Role of risperidone in children with autism spectrum disorder

Exploring the impact of stimulant medications on weight in children with attention deficit hyperactivity disorder in Dubai, United Arab Emirates

Objective

Attention deficit hyperactivity disorder (ADHD), prevalent in 5% of children worldwide, impacts academic performance and often coexists with psychiatric disorders. Psychostimulant medications are primary treatments for ADHD, enhancing dopamine to reduce symptoms. However, dopamine increase may cause appetite loss. This pioneering study in the United Arab Emirates (UAE) explores psychostimulant effects on weight in children diagnosed with ADHD, aiming to uncover unique regional characteristics and contributing factors to weight changes.

Methods

This retrospective cohort study assessed data from electronic medical records from 2017 to 2022, aiming to assess the impact of psychostimulants on weight in children aged 6-18 years. Inclusion criteria covered psychostimulant-treated and untreated patients with ADHD. Statistical analysis, involving longitudinal data methods aimed to demonstrate significant weight differences.

Results

Data from 107 pediatric patients diagnosed with ADHD were analyzed, with 86 meeting inclusion criteria. Most patients were male (80.2%). ADHD presentations varied, and methylphenidate immediate release was the most prescribed stimulant medication. Patients experienced initial weight loss followed by overall gain over 12 months. Coexisting conditions, maternal factors, family history, and correlations with autism spectrum disorder were explored.

Conclusion

This study provides valuable insights into the effects of psychostimulant medications on the weight of children and adolescents diagnosed with ADHD in the UAE. It suggests avenues for future research, emphasizing extended follow-ups to understand long-term psychostimulant effects, nuanced examinations of age and gender, and exploring interactions with comorbidities. Despite limitations, the research provides insights into ADHD medication effects, guiding personalized treatment approaches for pediatric populations.

Stem Cell Secretions as a Potential Therapeutic Agent for Autism Spectrum Disorder: A Narrative Review

Autism spectrum disorder (ASD) is a neurodevelopmental illness characterized by impaired social interaction and restricted repetitive behaviors or interests. The rising prevalence of ASD diagnosis has triggered a surge in research into investigating the underlying neuropathological processes and finding new therapeutic approaches. ASD is characterized by neuroinflammation and dysregulation of neuro-immune cross-talk, which suggests that stem cell treatment might be a potential therapeutic approach. The beneficial and restorative effects of stem cells are mainly due to their paracrine activity, in which stem cells generate and release extracellular vesicles such as exosomes and distinct secreted non-vesicle soluble proteins, including, growth factors, chemokines, cytokines, and immunomodulatory molecules referred to as the Secretome. In this paper, we reviewed the existing research exploring the therapeutic potential of stem cell secretome focusing on their role in addressing ASD pathology. Furthermore, we proposed a comprehensive mechanism of action for stem cell secretions, encompassing the broader secretome as well as the specific contribution of exosomes, in alleviating ASD neuropathology. Across the reviewed studies, exosomes and secreted soluble factors of the transplanted stem cell demonstrate a potential efficacy in ameliorating autistic-like behaviors. The proposed mechanism of action involves the modulation of signaling pathways implicated in neuroinflammation, angiogenesis, cellular apoptosis, and immunomodulation.

Guava-fruit based synthesis of carbon quantum dots for spectrofluorometric quantitative analysis of risperidone in spiked human plasma and pharmaceutical dosage forms

