children compared with adults could influence the detection of the treatment effect and the extrapolation of the treatment benefit from adults to children. This study aims to explore this potential difference, using a meta-epidemiological approach.

METHODS

A systematic review of the literature was done to identify trials included in meta-analyses evaluating a drug intervention with separate data for adults and children. The standardized mean change and the proportion of responders (binary outcomes) were used to calculate the perceived placebo effect. A meta-regression analysis was conducted to test for the difference between adults and children of the perceived placebo effect.

RESULTS

For binary outcomes, the perceived placebo effect was significantly more favorable in children compared with adults (β = 0.13; P = 0.001). Parallel group trials (β = -1.83; P < 0.001), subjective outcomes (β = -0.76; P < 0.001), and the disease type significantly influenced the perceived placebo effect.

CONCLUSION

The perceived placebo effect is different between adults and children for binary outcomes. This difference seems to be influenced by the design, the disease, and outcomes. Calibration of new studies for children should consider cautiously the placebo effect in children.

Electrocortical effects of a disgust placebo in children

The electroencephalogram has been widely used to study voluntary emotion regulation (ER), whereas automatic ER has hardly been investigated. This experiment focused on automatic changes of disgust feelings and event-related potentials due to placebo treatment. Twenty-eight disgust-prone 8- to 13-year-old girls were presented with disgusting, fear-eliciting and neutral pictures once with and once without a placebo (syrup presented with the suggestion that it is able to ease disgust symptoms). In the disgust condition, the placebo reduced experienced disgust and increased frontal late positivity (400-1000 ms after picture onset). A similar electrocortical placebo effect was obtained for the fear pictures. These findings suggest that the placebo had the function of a safety signal which helped the children to direct their automatic attention to the aversive stimuli and to overcome visual avoidance. Future studies should integrate behavioral designs and should use additional psychophysiological measures (e.g., eye-tracking) in order to substantiate this interpretation.

Pain and placebo in pediatrics: a comprehensive review of laboratory and clinical findings

Pain modulation by placebo mechanisms is one of the most robust and best-studied phenomena, yet almost all research investigating the mechanisms and implications of the placebo analgesia are based on adult research. After highlighting crucial aspects that need to be considered in studying pain modulation in children, this comprehensive review examines studies related to pain modulation with an emphasis on factors such as age, neural development and pain measures. We critically discuss psychological mechanisms underlying placebo effects, including (1) verbally induced expectations, (2) conditioning and learning mechanisms, and (3) child-parent-physician interactions. Taken together, research suggests that placebo mechanisms can affect therapeutic outcomes and potentially be exploited clinically to improve clinical outcomes in pediatric population. Recommendations for further investigating the mechanistic bases and harnessing placebo effects for supportive therapeutic applications are given.

Placebo effects in children: a review

Of more than 155,000 PubMed citations found with the search term "placebo," only ~9,000 (5.8%) included the terms "children" or "adolescents." When all these papers were screened, only ~2,000 of them investigated the placebo effect per se, and of those, only ~50 (2.5%) discussed the placebo effect in children and adolescents. In this narrative review, we explore four aspects of the placebo response in children and adolescents: (i) the legal and ethical limitations and restrictions for the inclusion of children in clinical trials as well as in experimental (placebo) research that may explain the poor knowledge base; (ii) the question of whether or not the placebo effect is larger in children and adolescents as compared with adults; (iii) whether the mechanisms underlying the placebo effect are similar between children and adults; and (iv) whether mediators and moderators of the placebo effect are comparable between children and adults. We finally discuss some of the consequences from the current placebo research in adults that may affect both experimental and clinical research in children and adolescents.

Pharmacological treatment of Gilles de la Tourette syndrome

Pharmacological treatment is usually indicated in moderate to severe tics in psychosocial and/or functional impairment. Neuroleptics with D2 antagonistic activity remain the cornerstone of anti-tic therapy. Lack of randomized controlled clinical trials base therapeutic decisions mainly on clinical expertise and common sense. Recently, aripiprazole has emerged as the neuroleptic with the most advantageous efficacy/side effect ratio for treating tics. Yet, in non-responders to aripiprazole, many neuroleptic and non-neuroleptic drugs, including botulinum toxin injections, are available and often successful. Apart from conducting methodologically sound trials (which includes sufficiently long observation periods), future efforts in the field should test the combination of cognitive-behavioral therapy with drugs or of multi-drug therapy as well as the development of biomarkers (endophenotypes) to monitor and even predict treatment response.

