Guideline Adherence of Monitoring Antipsychotic Use for Nonpsychotic Indications in Children and Adolescents: A Patient Record Review.

BACKGROUND: Antipsychotics are frequently prescribed to children and adolescents for nonpsychotic indications. Guidelines recommend regularly assessing treatment response and adverse effects and the ongoing need for their use. We aimed to assess adherence to recommendations of available guidelines regarding monitoring antipsychotic use and to test the influence of children's age, sex, intelligence quotient, and diagnosis on adherence. METHODS: We reviewed 426 medical records from 26 centers within 3 large Dutch child and adolescent psychiatry organizations, excluding children with schizophrenia, psychosis, mania, or an intelligence quotient below 70. We investigated whether there was regular assessment of treatment response, adverse events (physical and laboratory), and at least annual discussion of the need of continued use. RESULTS: On average, treatment response was assessed in 69.3% of the recommended treatment periods, height in 25.6%, weight in 30.6%, blood pressure in 20.6%, evaluation of adverse events in 19.4%, and cardiometabolic measures in 13.7%; discontinuation and/or continued need was discussed at least annually in 36.2%. Extrapyramidal and prolactin-related adverse effects, waist circumference, glucose, and lipids were rarely investigated. Higher age was associated with lower rates of assessment of treatment response. Most antipsychotics were prescribed long-term. In those children with sufficient documentation of the course of treatment, 57.7% was still using an antipsychotic 3 years after initiation. CONCLUSIONS: Our findings indicate insufficient adherence to guideline recommendations for monitoring antipsychotic use in children and adolescents, as well as long duration of use in the majority of children. Especially, older children are at higher risk of receiving suboptimal care.

Aripiprazole in youth with intellectual disabilities: A retrospective chart study.

A retrospective chart study of patients on open-label aripiprazole treatment was conducted in the Netherlands to add to the knowledge of aripiprazole in children and young adults with mild and borderline intellectual disabilities (IDs). Fifty-three youths, mean age 14.7 ± 3.4 years and mean IQ 64.5 ±13.8, were included. Treatment responders were defined as "much improved" or "very much improved" based on the Clinical Global Impression -Improvement scale. For 83% of the patients, disruptive behavior was the main target symptom. The overall response rate was 30% after 1-4 weeks and 69% after 5-8 weeks. The 5-8 weeks responders showed a response rate of 64% at 22-26 weeks. Mild adverse events were observed in 53% of the patients of which fatigue and weight gain were the most common. Seven patients (13.2%) discontinued because of adverse events. In 53 children and young adults with mild and borderline IDs, aripiprazole was effective in both the short and the long term. No serious adverse events were observed.

Prescribing antipsychotics in child and adolescent psychiatry: guideline adherence.

Antipsychotics are often prescribed to children and adolescents, mostly off-label. We aimed to assess adherence to recommendations of guidelines for antipsychotic prescription. We reviewed 436 medical records from 155 clinicians from 26 clinics within three Dutch child and adolescent psychiatry organizations (n = 398 outpatient, n = 38 inpatient care). We assessed target symptoms, diagnostic process, prior and concomitant treatment, and consideration of contra-indications. Multiple logistic regression assessed the role of age, sex, and psychiatric diagnosis on adherence to three main recommendations: to (1) prescribe antipsychotics only after other treatments proved insufficient, (2) always combine antipsychotics with psychosocial interventions, and (3) not prescribe multiple antipsychotics simultaneously. Most patients received off-label antipsychotics. Main target symptoms were inattention/hyperactivity (25%), aggression (24%), and other disruptive behaviors (41%). Most patients underwent diagnostic evaluation before the first prescription; however, screening of contra-indications was low (0.2-19%). About 84% had previously received psychosocial treatment and 48% other psychoactive medication, but 9% had not received any treatment. Notably, only 37% continuously received concomitant psychosocial treatment. Simultaneous use of multiple antipsychotics occurred in 3.2%. Younger children were at higher risk of non-adherence to guideline recommendations regarding prior and concomitant treatment, children with autism spectrum disorder or attention-deficit/hyperactivity disorder more likely not to receive concomitant psychosocial treatment. Sex did not significantly affect adherence. Our findings implicate insufficient adherence to important recommendations regarding antipsychotic use in children and adolescents. Especially younger children are at higher risk of receiving suboptimal care. There is an urgency to consistently offer psychosocial interventions during antipsychotic treatment.

