Does Placebo Response Differ between Objective and Subjective Measures in Children with Attention-Deficit/Hyperactivity Disorder?

Bright light therapy and early morning attention, mathematical performance, electroencephalography and brain connectivity in adolescents with morning sleepiness

Adolescents typically sleep too little and feel drowsy during morning classes. We assessed whether morning use of an LED bright light device could increase alertness in school students. Twenty-six (8M/18F) healthy, unmedicated participants, ages 13-18 years, (mean 17.1±1.4) were recruited following screenings to exclude psychopathology. Baseline assessments were made of actigraph-assessed sleep, attention, math solving ability, electroencephalography and structural and functional MRI (N = 10-11, pre-post). Participants nonrandomly received 3-4 weeks of bright light therapy (BLT) for 30 minutes each morning and used blue light blocking glasses for 2 hours before bedtime. BLT devices were modified to surreptitiously record degree of use so that the hypothesis tested was whether there was a significant relationship between degree of use and outcome. They were used 57±18% (range 23%-90%) of recommended time. There was a significant association between degree of use and: (1) increased beta spectral power in frontal EEG leads (primary measure); (2) greater post-test improvement in math performance and reduction in errors of omission on attention test; (3) reduced day-to-day variability in bed times, sleep onset, and sleep duration during school days; (4) increased dentate gyrus volume and (5) enhanced frontal connectivity with temporal, occipital and cerebellar regions during Go/No-Go task performance. BLT was associated with improvement in sleep cycle consistency, arousal, attention and functional connectivity, but not sleep onset or duration (primary measures). Although this was an open study, it suggests that use of bright morning light and blue light blocking glasses before bed may benefit adolescents experiencing daytime sleepiness. Clinical trial registration: Clinicaltrials.gov ID-NCT05383690.

Methylphenidate for children and adolescents with attention deficit hyperactivity disorder (ADHD)

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and treated psychiatric disorders in childhood. Typically, children and adolescents with ADHD find it difficult to pay attention and they are hyperactive and impulsive. Methylphenidate is the psychostimulant most often prescribed, but the evidence on benefits and harms is uncertain. This is an update of our comprehensive systematic review on benefits and harms published in 2015.

OBJECTIVES

To assess the beneficial and harmful effects of methylphenidate for children and adolescents with ADHD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, three other databases and two trials registers up to March 2022. In addition, we checked reference lists and requested published and unpublished data from manufacturers of methylphenidate.

SELECTION CRITERIA

We included all randomised clinical trials (RCTs) comparing methylphenidate versus placebo or no intervention in children and adolescents aged 18 years and younger with a diagnosis of ADHD. The search was not limited by publication year or language, but trial inclusion required that 75% or more of participants had a normal intellectual quotient (IQ > 70). We assessed two primary outcomes, ADHD symptoms and serious adverse events, and three secondary outcomes, adverse events considered non-serious, general behaviour, and quality of life.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted data extraction and risk of bias assessment for each trial. Six review authors including two review authors from the original publication participated in the update in 2022. We used standard Cochrane methodological procedures. Data from parallel-group trials and first-period data from cross-over trials formed the basis of our primary analyses. We undertook separate analyses using end-of-last period data from cross-over trials. We used Trial Sequential Analyses (TSA) to control for type I (5%) and type II (20%) errors, and we assessed and downgraded evidence according to the GRADE approach.

MAIN RESULTS

We included 212 trials (16,302 participants randomised); 55 parallel-group trials (8104 participants randomised), and 156 cross-over trials (8033 participants randomised) as well as one trial with a parallel phase (114 participants randomised) and a cross-over phase (165 participants randomised). The mean age of participants was 9.8 years ranging from 3 to 18 years (two trials from 3 to 21 years). The male-female ratio was 3:1. Most trials were carried out in high-income countries, and 86/212 included trials (41%) were funded or partly funded by the pharmaceutical industry. Methylphenidate treatment duration ranged from 1 to 425 days, with a mean duration of 28.8 days. Trials compared methylphenidate with placebo (200 trials) and with no intervention (12 trials). Only 165/212 trials included usable data on one or more outcomes from 14,271 participants. Of the 212 trials, we assessed 191 at high risk of bias and 21 at low risk of bias. If, however, deblinding of methylphenidate due to typical adverse events is considered, then all 212 trials were at high risk of bias.

