Naltrexone in autistic children: an acute open dose range tolerance trial

Developmental Considerations for the Use of Naltrexone in Children and Adolescents

Naltrexone (NTX) is a well-tolerated drug with a wide safety margin and mechanism of action that affords use across a wide variety of indications in adults and children. By antagonizing the opioid reward system, NTX can modulate behaviors that involve compulsivity or impulsivity, such as substance use, obesity, and eating disorders. Evidence regarding the disposition and efficacy of NTX is mainly derived from adult studies of substance use disorders and considerable variability exists. Developmental changes, plausible disease-specific alterations and genetic polymorphisms in NTX disposition, and pharmacodynamic pathways should be taken into consideration when optimizing the use of NTX in the pediatric population. This review highlights the current state of the evidence and gaps in knowledge regarding NTX to facilitate evidence-based pharmacotherapy of mental health conditions, for which few pharmacologic options exist.

Autism Case Report: Cause and Treatment of "High Opioid Tone" Autism

Introduction: Neurobiological systems engineering models are useful for treating patients. We show a model of “high opioid tone” autism and present a hypothesis about how autism is caused by administration of opioids during childbirth.

Main Symptoms: Clinical diagnosis of autism in a 25 year old man was confirmed by a Social Responsiveness Scale (SRS) self-rating of 79, severe, and a Social Communications Questionnaire (SCQ-2) by the patient's father scoring 27. Cold pressor time (CPT) was 190 seconds—unusually long, consonant with the high pain tolerance of autism.

Therapeutic Intervention and Outcomes: At naltrexone 50 mg/day SRS fell to 54 and SCQ-−2–9; both non-significant. CPT fell to 28, repeat 39 s. Improved relatedness was experienced ambivalently, understood as feelings never before experienced—causing pain. Non-compliance with naltrexone was followed by cutting open his palm and drinking alcoholically. Transference focused psychotherapy has helped him remain naltrexone—compliant while he works on issues of identity and relatedness.

Conclusion: The model suggests studies that could be conducted to both prevent and treat this form of autism.

Oxytocin under opioid antagonism leads to supralinear enhancement of social attention

To provide new preclinical evidence toward improving the efficacy of oxytocin (OT) in treating social dysfunction, we tested the benefit of administering OT under simultaneously induced opioid antagonism during dyadic gaze interactions in monkeys. OT coadministered with a μ-opioid receptor antagonist, naloxone, invoked a supralinear enhancement of prolonged and selective social attention, producing a stronger effect than the summed effects of each administered separately. These effects were consistently observed when averaging over entire sessions, as well as specifically following events of particular social importance, including mutual eye contact and mutual reward receipt. Furthermore, attention to various facial regions was differentially modulated depending on social context. Using the Allen Institute's transcriptional atlas, we further established the colocalization of μ-opioid and κ-opioid receptor genes and OT genes at the OT-releasing sites in the human brain. These data across monkeys and humans support a regulatory relationship between the OT and opioid systems and suggest that administering OT under opioid antagonism may boost the therapeutic efficacy of OT for enhancing social cognition.

Pediatrics Efficacy and Safety of Naltrexone Use in Pediatric Patients with Autistic Disorder

Objective:

To review the efficacy and safety of naltrexone in pediatric patients with autistic disorder (AD).

Data Sources:

Using the terms pediatric, child, naltrexone, autism, and autistic disorder, a literature search was performed using MEDLINE (1966–May 18, 2006) and the International Pharmaceutical Abstracts (1971–May 18, 2006) database. The references of these articles were scanned for additional relevant literature.

Study Selection and Data Extraction:

All articles describing or evaluating the efficacy and/or safety of naltrexone in pediatric patients with AD were included in this review. Three case reports, 8 case series, and 14 clinical studies were identified as pertinent.

Data Synthesis:

Naltrexone has been used most commonly at doses ranging from 0.5 to 2 mg/kg/day and found to be predominantly effective in decreasing self-injurious behavior. Naltrexone may also attenuate hyperactivity, agitation, irritability, temper tantrums, social withdrawal, and stereotyped behaviors. Patients may also exhibit improved attention and eye contact. Transient sedation was the most commonly reported adverse event. Small sample size, short duration, and inconsistent evaluative methods characterize the available research.

Conclusions:

A child affected by AD may benefit from a trial of naltrexone therapy, particularly if the child exhibits self-injurious behavior and other attempted therapies have failed. Serious adverse effects have not been reported in short-term studies.

