Annual Research Review: New frontiers in developmental neuropharmacology: can long-term therapeutic effects of drugs be optimized through carefully timed early intervention?

Is combined antidepressant medication (ADM) and psychotherapy better than either monotherapy at preventing suicide attempts and other psychiatric serious adverse events for depressed patients? A rare events meta-analysis

Antidepressant medication (ADM)-only, psychotherapy-only, and their combination are the first-line treatment options for major depressive disorder (MDD). Previous meta-analyses of randomized controlled trials (RCTs) established that psychotherapy and combined treatment were superior to ADM-only for MDD treatment remission or response. The current meta-analysis extended previous ones by determining the comparative efficacy of ADM-only, psychotherapy-only, and combined treatment on suicide attempts and other serious psychiatric adverse events (i.e. psychiatric emergency department [ED] visit, psychiatric hospitalization, and/or suicide death; SAEs). Peto odds ratios (ORs) and their 95% confidence intervals were computed from the present random-effects meta-analysis. Thirty-four relevant RCTs were included. Psychotherapy-only was stronger than combined treatment (1.9% v. 3.7%; OR 1.96 [1.20-3.20], p = 0.012) and ADM-only (3.0% v. 5.6%; OR 0.45 [0.30-0.67], p = 0.001) in decreasing the likelihood of SAEs in the primary and trim-and-fill sensitivity analyses. Combined treatment was better than ADM-only in reducing the probability of SAEs (6.0% v. 8.7%; OR 0.74 [0.56-0.96], p = 0.029), but this comparative efficacy finding was non-significant in the sensitivity analyses. Subgroup analyses revealed the advantage of psychotherapy-only over combined treatment and ADM-only for reducing SAE risk among children and adolescents and the benefit of combined treatment over ADM-only among adults. Overall, psychotherapy and combined treatment outperformed ADM-only in reducing the likelihood of SAEs, perhaps by conferring strategies to enhance reasons for living. Plausibly, psychotherapy should be prioritized for high-risk youths and combined treatment for high-risk adults with MDD.

Word-Finding Difficulties as a Prominent Early Finding in a Later Diagnosis of Attention Deficit Hyperactivity Disorder

OBJECTIVE

 Attention deficit hyperactivity disorder (ADHD) is a common neuropsychological disorder primarily diagnosed in childhood. Early intervention was found to significantly improve developmental outcomes, implicating on the role of early identification of ADHD markers. In the current study, we explored the developmental history of children referred to neurological assessment to identify early ADHD predictors.

METHODS

 A total of 92 children and adolescents (41 females) recruited at a pediatric neurology clinic, with suspected ADHD (n = 39) or other neurological difficulties (n = 53) such as headaches, seizures, tic disorders, orthostatic hypotension, postischemic stroke, intermittent pain, and vasovagal syncope. Developmental history information was obtained from caregivers, and evaluation for possible ADHD was performed. Developmental details were compared between children with and without current ADHD diagnosis.

RESULTS

 Word-finding difficulties (WFDs) in preschool age was reported in 30.4% of the sample. Among children diagnosed with ADHD, 43% had WFDs history, compared with only 5% in children without ADHD. Among children with WFDs history, 93% were later diagnosed with ADHD compared with 42% in children without WFDs history. The relationship between WFDs and ADHD was significant (chi-square test [1, N = 92] = 20.478, p < 0.0001), and a logistic regression model demonstrated that asides from a family history of ADHD, the strongest predictor for ADHD in school age children was a history of WFDs.

CONCLUSION

 Preliminary evidence supports a predictive link between preschool WFDs and later ADHD diagnosis, highlighting the importance of early WFDs clinical attention.

Antidepressant Use and Risk of Manic Episodes in Children and Adolescents With Unipolar Depression

Importance

Antidepressants are increasingly prescribed to pediatric patients with unipolar depression, but little is known about the risk of treatment-emergent mania. Previous research suggests pediatric patients may be particularly vulnerable to this adverse outcome.

