Clozapine in the Treatment of Aggression in Conduct Disorder in Children and Adolescents: A Randomized, Double-blind, Controlled Trial

Beyond the Off-Label: A Systematic Review of What We Know About Clozapine Use for Children

Introduction: It is essential not to delay behavior management and control for aggression, violence, and impulsive behavior in young people. Clozapine has been widely used in adolescents and adults to manage violence and aggression in Schizophrenia. However, there are limited data on the use of clozapine in children, and no systematic review has addressed its use in this population. Objective and Methods: To better understand the conditions under which clozapine is used as a therapeutic alternative for nonschizophrenic diagnoses and to assess the current evidence supporting its prescription to children, a systematic review was conducted. The review followed PRISMA guidelines and was registered in PROSPERO under the ID CRD42024537707. Results: The review identified that all the studies used clozapine to address externalizing behavior, particularly aggressive behavior, and found positive outcomes supporting its use for treating children with treatment-resistant aggression. The studies also found that clozapine was well-tolerated in all cases. However, the studies were limited and mainly consisted of open trials without a control group. Conclusion: Further high-quality research is needed to establish precise guidelines for using clozapine in children.

A Systematic Review of Clozapine Concentration-Dose Ratio from Therapeutic Drug Monitoring Studies in Children and Adolescents Treated with Clozapine for Mental Disorders

BACKGROUND

Therapeutic drug monitoring of clozapine in children and adolescents has received insufficient attention. Calculation of concentration-to-dose (C/D) ratios from trough steady-state concentrations estimate drug clearance.

METHODS

A systematic electronic literature search was conducted in 3 article databases from inception until January 10, 2023, and articles reporting clozapine concentrations in children and adolescents were retrieved. The pharmacokinetic quality of the studies was assessed, and clozapine C/D ratios were calculated using the sample mean clozapine dose and concentration.

RESULTS

Of the 37 articles of potential interest, only 7 reported clozapine trough and steady-state concentrations. After excluding case reports and a study confounded by fluvoxamine, 4 studies on psychosis from Europe and the United States were included. The clozapine C/D ratios were similar to published adult values and ranged from 0.82 to 1.24 with a weighted mean of 1.08 ng/mL per mg/d. The weighted means were 334 mg/d for the dose and 380 ng/mL for the concentration. The stratified analysis of the weighted mean clozapine C/D ratios from 2 studies showed lower values in 52 male (1.05 ng/mL per mg/d) than in 46 female (1.46 ng/mL per mg/d) children and adolescents, with values similar to those reported for European adult nonsmokers. Two female adolescents had high clozapine C/D ratios (2.54 ng/mL per mg/d), an Asian American patient with borderline obesity and a patient with intellectual disability with low dosage (mean = 102 mg/d) and concentration (mean = 55 ng/mL).

CONCLUSIONS

Reports on clozapine therapeutic drug monitoring in children and adolescents are limited in number and quality. Future studies should focus on basic pharmacokinetic issues, such as stratification by sex, smoking, and relevant comedications with inductive or inhibitory properties.

Electroconvulsive therapy or clozapine for adolescents with treatment-resistant schizophrenia: an explorative analysis on symptom dimensions

OBJECTIVE

This study sought to compare pre-intervention patient characteristics and post-intervention outcomes in a naturalistic sample of adolescent inpatients with treatment-resistant psychotic symptoms who received either electroconvulsive therapy (ECT) or clozapine.

METHODS

Data of adolescents with schizophrenia/schizoaffective disorder receiving ECT or clozapine were retrospectively collected from two tertiary-care psychiatry-teaching university hospitals. Subscale scores of the Positive and Negative Symptom Scale (PANSS) factors were calculated according to the five-factor solution. Baseline demographics, illness characteristics, and post-intervention outcomes were compared.

RESULTS

There was no significant difference between patients receiving ECT (n = 13) and clozapine (n = 66) in terms of age, sex, and the duration of hospital stay. The ECT group more commonly had higher overall illness and aggression severity. Smoking was less frequent in the clozapine group. Baseline resistance/excitement symptom severity was significantly higher in the ECT group, while positive, negative, affect, disorganisation, and total symptom scores were not. Both interventions provided a significant reduction in PANSS scores with large effect sizes.