Are opioid antagonists effective in reducing self-injury in adults with intellectual disability? A systematic review

BACKGROUND

Self-injury in people with intellectual disability (ID) may be due to variety of factors both environmental and biological. As the drive in UK is to manage people with ID and problem behaviours in the community, it is important to critically examine all treatment options available. As abnormalities in the endogenous opioid system may be a factor in some people with ID, we undertook a systematic review to evaluate the evidence for the effectiveness of opioid antagonists.

METHODS

Four electronic databases were searched for relevant journal articles. In addition, cross-referencing of pertinent reviews and a hand search for articles in major international ID journals between the years 2010 and 2012 was carried out to ensure that all relevant articles were identified. We also searched databases for unpublished clinical trials to overcome publication bias. Each database was searched up to present (February 2013) with no restrictions on the date of publication. The search terms consisted of broad expressions used to describe ID and autistic spectrum disorder as well as terms relating to opioid antagonists and specific drugs. All studies identified by the electronic database search and hand search were examined on the basis of title alone for relevance and duplication. The abstracts of the remaining papers were then scrutinised against the inclusion criteria. Where abstracts failed to provide adequate information, the full texts for these papers were obtained. All the full texts were then evaluated against the inclusion proforma. Two reviewers carried out all the stages of the process independently. The reviewers met to discuss their selections and where disagreements arose, these were settled by discussion with a member of the study group. Data from each study meeting the inclusion criteria was extracted on a pre-piloted data extraction form. The quality of each study was further assessed using the Jadad scale, a tool developed to assess the quality of randomised controlled trials.

RESULTS

Out of 10 randomised control trials eight reported a reduction in the frequency of self-injurious behaviour. This meant that 62 participants out of 124 (50%) showed an improvement of which 61 were statistically significant. Forty-nine participants had autism. Eleven (9%) had minor side-effects. The improvement was more marked in people with severe and profound ID and was not affected by the coexistence of autism.

CONCLUSIONS

This review suggests that some people respond to opioid antagonists with a reduction in self-injury but the trials do not predict who they may be. Future research may identify this sub-group when opioid antagonists may prove to be a useful addition in the pharmacotherapy of self-injury.

Pharmacological management in children and adolescents with pervasive developmental disorder

OBJECTIVE

Pervasive developmental disorder (PDD) is associated with emotional and behavioural problems. There is no pharmacological cure for PDD, but some comorbidities and dysfunctional behaviours in PDD can be managed pharmacologically. The aim of the present study was to provide a better understanding of the efficacy and limitations in the currently available agents.

METHODS

Electronic literature searches were conducted from the following sources: MEDLINE, Cochrane Library, PSYARTICLES and PsycINFO. Search terms included, but were not limited to, 'autism', 'PDD', 'autism spectrum disorder' ('ASD'), and 'pharmacological management'.

RESULTS

A range of pharmacological agents are available for the management of various dysfunctional symptoms in PDD. Broadly speaking, these agents help in the management of repetitive stereotyped behaviours, anxiety, aggression/irritability/self-injurious behaviour, hyperactivity/inattention and in sleep.

CONCLUSIONS

There is a paucity of systemic, well-conducted trials on the use of pharmacological agents in the management of PDD, and more research in this area is warranted.

Treatment of Inattention, Overactivity, and Impulsiveness in Autism Spectrum Disorders

We reviewed the recent literature on medicines used to manage inattention, impulsiveness, and overactivity in children with pervasive developmental disorders (autistic disorder, pervasive developmental disorder not otherwise specified, Asperger's disorder) using computer searches of pharmacologic studies. A substantial number of reports were identified and summarized. The literature tends to be dominated by uncontrolled studies, although the number of controlled trials is growing. Findings are described for psychostimulants, noradrenergic reuptake inhibitors, antipsychotics, alpha adrenergic agonists, antidepressants, anxiolytics, cholinesterase inhibitors, N-methyl-D-aspartate receptor blockers, and antiepileptic mood stabilizers. Evidence for a positive effect is strongest for psychostimulants, noradrenergic reuptake inhibitors, antipsychotics, and alpha adrenergic agonists. Evidence for efficacy seems weakest for newer antidepressants, anxiolytics, and mood stabilizers.

Antipsychotics in the treatment of autism

Atypical antipsychotics have become indispensable in the treatment of a variety of symptoms in autism. They are frequently used to treat irritability and associated behaviors including aggression and self injury. They may also be efficacious for hyperactivity and stereotyped behavior. This review presents the rationale for the use of this drug class in autism and reviews the most important studies published on this topic to date. Significant adverse effects, including weight gain and the possibility of tardive dyskinesia, are reviewed. Future research directions are discussed.