Why do children decide not to participate in clinical research: a quantitative and qualitative study.

BACKGROUND: More pediatric drug trials are needed, but although specific pediatric regulations warrant safety, recruitment of children for these trials remains one of the main difficulties. Therefore, we investigated potential determining factors of nonparticipation in clinical research, in order to optimize research participation of children by recommending improved recruitment strategies. METHODS: Between 1 January 2012 and 1 January 2014, we performed a prospective study among161 pediatric patients, aged 6 to 18 y, who were eligible for clinical research. We quantitatively analyzed the association of potential explanatory variables (e.g., age, cognitive development, experience, ethnicity) with nonparticipation and qualitatively analyzed interviews on reasons for nonparticipation. RESULTS: Sixty percent of the children did not participate in the research project on offer (39% decided not to participate, 21% were indecisive). Lower age, less disease experience, and less complex research with lower risk were predictive for not participating. Time constraint and extra burden were expressed as decisive reasons for not participating. CONCLUSIONS: Strategies to optimize research participation should be aimed at younger children and their families, who are logistically challenged and unfamiliar with health care and research. Recommendations include informing pediatric patients and their families of the value of research; minimizing logistic burdens; and improving accessibility.

Feasibility of an Assessment Tool for Children's Competence to Consent to Predictive Genetic Testing: a Pilot Study.

Knowledge on children's capacities to consent to medical treatment is limited. Also, age limits for asking children's consent vary considerably between countries. Decision-making on predictive genetic testing (PGT) is especially complicated, considering the ongoing ethical debate. In order to examine just age limits for alleged competence to consent in children, we evaluated feasibility of a standardized assessment tool, and investigated cutoff ages for children's competence to consent to PGT. We performed a pilot study, including 17 pediatric outpatients between 6 and 18 years at risk for an autosomal dominantly inherited cardiac disease, eligible for predictive genetic testing. The reference standard for competence was established by experts trained in the relevant criteria for competent decision-making. The MacArthur Competence Assessment Tool for Treatment (MacCAT-T) served as index test. Data analysis included raw agreement between competence classifications, difference in mean ages between children judged competent and judged incompetent, and estimation of cutoff ages for judgments of competence. Twelve (71 %) children were considered competent by the reference standard, and 16 (94 %) by the MacCAT-T, with an overall agreement of 76 %. The expert judgments disagreed in most cases, while the MacCAT-T judgments agreed in 65 %. Mean age of children judged incompetent was 9.3 years and of children judged competent 12.1 years (p = .035). With 90 % sensitivity, children younger than 10.0 years were judged incompetent, with 90 % specificity children older than 11.8 years were judged competent. Feasibility of the MacCAT-T in children is confirmed. Initial findings on age cutoffs are indicative for children between the age of 12 and 18 to be judged competent for involvement in the informed consent process. Future research on appropriate age-limits for children's alleged competence to consent is needed.

Key factors in children's competence to consent to clinical research.

BACKGROUND: Although law is established on a strong presumption that persons younger than a certain age are not competent to consent, statutory age limits for asking children's consent to clinical research differ widely internationally. From a clinical perspective, competence is assumed to involve many factors including the developmental stage, the influence of parents and peers, and life experience. We examined potential determining factors for children's competence to consent to clinical research and to what extent they explain the variation in competence judgments. METHODS: From January 1, 2012 through January 1, 2014, pediatric patients aged 6 to 18 years, eligible for clinical research studies were enrolled prospectively at various in- and outpatient pediatric departments. Children's competence to consent was assessed by MacArthur Competence Assessment Tool for Clinical Research. Potential determining child variables included age, gender, intelligence, disease experience, ethnicity and socio-economic status (SES). We used logistic regression analysis and change in explained variance in competence judgments to quantify the contribution of a child variable to the total explained variance. Contextual factors included risk and complexity of the decision to participate, parental competence judgment and the child's or parents decision to participate. RESULTS: Out of 209 eligible patients, 161 were included (mean age, 10.6 years, 47.2 % male). Age, SES, intelligence, ethnicity, complexity, parental competence judgment and trial participation were univariately associated with competence (P < 0.05). Total explained variance in competence judgments was 71.5 %. Only age and intelligence significantly and independently explained the variance in competence judgments, explaining 56.6 % and 12.7 % of the total variance respectively. SES, male gender, disease experience and ethnicity each explained less than 1 % of the variance in competence judgments. Contextual factors together explained an extra 2.8 % (P > 0.05). CONCLUSIONS: Age is the factor that explaines most of to the variance in children's competence to consent, followed by intelligence. Experience with disease did not affect competence in this study, nor did other variables. CLINICAL TRIAL REGISTRATION: Development and use of a standardized instrument for assessing children's competence to consent in drug trials: Are legally established age limits valid?, NTR3918.