Autism is one of the most pressing issues facing the international community in recent years, particularly in Middle Eastern countries. Risperidone is a selective serotonin type 2 and dopamine type 2 receptor antagonist. It is the most administered antipsychotic medication in children with autism-related behavioral disorders. Therapeutic monitoring of risperidone may improve safety and efficacy in autistic individuals. The main objective of this work was to develop a highly sensitive green fitted method for the determination of risperidone in the plasma matrix and pharmaceutical dosage forms. Novel water-soluble N-carbon quantum dots were synthesized from guava fruit, a natural green precursor, and used for determination of risperidone based on quenching fluorescence spectroscopy phenomena. The synthesized dots were characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. The synthesized N-carbon quantum dots exhibited aquantum yield of 26.12% and showed a strong emission fluorescence peak at 475 nm when excited at 380 nm. The fluorescence intensity of the N-carbon quantum dots decreased with increasing risperidone concentration, indicating that the fluorescence quenching was concentration dependent. The presented method was carefully optimized and validated according to the guidelines of ICH, and it demonstrated good linearity in a concentration range of 5-150 ng mL-1. With a LOD of 1.379 ng mL-1 and a LOQ of 4.108 ng mL-1, the technique was extremely sensitive. Due to the high sensitivity of the proposed method, it could be effectively used for the determination of risperidone in the plasma matrix. The proposed method was compared with the previously reported HPLC method in terms of sensitivity and green chemistry metrics. The proposed method proved to be more sensitive and compatible with the principles of green analytical chemistry.

Effectiveness and Adverse Effects of Risperidone in Children with Autism Spectrum Disorder in a Naturalistic Clinical Setting at a University Hospital in Oman

Objective

This study aimed at examining the effectiveness of treating children with autism spectrum disorder (ASD) who present with irritability, aggression, and disruptive behavior at the Sultan Qaboos University Hospital (SQUH) in Muscat, Oman, with risperidone, and to note any sex-based differences among this cohort.

Method

This was a retrospective study conducted at the Department of Behavioral Medicine at SQUH over two years from January 2017 to December 2018. This study included all children aged 3 to 18 years attending the Child and Adolescent Mental Health Service (CAMHS) outpatient clinic with a diagnosis of ASD, based on the DSM-5 criteria, and comorbid disruptive behavior, who had been prescribed risperidone.

Result

This study identified 95 ASD patients (72 males). Male patients' BMI score after 12 months of risperidone treatment showed an increase by 0.62 (1.57 SD; P=0.001); however, there was no significant change among female patients. Somnolence was noted in 69.6% of female patients as compared to 34.7% of males (P=0.003). Among those with a family history of ASD, 5 out of 17 patients had treatment success (29.4%), whereas 70 out of 78 patients (90.0%) who did not have a similar history had successful treatment.

Conclusion

In conclusion, low-dose risperidone monotherapy is effective and well tolerated among some children with ASD who present with disruptive behavior in a naturalistic clinical setting. However, we found that some of the side effects, such as weight gain and somnolence, were concerning.

Practitioner's review: medication for children and adolescents with autism spectrum disorder (ASD) and comorbid conditions

Alleviating the multiple problems of children with autism spectrum disorder (ASD) and its comorbid conditions presents major challenges for the affected children, parents, and therapists. Because of a complex psychopathology, structured therapy and parent training are not always sufficient, especially for those patients with intellectual disability (ID) and multiple comorbidities. Moreover, structured therapy is not available for a large number of patients, and pharmacological support is often needed, especially in those children with additional attention deficit/hyperactivity and oppositional defiant, conduct, and sleep disorders.

Neural Mechanisms Underlying Repetitive Behaviors in Rodent Models of Autism Spectrum Disorders

Autism spectrum disorder (ASD) is comprised of several conditions characterized by alterations in social interaction, communication, and repetitive behaviors. Genetic and environmental factors contribute to the heterogeneous development of ASD behaviors. Several rodent models display ASD-like phenotypes, including repetitive behaviors. In this review article, we discuss the potential neural mechanisms involved in repetitive behaviors in rodent models of ASD and related neuropsychiatric disorders. We review signaling pathways, neural circuits, and anatomical alterations in rodent models that display robust stereotypic behaviors. Understanding the mechanisms and circuit alterations underlying repetitive behaviors in rodent models of ASD will inform translational research and provide useful insight into therapeutic strategies for the treatment of repetitive behaviors in ASD and other neuropsychiatric disorders.

Use of Atypical Antipsychotics in the Treatment of Autistic Disorder

Objective:

To review clinical trials and reports describing the efficacy and safety of atypical antipsychotics (olanzapine, ziprasidone, quetiapine, aripiprazole) in the treatment of autistic or other pervasive developmental disorders.