[Autistic disorder: current psychopharmacological treatments and areas of interest for future developments]

Autistic disorder and the group of related conditions defined as pervasive developmental disorders are chronic neurodevelopmental disorders starting in early childhood and affecting a significant number of children and families. Although the causes and much of the pathophysiology of the disorder remain unknown, in recent years a number of available medication treatments have been identified as holding promise in alleviating some of the most disabling maladaptive behaviors, associated with pervasive developmental disorders. However these treatments do not address the core symptoms of the disease and oftentimes their side effects outweigh their benefits. Therefore there is substantial need for new medications that are safer and more effective in addressing the behavior symptoms of autism. The aim of this review is to highlight the available current pharmacotherapies and those emerging treatments with potential to enhance the treatment options of patients with pervasive developmental disorders.

Neurochemical correlates of autistic disorder: a review of the literature

Review of neurochemical investigations in autistic disorder revealed that a wide array of transmitter systems have been studied, including serotonin, dopamine, norepinephrine, acetylcholine, oxytocin, endogenous opioids, cortisol, glutamate, and gamma-aminobutyric acid (GABA). These studies have been complicated by the fact that autism is a very heterogeneous disorder which often presents with comorbid behavioral problems. In addition, many of these studies employed very small samples and inappropriate control groups, making it difficult to draw conclusions with confidence. Overall, serotonin appears to have the most empirical evidence for a role in autism, but this requires further investigation and replication. There is little support for the notion that a dysfunction of norepinephrine or the endogenous opioids are related to autism. The role of dopaminergic functioning has not been compelling thus far, though conflicting findings on central dopamine turnover require further study. Promising new areas of study may include possible dysfunction of the cholinergic system, oxytocin, and amino acid neurotransmitters. Implications for pharmacotherapy are briefly discussed for each neurotransmitter system with brief research examples. Review of this work emphasizes the need for future studies to control for subject variables, such as race, sex, pubertal status, and distress associated with blood draws, which can affect measures of neurochemical function. In addition, research in neurochemistry must continue to work in concert with other subspecialties to form a more comprehensive and theory-based approach to the neurobiological correlates of autistic disorder.

Advances in drug treatments for children and adolescents with autism and other pervasive developmental disorders

Autism is a disorder characterised by abnormalities in language and social development, and repetitive behaviours. Antipsychotics, including haloperidol and risperidone, are the most widely studied drugs for reducing symptoms in children and adolescents with autism. When administered at relatively low dosages, antipsychotics have been shown to reduce repetitive behaviours (stereotypies) and social withdrawal, as well as a number of related symptoms, such as hyperactivity, aggression, self-abusive behaviour, temper tantrums, lability of mood and irritability. Adverse effects of antipsychotics include sedation, dizziness, increased appetite, weight gain, changes in the electrocardiogram parameters, drooling, hyperprolactinemia and a risk of drug-related dyskinesias. Other agents have been less well studied for the treatment of autism, but there are suggestive data regarding their safety and efficacy. Of these agents, a number have been investigated, based on theories about the aetiology of autism, including SSRIs and naltrexone, although the efficacy of these agents has been limited. Stimulant drugs have been shown to reduce hyperactivity and improve focus, but they may cause behavioural worsening, weight loss and stereotypies de novo. Secretin is a treatment that has received much media attention after reports of efficacy from small open studies, but all controlled studies have failed to show any benefit. In autism, alternative treatments have also been used, but none have shown benefit in well-designed studies.

Self-injurious behavior and the efficacy of naltrexone treatment: a quantitative synthesis

People with mental retardation, autism, and related developmental disabilities who self-injure are treated with a wide array of behavioral techniques and psychotropic medications. Despite numerous reports documenting short-term and some long-term changes in self-injury associated with the opiate antagonist naltrexone hydrochloride, no quantitative review of its efficacy has been reported. We conducted a quantitative synthesis of the peer-reviewed published literature from 1983 to 2003 documenting the use of naltrexone for the treatment of self-injurious behavior (SIB). Individual-level results were analyzed given subject and study characteristics. A sample of 27 research articles involving 86 subjects with self-injury was reviewed. Eighty percent of subjects were reported to improve relative to baseline (i.e., SIB reduced) during naltrexone administration and 47% of subjects SIB was reduced by 50% or greater. In studies reporting dose levels in milligrams, males were more likely than females to respond. No significant relations were found between treatment outcomes and autism status or form of self-injury. Results are discussed with respect to future efficacy work related to study outcomes and the pharmacological treatment of self-injury.