Informed consent instead of assent is appropriate in children from the age of twelve: Policy implications of new findings on children's competence to consent to clinical research.

BACKGROUND: For many decades, the debate on children's competence to give informed consent in medical settings concentrated on ethical and legal aspects, with little empirical underpinnings. Recently, data from empirical research became available to advance the discussion. It was shown that children's competence to consent to clinical research could be accurately assessed by the modified MacArthur Competence Assessment Tool for Clinical Research. Age limits for children to be deemed competent to decide on research participation have been studied: generally children of 11.2 years and above were decision-making competent, while children of 9.6 years and younger were not. Age was pointed out to be the key determining factor in children's competence. In this article we reflect on policy implications of these findings, considering legal, ethical, developmental and clinical perspectives. DISCUSSION: Although assessment of children's competence has a normative character, ethics, law and clinical practice can benefit from research data. The findings may help to do justice to the capacities children possess and challenges they may face when deciding about treatment and research options. We discuss advantages and drawbacks of standardized competence assessment in children on a case-by-case basis compared to application of a fixed age limit, and conclude that a selective implementation of case-by-case competence assessment in specific populations is preferable. We recommend the implementation of age limits based on empirical evidence. Furthermore, we elaborate on a suitable model for informed consent involving children and parents that would do justice to developmental aspects of children and the specific characteristics of the parent-child dyad. Previous research outcomes showed that children's medical decision-making capacities could be operationalized into a standardized assessment instrument. Recommendations for policies include a dual consent procedure, including both child as well as parents, for children from the age of 12 until they reach majority. For children between 10 and 12 years of age, and in case of children older than 12 years in special research populations of mentally compromised patients, we suggest a case-by-case assessment of children's competence to consent. Since such a dual consent procedure is fundamentally different from a procedure of parental permission and child assent, and would imply a considerable shift regarding some current legislations, practical implications are elaborated.

Why is it hard to make progress in assessing children's decision-making competence?

BACKGROUND: For decades, the discussion on children's competence to consent to medical issues has concentrated around normative concerns, with little progress in clinical practices. Decision-making competence is an important condition in the informed consent model. In pediatrics, clinicians need to strike a proper balance in order to both protect children's interests when they are not fully able to do so themselves and to respect their autonomy when they are. Children's competence to consent, however, is currently not assessed in a standardized way. Moreover, the correlation between competence to give informed consent and age in children has never been systematically investigated, nor do we know which factors exactly contribute to children's competence.This article aims at identifying these gaps in knowledge and suggests options for dealing with the obstacles in empirical research in order to advance policies and practices regarding children's medical decision-making competence. DISCUSSION: Understanding children's competency is hampered by the law. Legislative regulations concerning competency are established on a strong presumption that persons older than a certain age are competent, whereas younger persons are not. Furthermore, a number of contextual factors are believed to be of influence on a child's decision-making competence: the developmental stage of children, the influence of parents and peers, the quality of information provision, life experience, the type of medical decision, and so on. Ostensibly, these diverse and extensive barriers hinder any form of advancement in this conflicted area. Addressing these obstacles encourages the discussion on children's competency, in which the most prominent question concerns the lack of a clear operationalization of children's competence to consent. Empirical data are needed to substantiate the discussion. SUMMARY: The empirical approach offers an opportunity to give direction to the debate. Recommendations for future research include: studying a standardized assessment instrument covering all four relevant dimensions of competence (understanding, reasoning, appreciation, expressing a choice), including a study population of children covering the full age range of 7 to 18 years, improving information provision, and assessing relevant contextual data.