PRIMARY OUTCOMES

methylphenidate versus placebo or no intervention may improve teacher-rated ADHD symptoms (standardised mean difference (SMD) -0.74, 95% confidence interval (CI) -0.88 to -0.61; I² = 38%; 21 trials; 1728 participants; very low-certainty evidence). This corresponds to a mean difference (MD) of -10.58 (95% CI -12.58 to -8.72) on the ADHD Rating Scale (ADHD-RS; range 0 to 72 points). The minimal clinically relevant difference is considered to be a change of 6.6 points on the ADHD-RS. Methylphenidate may not affect serious adverse events (risk ratio (RR) 0.80, 95% CI 0.39 to 1.67; I² = 0%; 26 trials, 3673 participants; very low-certainty evidence). The TSA-adjusted intervention effect was RR 0.91 (CI 0.31 to 2.68).

SECONDARY OUTCOMES

methylphenidate may cause more adverse events considered non-serious versus placebo or no intervention (RR 1.23, 95% CI 1.11 to 1.37; I² = 72%; 35 trials 5342 participants; very low-certainty evidence). The TSA-adjusted intervention effect was RR 1.22 (CI 1.08 to 1.43). Methylphenidate may improve teacher-rated general behaviour versus placebo (SMD -0.62, 95% CI -0.91 to -0.33; I² = 68%; 7 trials 792 participants; very low-certainty evidence), but may not affect quality of life (SMD 0.40, 95% CI -0.03 to 0.83; I² = 81%; 4 trials, 608 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

The majority of our conclusions from the 2015 version of this review still apply. Our updated meta-analyses suggest that methylphenidate versus placebo or no-intervention may improve teacher-rated ADHD symptoms and general behaviour in children and adolescents with ADHD. There may be no effects on serious adverse events and quality of life. Methylphenidate may be associated with an increased risk of adverse events considered non-serious, such as sleep problems and decreased appetite. However, the certainty of the evidence for all outcomes is very low and therefore the true magnitude of effects remain unclear. Due to the frequency of non-serious adverse events associated with methylphenidate, the blinding of participants and outcome assessors is particularly challenging. To accommodate this challenge, an active placebo should be sought and utilised. It may be difficult to find such a drug, but identifying a substance that could mimic the easily recognised adverse effects of methylphenidate would avert the unblinding that detrimentally affects current randomised trials. Future systematic reviews should investigate the subgroups of patients with ADHD that may benefit most and least from methylphenidate. This could be done with individual participant data to investigate predictors and modifiers like age, comorbidity, and ADHD subtypes.

Open assessment of the therapeutic and rate-dependent effects of brain balance center® and interactive metronome® exercises on children with attention deficit hyperactivity disorder

The aim of this open study was to delineate domains of benefit and effect size measures to design an appropriately powered randomized control trial to assess the efficacy of Brain Balance^@ exercises and Interactive Metronome^@ training (BB/IM) on ADHD symptoms in children. Participants underwent an extensive 15-week, 5 time per week, at-home training program. Results were assessed in 16 youths with ADHD (14M/2F, 10.8±1.7 years) who completed the program and compared to 8 typically developing controls (4M/F4, 11.0±1.8 years). BB/IM was associated with a significant reduction of 8.3 and 8.2 points on the Conner's Parent Rating Scale - Revised and the ADHD Rating Scale - IV. BB/IM was not associated with improvement on the Quotient ADHD System but with rate-dependent effects on hyperactivity and attention that were similar to previously reported effects of low dose methylphenidate. Both therapeutic and rate-dependent effects were observed on the Tower of London. The study provides information that could be used to design a randomized control trial, which is required for proof of efficacy. A key limitation is that 59% of the 39 enrolled participants with ADHD dropped out of the study and a new study should include multiple ratings during the course of treatment.