Objective

To estimate whether pediatric patients treated with antidepressants have an increased incidence of mania/hypomania compared with patients not treated with antidepressants and to identify patient characteristics associated with the risk of mania/hypomania.

Design, Setting, and Participants

In a cohort study applying the target trial emulation framework, nationwide inpatient and outpatient care in Sweden from July 1, 2006, to December 31, 2019, was evaluated. Follow-up was conducted for 12 and 52 weeks after treatment initiation, with administrative follow-up ending December 31, 2020. Data were analyzed between May 1, 2022, and June 28, 2023. Individuals aged 4 to 17 years with a diagnosis of depression, but without a prior diagnosis of mania/hypomania, bipolar disorder, or psychosis or treatment with mood stabilizer (lithium, valproate, or carbamazepine), prescriptions were included.

Exposures

The treatment group included patients who initiated any antidepressant medication within 90 days of diagnosis. The control group included patients who did not initiate antidepressants within 90 days.

Main Outcomes and Measures

Diagnosis of mania/hypomania or initiation of mood stabilizer therapy. Incidences were estimated with Kaplan-Meier estimator, and inverse probability of treatment weighting was used to adjust for group differences at baseline.

Results

The cohort included 43 677 patients (28 885 [66%] girls); 24 573 in the treatment group and 19 104 in the control group. The median age was 15 (IQR, 14-16) years. The outcome occurred in 96 individuals by 12 weeks and in 291 by 52 weeks. The cumulative incidence of mania was 0.26% (95% CI, 0.19%-0.33%) in the treatment group and 0.20% (95% CI, 0.13%-0.27%) in the control group at 12 weeks, with a risk difference of 0.06% (95% CI, -0.04% to 0.16%). At 52 weeks, the cumulative incidence was 0.79% (95% CI, 0.68%-0.91%) in the treatment group and 0.52% (95% CI, 0.40%-0.63%) in the control group (risk difference, 0.28%; 95% CI, 0.12%-0.44%). Hospitalizations, parental bipolar disorder, and use of antipsychotics and antiepileptics were the most important predictors of mania/hypomania by 12 weeks.

Conclusion

This cohort study found no evidence of treatment-emergent mania/hypomania by 12 weeks in children and adolescents. This corresponds to the time frame for antidepressants to exert their psychotropic effect. A small risk difference was found only with longer follow-up. Certain patient characteristics were associated with mania/hypomania, which warrants clinical attention.

Antipsychotic Medications for Low-Income Preschoolers: Long Duration and Psychotropic Medication Polypharmacy

OBJECTIVE

This study aimed to evaluate prescribing patterns of antipsychotic medication and factors that predict duration of use among low-income, preschool-age children.

METHODS

State Medicaid claims from 2012 to 2017 were used to identify antipsychotic medication use for children <6 years old. ICD-9 and ICD-10 codes were used to describe child diagnoses. Descriptive and multivariable analyses were used to determine patterns of antipsychotic medication use and factors that predicted duration of use.

RESULTS

In 2012, 316 children <6 years of age started an antipsychotic medication in a southeastern state. Most were non-Hispanic White (N=202, 64%) and boys (N=231, 73%). Diagnoses included attention-deficit hyperactivity disorder (N=288, 91%), neurodevelopmental disorders (N=208, 66%), anxiety and trauma-related diagnoses (N=202, 64%), and autism spectrum disorders (ASDs) (N=137, 43%). The mean±SD duration of exposure to antipsychotic medication for children in the cohort was 2.6±1.7 years, but 86 children (27%) had >4 years of exposure. Almost one-third (N=97, 31%) received polypharmacy of four or more medication classes, and 42% (N=131) received metabolic screening. Being male, being in foster care, and having a diagnosis of ASD or disruptive mood dysregulation disorder were significantly associated with duration of use of antipsychotic medications; race-ethnicity was not significantly associated with duration of use. Emergency department visits (N=277, 88%) and inpatient hospitalizations (N=107, 34%) were observed during the study period.