Long-Term Effectiveness of Off-Label Risperidone Treatment in Children and Adolescents: A Randomized, Placebo-Controlled Discontinuation Study.

Objectives: Risperidone is commonly prescribed off-label in children and adolescents to manage disruptive behavior. This study aimed to investigate continued benefits of risperidone after at least 1 year of treatment and effects of discontinuation on physical health. Methods: Thirty-five youths (aged 6-18 years, intelligence quotient [IQ] >70) who were treated with risperidone for at least 1 year in regular clinical practice receiving outpatient care were randomly assigned to double-blind continuation of risperidone during 16 weeks or continuation for 2 weeks, gradual dose lowering over 6 weeks, and placebo for 8 weeks. Primary outcome was the total Disruptive Behavior (D-total) score of the parent-reported Nisonger Child Behavior Rating Form-Typical IQ (NCBRF-TIQ). Secondary outcome measures were the clinician-rated Clinical Global Impressions-Improvement scale (CGI-I), the parent, child, and teacher-rated Strengths and Difficulties Questionnaire (SDQ), the parent-rated Retrospective Modified Overt Aggression Scale (R-MOAS), and several health parameters (Udvalg for Kliniske Undersøgelser Side Effect Rating Scale [UKU-SERS], dyskinesia, akathisia, parkinsonism, body mass index (BMI), waist circumference, and laboratory outcomes). Mixed models for repeated measures were conducted for continuous outcomes and a chi-square test for the CGI-I. Results: Discontinuation of risperidone, as compared with continuation, was not associated with significant changes in parent-reported disruptive behaviors. However, discontinuation was related to significant deterioration in parent-rated verbal aggression, teacher-rated behavioral functioning, clinician-rated general functioning, and significant improvements in weight, BMI, waist circumference, and glucose, insulin, and prolactin levels. Although 56% of participants in the discontinuation group experienced relapse, causing premature withdrawal from the study, 44% was able to successfully discontinue risperidone. Conclusion: Discontinuation of risperidone was associated with deterioration on some, but not all behavioral measures according to this explorative study. Discontinuation was associated with important health gains. Despite long-term benefits of risperidone, attempts to withdraw risperidone should be undertaken in individual children. This is a crucial step in preventing harm and fostering health.

Assessing children's competence to consent in research by a standardized tool: a validity study.

BACKGROUND: Currently over 50% of drugs prescribed to children have not been evaluated properly for use in their age group. One key reason why children have been excluded from clinical trials is that they are not considered able to exercise meaningful autonomy over the decision to participate. Dutch law states that competence to consent can be presumed present at the age of 12 and above; however, in pediatric practice children's competence is not that clearly presented and the transition from assent to active consent is gradual. A gold standard for competence assessment in children does not exist. In this article we describe a study protocol on the development of a standardized tool for assessing competence to consent in research in children and adolescents. METHODS/DESIGN: In this study we modified the MacCAT-CR, the best evaluated competence assessment tool for adults, for use in children and adolescents. We will administer the tool prospectively to a cohort of pediatric patients from 6 to18 years during the selection stages of ongoing clinical trials. The outcomes of the MacCAT-CR interviews will be compared to a reference standard, established by the judgments of clinical investigators, and an expert panel consisting of child psychiatrists, child psychologists and medical ethicists. The reliability, criterion-related validity and reproducibility of the tool will be determined. As MacCAT-CR is a multi-item scale consisting of 13 items, power was justified at 130-190 subjects, providing a minimum of 10-15 observations per item. MacCAT-CR outcomes will be correlated with age, life experience, IQ, ethnicity, socio-economic status and competence judgment of the parent(s). It is anticipated that 160 participants will be recruited over 2 years to complete enrollment. DISCUSSION: A validity study on an assessment tool of competence to consent is strongly needed in research practice, particularly in the child and adolescent population. In this study we will establish a reference standard of children's competence to consent, combined with validation of an assessment instrument. Results can facilitate responsible involvement of children in clinical trials by further development of guidelines, health-care policies and legal policies.