What is Known About Autism

Autism is a neurodevelopmental disorder of genetic origins, with a heritability of about 90%. Autistic disorder is classed within the broad domain of pervasive developmental disorders (PDD) that also includes Rett syndrome, childhood disintegrative disorder, Asperger syndrome, and PDD not otherwise specified (PDD-NOS). Prevalence estimates suggest a rate of 0.1-0.2% for autism and 0.6% for the range of PDD disorders. There is considerable phenotypic heterogeneity within this class of disorders as well as continued debate regarding their clinical boundaries. Autism is the prototypical PDD, and is characterized by impairments in three core domains: social interaction, language development, and patterns of behavior (restricted and stereotyped). Clinical pattern and severity of impairment vary along these dimensions, and the level of cognitive functioning of individuals with autism spans the entire range, from profound mental retardation to superior intellect. There is no single biological or clinical marker for autism, nor is it expected that a single gene is responsible for its expression; as many as 15+ genes may be involved. However, environmental influences are also important, as concordance in monozygotic twins is less than 100% and the phenotypic expression of the disorder varies widely, even within monozygotic twins. Multiple susceptibility factors are being explored using varied methodologies, including genome-wide linkage studies, and family- and case-control candidate gene association studies. This paper reviews what is currently known about the genetic and environmental risk factors, neuropathology, and psychopharmacology of autism. Discussion of genetic factors focuses on the findings from linkage and association studies, the results of which have implicated the involvement of nearly every chromosome in the human genome. However, the most consistently replicated linkage findings have been on chromosome 7q, 2q, and 15q. The positive associations from candidate gene studies are largely unreplicated, with the possible exceptions of the GABRB3 and serotonin transporter genes. No single region of the brain or pathophysiological mechanism has yet been identified as being associated with autism. Postmortem findings, animal models, and neuroimaging studies have focused on the cerebellum, frontal cortex, hippocampus, and especially the amygdala. The cerebello-thalamo-cortical circuit may also be influential in autism. There is evidence that overall brain size is increased in some individuals with autism. Presently there are no drugs that produce major improvements in the core social or pragmatic language deficits in autism, although several have limited effects on associated behavioral features. The application of new techniques in autism research is being proposed, including the investigation of abnormal regulation of gene expression, proteomics, and the use of MRI and postmortem analysis of the brain.

Autism and pervasive developmental disorders

The quantity and quality of research into autism and related conditions have increased dramatically in recent years. Consequently we selectively review key accomplishments and highlight directions for future research. More consistent approaches to diagnosis and more rigorous assessment methods have significantly advanced research, although the boundaries of the 'broader phenotype' remain to be defined and the validity of Asperger's disorder as a discrete syndrome remains controversial. Recent epidemiological studies have shown that Autism Spectrum Disorders are common, but there continues to be debate about the causes of the increase in the frequency with which autism is diagnosed. Psychological research has helped to develop new developmental models for the disorder and there have also been significant advances in the molecular genetics of autism and understanding of the underlying neurobiological processes. Areas important for future research include the study of autism as it first develops, i.e., in infants and very young children, and of specific processes (psychological and neurobiological) which underlie the disorder. Significant challenges lie ahead in evaluating the growing number of treatments for autism and in integrating the results of research into treatment and educational settings.

Opiate antagonists in children and adolescents

Naltrexone a pure opioid antagonist, well tolerated in young patients, has been found to be an interesting treatment in some disorders in children and adolescents. Naltrexone has been first tried in mental retardation and autism disorders in children and adolescents. Symptoms like self-injury behaviours, hyperactivity, stereotyped and ritualistic conducts appear to be improved in a subgroup of children with the opiate antagonist. But new controlled studies still need to be done before recommending naltrexone in autism. Preliminary results in the treatment of alcoholic adolescents seem to support the efficacy of naltrexone on abstinence when combined with a supportive psychotherapy. In adults, results found with the use of naltrexone in eating disorders are different, when considering the duration and the dosage of the treatment and the kind of eating disorder (bulimia, binge eating or anorexia nervosa). Studies in children and adolescents are needed before proposing naltrexone in eating disorders. We resumed here the results found with this treatment in these indications.

