Pharmacology and pharmacogenetics of pediatric ADHD with associated aggression: a review

Effects of comorbidity on executive functions among children with ADHD, finding trends

There is still no basic overview about the effect of various types of comorbidity in executive functions due to two main reasons: (1) the type and number of comorbidities in ADHD is significantly varied, (2) EFs are very diverse and have different neuropsychological properties. Our objective was to determine the effect of comorbid disorders (number and type) on the performance in a wide range (seven) of executive functions in a sample of children with ADHD. Fifty-five male children aged seven to nine years with ADHD were divided into six groups: G1 = ADHD only (ADHD-O), G1 = Oppositional defiant disorder (ODD), G3 = (anxiety/depressive disorder (ADD), G4 = ODD + ADD, G5 = ODD + learning disorder (LD), G6 = ODD + LD + conduct disorder (CD). The six groups exhibited different number of deficits in EFs; G1 showed only 1 deficit in contrast, G6 presented 11. Statistical analysis (ANOVA and logistic regression) identified three most affected EFs: Working memory, generation/classification of semantic categories, and inhibitory control. Alterations in EFs increased mainly in relation to the increase of the specific number and type of comorbidity. To date, no studies have addressed comorbidity from this perspective. A wide range approach of EF confirms the need to further study comorbidity in ADHD from a wide range/variety perspective and determine all possible combinations (number/type) to clarify its contribution to the complex neuropsychology functioning in ADHD.

Effect of Lithium on Orthodontic Tooth Movement: a Systematic Review of Animal Studies

Objective

This study aimed to systematically review the effect of lithium on orthodontic tooth movement (OTM).

Methods

The focus question was "does lithium have an effect on OTM?" A systematic search was conducted using indexed databases and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. The quality assessment of the selected studies was performed according to the systematic review center for laboratory animal experimentation.

Results

Five of the initially identified 656 articles fulfilled the eligibility criteria and were selected for this review. The studies reported that lithium administration lowered the rate of OTM by inducing a reduction in the number of osteoclasts and possibly inhibiting osteoclastogenesis. These studies further showed an increase in bone density and bone volume by promoting the Wnt/ß-catenin signaling pathway and osteoblastogenesis. It was also noted that lithium reduced orthodontically induced root resorption during experimental OTM. Further, standardized studies are warranted to understand the impact of lithium in OTM. Overall, the risk of bias for 3 studies was very high, high in 1 study, and moderate in 1 study.

Conclusion

On an experimental level in animals, lithium decreased the rate of OTM during the active treatment phase by increasing bone density and bone volume and reducing root resorption. In addition, lithium may enhance alveolar bone formation during orthodontic retention. Clinically, this may impact the orthodontic treatment duration in patients receiving lithium, and further studies are needed to understand the true impact of lithium on OTM.

Psychological Treatments for Hyperactivity and Impulsivity in Children with ADHD: A Narrative Review

Treatment of the ADHD types (hyperactive-impulsive, inattentive, and combined) in children has rarely been studied separately, although their prognostic courses differ widely. In addition, data show that improvements in hyperactivity/impulsivity are hard to achieve. Thus, we focused on treatments tailored to hyperactivity/impulsivity. We examined meta-analyses and systematic reviews within the inter- and intra-individual treatments and found that psychoeducation and training for parents, school-based interventions, reinforcement strategies, and neurofeedback consistently showed small to moderate effect sizes in reducing hyperactivity/impulsivity in children. Conversely, emotional self-regulation, social skills, and cognitive trainings showed unsatisfactory results. In summary, we found that the quality of usual care can be surpassed when the designated interventions are purposefully combined into a multimodal treatment program.

Breviscapine Ameliorates Fear Extinction and Anxiety in BALB/cJ Mice

OBJECTIVE

In this research, the influence of breviscapine on anxiety, fear elimination, and aggression and the potential mechanism was investigated.

METHODS

Anxiety and locomotion were analyzed by elevated plus maze and open field test in mice. Bussey-Saksida Mouse Touch Screen Chambers were used to perform fear conditioning. Territorial aggression was assessed by resident intruder test. Protein levels were evaluated by Western blot. Breviscapine improved fear-extinction learning in BALB/cJ mice.