Neuropsychological effects of risperidone in children with pervasive developmental disorders: a blinded discontinuation study.

OBJECTIVE: Little is known about the neuropsychological effects of risperidone in children with pervasive developmental disorders. METHOD: Twenty-four children (aged 5-17 years) with pervasive developmental disorders and co-morbid disruptive behavior who responded favorably to open-label treatment with risperidone as part of a previously described controlled discontinuation study completed two different computerized attention tasks at baseline, weeks 4, 8, and 24 of open-label treatment, and, at 8 weeks after random assignment to either placebo or risperidone. The primary efficacy measures were response latencies to visually presented stimuli requiring two different types of attention-controlled processing, i.e., focused and divided attention. RESULTS: About half of the clinical responders did not produce valid performance measures. These could be shown to be of younger mental age and less adaptive as measured by the Vineland Behavior Scales. For the valid task performers divided attention (serial search in working memory) was shown to regress in the placebo group (n = 7), while in the risperidone group (n = 7) there was further improvement. No such group difference was found for focused attention. CONCLUSIONS: The study suggests a beneficial effect of risperidone after several months of treatment, enhancing divided attention in children with pervasive developmental disorders.

Atomoxetine for attention-deficit/hyperactivity disorder symptoms in children with pervasive developmental disorders: a pilot study.

OBJECTIVE: This pilot study examined the effects of atomoxetine on attention-deficit/hyperactivity disorder (ADHD) symptoms and autistic features in children with pervasive developmental disorders (PDD). METHOD: Twelve children (aged 6-14 years) with PDD accompanied by ADHD symptoms entered a 10-week open-label study with atomoxetine (1.19 +/- 0.41 mg/kg/day). Response was assessed by using parent and clinician rating scales with change in the ADHD-Rating Scale (ADHDRS) as primary outcome measure. RESULTS: Atomoxetine reduced ADHD-symptoms as measured by the ADHDRS (44% decrease vs. baseline, p < 0.003), the Conners' Parent Rating Scale-R:S (CPRS-R) (25% in the subscale "Cognitive Problems," p < 0.028; 32% in "Hyperactivity," p < 0.030; and 23% in "ADHD index," p < 0.023). We found a reduction of 21% (p = 0.071) for changes in the subscale "Hyperactivity" of the Aberrant Behavior Checklist (ABC). No change was found in any of the other ABC subscales, nor in the subscale "Oppositional" of the CPRS-R. Five patients (42%) discontinued because of side effects. Gastrointestinal symptoms, irritability, sleep problems, and fatigue were the most frequent side effects. CONCLUSIONS: These preliminary findings indicate that atomoxetine may be a promising new agent in the treatment of ADHD symptoms in children with PDD. However, children with PDD may have a higher vulnerability for some of the known side-effects of atomoxetine.

Long-term effects of risperidone in children with autism spectrum disorders: a placebo discontinuation study.

OBJECTIVE: The short-term benefit of risperidone in ameliorating severe disruptive behavior in pediatric patients with autism spectrum disorders is well established; however, only one placebo-controlled, long-term study of efficacy is available. METHOD: Thirty-six children with an autism spectrum disorder (5-17 years old) accompanied by severe tantrums, aggression, or self-injurious behavior, started 8-week open-label treatment with risperidone. Responders (n = 26) continued treatment for another 16 weeks, followed by a double-blind discontinuation (n = 24; two patients discontinued treatment because of weight gain) consisting of either 3 weeks of taper and 5 weeks of placebo only or continuing use of risperidone. Relapse was defined as a significant deterioration of symptoms based on clinical judgment and a parent questionnaire. RESULTS: Risperidone was superior to placebo in preventing relapse: this occurred in 3 of 12 patients continuing on risperidone versus 8 of 12 who switched to placebo (p = .049). Weight gain, increased appetite, anxiety, and fatigue were the most frequently reported side effects. CONCLUSIONS: This study indicates the effectiveness of risperidone during a period of several months, reducing disruptive behavior in about half of the children with autism spectrum disorders. The results provide a rationale for the continuing use of risperidone beyond 6 months, although considerable weight gain can limit the use of this agent.