CONCLUSIONS

Many preschoolers received antipsychotic medications for substantial periods. Further research is needed to identify evidence-based practices to reduce medication use and improve outcomes.

Early antipsychotic treatment in juvenile rats elicits long-term alterations to the adult serotonin receptors

BACKGROUND

Antipsychotic drug (APD) prescription/use in children has increased significantly worldwide, despite limited insight into potential long-term effects of treatment on adult brain functioning. While initial long-term studies have uncovered alterations to behaviors following early APD treatment, further investigations into potential changes to receptor density levels of related neurotransmitter (NT) systems are required.

METHODS

The current investigation utilized an animal model for early APD treatment with aripiprazole, olanzapine, and risperidone in male and female juvenile rats to investigate potential long-term changes to the adult serotonin (5-HT) NT system. Levels of 5-HT1A, 5-HT2A, and 5-HT2C receptors were measured in the prefrontal cortex (PFC), caudate putamen (CPu), nucleus accumbens (NAc), and hippocampus via Western Blot and receptor autoradiography.

RESULTS

In the male cohort, long-term changes to 5-HT2A and 5-HT2C receptors were found mostly across hippocampal and cortical brain regions following early aripiprazole and olanzapine treatment, while early risperidone treatment changed 5-HT1A receptor levels in the NAc and PFC. Lesser effects were uncovered in the female cohort with aripiprazole, olanzapine and risperidone to alter 5-HT1A and 5-HT2A receptors in NAc and hippocampal brain regions, respectively.

CONCLUSION

The results of this study suggest that early treatment of various APDs in juvenile rats may cause gender and brain regional specific changes in 5-HT2A and 5-HT2C receptors in the adult brain.

Development of Posterior Medial Frontal Cortex Function in Pediatric Obsessive-Compulsive Disorder

OBJECTIVE

Abnormal engagement of the posterior medial frontal cortex (pMFC) occurs during performance monitoring in obsessive-compulsive disorder (OCD), including in pediatric patients. Yet, the development of pMFC function in OCD-affected youth remains poorly understood.

METHOD

A total of 69 patients with pediatric OCD and 72 healthy controls (HC), 8 to 19 years of age, were scanned during the Multisource Interference Task (MSIT). The effects of group, age, performance, and interactions on pMFC response to errors and interference were tested in the region of interest [ROI]) and whole-brain analyses. Secondary analyses considered bilateral anterior insula/frontal operculum (aI/fO), given the contribution of these regions with pMFC to a cingulo-opercular network (CON) for task control (e.g., error and interference processing).

RESULTS

Error-related pMFC activity was greater for OCD patients than for HC, increased with age in OCD patients, but decreased with age in HC. Greater pMFC activation associated with better performance in HC but not OCD patients. In the patients, greater pMFC activation to errors was associated with lower OCD severity. Altered error-related activation and performance associations were also observed in the right aI/fO in OCD patients, whereas the left aI/fO response to interference was associated with lower OCD severity.

CONCLUSION

Atypical increase in error-related pMFC activation with age in pediatric OCD suggests altered development of pMFC function during the early course of illness. Greater pMFC activation with better performance in HC, and with age and lower symptom severity in OCD patients, suggests an adaptive function of heightened pMFC response to errors that could be further enhanced (e.g., via cognitive training) to improve outcomes in OCD from the early course of illness.