RESULTS

Breviscapine at 20-100 mg/kg increased center cross number, total distance traveled, and velocity in a dose-dependent manner. On the other hand, breviscapine at 20-100 mg/kg decreased the immobility time in open field test. In addition, breviscapine at 20-100 mg/kg increased the ratio of time on the open arm, time on the distal parts of the open arm, and total distance traveled in elevated plus maze. Breviscapine at 100 mg/kg increased the average attack latency and decreased the number of attacks over the last 3 days of resident intruder test. In hippocampus, protein levels of postsynaptic density protein-95 and synaptophysin were elevated by breviscapine at these three doses.

CONCLUSION

The administration of breviscapine alleviates fear extinction, anxiety, and aggression, while increases locomotor in a dose-dependent manner, which might be associated with its influence on synaptic function.

Kamishoyosan (a Japanese traditional herbal formula), which effectively reduces the aggressive biting behavior of male and female mice, and potential regulation through increase of Tph1, Tph2, and Esr2 mRNA levels

Kamishoyosan (KSS), a Japanese traditional herbal formula, is used to treat symptoms related to the autonomic nervous system in men and women; it is especially known for improving the symptoms of irritability (e.g., bad temper and persistent anger). Although clinical and ethological studies of KSS have been conducted, its efficacy in reducing irritability remains to be validated. In the present study, male and female ddY-strain mice were isolation-reared for 8 weeks (from the third postnatal week) to induce pathologically aggressive biting behavior (ABB), which was used as an indicator of irritability. The ABB of mice toward metal rods was measured using the Aggressive Response Meter. An intraperitoneal administration of KSS (100 mg/kg) effectively reduced ABB in male and female mice at 2 h after the administration; however, this effect was canceled by prior administration of WAY-100635 [a 5-hydroxytryptoamine (5-HT)-1A receptor antagonist; 0.5 mg/kg] and bicuculline (a type-A gamma-aminobutyric acid receptor antagonist; 1.0 mg/kg). Additionally, tamoxifen, ICI-182780, and G-15 (all estrogen receptor antagonists) inhibited the action of KSS in a dose-dependent manner. Furthermore, gene expression of tryptophan hydroxylase (Tph) 1 and Tph2 were increased and 5-HT immunofluorescence was slightly increased in the dorsal raphe nucleus (DRN) of isolation-reared mice administered with KSS. Collectively, these results indicate that KSS effectively reduces ABB in isolation-reared male and female mice through stimulation of 5-HT production in the DRN. Our findings also suggest that gene expression of estrogen receptor (Esr) 2 increased in the DRN might be associated with the reduction of ABB.

Understanding Chronic Aggression and Its Treatment in Children and Adolescents

PURPOSE OF REVIEW

Youth aggression is common and has a significant burden on individuals, families, and society. However, its treatment is often a challenge for clinicians. Thus, this review will examine the current understanding of youth aggression, conceptualize aggression as a symptom rather than its own disorder, and provide an overview of treatment strategies.

RECENT FINDINGS

Youth aggression is associated with complex genetic, neurobiological, and environmental risks. Prevention strategies are of the utmost importance for at-risk families and youth. Psychosocial interventions are the first line treatment. But if not fully effective, then pharmacologic interventions-including psychostimulants, alpha-2 agonists, atomoxetine, and risperidone-have shown benefits. Other medications, such as SSRIs, can be useful in certain scenarios. It is important to conceptualize youth aggression as being a trans-diagnostic symptom in psychopathology. Determining the underlying cause of aggression will help to guide treatment.