Placebo effect in child and adolescent psychiatric trials

Much literature has been written in the field of child psychiatry regarding the placebo as a tool to test drug efficacy in clinical trials, but quite little regarding the placebo effect itself or its clinical use in child psychiatry. In this article, we aim to critically review the literature regarding the placebo effect in children and adolescents with mental disorders, focusing especially on factors influencing the placebo effect and how they may influence the interpretation of clinical trials. The placebo effect seems to be more marked in children than adults, and particularly in children and adolescents with depression, although it is pervasive across ages and is present in non-psychiatric conditions as well. The use of a placebo in clinical trials as a comparator with drugs that have moderate efficacy at most makes it difficult to obtain positive results, and much effort is needed to design very high quality clinical trials that may overcome the limitations of using a placebo. In addition, the placebo effect across ages and clinical conditions must be tested directly (compared with no treatment whenever possible), in order to characterise which placebos work for what and to determine their use in clinical settings.

Does experimental research support psychoanalysis?

The question of whether a psychodynamic view is compatible with experimental research is still a challenging issue-especially for child and adolescent psychopathology-despite the influence of psychoanalytic theory in this field until the 1980s. In this article, is explored the relationship between psychodynamic theory and experimental research using examples of evidence-based studies in the fields of (i) psychotherapeutic intervention assessment, (ii) placebo response in children and adolescents, (iii) unconscious lasting traumatic effects in children and adolescents, (iv) psychodynamic-oriented psychological testing. There are now a sufficient number of evidence-based studies to support the use of psychodynamic therapy in mental disorders, particularly in personality disorder and anxious/depressive disorder. In addition, placebo responses in children and adolescents with internalizing disorders are significantly higher in major depression compared to obsessive-compulsive disorder or other anxiety disorders, which highlights differential psychopathologies regarding the experience of loss. Also, using an experimental task, psychoanalysts are able to identify, without explicit knowledge and above the level of chance, healthy adults whose siblings had experienced cancer during childhood. This experiment suggests that implicit information regarding a participant's history is conveyed in interpersonal exchanges that can be intuitively perceived by judges experienced in listening to free associations from a psychodynamic perspective. Finally, psychodynamic-oriented psychological testing may predict the transition to schizophrenia in adolescents with a history of manic/mixed episodes. It can be concluded that there are no discrepancies between psychodynamic views and experimental data, whether one tests psychotherapeutic approaches, discusses data from other fields such as psychopharmacology, or designs experiments based on psychodynamic theory.

Deconstructing pediatric depression trials: an analysis of the effects of expectancy and therapeutic contact

OBJECTIVE

This study investigated how study type, mean patient age, and amount of contact with research staff affected response rates to medication and placebo in acute antidepressant trials for pediatric depression.

METHOD

Data were extracted from nine open, four active comparator, and 18 placebo-controlled studies of antidepressants for children and adolescents with depressive disorders. A multilevel meta-analysis examined how study characteristics affected response rates to antidepressants and placebo.

RESULTS

The primary finding was a main effect of study type across patient age and contact amount, such that the odds of medication response were greater in open versus placebo-controlled studies (odds ratio 1.87, 95% confidence interval 1.17-2.99, p = .012) and comparator studies (odds ratio 2.01, 95% confidence interval 1.16-3.48, p = .015) but were not significantly different between comparator and placebo-controlled studies. No significant main effects of patient age or amount of contact with research staff were found for analyses of response rates to medication and placebo. Response to placebo in placebo-controlled trials did significantly increase with the amount of therapeutic contact in older patients (age by contact; odds ratio 1.08, 95% confidence interval 1.01-1.15, p = .038).

CONCLUSIONS

Although patient expectancy strongly influences response rates to medication and placebo in depressed adults, it appears to be less important in the treatment of children and adolescents with depression. Attempts to limit placebo response and improve the efficiency of antidepressant trials for pediatric depression should focus on other causes of placebo response apart from expectancy.