Pharmacological interventions in autism: theoretical and practical issues

Focused on issues of drug treatment in relation to autism. Pharmacological treatment studies in autism are complicated by various factors including a tremendous range of syndrome expression, a lack of robust animal models of the disorder, and various methodological problems. Theories have tended to follow treatments, and various neurochemical systems have been the focus of study. Neurochemical systems potentially implicated include those involving dopamine, norepinephrine, serotonin, and neuropeptides. The dopaminergic system has been the most extensively studied. Treatments developed are effective relative to certain disabling symptoms but "core" problems (e.g., in social relatedness and communication) appear less responsive to medications. The development of new approaches to assessment, including integration of behavioral and pharmacological approaches, is an important research priority.

Pharmacotherapy for hyperactivity in children with autism and other pervasive developmental disorders

We reviewed pharmacological treatments used in children with autism and PDD-NOS who present with hyperactive symptoms. Some 41 studies were identified from the following drug categories: antipsychotics (n = 13), serotonin reuptake inhibitors (n = 3), antianxiety drugs (n = 4), psychostimulants (n = 10), alpha adrenergic agonists (n = 2), opiate blockers (n = 7), and other drugs (n = 2). Empirical evidence for significant reductions in hyperactive symptoms was strongest for the antipsychotics, psychostimulants, and naltrexone. Most studies have focused on the reduction of overactivity, and more emphasis needs to be placed on distractibility and attentional variables. A theoretical model was proposed in which participants' attentional performance may be used to predict clinical response to psychostimulants. More carefully controlled and comprehensive studies of hyperactivity are badly needed in these children.

Using analog baselines to assess the effects of naltrexone on self-injurious behavior

Naltrexone (NLTX), an opiate receptor antagonist, has been prescribed as a pharmacological intervention for the treatment of self-injurious behavior (SIB). Previous research has investigated NLTX's effects in the absence of information about the role of environmental events related to SIB. This study extended previous analyses by administering NLTX on analog baselines using a double-blind, placebo-controlled reversal design. Pretreatment functional analysis results showed that the SIB of the two participants occurred in more that one assessment condition. For one participant NLTX produced slight reductions in SIB across baseline conditions. The second participant's results showed that NLTX reduced head-slapping occurring during demand sessions, but had no apparent effect on head-banging occurring during alone and demand sessions. These outcomes suggest that NLTX may have function- and/or response-specific treatment effects. The potential utility of this model as a general method for assessing pharmacological interventions, as well as other implications and limitations, are discussed.

Pain tolerance in opioid addicts on and off naltrexone pharmacotherapy: a pilot study

Under certain experimental and clinical conditions, opioid antagonists have been demonstrated to have analgesic properties. In this open-label, nonrandomized, within-subject comparison, the effect of chronic treatment with the antagonist, naltrexone, on tolerance for experimental pain was evaluated in a small sample of male opioid addicts (N = 10) receiving naltrexone maintenance. Cold-pressor pain tolerance was measured during (> or = 6 weeks) and after discontinuation (> or = 1 week) of naltrexone treatment. Intra-subject comparison revealed that eight of the ten subjects were more pain tolerant (median + 20 sec) while receiving naltrexone. It is suggested that either midbrain opioid system upregulation in the presence of naltrexone or underlying individual differences in pain tolerance in persons with addictive disease provide potential explanations for these findings.

Naltrexone in young autistic children: replication study and learning measures

OBJECTIVE

This study expanded upon previous work on naltrexone efficacy and safety in young autistic children and assessed performance on learning measures.

METHOD

Eleven children with autistic disorder, aged 3.0 to 8.3 years, were studied in home, school, and outpatient laboratory, bringing to 24 the combined study sample. Naltrexone, 1.0 mg/kg, was given daily in a randomized, double-blind, crossover design. Dependent measures were parent and teacher Clinical Global Impressions (CGI) and Naltrexone Side Effects Rating Scale (SE), Conners Parent Impulsivity/Hyperactivity Factor, Teacher Hyperactivity Factor, laboratory CGI, and analysis of videotaped behavior. Learning measures were the Early Intervention Developmental Profile-Language and paired-associate learning.

RESULTS

Comparisons between naltrexone and baseline, but not naltrexone and placebo, on parent and teacher ratings showed statistical significance. Three of 11 subjects improved in two or more settings. Side effects were mild. Administering naltrexone was a challenge. The combined study sample showed improvement on all parent measures and on Teacher CGI and SE-Restlessness compared with baseline and placebo. Eleven of the 24 children improved in two or more settings. Scores on learning measures did not change across conditions.