Long-lasting effects of fluoxetine and/or exercise augmentation on bio-behavioural markers of depression in pre-pubertal stress sensitive rats

Juvenile depression is of great concern with only limited treatment currently approved. Delayed onset of action, low remission and high relapse rates, and potential long-lasting consequences further complicates treatment and highlights the need for new treatment options. Studies reporting on long-lasting effects of early-life treatment have reported conflicting results, with the pre-adolescent period mostly overlooked. The anti-depressive effect of exercise, as a possible treatment option or augmentation strategy, is dependent on age and exercise intensity. We investigated the immediate (i.e. postnatal day 35 (PND35)) and lasting (PND60 to PND61) effects of pre-pubertal (PND21 to PND34) fluoxetine and/or exercise on bio-behavioural markers of depression and oxidative stress in stress sensitive Flinders Sensitive Line rats. Low, but not moderate, intensity exercise or 5, but not 10, mg/kg/day fluoxetine displayed anti-depressant-like properties at PND35. Pre-pubertal treatment with 5mg/kg/day fluoxetine or low intensity exercise exerted lasting anti-depressive-like effects into adulthood, whereas the combination of these two treatments did not. Furthermore, the combination of fluoxetine plus exercise reduced hippocampal BDNF levels as compared to exercise alone, which may explain the latter findings. In all treatment groups hippocampal SOD activity was significantly increased at PND61, suggesting an increased anti-oxidant capacity in adulthood. In conclusion, the data confirm the anti-depressant-like properties of both early-life fluoxetine and exercise in a genetic animal model of depression. However, optimal lasting effects of early-life interventions may require adjustment of antidepressant dose and/or exercise intensity to developmental age, and that a combination of antidepressant and exercise may not necessarily be augmentative.

Sensitive periods of substance abuse: Early risk for the transition to dependence

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Early substance use dramatically increases the risk of substance use disorder (SUD).

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Although many try drugs, only a small percentage transition to SUD.

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High reactivity of reward, habit, and stress systems increase risk.

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Identification of early risk enables targeted, preventative interventions for SUD.

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Prevention must start before the sensitive adolescent period to maximize resilience.

Early adolescent substance use dramatically increases the risk of lifelong substance use disorder (SUD). An adolescent sensitive period evolved to allow the development of risk-taking traits that aid in survival; today these may manifest as a vulnerability to drugs of abuse. Early substance use interferes with ongoing neurodevelopment to induce neurobiological changes that further augment SUD risk. Although many individuals use drugs recreationally, only a small percentage transition to SUD. Current theories on the etiology of addiction can lend insights into the risk factors that increase vulnerability from early recreational use to addiction. Building on the work of others, we suggest individual risk for SUD emerges from an immature PFC combined with hyper-reactivity of reward salience, habit, and stress systems. Early identification of risk factors is critical to reducing the occurrence of SUD. We suggest preventative interventions for SUD that can be either tailored to individual risk profiles and/or implemented broadly, prior to the sensitive adolescent period, to maximize resilience to developing substance dependence. Recommendations for future research include a focus on the juvenile and adolescent periods as well as on sex differences to better understand early risk and identify the most efficacious preventions for SUD.

Language Delay in 3-Year-Old Children With ADHD Symptoms

OBJECTIVE

Little is known about cognition in preschoolers with ADHD and language delay (LD). The objective was to investigate cognitive functions in preschoolers with ADHD symptoms and LD compared with children with ADHD symptoms only and to estimate the frequency of children with ADHD symptoms, co-occurring language delay, and delays on cognitive measures.

METHOD

Participants were recruited from the Norwegian Mother and Child Cohort Study. The teacher report of expressive language and the cognitive tests from 119 3-year-old children with parent reported ADHD symptoms and LD were compared with those of 258 children with ADHD symptoms only.

RESULTS

The ADHD + LD group performed significantly worse than the ADHD group on most language-related measures. There were no differences between the groups on most nonverbal measures. Single measures had a limited potential of differentiating between the groups.

CONCLUSION

ADHD symptoms and co-occurring LD in preschoolers were characterized by cognitive deficits associated with both disorders, not with global neurodevelopmental delay.