CONCLUSION

Both ECT and clozapine yielded high effectiveness rates in adolescents with treatment-resistant schizophrenia/schizoaffective disorder. Youth receiving ECT were generally more activated than those who received clozapine.

Contemporary diagnosis and treatment of conduct disorder in youth

INTRODUCTION

Conduct disorder (CD) is characterized by repetitive and persistent antisocial behaviors, being among the most frequently reported reasons of referral in youth. CD is a highly heterogeneous disorder, with possible specifiers defined according to age at onset, Limited Prosocial Emotions (LPE) otherwise known as Callous-Unemotional (CU) traits, Emotional Dysregulation (ED), and patterns of comorbidity, each with its own specific developmental trajectories.

AREAS COVERED

The authors review the evidence from published literature on the clinical presentations, diagnostic procedures, psychotherapeutic and psychoeducational approaches, and pharmacological interventions from RCT and naturalistic studies in youth. Evidence from studies including youths with LPE/CU traits, ED and aggression are also reviewed, as response moderators.

EXPERT OPINION

Due to its clinical heterogeneity, relevant subtypes of CD should be carefully characterized to gain reliable information on prognosis and treatments. Thus, disentangling this broad category in subtypes is crucial as a first step in diagnosis. Psychosocial interventions are the first option, possibly improving LPE/CU traits and ED, especially if implemented early during development. Instead, limited information, based on low-quality studies, supports pharmacological options. Second-generation antipsychotics, mood stabilizers, and stimulants are first-line medications, according to different target symptoms, such as aggression and emotional reactivity. Developmental pathways including ADHD suggest a specific role of psychostimulants.

Clozapine Use in Early-Onset Schizophrenia

Schizophrenia in the pediatric population poses unique challenges and has been associated with poorer prognosis. Early intervention and symptom stability are paramount. There are several antipsychotic medications with U.S. Food and Drug Administration approval, but when treatment resistance occurs, clozapine is an option that has demonstrated superiority in effectiveness. Due to side effect burden and monitoring requirements, clozapine remains an alternative to other pharmacotherapy options that have failed rather than a mainstay of treatment. Clinicians, nurses, family members, and others involved in pediatric mental health care must be knowledgeable about this option and how to maintain safety with its use. [Journal of Psychosocial Nursing and Mental Health Services, 61(2), 6-8.].

Antipsychotics in the Management of Disruptive Behavior Disorders in Children and Adolescents: An Update and Critical Review

Disruptive behaviour disorders (DBDs) in childhood include conduct disorder (CD) and oppositional defiant disorder (ODD). Though psychological therapies are considered to be the first-line treatment for DBDs, many patients require adjunctive pharmacotherapy for the control of specific symptoms, such as aggression. Three prior systematic reviews have examined the evidence for the use of antipsychotics in DBDs and have concluded that their efficacy is marginal and limited by adverse effects. This paper has two objectives: (i) to summarize the findings of existing systematic reviews of antipsychotics for the management of DBDs in children and adolescents (2012-2017), and (ii) to provide an update to these reviews by examining recent clinical trials of antipsychotics in this population, published in the period from 2 January 2017 to 10 October 2022. The PubMed, Scopus and ScienceDirect databases were searched for relevant citations using the search terms "disruptive behaviour disorder", "oppositional defiant disorder", "conduct disorder" and their variants, along with "antipsychotic", "atypical antipsychotic" and the generic names of all currently approved atypical antipsychotics. Six relevant trials were identified during this period, including five randomized controlled trials and one naturalistic open-label trial. These trials were critically evaluated in terms of outcome measures, efficacy and safety. Overall, the data from these trials suggests that of all available antipsychotics, risperidone appears to be effective in the short-term management of DBDs. All available antipsychotics are associated with significant metabolic adverse effects in this population. These results are discussed in the light of global trends towards increasing off-label prescription of antipsychotic medication in children and adolescents and of recent literature on the neuropharmacology of aggression in this patient population. The need for rational, short-term use of these drugs is highlighted, as well as the importance of post-marketing surveillance for long-term or severe adverse events.

Management of Emotion Dysregulation and Outbursts in Children and Adolescents

PURPOSE OF REVIEW

Emotion dysregulation and outbursts are very common reasons for referral to child and adolescent mental health services and a frequent cause of admission to hospitals and residential programs. Symptoms of emotion dysregulation and outburst are transdiagnostic, associated with many disorders, have the potential to cause severe impairment and their management presents a major challenge in clinical practice.