A virtual reality application for assessment for attention deficit hyperactivity disorder in school-aged children

Background and objective: The development of objective assessment tools for attention deficit hyperactivity disorder (ADHD) has become a hot research topic in recent years. This study was conducted to explore the feasibility and availability of virtual reality (VR) for evaluating symptoms of ADHD. Methods: School-aged children were recruited. The children with ADHD or without ADHD were assigned into the ADHD group or Control group, respectively. They were all evaluated using the Conners' Parent Rating Scale (CPRS), Child Behavior Checklist (CBCL), Integrated Visual and Auditory Continuous Performance Test (IVA-CPT), and a VR test. Results: The correct items, incorrect items, and the accuracy rate of the VR test of the children with ADHD were significantly different with those of the children in the Control group. The correct items, incorrect items, total time, and accuracy of the VR test were significantly correlated with the scores of IVA-CPT (auditory attention and visual attention), CPRS (impulsion/hyperactivity and ADHD index), and CBCL (attention problems and social problems), respectively. Discussion: The results supported the discriminant validity of the VR test for evaluating ADHD in school-age children suffering from learning problems. The VR test results are associated with the commonly used clinical measurements results. A VR test is interesting for children and therefore it attracts them to complete the test; whilst at the same time, it can also effectively evaluate ADHD symptoms.

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.

The Groundskeeper Gaming Platform as a Diagnostic Tool for Attention-Deficit/Hyperactivity Disorder: Sensitivity, Specificity, and Relation to Other Measures

OBJECTIVE

The purpose of this study was to assess the relative accuracies of the Conners' Brief Rating Scale, Parent Version, the Conners' Continuous Performance Test II (CPT II), and a novel interactive game called "Groundskeeper" to discriminate child psychiatric patients with and without attention-deficit/hyperactivity disorder (ADHD).

METHODS

We administered the three assessments to 113 clinically referred ADHD and non-ADHD patients who had been diagnosed with the Kiddie-Schedule of Affective Disorders and Schizophrenia- Present and Lifetime (K-SADS-PL), Version 19.

RESULTS

As measured by the area under the curve (AUC) statistic from receiver operating characteristic (ROC) analysis, the diagnostic accuracy of Groundskeeper (0.79) was as high as the accuracy of the Conners' parent rating of inattention (0.76) and better than the CPT II percent correct (0.62). Combining the three tests produced an AUC of 0.87. Correlations among the three measures were small and, mostly, not significant.

CONCLUSIONS

Our finding of similar diagnostic accuracies between Groundskeeper and the Conners' inattention scale is especially remarkable given that the Conners' inattention scale shares method variance with the diagnostic process. Although our work is preliminary, it suggests that computer games may be useful in the diagnostic process. This provides an important direction for research, given the objectivity of such measures and the fact that computer games are well tolerated by youth.

Methylphenidate for children and adolescents with attention deficit hyperactivity disorder (ADHD)

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and treated psychiatric disorders in childhood. Typically, children with ADHD find it difficult to pay attention, they are hyperactive and impulsive.Methylphenidate is the drug most often prescribed to treat children and adolescents with ADHD but, despite its widespread use, this is the first comprehensive systematic review of its benefits and harms.

OBJECTIVES

To assess the beneficial and harmful effects of methylphenidate for children and adolescents with ADHD.

SEARCH METHODS

In February 2015 we searched six databases (CENTRAL, Ovid MEDLINE, EMBASE, CINAHL, PsycINFO, Conference Proceedings Citations Index), and two trials registers. We checked for additional trials in the reference lists of relevant reviews and included trials. We contacted the pharmaceutical companies that manufacture methylphenidate to request published and unpublished data.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing methylphenidate versus placebo or no intervention in children and adolescents aged 18 years and younger with a diagnosis of ADHD. At least 75% of participants needed to have an intellectual quotient of at least 70 (i.e. normal intellectual functioning). Outcomes assessed included ADHD symptoms, serious adverse events, non-serious adverse events, general behaviour and quality of life.

DATA COLLECTION AND ANALYSIS

Seventeen review authors participated in data extraction and risk of bias assessment, and two review authors independently performed all tasks. We used standard methodological procedures expected within Cochrane. Data from parallel-group trials and first period data from cross-over trials formed the basis of our primary analyses; separate analyses were undertaken using post-cross-over data from cross-over trials. We used Trial Sequential Analyses to control for type I (5%) and type II (20%) errors, and we assessed and downgraded evidence according to the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach for high risk of bias, imprecision, indirectness, heterogeneity and publication bias.