Age and DRD4 Genotype Moderate Associations Between Stimulant Treatment History and Cortex Structure in Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) has been associated with dopaminergic imbalance and subtle volume decreases in the brain. Stimulants acutely enhance dopaminergic neurotransmission. Long-term effects of prolonged manipulation of the dopaminergic system on brain structure remain poorly understood; they could be beneficial or unfavorable and could be moderated by common genetic variants and/or age.

METHOD

In a large observational ADHD cohort study (N = 316), the effects of cumulative stimulant treatment, genotype (for DAT1 haplotype and DRD4 variants), and treatment-by-genotype interactions on striatal, frontal, and hippocampal volumes and their interactions with age were evaluated.

RESULTS

No main effects of treatment were found. Associations between treatment and bilateral frontal and left hippocampal volume depended on DRD4 genotype and age. At a younger age and lower treatment levels, but not at a younger age and higher treatment levels, carriers of the DRD4 7R allele showed decreased frontal cortex volumes. At an older age, carriers and non-carriers showed smaller frontal volumes irrespective of treatment history. Left hippocampal volume was similar to that in controls at average treatment levels and increased with treatment only in carriers of the DRD4 risk allele and at a younger age. No interaction effects were found in the striatum.

CONCLUSION

Carriers of the DRD4 risk allele at a younger age might be sensitive to cortical remodeling after stimulant treatment. The cross-sectional nature of this study warrants cautious interpretation of age effects. The present findings, although of small effect size, might ultimately contribute to optimal care for individuals with ADHD.

Neural changes induced by antipsychotic administration in adolescence: A review of studies in laboratory rodents

Adolescence is characterized by major remodelling processes in the brain. Use of antipsychotic drugs (APDs) in adolescents has increased dramatically in the last 20 years; however, our understanding of the neurobiological consequences of APD treatment on the adolescent brain has not kept the same pace and significant concerns have been raised. In this review, we examined currently available preclinical studies of the effects of APDs on the adolescent brain. In animal models of neuropsychiatric disorders, adolescent APD treatment appears to be protective against selected structural, behavioural and neurochemical phenotypes. In "neurodevelopmentally normal" adolescent animals, a range of short- and long-term alterations in behaviour and neurochemistry have been reported. In particular, the adolescent brain appears to be sensitive to long-term locomotor/reward effects of chronic atypical APDs in contrast with the outcomes in adults. Long-lasting changes in dopaminergic, glutamatergic and gamma-amino butyric acid-ergic systems induced by adolescent APD administration have been observed in the nucleus accumbens. A detailed examination of other potential target regions such as striatum, prefrontal cortex and ventral tegmental area is still required. Through identification of specific neural pathways targeted by adolescent APD treatment, future studies will expand the current knowledge on long-term neural outcomes which are of translational value.

Contrasting regional Fos expression in adolescent and young adult rats following acute administration of the antidepressant paroxetine

Adolescents and adults may respond differently to antidepressants, with poorer efficacy and greater probability of adverse effects in adolescents. The mechanisms underlying this differential response are largely unknown, but likely relate to an interaction between the neural effects of antidepressants and brain development. We used Fos immunohistochemistry to examine regional differences in adolescent (postnatal day (PND) 28) and young adult (PND 56) male, Wistar rats given a single injection of the selective serotonin reuptake inhibitor paroxetine (10mg/kg). Paroxetine induced widespread Fos expression in both adolescent and young adult rats. Commonly affected areas include the bed nucleus of the stria terminalis (dorsolateral), medial preoptic area, paraventricular hypothalamic and thalamic nuclei and central nucleus of the amygdala. Fos expression was generally lower in adolescents with significantly greater Fos expression observed in young adults in the prelimbic cortex, supraoptic nucleus, basolateral amygdala, lateral parabrachial and Kölliker-Fuse nuclei. However, a small subset of regions showed greater adolescent Fos expression including the nucleus accumbens shell, lateral habenula and dorsal raphe. Paroxetine increased plasma corticosterone concentrations in young adults, but not adolescents. Plasma paroxetine levels were not significantly different between the age groups. These results indicate a different c-Fos signature of acute paroxetine in adolescent rats, with greater activation in key mesolimbic and serotonergic regions, but a more subdued cortical, brainstem and hypothalamic response. This suggests that the atypical response of adolescents to paroxetine may be related to a blunted neuroendocrine response, combined with insufficient top-down regulation of limbic regions involved in reward and impulsivity.