Increased seroreactivity in tic disorder patients to a 60 kDa protein band from a neuronal cell line.

In tic disorders, increased seroreactivity against neuronal antigens has been demonstrated, without performing molecular characterization of antigens. Here, unselected patients with a tic disorder were compared with healthy controls, autistic disorder (AD), and obsessive-compulsive disorder (OCD) patients. Seroreactivity against neuroblastoma cells was analyzed by Western blot. Anti-60 kDa binding occurred significantly more frequently in tic disorder patients (67.1%) than in AD (40.0%), OCD (40.0%) and healthy controls (41.9%). Sequence analysis of the 60 kDa protein band identified this as a ubiquitous heat shock protein. However, the involvement of other autoantigens with a molecular weight of 60 kDa cannot be excluded.

Relative contribution of attention-deficit hyperactivity disorder, obsessive-compulsive disorder, and tic severity to social and behavioral problems in tic disorders.

The aim of this study was to investigate social and behavioral problems related to attention-deficit hyperactivity disorder (ADHD), obsessions and compulsions, and tic severity in children with a tic disorder. Parents of 58 children with a tic disorder with and without different forms of ADHD completed the Child Behavior Checklist (CBCL) and the Children's Social Behavior Questionnaire. Patients with a tic disorder with primarily hyperactive-impulsive ADHD had the highest questionnaire scores, patients with primarily inattentive ADHD had medium scores, and patients without ADHD had the lowest scores. On most subscales, significant part correlations with ADHD severity, but not tic severity, were obtained. Severity of obsessions and compulsions was independently correlated with the CBCL Thought Problems subscale but not with most other subscales. There was no significant correlation between tic severity and ADHD severity. Thus, in patients with a tic disorder, the presence and severity of ADHD are the main predictors of associated behavioral and social problems.

Accuracy of the MacArthur competence assessment tool for clinical research (MacCAT-CR) for measuring children's competence to consent to clinical research.

IMPORTANCE: An objective assessment of children's competence to consent to research participation is currently not possible. Age limits for asking children's consent vary considerably between countries, and, to our knowledge, the correlation between competence and children's age has never been systematically investigated. OBJECTIVES: To test a standardized competence assessment instrument for children by modifying the MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR), to investigate its reliability and validity, and to examine the correlation of its assessment with age and estimate cutoff ages. DESIGN, SETTING, AND PARTICIPANTS: This prospective study included children and adolescents aged 6 to 18 years in the inpatient and outpatient departments of allergology, gastroenterology, oncology, ophthalmology, and pulmonology from January 1, 2012, through January 1, 2014. Participants were eligible for clinical research studies, including observational studies and randomized clinical trials. EXPOSURES: Competence judgments by experts aware of the 4 relevant criteria-understanding, appreciation, reasoning, and choice-were used to establish the reference standard. The index test was the MacCAT-CR, which used a semistructured interview format. MAIN OUTCOMES AND MEASURES: Interrater reliability, validity, and dimensionality of the MacCAT-CR and estimated cutoff ages for competence. RESULTS: Of 209 eligible patients, we included 161 (mean age, 10.6 years; 47.2% male). Good reproducibility of MacCAT-CR total and subscale scores was observed (intraclass correlation coefficient range, 0.68-0.92). We confirmed unidimensionality of the MacCAT-CR. By the reference standard, we judged 54 children (33.5%) to be incompetent; by the MacCAT-CR, 61 children (37.9%). Criterion-related validity of MacCAT-CR scores was supported by high overall accuracy in correctly classifying children as competent against the reference standard (area under the receiver operating characteristics curve, 0.78). Age was a good predictor of competence on the MacCAT-CR (area under the receiver operating characteristics curve, 0.90). In children younger than 9.6 years, competence was unlikely (sensitivity, 90%); in those older than 11.2 years, competence was probable (specificity, 90%). The optimal cutoff age was 10.4 years (sensitivity, 81%; specificity, 84%). CONCLUSIONS AND RELEVANCE: The MacCAT-CR demonstrated strong psychometric properties. In children aged 9.6 to 11.2 years, consent may be justified when competence can be demonstrated in individual cases by the MacCAT-CR. The results contribute to a scientific underpinning of regulations for clinical research directed toward children.