MAIN RESULTS

The studies.We included 38 parallel-group trials (5111 participants randomised) and 147 cross-over trials (7134 participants randomised). Participants included individuals of both sexes, at a boys-to-girls ratio of 5:1, and participants' ages ranged from 3 to 18 years across most studies (in two studies ages ranged from 3 to 21 years). The average age across all studies was 9.7 years. Most participants were from high-income countries.The duration of methylphenidate treatment ranged from 1 to 425 days, with an average duration of 75 days. Methylphenidate was compared to placebo (175 trials) or no intervention (10 trials). Risk of Bias.All 185 trials were assessed to be at high risk of bias. Primary outcomes. Methylphenidate may improve teacher-rated ADHD symptoms (standardised mean difference (SMD) -0.77, 95% confidence interval (CI) -0.90 to -0.64; 19 trials, 1698 participants; very low-quality evidence). This corresponds to a mean difference (MD) of -9.6 points (95% CI -13.75 to -6.38) on the ADHD Rating Scale (ADHD-RS; range 0 to 72 points; DuPaul 1991a). A change of 6.6 points on the ADHD-RS is considered clinically to represent the minimal relevant difference. There was no evidence that methylphenidate was associated with an increase in serious (e.g. life threatening) adverse events (risk ratio (RR) 0.98, 95% CI 0.44 to 2.22; 9 trials, 1532 participants; very low-quality evidence). The Trial Sequential Analysis-adjusted intervention effect was RR 0.91 (CI 0.02 to 33.2).

SECONDARY OUTCOMES

Among those prescribed methylphenidate, 526 per 1000 (range 448 to 615) experienced non-serious adverse events, compared with 408 per 1000 in the control group. This equates to a 29% increase in the overall risk of any non-serious adverse events (RR 1.29, 95% CI 1.10 to 1.51; 21 trials, 3132 participants; very low-quality evidence). The Trial Sequential Analysis-adjusted intervention effect was RR 1.29 (CI 1.06 to 1.56). The most common non-serious adverse events were sleep problems and decreased appetite. Children in the methylphenidate group were at 60% greater risk for trouble sleeping/sleep problems (RR 1.60, 95% CI 1.15 to 2.23; 13 trials, 2416 participants), and 266% greater risk for decreased appetite (RR 3.66, 95% CI 2.56 to 5.23; 16 trials, 2962 participants) than children in the control group.Teacher-rated general behaviour seemed to improve with methylphenidate (SMD -0.87, 95% CI -1.04 to -0.71; 5 trials, 668 participants; very low-quality evidence).A change of seven points on the Child Health Questionnaire (CHQ; range 0 to 100 points; Landgraf 1998) has been deemed a minimal clinically relevant difference. The change reported in a meta-analysis of three trials corresponds to a MD of 8.0 points (95% CI 5.49 to 10.46) on the CHQ, which suggests that methylphenidate may improve parent-reported quality of life (SMD 0.61, 95% CI 0.42 to 0.80; 3 trials, 514 participants; very low-quality evidence).

AUTHORS' CONCLUSIONS

The results of meta-analyses suggest that methylphenidate may improve teacher-reported ADHD symptoms, teacher-reported general behaviour, and parent-reported quality of life among children and adolescents diagnosed with ADHD. However, the low quality of the underpinning evidence means that we cannot be certain of the magnitude of the effects. Within the short follow-up periods typical of the included trials, there is some evidence that methylphenidate is associated with increased risk of non-serious adverse events, such as sleep problems and decreased appetite, but no evidence that it increases risk of serious adverse events.Better designed trials are needed to assess the benefits of methylphenidate. Given the frequency of non-serious adverse events associated with methylphenidate, the particular difficulties for blinding of participants and outcome assessors point to the advantage of large, 'nocebo tablet' controlled trials. These use a placebo-like substance that causes adverse events in the control arm that are comparable to those associated with methylphenidate. However, for ethical reasons, such trials should first be conducted with adults, who can give their informed consent.Future trials should publish depersonalised individual participant data and report all outcomes, including adverse events. This will enable researchers conducting systematic reviews to assess differences between intervention effects according to age, sex, comorbidity, type of ADHD and dose. Finally, the findings highlight the urgent need for large RCTs of non-pharmacological treatments.