CONCLUSIONS

Naltrexone was associated with modest improvement of behavior in 11 of 24 children, but learning did not improve.

The effects of chronic naltrexone treatment in young autistic children: a double-blind placebo-controlled crossover study

In a double-blind placebo-controlled crossover trial 23 autistic children, aged 3-7 years, were treated with a mean daily dosage of 1 mg/kg naltrexone for 4 weeks. Drug effects were monitored with behavior checklists rated by parents and teachers, and ethological playroom observations. On average, parents' checklists and playroom data could not differentiate between naltrexone treatment and placebo treatment; however, teachers significantly favored naltrexone treatment. They reported a decrease in hyperactivity and irritability. No effects of naltrexone on social and stereotypic behavior could be demonstrated.

Treatment of autistic disorder

OBJECTIVE

To present an overview of a variety of treatment approaches in individuals with autistic disorder.

METHOD

Selected studies and articles are reviewed.

RESULTS

In the past three decades, great progress has been made in the treatment of autistic disorder, particularly in the area of education and parental involvement, with the objective to transfer to home and in other situations learning acquired in school. A role for psychoactive agents, when combined with psychosocial treatments, has been identified.

CONCLUSIONS

Although considerable advances have been made in a variety of interventions-educational, psychosocial, and biological-knowledge about the comparative and combined efficacy of the various treatment modalities is lacking. From the parents' perspective, particularly, support and continuity of services require improvement.

Placebo-controlled acute dosage naltrexone study in young autistic children

In a double-blind, placebo-controlled crossover trial 23 autistic children were treated with a single 40-mg dose of the opiate antagonist naltrexone. Drug effects were monitored by detailed playroom observations, actometers, and parents' checklist ratings (Aberrant Behavior Checklist, social items and target behaviors). Naltrexone treatment failed to produce significant changes in social behavior, but it did reduce irritability and target scores on behavior checklists. The playroom data indicated that naltrexone significantly affected indices of activity and attention.

Psychopharmacology in child and adolescent psychiatry: a review of the past seven years. Part I

OBJECTIVE

To present a critical overview of the literature published in the past 7 years on the efficacy and safety of psychoactive agents in mental retardation with associated psychiatric disorders, autistic disorder, Tourett's disorder, and attention-deficit/hyperactivity disorder.

METHOD

Double-blind and placebo-controlled clinical trials and open studies were reviewed and selected reports presented.

RESULTS

The literature review reveals that progress has been made in the psychopharmacological treatment of the above conditions. This is partly because more studies use larger sample sizes and a narrower age range of diagnostically homogeneous patients and use a more sophisticated methodology than in previous years. Greater attention is being paid to a critical assessment of psychoactive agents and to their safety, to the efficacy as well as to the effectiveness of drugs. The 5-year National Plan for Research on Child and Adolescent Mental Disorders (1991) based on the Institute of Medicine Report (1989) already has had a significant impact on psychophamacology research.

CONCLUSIONS

Advances in methodology, initiatives of the National Institute of Mental Health, and the advent of DSM-IV should continue to enhance research and improve pharmacotherapy in clinical practice.

Endogenous opioids and opiate antagonists in autism: brief review of empirical findings and implications for clinicians

Endogenous opioid dysfunction hypotheses for the development of autism are reviewed, along with clinical empirical studies of opiate antagonists in autism and self-injurious behaviour. There is not yet sufficient evidence to suggest the use of opiate antagonists in the treatment of autism. Further research, particularly of natrexone in severe self-injury, is warranted.

Naltrexone in young autistic children: a double-blind, placebo-controlled crossover study

OBJECTIVE

This study evaluated the efficacy and safety of naltrexone, an opiate blocker, in the treatment of autism.

METHOD

Thirteen children with autistic disorder, aged 3.4 to 8.3 years (mean 5.4), were studied in home, school, and outpatient laboratory. Naltrexone, 1.0 mg/kg, was given daily in a randomized, double-blind, placebo-controlled crossover design. Dependent measures included parent and teacher Clinical Global Impressions (CGI), Conners Rating Scales, and Naltrexone Side-Effects (SE) Rating Scale; laboratory CGI, movement actometer readings, and a 10-second interval recording system analysis of on-task, communication initiations, disruptive behavior, and self-stimulation.