RECENT FINDINGS

There are an increasing number of psychosocial interventions that demonstrate promise in improving emotion dysregulation and outbursts. Acute care systems to manage the most severely ill patients have limited best practice guidelines but program advancements indicate opportunities to improve care models. Pharmacotherapy may be of assistance to psychosocial interventions but must be used with caution due to potential adverse effects. Much remains to be discovered however evidence informed, targeted treatments for specific populations show potential for future improvements in outcomes.

Neuropsychological Characterization of Aggressive Behavior in Children and Adolescents with CD/ODD and Effects of Single Doses of Medications: The Protocol of the Matrics_WP6-1 Study

Aggressive behaviors and disruptive/conduct disorders are some of the commonest reasons for referral to youth mental health services; nevertheless, the efficacy of therapeutic interventions in real-world clinical practice remains unclear. In order to define more appropriate targets for innovative pharmacological therapies for disruptive/conduct disorders, the European Commission within the Seventh Framework Programme (FP7) funded the MATRICS project (Multidisciplinary Approaches to Translational Research in Conduct Syndromes) to identify neural, genetic, and molecular factors underpinning the pathogenesis of aggression/antisocial behavior in preclinical models and clinical samples. Within the program, a multicentre case-control study, followed by a single-blind, placebo-controlled, cross-over, randomized acute single-dose medication challenge, was conducted at two Italian sites. Aggressive children and adolescents with conduct disorder (CD) or oppositional defiant disorder (ODD) were compared to the same age (10–17 y) typically developing controls (TDC) on a neuropsychological tasks battery that included both “cold” (e.g., inhibitory control, decision making) and “hot” executive functions (e.g., moral judgment, emotion processing, risk assessment). Selected autonomic measures (heart rate variability, skin conductance, salivary cortisol) were recorded before/during/after neuropsychological testing sessions. The acute response to different drugs (methylphenidate/atomoxetine, risperidone/aripiprazole, or placebo) was also examined in the ODD/CD cohort in order to identify potential neuropsychological/physiological mechanisms underlying aggression. The paper describes the protocol of the clinical MATRICS WP6-1 study, its rationale, the specific outcome measures, and their implications for a precision medicine approach.

Psychotropic medication prescribing in people with autism spectrum disorders with and without psychiatric comorbidity

Autism spectrum disorders (ASDs) are a group of lifelong neurodevelopmental disorders characterised by difficulties in social interactions and social communication, and restricted and repetitive behaviours. Relative to the general population, individuals with ASDs are likely to be overrepresented in secure psychiatric care and custodial settings. Outcomes vary and can be problematic in the context of co-occurring intellectual disability, psychiatric disorder and challenging behaviours. To date, there is little in the way of specialised clinical guidance on the prescription of psychotropic medicines for individuals with ASDs, particularly information on any differences in efficacy and/or tolerability of specific medications. This review summarises the key research to date on the prescription of psychotropic medication in ASD with and without comorbid psychiatric or neurodevelopmental disorders, within the context of the existing clinical guidance. Some critical analysis is provided to aid clinicians in following a safe, effective and individualised approach to prescribing for people with ASDs.

The Importance of Conduct Disorder in the Treatment of Violence in Schizophrenia: Efficacy of Clozapine Compared With Olanzapine and Haloperidol

OBJECTIVE

Treatment of violence in schizophrenia remains a challenging problem, especially in patients with conduct disorder. Previous clinical studies did not select patients on the basis of violence and did not focus on conduct disorder. This study is a head-to-head comparison of clozapine, olanzapine, and haloperidol in the treatment of violent schizophrenia patients with and without conduct disorder.

METHODS

Physically assaultive schizophrenia patients (N=99) were randomly assigned to receive clozapine, olanzapine, or haloperidol in a 12-week double-blind trial. They were characterized on the basis of the presence or absence of conduct disorder before age 15. Assaults were recorded; their frequency and severity were scored on the Modified Overt Aggression Scale. Psychiatric symptoms were evaluated through the Positive and Negative Syndrome Scale.