A proposed anti-maladaptive aggression agent classification: improving our approach to treating impulsive aggression

Proper drug categorization enables clinicians to readily identify the agents most appropriate for patients in need. Currently, patients with maladaptive aggression do not all always fall into a single existing diagnostic or treatment category. Such is the case for those with impulsive aggression (IA). IA is an associated feature of numerous neuropsychiatric disorders, and can be described as eruptive, aggressive behavior or a 'short fuse'. Although agents from a broad spectrum of drug classes have been used to treat maladaptive aggression, few have been tested distinctly in patients with IA, and there is no drug specifically indicated by the US Food and Drug Administration (US FDA) for IA. Further, current treatments often fail to sufficiently treat IA symptomatology. These issues create an unclear and inadequate treatment path for patients. Here we will propose the establishment of a class of anti-maladaptive aggression agents to begin addressing this clinical issue. The development of such a class would unify the various drugs currently used to treat maladaptive aggression and streamline the treatment approach towards IA. As an important case example of the range of candidate drugs that could fit into a new anti-maladaptive aggression agent category, we will review an investigational IA pharmacotherapy. SPN-810 (extended-release molindone) is currently being investigated as a novel treatment for children with IA and ADHD. Based on these studies we will review how SPN-810 may be well suited for a new, anti-maladaptive aggression drug class and more precisely, a proposed subgroup of IA modulators. The goal of this review is to begin improving the identification of and therapeutic approach for maladaptive aggression as well as IA through more precise anti-maladaptive aggression agent categorization.

Methylphenidate Dose-Dependently Affects Aggression and Improves Fear Extinction and Anxiety in BALB/cJ Mice

Overt aggression, increased anxiety, and dysfunctional fear processing are often observed in individuals with conduct disorder (CD) and attention-deficit hyperactivity disorder (ADHD). Methylphenidate (MPH), a psychostimulant increasing dopamine and noradrenaline tone, is effective in reducing aggression in both CD and ADHD individuals. However, it is unclear to which extent these effects of MPH are dose dependent. Here, the effects of acute intraperitoneal MPH (3 and 10 mg/kg) on aggression, anxiety, social behavior, and fear extinction were investigated in BALB/cJ mice. Previous studies in BALB/cJ mice have revealed high levels of aggression and anxiety that are associated with reduced top-down cortical control. Administration of 3 mg/kg MPH prolonged the attack latency and prevented escalation of aggression over time compared to vehicle-treated mice, while 10 mg/kg MPH increased number of bites and attacks. In addition, 3 mg/kg MPH decreased social interaction slightly. A strong anxiolytic effect was found after administration of both the 3 and 10 mg/kg doses in the elevated plus maze and the open-field test. In addition, while vehicle-treated BALB/cJ animals showed intact freezing, both doses of MPH decreased freezing to the unconditioned stimulus in a fear-conditioning paradigm. A long-lasting effect on fear extinction was visible after treatment with the 10 mg/kg dose. The data support a role for MPH in the regulation of anxiety, fear processing, and aggression in BALB/cJ mice, with the latter effect in a dose-dependent manner. The findings provide a further context for examining the effects of MPH in clinical disorders such as ADHD and CD.

Crisis in the Emergency Department: The Evaluation and Management of Acute Agitation in Children and Adolescents

Acute agitation in children and adolescents in the emergency department carries significant risks to patients and staff and requires skillful management, using both nonpharmacologic and pharmacologic strategies. Effective management of agitation requires understanding and addressing the multifactorial cause of the agitation. Careful observation and multidisciplinary collaboration is important. Medical work-up of agitated patients is also critical. Nonpharmacologic deescalation strategies should be first line for preventing and managing agitation and should continue during and after medication administration. Choice of medication should focus on addressing the cause of the agitation and any underlying psychiatric syndromes.

Effect of the Chronic Use of Lithium Carbonate on Induced Tooth Movement in Wistar Rats