The efficacy of atomoxetine for the treatment of children and adolescents with attention-deficit/hyperactivity disorder: a comprehensive review of over a decade of clinical research

Atomoxetine was first licensed to treat attention-deficit/hyperactivity disorder (ADHD) in children and adolescents in the US in 2002. The aim of this paper is to comprehensively review subsequent publications addressing the efficacy of atomoxetine in 6- to 18-year-olds with ADHD. We identified 125 eligible papers using a predefined search strategy. Overall, these papers demonstrate that atomoxetine is an effective treatment for the core ADHD symptoms (effect sizes 0.6-1.3, vs. placebo, at 6-18 weeks), and improves functional outcomes and quality of life, in various pediatric populations with ADHD (i.e., males/females, patients with co-morbidities, children/adolescents, and with/without prior exposure to other ADHD medications). Initial responses to atomoxetine may be apparent within 1 week of treatment, but can take longer (median 23 days in a 6-week study; n=72). Responses often build gradually over time, and may not be robust until after 3 months. A pooled analysis of six randomized placebo-controlled trials (n=618) indicated that responses at 4 weeks may predict response at 6-9 weeks, although another pooled analysis of open-label data (n=338) suggests that the probability of a robust response to atomoxetine [≥40% decrease in ADHD-Rating Scale (ADHD-RS) scores] may continue to increase beyond 6-9 weeks. Atomoxetine may demonstrate similar efficacy to methylphenidate, particularly immediate-release methylphenidate, although randomized controlled trials are generally limited by short durations (3-12 weeks). In conclusion, notwithstanding these positive findings, before initiating treatment with atomoxetine, it is important that the clinician sets appropriate expectations for the patient and their family with regard to the likelihood of a gradual response, which often builds over time.

Relationships between computer-based testing and behavioral ratings in the assessment of attention and activity in a pediatric ADHD stimulant crossover trial

This study investigated the relationships between computer-based testing and behavioral ratings in the assessment of stimulant-induced changes in attention and activity in a pediatric ADHD crossover trial with methylphenidate, dextroamphetamine, and a placebo. Here 36 children between 9 and 14 years old were randomly and evenly assigned to each of six counterbalanced drug orders. A computer-based continuous performance test combined with a motion-tracking system (cb-CPT-MTS) and an ADHD questionnaire rated by teachers constituted the outcome measures. All outcome measures responded to stimulants in a comparable way at the group level, as shown by significant treatment effects of similar size for the two stimulants compared with a placebo. Computer-based and rating-based measures were unrelated in the assessment of stimulant-induced changes in attention and activity in individual children; no significant correlations between these measures in the assessment of change from placebo to stimulant conditions across the sample were detected. Results suggest that computer-based testing and behavioral ratings cannot be considered equivalent in the assessment of stimulant-induced changes in attention and activity among ADHD children.

Minimizing adverse events while maintaining clinical improvement in a pediatric attention-deficit/hyperactivity disorder crossover trial with dextroamphetamine and methylphenidate

OBJECTIVE

The purpose of this study was to investigate whether the availability of both dextroamphetamine and methylphenidate provides an opportunity to minimize adverse events in a pediatric attention-deficit/hyperactivity disorder (ADHD) stimulant trial.

METHODS

Thirty-six medication-naïve children 9-14 years of age, diagnosed with ADHD, were enrolled for 6 weeks in a crossover trial, with 2 weeks of methylphenidate, dextroamphetamine, and a placebo in a randomly assigned, counterbalanced sequence. Barkley's Side-Effect Rating Scale (SERS), rated by parents, was used to assess adverse events. SERS were available for 34 children, and data were analyzed both at the group and the single-subject level.