Risperidone-induced weight gain in referred children with autism spectrum disorders is associated with a common polymorphism in the 5-hydroxytryptamine 2C receptor gene.

Weight gain is an important adverse effect of risperidone, but predictors of significant weight gain have yet to be identified in pediatric patients. Here, we investigated differences between age- and gender-normed body mass index-standardized z scores at baseline and after 8 weeks of open-label, flexible-dose risperidone treatment (mean dose: 1.70 mg/day) in 32 youths with pervasive developmental disorder (mean age = 8.74, range = 5-16 years) in relation to -759C/T 5-hydroxytryptamine 2C receptor (HTR2C) promoter and rs1414334 HTR2C intragenic C/G alleles, along with gender, age, and risperidone dose, using repeated measures analyses of variance. Carriers of the HTR2C promoter T allele gained an average of 0.043 ± 0.017 body mass index-standardized z scores (1.84 ± 1.51 kg) versus 0.64 ± 0.35 z (3.23 ± 1.47 kg) for non-T-allele carriers (p < 0.001). Presence of the rs1414334 C allele played no significant role. Further, weight gain appeared to be associated with younger age and higher doses of risperidone. The current preliminary findings suggest that the variant T allele of the -759C/T HTR2C promoter polymorphism is protective against risperidone-induced weight gain. Younger children and those treated with higher doses of risperidone may be at higher risk for weight gain.

Plasma kynurenine and related measures in tic disorder patients.

OBJECTIVE: Increased plasma kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of kynurenine and related molecules in a group of tic disorder patients. METHODS: Plasma concentrations of tryptophan, kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined. RESULTS: No significant differences were found between patient and control groups in plasma levels of tryptophan, kynurenine, and cortisol concentrations, nor in the kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/l) than in controls (mean = 3.30 nmol/l). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = -0.289, p = 0.049). In patients, plasma neopterin correlated with kynurenine (r = 0.438, p = 0.002); in healthy subjects, tryptophan correlated with kynurenine (r = 0.670, p < 0.001). CONCLUSION: While the observed elevation in plasma neopterin is consistent with immune activation in a subset of tic disorder patients, metabolism of tryptophan through the kynurenine pathway appears to be unaltered in tic disorder patients.

Prolactin release in children treated with risperidone: impact and role of CYP2D6 metabolism.

OBJECTIVE: Little is known about the role of CYP2D6 polymorphism in risperidone-induced prolactin release in children. METHOD: Twenty-five children (aged 5-15 years) with pervasive developmental disorders were genotyped for CYP2D6 polymorphisms. Serum prolactin, risperidone, and 9-hydroxyrisperidone were assessed at baseline and after 8 weeks of risperidone treatment (mean dosage, 0.06 +/- 0.03 mg/kg/d). After 24 weeks of treatment, prolactin was measured in a subsample of 15 children. Adverse effects were evaluated using a clinician-rated survey. RESULTS: Mean +/- SD prolactin levels increased from 7.8 +/- 8.0 ng/mL at baseline to 33.2 +/- 12.8 ng/mL at week 8 (P < 0.001), with a slight decrease to 28.8 +/- 13.6 ng/mL at week 24. At week 8, serum prolactin level was positively correlated with dose per kilogram (r = 0.648, P < 0.001), number of functional CYP2D6 genes (J = 2.117, P = 0.034), and serum 9-hydroxyrisperidone concentration (r = 0.664, P = 0.001) and was negatively correlated with the risperidone/9-hydroxyrisperidone ratio (r = -0.571, P = 0.004) but not with risperidone concentration (r = -0.243, P = 0.264) nor age (r = 0.072, P = 0.733). Prolactin elevation was not associated with adverse effects. CONCLUSIONS: Low-to-intermediate doses of risperidone induced a 4-fold prolactin increase in children without a clear development of tolerance up to 6 months. CYP2D6 ultrarapid metabolism may be a risk factor for more pronounced prolactin elevation.