Data Sources:

English-language publications from the MEDLINE database (1966–February 2007) including clinical trials, case reports, and retrospective series were reviewed.

Study Selection and Data Extraction:

Relevant data were extracted from studies of selected atypical antipsychotics in the treatment of autistic disorder in children, adolescents, and adults. Most literature found was in the form of case reports or case series; however, several open-label and double-blind trials were also identified.

Data Synthesis:

Autistic disorder is a chronic neurodevelopmental disorder with limited treatment options. Nonpharmacologic approaches may be the most beneficial, but pharmacologic agents are needed for some patients with significant behavioral manifestations of the disorder. The atypical antipsychotics (olanzapine, ziprasidone, quetiapine, aripiprazole) have shown some efficacy in improving certain behavioral symptoms of autistic disorder—primarily aggressiveness, hyperactivity, and self-injurious behavior. Efficacy was based on observation or changes from baseline in behavioral rating scores. Data appear to be strongest for olanzapine compared with quetiapine, with several open-label trials suggesting its efficacy. Weight gain and sedation were frequently reported adverse events with both agents. Aripiprazole has demonstrated efficacy in limited case series, with minimal adverse effects reported.

Conclusions:

Atypical antipsychotics represent a treatment option for symptoms associated with autistic disorder. However, these drugs do not affect the core symptoms of autistic disorder and are associated with potentially significant adverse effects. In addition, there is a lack of randomized controlled trials to determine the true efficacy and long-term safety of these agents in the pediatric population.

Translational Mouse Models of Autism: Advancing Toward Pharmacological Therapeutics

Animal models provide preclinical tools to investigate the causal role of genetic mutations and environmental factors in the etiology of autism spectrum disorder (ASD). Knockout and humanized knock-in mice, and more recently knockout rats, have been generated for many of the de novo single gene mutations and copy number variants (CNVs) detected in ASD and comorbid neurodevelopmental disorders. Mouse models incorporating genetic and environmental manipulations have been employed for preclinical testing of hypothesis-driven pharmacological targets, to begin to develop treatments for the diagnostic and associated symptoms of autism. In this review, we summarize rodent behavioral assays relevant to the core features of autism, preclinical and clinical evaluations of pharmacological interventions, and strategies to improve the translational value of rodent models of autism.

Dysfunctional dopaminergic neurotransmission in asocial BTBR mice

Autism spectrum disorders (ASD) are neurodevelopmental conditions characterized by pronounced social and communication deficits and stereotyped behaviours. Recent psychosocial and neuroimaging studies have highlighted reward-processing deficits and reduced dopamine (DA) mesolimbic circuit reactivity in ASD patients. However, the neurobiological and molecular determinants of these deficits remain undetermined. Mouse models recapitulating ASD-like phenotypes could help generate hypotheses about the origin and neurophysiological underpinnings of clinically relevant traits. Here we used functional magnetic resonance imaging (fMRI), behavioural and molecular readouts to probe dopamine neurotransmission responsivity in BTBR T(+) Itpr3(tf)/J mice (BTBR), an inbred mouse line widely used to model ASD-like symptoms owing to its robust social and communication deficits, and high level of repetitive stereotyped behaviours. C57BL/6J (B6) mice were used as normosocial reference comparators. DA reuptake inhibition with GBR 12909 produced significant striatal DA release in both strains, but failed to elicit fMRI activation in widespread forebrain areas of BTBR mice, including mesolimbic reward and striatal terminals. In addition, BTBR mice exhibited no appreciable motor responses to GBR 12909. DA D1 receptor-dependent behavioural and signalling responses were found to be unaltered in BTBR mice, whereas dramatic reductions in pre- and postsynaptic DA D2 and adenosine A2A receptor function was observed in these animals. Overall these results document profoundly compromised DA D2-mediated neurotransmission in BTBR mice, a finding that is likely to have a role in the distinctive social and behavioural deficits exhibited by these mice. Our results call for a deeper investigation of the role of dopaminergic dysfunction in mouse lines exhibiting ASD-like phenotypes, and possibly in ASD patient populations.