RESULTS

The side-effect profiles of dextroamphetamine and methylphenidate appeared similar at the group level. Overall, insomnia and decreased appetite were the only adverse events associated with the stimulants as compared with placebo. No significant increase from placebo to stimulant conditions was detected on SERS items reflecting emotional symptoms. Furthermore, dextroamphetamine and methylphenidate did not differ from each other on any SERS item, except that dextroamphetamine was associated with higher severity of "insomnia" and a higher prevalence of "unusually happy." Single-subject analyses showed that one or more adverse events were reported in 14 children (41%), and were evenly distributed between those with dextroamphetamine as the drug that showed the greatest reduction in their ADHD symptoms ("best drug") and those with methylphenidate as their best drug. Among children in whom both stimulants were associated with a decrease in ADHD symptoms, a clinically valid difference between the two stimulants in total adverse events score was found in 7 (39%) of the 18 cases. In these children, the availability of both stimulants provided an opportunity to minimize adverse events, while maintaining a reduction in ADHD symptoms.

CONCLUSIONS

The availability of both dextroamphetamine and methylphenidate may contribute to minimize adverse events in a subsample of children in pediatric ADHD stimulant trials.

CLINICAL TRIALS REGISTRY

The study was first registered in clinical trials September 28, 2010. Clinical Trials.gov Identifier: NCT01220440.

Clinical gains from including both dextroamphetamine and methylphenidate in stimulant trials

OBJECTIVE

The purpose of this study was to investigate clinical gains from including both dextroamphetamine and methylphenidate in stimulant trials.

METHOD

Thirty-six medication-naïve children ages 9-14 years diagnosed with attention-deficit/hyperactivity disorder (ADHD) were enrolled for 6 weeks in a crossover trial, with 2 weeks of methylphenidate, dextroamphetamine, and placebo, in a randomly assigned, counterbalanced sequence. Outcome measures constituted a computer-based continuous performance test combined with a motion tracking system (Qb Test) and an ADHD questionnaire rated by parents and teachers.

RESULTS

Group analyses found significant treatment effects of similar size for the two stimulants on both outcome measures. Single-subject analyses revealed that each stimulant produced a favourable response in 26 children; however, an individual child frequently responded qualitatively or quantitatively differently to the two stimulants. By including both stimulants in the trial, the number of favorable responders increased from 26 (72%) to 33 (92%). In children with favorable responses of unequal strength to the two stimulants, a shift from inferior drug to best drug was associated with a 64% mean increase in the overall response strength score, as measured by the ADHD questionnaire.

CONCLUSIONS

The likelihood of a favorable response and optimal response strength is increased by including both stimulants in the stimulant trial. The study was first registered in clinical trials 28 September 2010. Clinical Trials.gov Identifier: NCT01220440.

Baseline severity of parent-perceived inattentiveness is predictive of the difference between subjective and objective methylphenidate responses in children with attention-deficit/hyperactivity disorder

OBJECTIVE

The purpose of this study was to find potential variables associated with the difference between subjective and object treatment responses in children with attention-deficit/hyperactivity disorder (ADHD) treated with OROS-methylphenidate (MPH).

METHODS

We conducted a post-hoc analysis of data from a multicenter, open-label, 12 week trial of OROS-MPH in Korean children with ADHD. The subjective outcome measurement was the parent version of the ADHD Rating Scale-IV (ARS-P), and the objective outcome measurement was the Continuous Performance Test (CPT). We compared the children's demographic and disease-related variables among four groups, classified according to whether they showed subjective or objective improvement after MPH treatment.

RESULTS

Higher baseline inattentive scores on the ARS-P were associated with a significantly higher probability of subjective treatment response among objective nonresponders (p=0.033). Lower baseline inattentive scores on the ARS-P were associated with a significantly higher probability of subjective nonresponse among objective responders (p=0.045). Lower baseline omission errors (p=0.006) and response time variability scores (p=0.011) on the CPT were associated with a significantly higher probability of both objective and subjective responses, compared with both types of nonresponse to treatment.

CONCLUSIONS

The baseline severity of parent-perceived inattentive symptoms was predictive of differences in subjective and objective treatment responses, and the baseline severity of neuropsychological deficit (inattention and inconsistency of attention) was predictive of responses, using both subjective and objective measurements.

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.