Antidepressant and antipsychotic use in an Italian pediatric population

BACKGROUND

The safety and effectiveness of psychotropic drug use in the paediatric population is widely debated, in particular because of the lack of data concerning long term effects.In Italy the prevalence of psychotropic drug prescriptions increased in the early 2000s and decreased afterwards. In such a context, a study with the aim to estimate the incidence and prevalence of psychotropic drug prescription in the paediatric population and to describe diagnostic and therapeutic approaches was performed.

METHODS

The study population was composed of 76,000 youths less than 18 years and living in the area covered by the local health unit of Verona, Italy. The data source was the Verona local health unit's administrative prescription database. Prevalence and incidence of antidepressant and/or antipsychotic drug prescriptions in the 2004-2008 period were estimated. Children and adolescents receiving antidepressant and/or antipsychotic drug prescriptions between 1 January 2005 and 31 December 2006 were identified and questionnaires were sent to the prescribers with the aim to collect data concerning diagnostic and therapeutic approaches, and care strategies.

RESULTS

The prevalence of psychotropic drug prescriptions did not change in the 2004-2008 period, while incidence slightly increased (from 7.0 in 2005 to 8.3 per 10,000 in 2008). Between 1 January 2005 and 31 December 2006, 111 youths received at least one psychotropic drug prescription, 91 of whom received antidepressants. Only 28 patients attended child and adolescent psychiatry services. Information concerning diagnostic and therapeutic approaches, and care strategies was collected for 52 patients (47%). Anxiety-depressive syndrome and attention disorders were the diseases for which psychotropic drugs were most commonly prescribed. In all, 75% youths also received psychological support and 20% were prescribed drugs for 2 or more years.

CONCLUSIONS

Despite the low drug prescription prevalence, the finding that most children were not cared for by child and adolescent psychiatric services is of concern and calls for a systematic, continuous monitoring of psychopharmacological treatments.

Psychodynamic-oriented psychological assessment predicts evolution to schizophrenia at 8-year follow-up in adolescents hospitalized for a manic/mixed episode: interest of an overall subjective rating

Little is known concerning the prognostic significance of manic/mixed episodes in adolescents. In particular, whether the use of psychodynamic-oriented projective psychological testing predicts evolution to schizophrenia at follow-up has not been established. Eighty subjects, aged 12-20years old, consecutively hospitalized for a manic or mixed episode between 1994 and 2003 were recruited. All patients were contacted in 2005-2006 for a follow-up assessment. For the subgroup of adolescents (N=40) who had psychodynamic-oriented psychological testing (Rorschach and TAT), two scores regarding psychosocial risk and schizophrenia risk were computed using the clinical global impression (CGI) assessment based on an overall subjective rating given by a panel of expert psychologists who reviewed all protocols. At follow-up (average 8years), 25 (62.5%) patients, 16 females and nine males, were assessed: 14 still had a diagnosis of bipolar disorder; eight changed to schizo-affective disorder and three to schizophrenia. Inter-rater reliability of both CGI-risk scores (psychosocial risk and schizophrenia risk) showed good clinical consensus with intraclass correlation and Kappa scores ranging from 0.53 to 0.75. Univariate analysis showed that CGI-psychosocial risk score (p=0.017), type of index episode (p=0.049) and CGI-schizophrenia risk score (p=0.09) were associated with transition to schizophrenia spectrum disorder at follow-up. Age, sex, socioeconomic status, duration of stay and the presence of psychotic features at index episode were not associated with the transition. We conclude that the CGI assessment appears to be valid to score risk of poor outcome using psychodynamic-oriented psychological testing and that these scores may predict, in part, the transition to schizophrenia in adolescents with a history of manic/mixed episode.

Escitalopram: in the treatment of major depressive disorder in adolescent patients