Early antipsychotic treatment in childhood/adolescent period has long-term effects on depressive-like, anxiety-like and locomotor behaviours in adult rats

Childhood/adolescent antipsychotic drug (APD) use is exponentially increasing worldwide, despite limited knowledge of the long-term effects of early APD treatment. Whilst investigations have found that early treatment has resulted in some alterations to dopamine and serotonin neurotransmission systems (essential to APD efficacy), there have only been limited studies into potential long-term behavioural changes. This study, using an animal model for childhood/adolescent APD treatment, investigated the long-term effects of aripiprazole, olanzapine and risperidone on adult behaviours of male and female rats. Open-field/holeboard, elevated plus maze (EPM), social interaction and forced swim (FS) tests were then conducted in adult rats. Our results indicated that in the male cohort, early risperidone and olanzapine treatment elicited long-term hyper-locomotor effects (open-field/holeboard and FS tests), whilst a decrease in depressive-like behaviour (in FS test) was observed in response to olanzapine treatment. Furthermore, anxiolytic-like behaviours were found following testing in the open-field/holeboard and EPM in response to all three drug treatments. Effects in the female cohort, however, were to a far lesser extent, with behavioural attributes indicative of an increased depressive-like behaviour and hypo-locomotor activity exhibited in the FS test following early risperidone and olanzapine treatment. These results suggest that various APDs have different long-term effects on the behaviours of adult rats.

A groundwork for allostatic neuro-education

We propose to enliven educational practice by marrying a conception of education as guided human development, to an advanced scientific understanding of the brain known as allostasis (stability through change). The result is a groundwork for allostatic neuro-education (GANE). Education as development encompasses practices including the organic (homeschooling and related traditions), cognitive acquisition (emphasis on standards and testing), and the constructivist (aimed to support adaptive creativity for both learner and society). Allostasis views change to be the norm in biology, defines success in contexts of complex natural environments rather than controlled settings, and identifies the brain as the organ of central command. Allostatic neuro-education contrasts with education focused dominantly on testing, or neuroscience based on homeostasis (stability through constancy). The GANE perspective is to view learners in terms of their neurodevelopmental trajectories; its objective is to support authentic freedom, mediated by competent, integrated, and expansive executive functionality (concordant with the philosophy of freedom of Rudolf Steiner); and its strategy is to be attuned to rhythms in various forms (including those of autonomic arousal described in polyvagal theory) so as to enable experiential excitement for learning. The GANE presents a variety of testable hypotheses, and studies that explore prevention or mitigation of the effects of early life adversity or toxic stress on learning and development may be of particular importance. Case studies are presented illustrating use of allostatic neurotechnology by an adolescent male carrying diagnoses of Asperger’s syndrome and attention-deficit hyperactivity disorder, and a grade school girl with reading difficulties. The GANE is intended as a re-visioning of education that may serve both learners and society to be better prepared for the accelerating changes of the 21st century.

Trends in Atypical Antipsychotics Prescribed to Children Six Years of Age or Less on Medicaid in Kentucky

OBJECTIVE

Studies have shown an increase in the use of antipsychotics to preschoolers for disruptive behavior and aggression. This study investigated the use of atypical antipsychotics in children ≤6 years of age in Kentucky who were on Medicaid.

METHODS

Kentucky Medicaid prescription claims data between 2001 and 2010 were examined for all children ≤6 years of age who had received an atypical antipsychotic. Drug type, diagnosis codes, and geographic trends were analyzed using descriptive statistics.

