Effect of Fluoxetine on Obsessive-Compulsive Behaviors in Children and Adolescents With Autism Spectrum Disorders: A Randomized Clinical Trial.

Importance: Selective serotonin receptor inhibitors are prescribed to reduce the severity of core behaviors of autism spectrum disorders, but their efficacy remains uncertain. Objective: To determine the efficacy of fluoxetine for reducing the frequency and severity of obsessive-compulsive behaviors in autism spectrum disorders. Design, Setting, and Participants: Multicenter, randomized, placebo-controlled clinical trial. Participants aged 7.5-18 years with autism spectrum disorders and a total score of 6 or higher on the Children's Yale-Brown Obsessive Compulsive Scale, modified for pervasive developmental disorder (CYBOCS-PDD) were recruited from 3 tertiary health centers across Australia. Enrollment began November 2010 and ended April 2017. Follow-up ended August 2017. Interventions: Participants were randomized to receive fluoxetine (n = 75) or placebo (n = 71). Study medication was commenced at 4 or 8 mg/d for the first week, depending on weight, and then titrated to a maximum dose of 20 or 30 mg/d over 4 weeks. Treatment duration was 16 weeks. Main Outcomes and Measures: The primary outcome was the total score on the CYBOCS-PDD (scores range from 0-20; higher scores indicate higher levels of maladaptive behaviors; minimal clinically important difference, 2 points) at 16 weeks postrandomization, analyzed with a linear regression model adjusted for stratification factors (site, age at baseline, and intellectual disability), with an additional prespecified model that included additional adjustment for baseline score, sex, communication level, and imbalanced baseline and demographic variables. Results: Among the 146 participants who were randomized (85% males; mean age, 11.2 years), 109 completed the trial; 31 in the fluoxetine group and 21 in the placebo group dropped out or did not complete treatment. The mean CYBOCS-PDD score from baseline to 16 weeks decreased in the fluoxetine group from 12.80 to 9.02 points (3.72-point decrease; 95% CI, -4.85 to -2.60) and in the placebo group from 13.13 to 10.89 points (2.53-point decrease; 95% CI, -3.86 to -1.19). The between-group mean difference at 16 weeks was -2.01 (95% CI, -3.77 to -0.25; P = .03) (adjusted for stratification factors), and in the prespecified model with further adjustment, it was -1.17 (95% CI, -3.01 to 0.67; P = .21). Conclusions and Relevance: In this preliminary study of children and adolescents with autism spectrum disorders, treatment with fluoxetine compared with placebo resulted in significantly lower scores for obsessive-compulsive behaviors at 16 weeks. Interpretation is limited by the high dropout rate, null findings of prespecified analyses that accounted for potentially confounding factors and baseline imbalances, and CIs for the treatment effect that included the minimal clinically important difference. Trial Registration: anzctr.org.au Identifier: ACTRN12608000173392.

Differentiating Autism Spectrum Disorder From ADHD Using the Social Communication Questionnaire.

OBJECTIVE: This study examined the ability of the Social Communication Questionnaire (SCQ) to differentiate between autism spectrum disorder (ASD), ADHD, and typically developing (TD) children. METHOD: Children ( Mage = 11.27 years, SDage = 3.28) identified with ASD Severity Levels "1" and/or "2" ( n = 28), ADHD ( n = 44), dual diagnoses of ADHD and ASD ( n = 29), and TD ( n = 61) were assessed using the SCQ. RESULTS: The SCQ differentiated between ASD and non-ASD groups. Children with ASD had higher total and domain scores on the SCQ than ADHD and TD children. The optimal cutoff total score of 13 was identified for differentiating between ASD and ADHD groups (area under the curve [AUC] = .96). Twenty eight of the 39 items were identified as significant in differentiating between ASD and ADHD. CONCLUSION: The SCQ continues to be a well-validated screening tool for ASD and is suitable for determining whether further ASD assessment is warranted in children with ADHD symptoms.

Fluoxetine for Autistic Behaviors (FAB trial): study protocol for a randomized controlled trial in children and adolescents with autism.

BACKGROUND: Serotonin reuptake inhibitors (SSRIs) are commonly prescribed off-label for children with autism. To date, clinical trials examining the use of SSRIs in autism have been limited by small sample sizes and inconclusive results. The efficacy and safety of SSRIs for moderating autistic behaviors is yet to be adequately examined to provide evidence to support current clinical practice. The aim of the Fluoxetine for Autistic Behaviors (FAB) study is to determine the efficacy and safety of low dose fluoxetine compared with placebo, for reducing the frequency and severity of repetitive stereotypic behaviors in children and adolescents with an autism spectrum disorder (ASD). The relationship between the effectiveness of fluoxetine treatment and serotonin transporter genotype will also be explored. METHODS/DESIGN: The FAB study is a multicenter, double-blinded, randomized controlled trial, funded by the Australian Government's National Health and Medical Research Council (NHMRC) grant. Participants will be aged between 7.5 and 17 years with a confirmed diagnosis of ASD. Eligible participants will be randomized to either placebo or fluoxetine for a 16-week period. Medication will be titrated over the first four weeks. Reponses to medication will be monitored fortnightly using the Clinical Global Impressions Scale (CGI). The primary outcome measure is the Children's Yale-Brown Obsessive Compulsive Scale-Modified for Pervasive Developmental Disorders (CYBOCS-PDD), administered at baseline and 16 weeks. Secondary outcome measures include the Aberrant Behaviour Scale (ABC), the Spence Children's Anxiety Scale Parent Report (SCAS-P), and the Repetitive Behaviors Scale (RBS-R), measured at baseline and 16 weeks. Participants will be invited to undergo genetic testing for SLC6A4 allele variants using a cheek swab. Continuous outcomes, including the primary outcome will be compared between the active and placebo groups using unadjusted linear regression. Binary outcomes will be compared using unadjusted logistic regression. DISCUSSION: The FAB study is a large clinical trial to specifically investigate the efficacy of low dose fluoxetine for restricted, repetitive, and stereotyped behaviors in ASD. The outcomes of this study will contribute to evidence-based interventions used in clinical practice to assist children with ASD. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry ACTRN12608000173392; registered on 9 April, 2008.