Escitalopram is a selective serotonin reuptake inhibitor (SSRI), and is the second antidepressant to be approved for use in treating major depressive disorder (MDD) in adolescent patients (aged 12-17 years) in the US. In a randomized, double-blind, flexible-dose, multicenter trial, once-daily escitalopram 10-20 mg (n = 154) for 8 weeks was significantly better than placebo (n = 157) in improving the severity of depressive symptoms (as assessed by the change in the Children's Depression Rating Scale-Revised [CDRS-R] total score) in adolescent patients with MDD. Preliminary data from a combined analysis of the double-blind data from this trial and double-blind data from a 16-week, fixed-dose, extension study suggest a significant difference between escitalopram and placebo recipients in the change in CDRS-R total scores after 24 weeks of treatment. In a similarly designed flexible-dose trial in pediatric patients (aged 6-17 years), a significant difference between once-daily escitalopram 10-20 mg (n = 77) and placebo (n = 80) for 8 weeks, as assessed by the change in CDRS-R total score, was not shown in the primary analysis (i.e. patients of all ages). In a pre-specified subgroup of adolescent patients, no significant difference was shown between the escitalopram and the placebo groups when analyzed using the last observation carried forward method, but was shown using the observed case method. Escitalopram 10-20 mg/day showed better efficacy than placebo for some secondary endpoints (e.g. the change in the Clinical Global Impression [CGI]-Severity score, the CGI-Improvement response rate) but not others (e.g. CDRS-R response rate, rate of remission) [corrected].Once-daily escitalopram 10-20 mg for 8 weeks was generally well tolerated in clinical trials in adolescent or pediatric patients with MDD. The incidence of suicidality-related adverse events was generally similar between escitalopram and placebo recipients.

Predictors of placebo response in randomized controlled trials of psychotropic drugs for children and adolescents with internalizing disorders

OBJECTIVE

The aim of this study was to assess predictors of placebo response in all available short-term, placebo-controlled trials of psychotropic drugs for children and adolescents with internalizing disorders, major depressive disorder (MDD), obsessive compulsive disorder (OCD,) and anxiety disorders (ANX) exclusive of OCD and posttraumatic stress disorder (PTSD).

METHOD

We reviewed the literature relevant to the use of psychotropic medication in children and adolescents with internalizing disorders, restricting our review to double-blind studies including a placebo arm. Placebo response, defined according to each trial's primary response outcome variable and Clinical Global Impressions-Improvement, when available, and potential predictive variables were extracted from 40 studies.

RESULTS

From 1972 to 2007, we found 23 trials that evaluated the efficacy of psychotropic medication involving youth with MDD, 7 pertaining to youths with OCD, and 10 pertaining to youths with ANX (N = 2,533 patients in placebo arms). For all internalizing disorders combined, predictors of nonresponse to placebo were the percentage of Caucasian patients included in the study and the duration of the disorder: Both variables were negatively correlated with the percent of placebo responders. The type of disorder was found to predict the robustness of placebo response: (OCD < ANX < MDD). For a subset of MDD studies, we found that baseline illness severity tended to be negatively correlated with placebo response. Finally, trial "success" was significantly associated with lower placebo response rate.

CONCLUSION

Predictors of placebo response in internalizing disorders of youths parallel those in adult studies, with the exception of race. These predictors should be considered when designing placebo-controlled trials in youths to enhance findings of true drug-placebo differences.

Medication use in adolescents treated in a French psychiatric setting for acute manic or mixed episode

OBJECTIVE

In the absence of recommendations from drug regulatory agencies for most medications to treat severe manic or mixed episode in adolescence, this study aims to (i) describe the pharmacological treatment prescribed in an inpatient setting for acute manic or mixed episodes in adolescents; (ii) determine whether type of episode, duration of stay, improvement, and psychotic features were associated with the nature of the given treatment; (iii) compare the results with evidence-based data.

METHOD

From 1993 to 2003, we received 80 subjects, aged 12 to 20 years, consecutively hospitalized for a manic or mixed episode. Socio-demographic, clinical and treatment data were extracted by reviewing patients' charts. Treatment data were available for 75 subjects.

RESULTS

Most patients received a combination treatment including mood stabilizer (82.6%), classical antipsychotic (AP) (86.6%) and atypical AP (24%). Despite prolonged hospitalisation (minimum stay = 17 days), 69 (86.2%) patients were scored very much or much improved at discharge. Secondary therapeutic options occurred in 15 subjects because of poor therapeutic response (N=13), severe adverse effects (N=5) or both. Two patients had electroconvulsive therapy as third therapeutic option. Adolescents with psychotic symptoms were significantly more frequently treated by lithium (Fisher exact test: p=0,0052). No other variable was associated with treatment.

CONCLUSIONS

This study reported on patterns of medication use that mainly followed treatment recommendations and evidence-based data existing in adults. However, the presence of psychotic features appeared to favour the use of lithium in this French sample.