Characterizing social behavior in genetically targeted mouse models of brain disorders

Fragile X syndrome, the leading inherited cause of mental retardation and autism spectrum disorders worldwide, is caused by a tandem repeat expansion in the FMR1 (fragile X mental retardation 1) gene. It presents with a distinct behavioral phenotype which overlaps significantly with that of autism. Emerging evidence suggests that tandem repeat polymorphisms (TRPs) might also play a key role in modulating disease susceptibility for a range of common polygenic disorders, including the broader autism spectrum of disorders (ASD) and other forms of psychiatric illness such as schizophrenia, depression, and bipolar disorder [1]. In order to understand how TRPs and associated gene mutations mediate pathogenesis, various mouse models have been generated. A crucial step in such functional genomics is high-quality behavioral and cognitive phenotyping. This chapter presents a basic behavioral battery for standardized tests for assaying social phenotypes in mouse models of brain disorders, with a focus on aggression.

Efficacy of risperidone in children with disruptive behavioural disorders

This study aims to review the evidence for the efficacy of risperidone in the treatment of disruptive behavioural disorders (DBDs) in children and adolescents. Established databases were searched using the terms 'Risperidone and efficacy and children' and 'Risperidone and efficacy and adolescents'. Randomised, double-blind controlled studies were retained for analysis. Janseen-Cilag was contacted to identify any unpublished studies. Quality of studies was measured using Jadad scores. Seven studies of 657 subjects with a mean age of 9.9 years (SD= 2.0) (range 4-18 years) were identified. Only one study was judged to use the highest quality of methodology according to the Jadad score. Patients with DBD who were treated with risperidone showed clinical improvement compared with placebo. Weight gain, somnolence and gastrointestinal complaints were common. Risperidone was found to be efficacious in reducing symptoms in children and adolescents with DBD. However, studies were mostly of short duration and had deficiencies in the descriptions of blinding and randomisation. Research using rigorous methodology examining the long-term outcomes of efficacy and safety are required to inform clinicians and families of the therapeutic benefits and risks of risperidone in this clinical population.

Low-dose quetiapine for adolescents with autistic spectrum disorder and aggressive behavior: open-label trial

BACKGROUND

Atypical antipsychotics may be useful in treating aggression associated with autistic spectrum disorder (ASD). We evaluated the effectiveness of low-dose quetiapine treatment in ASD adolescent patients with aggressive behavior.

METHOD

Eleven adolescent patients (8 boys and 3 girls) diagnosed with ASD, aged 13 to 17 years, were treated with quetiapine in an open-label study over an 8-week period. The severity of ASD, aggressive behavior, and sleep disturbances were assessed using the Clinical Global Impression-Severity (CGI-S), Overt Aggression Scale, and Child Sleep Habits Questionnaire, respectively.

RESULTS

Nonsignificant changes were obtained in autistic behavior after quetiapine treatment (CGI-S: 4.0 ± 0.6 vs CGI-S after: 3.1 ± 1.1; 2-tailed paired t = 1.93; df = 10; P = 0.08). Severity of aggressive behavior decreased significantly after quetiapine treatment (Overt Aggression Scale: 2.1 ± 0.94 vs 1.3 ± 0.64, respectively; 2-tailed paired t = 2.37; df =10; P = 0.028). Sleep disturbances improved significantly (Child Sleep Habits Questionnaire: 49.0 ± 12 vs 44.1 ± 9.6; 2-tailed paired t = 2.98; df =10; P = 0.014) and a positive correlation was found between the improvements in aggression and sleep (Spearman correlation: r = 0.43; N = 11; P = 0.013). Quetiapine was well tolerated.

CONCLUSION

Short-term low-dose quetiapine treatment may reduce aggression levels and improve sleep quality in adolescents with ASD.