RESULTS

Eight of 13 subjects improved in two or more settings. Changes in parent measures (CGI, Conners Impulsivity-Hyperactivity Factor, and SE-Restlessness) and Teacher CGI achieved statistical significance. Teacher SE-Restlessness and initiation of communication in the clinic showed a trend toward improvement. Actometer readings improved in two children who were very active at baseline. Adverse side effects were behavioral, mild, and transient. Administering the bitter tablet was a challenge.

CONCLUSIONS

Naltrexone offers promise as an agent for modest improvement of behavior and social communication in young children with autism. Parent and teacher measures can be useful in outpatient trials to evaluate change.

Autism and associated behavioral disorders: pharmacotherapeutic intervention

OBJECTIVE

To review the literature on autism and pervasive developmental disorders (PDDs) as well as their respective pharmacotherapies.

DATA SOURCES

An Index Medicus, MEDLINE, and bibliographic search of the literature pertaining to autism, PDDs, and respective treatments.

STUDY SELECTION

Because of the paucity of literature on the treatment of autism and PDDs, the selection of reported data for this review included both controlled and uncontrolled studies, as well as case reports and any other information reported in the literature on the treatment of these disorders.

DATA SYNTHESIS

Autism and PDDs are severe developmental disabilities defined by behavioral criteria. These disorders are lifelong in nature and present in varying severity of clinical manifestations. Behavioral manifestations of patients with autism include core deficits in social interaction, communication, and imaginative activities, with a restricted repertoire of activities and interests. The present understanding of the neurochemical basis of the disorder is limited. The role of pharmacotherapy in the management of autism and PDDs is to ameliorate behavioral symptoms that interfere with the patient's ability to participate in educational, social, work, and family systems. Agents that have shown positive clinical effects in the treatment of children with autism and PDDs are reviewed in this article.

CONCLUSIONS

Autism is a complex developmental disorder representing a heterogeneous group of individuals with similar symptomatologies and multiple biologic etiologies. Present pharmacotherapeutic intervention seeks to resolve behavioral symptoms. Treatment of autism and PDDs requires appropriate delineation of the behaviors and neurobiologic disorders associated with each patient. No single therapeutic agent, or combination thereof, is appropriate for the treatment of all children and adults with autism or PDDs.

Effects of the opiate antagonist, naltrexone, on binging antecedents and plasma beta-endorphin concentrations

The effects of the opiate receptor antagonist, naltrexone, were examined on antecedent thoughts of binging and plasma beta-endorphin concentrations in an adolescent girl who was hospitalized with bulimia nervosa. Significant decreases in urge to binge were obtained during naltrexone administration compared with control sessions. Baseline plasma beta-endorphin concentrations for the bulimic adolescent were not different from those of nonbulimic controls, but plasma beta-endorphins increased significantly during naltrexone administration. After discharge from the hospital, the adolescent refused to take naltrexone because she felt she could not deal with her life without the "pleasure of binging." The case points to the interplay of biological and psychological factors in bulimia nervosa.

Naltrexone in autistic children: behavioral symptoms and attentional learning

OBJECTIVE

To assess critically the short-term efficacy and safety of naltrexone in autistic children and its effects on discrimination learning in the laboratory.

METHOD

A parallel group design was employed. After a 2-week placebo baseline period, children were randomly assigned either to naltrexone or to placebo for a period of 3 weeks followed by a one-week posttreatment placebo period. Multiple raters and rating scales were employed in a variety of conditions. Forty-one children, all inpatients, ages 2.9 to 7.8 years, completed the study. Naltrexone reduced hyperactivity and had no effect on discrimination learning in the laboratory. There was a suggestion that it had a beneficial effect on decreasing self-injurious behavior. Untoward effects were mild and transient.

CONCLUSION

In the present study, naltrexone significantly reduced only hyperactivity, and no serious untoward effects were observed. The effectiveness of naltrexone in the treatment of autism and self-injurious behavior requires additional assessment in a sample of children with moderate to severe self-injurious behavior.

The adrenocorticotrophic hormone (4-9) analog ORG 2766 benefits autistic children: report on a second controlled clinical trial

In a second controlled crossover trial, 20 autistic children received 40 mg/day of the neuropeptide ORG 2766, a synthetic analog of ACTH (4-9), for 8 weeks. Parents' checklist ratings (ABC) as well as clinicians' ratings (CGI) pointed to significant improvements after the course of treatment; improvements were clearest on the ABC social withdrawal subscale. The analysis of individual target symptoms and the parents' treatment preferences substantiated the beneficial effects of ORG 2766. In an ethologically analyzed playroom session, ORG 2766 treatment was associated with an improvement in the children's play behavior and a significant increase in the social interaction between child and experimenter. Gaze coordination between child and experimenter also was improved.