Patients who seek dental treatment may have bipolar disorder, and lithium carbonate (LC) is the drug of choice used in the treatment of this disorder. Taking into consideration the controversial results found in the literature, and the possible influence of LC on induced tooth movement, the objective was to evaluate tooth movement induced in rats after administration of lithium carbonate. One hundred and ninety-two rats were divided into 3 groups. In the L group, the animals received daily 60mg/kg of LC, they were not subjected to orthodontic movement, and they were euthanized after 33, 37, 44 or 51 days. In the LM group, the LC was administered for 30 days and during the subsequent 3, 7, 14 and 21 days, corresponding to the period of induced tooth movement, and they received a spring that produced a 30cN force. In the SM group, saline solution was applied. Measurements were made of tooth displacement, the numbers of osteoclasts and serum lithium phosphate (PO4), alkaline phosphatase (ALP) and creatinine levels. The tooth displacement was lower in the LM group compared to the SM group at 44 days. A tendency toward reduction in the number of osteoclasts was observed in the LM group compared to the SM group at 44 days. The average lithium were higher in the L and LM groups compared to the SM group. The opposite was observed for the PO4 group. A higher value for the ALP was found in the L group. The average creatinine level was lower in the LM group. LC inhibited tooth movement for 14 days, possibly due to the reduction in the number of osteoclasts.

Pharmacotherapy of Aggression in Child and Adolescent Psychiatric Disorders

OBJECTIVE

Aggression is a common, yet complex, behavioral complaint, and a frequent indication for referral to child and adolescent psychiatrist treatment. This article reviews the evidence supporting pharmacotherapy of aggression in youth, with a primary focus on impulsive aggression (the primary indication for this intervention). Relevant diagnostic considerations and consensus guidelines are discussed.

METHODS

Articles examining the role of medications in the treatment of aggression in youth with pathological aggression were identified using PubMed and MEDLINE® databases over the past 15 years (2000-2015); selected articles published prior to 2000 and deemed to be of high relevance were searched and also included. Search terms included: Aggression, aggressive, disruptive behavior, conduct, youth, children, and adolescents. Cited references were also searched for relevant articles.

RESULTS

There are a number of evidence-based medication treatments for aggression, which are generally best considered in the context of differential diagnosis and ongoing evidence-based psychosocial interventions. Impulsive aggression is generally considered the type of aggression most amenable to medication, but other aggression subtypes may also possibly respond to treatment. Medication classes with positive evidence include the psychostimulants and α-2 agonists (in the presence of attention-deficit/hyperactivity disorder [ADHD] and/or disruptive behavior disorders), mood stabilizing agents, and atypical antipsychotics. Published guidelines recommend systematic and adequate trials of medications in sequential order, to optimize response and minimize polypharmacy. Guidelines for safety monitoring are available for many of the medications used for aggression in youth, and are also discussed.

CONCLUSIONS

Aggression in children carries a high risk of poor outcomes, and, therefore, a better understanding of treatment options is a high priority. The available literature points to the importance of identifying the underlying disorder, when possible, and using this information to guide treatment selection. Future studies are needed to better inform the treatment of aggression across disorders, and the treatment of different aggression subtypes.

Differences in behavior and activity associated with a poly(a) expansion in the dopamine transporter in Belgian Malinois

In Belgian Malinois dogs, a 38-base pair variable number tandem repeat in the dopamine transporter gene (SLC6A3) is associated with behavior changes in Malinois. By additional sequencing in SLC6A3, we identified an intronic 12-nucleotide poly(A) insertion (“PolyA(22)”) before the terminal exon that was associated with seizure, “glazing over” behaviors, and episodic biting behaviors in a sample of 138 Malinois. We next investigated whether PolyA(22) was associated with 1) increased locomotor activity and 2) response to novelty. Using a sample of 22 Malinois and 25 dogs of other breeds, dogs’ activity was monitored in a novel and non-novel environment while wearing activity monitoring collars. All dogs were more active in novel compared with non-novel environments, and Malinois were more active overall than other breeds. There was an effect of PolyA(22) genotype on activity levels, and this effect appeared to underlie the difference detected between Malinois and other breeds. There was no effect of PolyA(22) genotype on the relative decrease in activity between novel and non-novel environments for either group or all dogs considered together. In addition to an association between PolyA(22) and owner reports of seizure, “glazing over” behaviors, and episodic biting behaviors, these findings support an effect of PolyA(22) on dopamine transporter function related to activity. Further investigation is required to confirm mechanistic effects of PolyA(22) on SLC6A3. The complex polygenic nature of behavior and the range of behaviors associated with this insertion predict that effects are likely also modified by additional genetic and environmental factors.