RESULTS

Patients with a history of conduct disorder had more frequent and severe assaults than those without conduct disorder during the 12-week trial. Clozapine was superior to haloperidol and olanzapine in reducing assaults; olanzapine was superior to haloperidol. Clozapine's greater antiaggressive efficacy over haloperidol was substantially more pronounced in patients with conduct disorder than in patients without conduct disorder. In patients with conduct disorder, clozapine was four times more likely than haloperidol to result in lower violence; in patients without conduct disorder, it was three times more likely to do so. Olanzapine's superiority over haloperidol was also more pronounced in patients with conduct disorder.

CONCLUSIONS

This study is the first to examine the effect of clozapine in violent schizophrenia patients with conduct disorder. When conduct disorder is present, clozapine is the optimal treatment.

Interest of Fluvoxamine as an Add-On to Clozapine in Children With Severe Psychiatric Disorder According to CYP Polymorphisms: Experience From a Case Series

Despite its drastic efficacy in resistant psychiatric disorders, clozapine remains rarely used in youth due to its side effects. Clozapine plasma level is determined through its metabolism involving several isoforms of cytochromes 450 (CYP450) family. Isoform CYP1A2 appears as a limiting enzyme involved in the metabolism of clozapine, while isoforms 2C19, 2D6, 3A4, and 3A5 also contribute in a minor way. Clozapine efficacy is limited by a significant inter-patient variability in exposure according to CYP's polymorphisms. Clozapine plasma levels may be increased with CYP inhibitors such as fluvoxamine. This drug is a potent enzymatic inhibitor of CYP1A2 and, to a lesser extent, of CYP3A4 and CYP2D6. Hence, in case of CYP's polymorphisms in youth, the use of fluvoxamine as add-on to clozapine could help in reaching clinical and biological efficacy and allowing lower clozapine dosage and a better tolerance profile as it has already been described in adults. We report four pediatric cases with severe psychiatric disorders underlying our experience with CYP polymorphism explorations and the use of fluvoxamine as add-on to clozapine. Our four patients clinically improved after the introduction of fluvoxamine, enhancing clozapine metabolism and therefore the clozapine plasma level within therapeutic range. Despite the interesting results of fluvoxamine, we report a severe issue of tolerance for one patient, emphasizing the need for caution regarding possible drug interactions when fluvoxamine is considered. Hence, we propose a detailed step-by-step multidisciplinary protocol.

A mechanism-based group-psychotherapy approach to aggressive behaviour in borderline personality disorder: findings from a cluster-randomised controlled trial

BACKGROUND

Aggressive behaviour is a prevalent and harmful phenomenon in patients with borderline personality disorder (BPD). However, no short-term, low-cost programme exists that specifically focuses on aggression.

AIMS

Attuning therapy modules to pathogenetic mechanisms that underlie reactive aggression in BPD, we composed a 6 week mechanism-based anti-aggression psychotherapy (MAAP) approach for the group setting, which we tested against a non-specific supportive psychotherapy (NSSP).

METHOD

A cluster-randomised two-arm parallel-group phase II trial of N = 59 patients with BPD and overt aggressive behaviour was performed (German Registry for Clinical Trials, DRKS00009445). The primary outcome was the externally directed overt aggression score of the Modified Overt Aggression Scale (M-OAS) post-treatment (adjusted for pre-treatment overt aggression). Secondary outcomes were M-OAS irritability, M-OAS response rate and ecological momentary assessment of anger post-treatment and at 6 month follow-up, as well as M-OAS overt aggression score at follow-up.

RESULTS

Although no significant difference in M-OAS overt aggression between treatments was found post-treatment (adjusted difference in mean 3.49 (95% CI -5.32 to 12.31, P = 0.22), the MAAP group showed a clinically relevant decrease in aggressive behaviour of 65% on average (versus 33% in the NSSP group), with particularly strong improvement among those with the highest baseline aggression. Most notably, significant differences in reduction in overt aggression between MAAP and NSSP were found at follow-up.

CONCLUSIONS

Patients with BPD and aggressive behaviour benefited from a short group psychotherapy, with improvements particularly visible at 6 month follow-up. Further studies are required to show whether these effects are specific to MAAP.