The use of adrenocorticotrophic hormone (4-9) analog ORG 2766 in autistic children: effects on the organization of behavior

In a double-blind placebo-controlled crossover trial, 14 autistic children were treated with the neuropeptide ORG 2766, a synthetic analog of adrenocorticotrophic hormone (ACTH) (4-9). ORG 2766 treatment (20 mg per day during 4 weeks) was associated with an increased amount and an improved quality of the social interaction of the autistic children with a familiar experimenter. These changes in interaction were clinically relevant. Following treatment with ORG 2766 gaze and smile behaviors of child and experimenter showed stronger temporal contingencies. Further, after ORG 2766, stereotypies were temporally disconnected from verbal initiatives. The data supported the notion of a stimulating effect of ORG 2766 on social interaction. The implications of these findings for the endogenous opioid theory of autism are discussed.

Pediatric psychopharmacotherapy: a review of recent research

In the past 5 years, we have witnessed the continuation of important trends in clinical research that began earlier in the decade. With regard to the treatment of specific disorders in children and adolescents, the most significant developments have been the examination of the tricyclics for the treatment of depression and the initiation of controlled studies for the treatment of Tourette syndrome. Unfortunately, the findings from the depression studies have been uniformly negative, and the results of research on both depression and tic disorders show a relatively high rate of placebo responsivity, which raises nagging questions about the role of case reports and open trials. Another important trend in pediatric psychopharmacotherapy is the search for substitutes for the neuroleptics. Potential candidates include agents such as lithium, naltrexone, fenfluramine, clonidine, and carbamazepine. The most underresearched disorders are a combination of the least common (e.g. schizophrenia, mania) and those that are apparently perceived as less serious (e.g. sleep disorders, certain anxiety disorders). Not surprisingly, the most studied disorder and treatment is hyperactivity and stimulant medication, respectively. Considerable progress has been made in understanding the social implications of the associated symptoms and their response to stimulant drugs, aided greatly by the use of direct observation procedures. Researchers are beginning to attend to the implications of comorbidity for assessing response to medication. There has been additional confirmation of efficacy of stimulant treatment for preschoolers and adolescents. Dose-response issues remain to some extent unresolved, the primary impediments being interpretive misconceptions associated with trend analysis, an overreliance on the syndromal perspective and too little attention to target behaviors and their clinical implications, and the failure to operationalize the minimal effective dose with regard to the normalization and supranormalization of target and collateral behaviors. Disagreement over whether hyperactivity is a learning or a behavior disorder (or both) and what academic underproductivity means clinically and socially is also impeding progress. With regard to developmental disorders, controlled studies indicate that fenfluramine and naltrexone are effective for managing associated symptoms in some individuals. However, given the limited amount of research on these agents, their status as clinically useful palliatives must be considered tentative.(ABSTRACT TRUNCATED AT 400 WORDS)

Diagnostic and assessment issues related to pharmacotherapy for children and adolescents with autism

Autism involves not only developmental delays but also aberrant behavior, both of which change in nature over time. Rating instruments may be useful to assess maladaptive and adaptive behaviors of autistic children in a standardized way and, perhaps, to measure change due to treatment. With the expansion of basic science, knowledge, and technology, there is increasing evidence that autism is etiologically heterogeneous. Currently, there is no biological marker specific to autism, although hyperserotonemia is a consistent finding in one third of autistic children. An aim of basic science research has been to develop a rational pharmacotherapy based upon the underlying neurochemistry. However, at the present time, this approach has not always been successful. It is expected that the development and use of more restrictive criteria, delineation of subtypes of autism, and interaction of descriptive, behavioral, clinical, and basic research will lead to more effective planning for treatment. The relationship of assessment to treatment response is presented and discussed.

A case report of naltrexone treatment of self-injury and social withdrawal in autism

The endogenous opiate release theory of self-injurious behavior (SIB) was investigated through double-blind placebo-controlled administration of naltrexone hydrochloride (Trexan) to a 14-year-old autistic and mentally retarded male for treatment of severe SIB. Results yielded a marked decrease in SIB during two phases of active drug treatment, though SIB did not revert to originally observed placebo levels during a second placebo phase. An increase in social relatedness also was observed during phases of active drug treatment. Opiate theories of self-injury and the possible interrelationship of self-injury with pituitary-adrenal arousal and with social relatedness are discussed.