Repetitive self-grooming behavior in the BTBR mouse model of autism is blocked by the mGluR5 antagonist MPEP

Autism is a neurodevelopmental disorder characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. BTBR T+tf/J (BTBR) is an inbred mouse strain that shows robust behavioral phenotypes with analogies to all three of the diagnostic symptoms of autism, including well-replicated deficits in reciprocal social interactions and social approach, unusual patterns of ultrasonic vocalization, and high levels of repetitive self-grooming. These phenotypes offer straightforward behavioral assays for translational investigations of pharmacological compounds. Two suggested treatments for autism were evaluated in the BTBR mouse model. Methyl-6-phenylethynyl-pyridine (MPEP), an antagonist of the mGluR5 metabotropic glutamate receptor, blocks aberrant phenotypes in the Fmr1 mouse model of Fragile X, a comorbid neurodevelopmental disorder with autistic features. Risperidone has been approved by the United States Food and Drug Administration for the treatment of irritability, tantrums, and self-injurious behavior in autistic individuals. We evaluated the actions of MPEP and risperidone on two BTBR phenotypes, low sociability and high repetitive self-grooming. Open field activity served as an independent control for non-social exploratory activity and motor functions. C57BL/6J (B6), an inbred strain with high sociability and low self-grooming, served as the strain control. MPEP significantly reduced repetitive self-grooming in BTBR, at doses that had no sedating effects on open field activity. Risperidone reduced repetitive self-grooming in BTBR, but only at doses that induced sedation in both strains. No overall improvements in sociability were detected in BTBR after treatment with either MPEP or risperidone. Our findings suggest that antagonists of mGluR5 receptors may have selective therapeutic efficacy in treating repetitive behaviors in autism.

Aripiprazole monotherapy in children and young adolescents with pervasive developmental disorders: a retrospective study

BACKGROUND

Pervasive developmental disorders (PDDs) are severe psychiatric disorders characterized by impairment in social interactions, in verbal and non-verbal communication, and by restricted and stereotyped patterns of interest and behaviour, with onset in the first 3 years of life. The appropriate use of pharmacotherapy can improve some aberrant symptoms and behaviours and increase the person's response to non-pharmacological interventions.

OBJECTIVE

To describe clinical outcomes, or symptom changes, and adverse effects during naturalistic treatment with aripiprazole monotherapy in children with PDDs and severe behavioural disorders (such as aggression against self and/or others, hostility, hyperactivity, severe impulsiveness).

METHOD

This retrospective naturalistic study included 34 patients (23 males and 11 females, age range 4.5-15 years, mean age 10.2 +/- 3.3 years), admitted during 2006-2007, diagnosed according to DSM-IV criteria and followed up for 4-12 months (mean 7.0 +/- 3.6 months). Outcome measures were three global measures of clinical and functional impairment and improvement from baseline: the Clinical Global Impression-Severity (CGI-S) and CGI-Improvement (CGI-I) scales; the Children's Global Assessment Scale (C-GAS); and the Childhood Autism Rating Scale (CARS), a specific measure of PDD symptoms.

RESULTS

The mean baseline CGI-S was 5.7 +/- 0.8 (markedly ill/severely ill). The mean final dosage of aripiprazole was 8.1 +/- 4.9 mg/day. At the endpoint, 11 patients (32.4%) were 'much improved' or 'very much improved' (CGI-I score of 1 or 2), 12 patients (35.3%) were 'minimally improved' (CGI-I score of 3) and 10 (29.4%) were 'unchanged' or 'worsened' (CGI-I score of 4 or 5). C-GAS and CARS scores significantly improved (p < 0.0001, effect sizes 0.59 and 0.62, respectively). Nine patients (26.5%) experienced moderate to severe agitation, which was associated with self-injurious behaviours in five of these patients, and five patients presented with sleep disorders. Twelve patients (35.3%) discontinued medication during the follow-up because of lack of efficacy or adverse effects.

CONCLUSIONS

In these severely impaired children with PDDs, aripiprazole monotherapy was associated with a significant improvement in maladaptive behaviours in one-third of patients. Agitation and insomnia were the most frequent adverse effects. Further controlled studies in larger samples to explore possible predictors of efficacy are warranted.