High-throughput multi-residue quantification of contaminants of emerging concern in wastewaters enabled using direct injection liquid chromatography-tandem mass spectrometry

A rapid quantitative method for 135 contaminants of emerging concern (CECs) in untreated wastewater enabled with direct injection liquid chromatography-tandem mass spectrometry is presented. All compounds were analysed within 5 min on a short biphenyl cartridge using only 10 μL of filtered sample per injection. Up to 76 compounds were monitored simultaneously during the gradient (including mostly two transitions per compound and stable isotope-labelled analogues) while yielding >10 data points per peak. Evaluation of seven solid phase extraction sorbents showed no advantage for wastewater matrix removal. Excellent linearity, range, accuracy and precision was achieved for most compounds. Matrix effects were <11 % and detection limits were <30 ng L^-1 on average. Application to untreated wastewater samples from three wastewater treatment works in the UK, USA and Mexico, enabled quantification of 56 compounds. Banned and EU 'watch-list' substances are critically discussed, including pesticides, macrolide antibiotics, diclofenac, illicit drugs as well as multiple pharmaceuticals and biocides. This high-throughput method sets a new standard for the speedy and confident determination of over a hundred CECs in wastewater at the part-per-trillion level, as demonstrated by performing over 260 injections per day.

Effectiveness of Stimulant Medications on Disruptive Behavior and Mood Problems in Young Children

Objective

There are very few studies on the effectiveness of stimulant medications for the treatment of disruptive mood and behavior problems in young children (less than 7 years) with Disruptive Behavior Disorders (DBD). The current study aims to determine whether young children (ages 4−7) in a long-term, intensive outpatient behavioral treatment program who are receiving stimulant medications show greater improvement in mood and behavior problems compared to peers who did not.

Methods

A retrospective chart review was conducted for 97 participants diagnosed with DBD, aged 4−7 years old who were enrolled in an intensive outpatient behavioral intervention program. Pre- and post-intervention Child Behavior Checklist (CBCL) scores for disruptive behavior and mood problems were compared between the children who received stimulant medications and those who did not.

Results

Paired t tests showed a statistically significant improvement in CBCL outcomes between pre- and post-intervention scores of disruptive behavior and mood problems. ANCOVA analysis, however, showed no clear further improvement in those same CBCL scores in the participants who received stimulant medications compared to the participants who did not. CBCL scores for Conduct Disorder were marginally significant for less improvement for the participants who received stimulant medications.

Conclusion

This retrospective review suggests a possibility that stimulant medications may not provide additional benefit for the long-term treatment of disruptive behavior and mood problems in young children under age 7. Future study is warranted to evaluate the efficacy/effectiveness of stimulant medications in the treatment of disruptive behavior and mood problems in this population.

Plasma Risperidone-related Measures in Children and Adolescents with Oppositional Defiant/Conduct Disorders

Objective

Therapeutic drug monitoring helps clinicians in choosing the right drug and adjust its dose in specific patients. To this end, we aimed to assess time patterns of risperidone and its metabolite, 9-hydroxyrisperidone, in children and adolescents with oppositional defiant and/or conduct disorder.

Methods

We measured plasma concentrations of risperidone and 9-hydroxyrisperidone, their sum (active moiety, AM) and ratio, as well as plasma concentrations corrected for daily dose (C/D), from 140 children/adolescents with the above-mentioned disorders. We used Student’s t test to compare females versus males, patients under versus over 16-year-old, patients with lower versus higher than the median body weight, and patients with lower versus higher than the median body mass index (BMI). Two mixed-effects logistic regression models were fitted for risperidone/9-hydroxyrisperidone ratio and AM, respectively, by considering risperidone daily dose and patients’ demographic characteristics.

Results

Females had higher 9-hydroxyrisperidone and AM plasma concentrations than males (p = 0.004 and p = 0.034). Younger patients had lower risperidone plasma concentration and risperidone/9-hydroxyrisperidone ratio (p = 0.02 and p = 0.021), but higher C/D 9-hydroxyrisperidone and AM than older patients (p = 0.013 and p = 0.043). Lower-weight patients had lower plasma risperidone and risperidone/9-hydroxyrisperidone ratio (p = 0.014 and p = 0.019), but higher C/D 9-hydroxyrisperidone concentration than heavier patients (p = 0.03). All these results could be accounted for by daily dose. Patients with lower and higher BMI did not differ significantly. Regression analyses showed that only risperidone daily dose predicted risperidone/9-hydroxyrisperidone ratio, whereas risperidone daily dose, sex, and age predicted AM.

Conclusion

Clinicians prescribing risperidone need to consider sex, age, and weight, but not BMI when adjusting daily doses.