Incidence of gastrointestinal symptoms in children with autism: a population-based study

OBJECTIVE

To determine whether children with autism have an increased incidence of gastrointestinal symptoms compared with matched control subjects in a population-based sample.

DESIGN/METHODS

In a previous study including all of the residents of Olmsted County, Minnesota, aged <21 years between 1976 and 1997, we identified 124 children who fulfilled criteria on the basis of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, for a research diagnosis of autism. Two matched control subjects were identified for each case subject. Through the Rochester Epidemiology Project, all medical diagnoses, are indexed for computerized retrieval. Gastrointestinal diagnoses before 21 years of age were grouped into 5 categories: (1) constipation; (2) diarrhea; (3) abdominal bloating, discomfort, or irritability; (4) gastroesophageal reflux or vomiting; and (5) feeding issues or food selectivity. The cumulative incidence of each category was calculated by using the Kaplan-Meier method. Cox proportional hazards models were fit to estimate the risk ratios (case subjects versus control subjects) and corresponding 95% confidence intervals.

RESULTS

Subjects were followed to median ages of 18.2 (case subjects) and 18.7 (control subjects) years. Significant differences between autism case and control subjects were identified in the cumulative incidence of constipation (33.9% vs 17.6%) and feeding issues/food selectivity (24.5% vs 16.1). No significant associations were found between autism case status and overall incidence of gastrointestinal symptoms or any other gastrointestinal symptom category.

CONCLUSIONS

As constipation and feeding issues/food selectivity often have a behavioral etiology, data suggest that a neurobehavioral rather than a primary organic gastrointestinal etiology may account for the higher incidence of these gastrointestinal symptoms in children with autism.

Risperidone in the treatment of behavioral disorders associated with autism in children and adolescents

This is a review of the clinical trials investigating the efficacy and safety of risperidone in the treatment of children with autistic spectrum disorders (ASD). The main clinical characteristics are impairment in social skills, communication difficulties, repetitive movements and behaviors, including stereotypies. Pharmacotherapy is mainly directed at the so-called target symptoms, ie, behavioral disorders and the various kinds of repetitions associated with ASD. According to the available data, risperidone seems to be moderately efficacious and safe for treating behavioral disorders. 4 double blind controlled trial. 3 reanalysis studies, and 12 open studies have documented the role of risperidone in children with ASD. Controlled studies have been thoroughly considered in this review.

What is new in autism?

PURPOSE OF REVIEW

Autism is now recognized in one out of 150 children. This review highlights the topics within the growing autism literature that are shaping current thinking on autism and advancing research and clinical understanding of autism spectrum disorders.

RECENT FINDINGS

The role of single-stranded microdeletions and epigenetic influences on brain development has dramatically altered our understanding of the etiology of the autisms. Recent research has focused on the role of synapse structure and function as central to the development of autism and suggests possible targets of interventions. Brain underconnectivity has been a focus in recent imaging studies and has become a central theme in conceptualizing autism. Despite increased awareness of autism there is no 'epidemic' and no one cause for autism. Data from the sibling studies are identifying early markers of autism and defining the broader autism phenotype.

SUMMARY

Larger datasets in genetics, a focus on the early signs of autism, and increased recognition of the importance of defining subgroups of children with autism are leading to a greater understanding of the etiologies of autism. A growing interest in defining the molecular biology of social cognition, which is at the core of autism, will lead to expansion of our presently limited choices of mechanistically based interventions.

A review of behavioral treatments for self-injurious behaviors of persons with autism spectrum disorders

Autism spectrum disorders (ASD) are considered to be among the most serious of the mental health conditions. Concomitant with many cases of ASD is intellectual disability. Further compounding the disability is the fact that both conditions are known risk factors for self-injurious behavior (SIB). To date, the most effective intervention methods, based on the available data, appear to be variants of behavior modification. This article provides an overview of the current status of learning-based interventions for SIB in ASD and provides a review of specific studies. Although most studies describe some combination of reinforcement and punishment procedures, efforts are under way to develop more positively oriented strategies, such as functional assessment, to decrease the use of punishment. However, almost all the treatment studies employ single case designs, thus preventing a comparison of treatment efficacy. These issues are discussed along with other strengths, weaknesses, and future directions for clinical practice and treatment.

Control of psychomotor agitation and aggressive behavior in patients with autistic disorder: a retrospective chart review

OBJECTIVE: To evaluate the efficacy of pharmacotherapy on the symptoms of psychomotor agitation and aggressive behavior in a sample of patients with autistic spectrum disorder. METHOD: The charts of all patients with a diagnosis of autistic spectrum disorder, receiving care for psychomotor agitation and/or aggressive behavior in two psychiatric outpatient departments between 2001 and 2006, were reviewed. The Clinical Global Impression-Severity and -Improvement scales (CGI-S and CGI-I) were applied to the data retrieved from the charts. RESULTS: The majority of the 26 patients included were treated with second-generation antipsychotics. A positive, statistically significant correlation was found between the implementation of pharmacotherapy and a reduction in CGI-S scores (p<0.05). Treatment response in patients with no mental retardation was better than in those mentally retarded (p<0.05). The majority of patients in whom clinical improvement was found following implementation of treatment had participated in at least one form of intervention therapy in addition to the principal treatment (p<0.05). CONCLUSION: Second-generation antipsychotics seem to reduce psychomotor agitation and aggressive behavior in patients with autistic spectrum disorder; however, further studies are required to evaluate the side effects of these drugs in relation to their beneficial effects.

Atypical antipsychotics in children with pervasive developmental disorders

The treatment of pervasive developmental disorders (PDDs) is a challenging task, which should include behavioral therapy modifications as well as pharmacologic therapy. There has been a lack of data on using medications in children with PDDs until recent years. Within the last 10 years, an increase in clinical research has attempted to provide efficacy and safety data to support the use of medications in children with PDDs. Double-blinded and open-label research of atypical antipsychotics has been of particular focus. Evidence shows that atypical antipsychotics (AAs) may be useful in treating certain symptoms associated with PDDs, such as aggression, irritability, and self-injurious behavior. This article reviews the literature regarding the use of AAs in children with PDDs. Of the AAs, risperidone has the largest amount of evidence with five published double-blinded, placebo-controlled trials and nine open-label trials. These risperidone trials have consistently shown improvements in aggression, irritability, self-injurious behavior, temper tantrums, and quickly changing moods associated with autistic disorder and other PDDs. Data for the other AAs are limited, but ziprasidone and aripiprazole appear to be promising treatment options. Based on clinical trials, olanzapine and quetiapine have shown minimal clinical benefit and a high incidence of weight gain and sedation. It should be noted that all AAs do have a risk of metabolic syndrome, and patients should be monitored appropriately while receiving these medications. Overall, AAs can be beneficial in alleviating behavioral symptoms, and should be considered an appropriate therapeutic option, as part of a comprehensive treatment strategy, for children with PDD.

Pharmacogenetics of risperidone response and induced side effects

Risperidone is an atypical antipsychotic that has been effectively used to treat several psychiatric diseases. Atypical antipsychotics present some advantages over conventional antipsychotics, primarily because they offer effective treatment alternatives that are relatively free of extrapyramidal symptoms. However, as with all antipsychotics, there are wide individual differences in response to risperidone, both regarding therapeutic effects and adverse effects, imposing some limitations with respect to the therapeutic use of the drug. Genetic factors are thought to play an important role in determining the variability to drug response. A growing number of studies are investigating how genetic polymorphisms of enzymes involved in drug metabolism or of receptors targeted by antipsychotic agents influence drug treatment of several neuropsychiatric diseases. In this article we will review the genetic variability in both the pharmacokinetics of risperidone action and in pharmacodynamic structures mediating risperidone effects, as well as the pharmacogenetic studies performed for these genes.