RESULTS

A total of 70,777 prescriptions were written to 6915 distinct children ≤6 years of age. The use of atypical antipsychotics in this age group increased over the years 2001-2010 with a peak ∼ 1.0% in 2004, and averaged 0.75% in 2010. Older male children were more likely to receive atypical antipsychotics, and risperidone accounted for two thirds of the prescriptions written. Mood disorders, primarily bipolar disorder, accounted for almost 75% of the diagnoses provided. Only 32% of the prescriptions were written by child psychiatrists. Geographic analysis showed significantly higher use in the Western part of the state (more than three times the state mean in some counties).

CONCLUSIONS

The use of atypical antipsychotics in children ≤6 years of age has declined from its peak, but remains substantial. The prescription rates for atypical antipsychotics by providers other than child psychiatrists, and the marked geographic variation in use across the state of Kentucky suggest that improved systems of mental healthcare for this population are needed.

Antidepressants and the adolescent brain

Major unipolar depression is a significant global health problem, with the highest incident risk being during adolescence. A depressive illness during this period is associated with negative long-term consequences including suicide, additional psychiatric comorbidity, interpersonal relationship problems, poor educational performance and poor employment attainment well into adult life. Despite previous safety concerns, selective serotonin reuptake inhibitors (SSRIs) remain a key component of the treatment of moderate to severe depression episodes in adolescents. The impact of SSRIs on the developing adolescent brain, however, remains unclear. In this review we first consider what is currently known about the developing brain during adolescence and how these development processes may be affected by a depressive illness. We then review our understanding of the action of SSRIs, their effects on the brain and how these may differ between adults and adolescents. We conclude that there is currently little evidence to indicate that the human adolescent brain is at developmental risk from SSRIs. Furthermore, there is no clear-cut evidence to support the concerns of marked suicidal adverse side effects accruing in depressed adolescents being treated with SSRIs. Neither, however, is there irrefutable evidence to dismiss all such concerns. This makes SSRI prescribing a matter of medical judgement, ensuring the benefits outweigh the risks for the individual patients, as with so much in therapeutics. Overall, SSRIs show clinical benefits that we judge to outweigh the risks to neurodevelopment and are an important therapeutic choice in the treatment of moderate to severe adolescent depression.

Olanzapine antipsychotic treatment of adolescent rats causes long term changes in glutamate and GABA levels in the nucleus accumbens

Atypical antipsychotic drugs (AAPDs) are widely used in children and adolescents to treat a variety of psychiatric disorders. However, little is known about the long-term effects of AAPD treatment before the brain is fully developed. Indeed, we and others have previously reported that treatment of adolescent rats with olanzapine (OLA; a widely prescribed AAPD) on postnatal days 28-49, under dosing conditions that approximate those employed therapeutically in humans, causes long-term behavioral and neurobiological perturbations. We have begun to study the mechanisms of these effects. Dopamine (DA) and serotonin (5HT) regulate many neurodevelopmental processes. Currently approved AAPDs exert their therapeutic effects principally through their DAergic activities, although in schizophrenia (SZ) and some other diseases for which AAPDs are prescribed, DAergic dysfunction is accompanied by abnormalities of glutamatergic (GLUergic) and γ-aminobutyric acidergic (GABAergic) transmission. Here, we use proton magnetic resonance spectroscopy ((1)H MRS) to investigate the effects of adolescent OLA administration on GABA and GLU levels. We found that the treatment caused long-term reductions in the levels of both GLU and GABA in the nucleus accumbens (NAc) of adult rats treated with OLA during adolescence. The NAc is a key node in the brain's "reward" system, whose function is also disrupted in schizophrenia. Further research into potential, OLA-induced changes in the levels of GLU and GABA in the NAc and other brain areas, and the dynamics and mechanisms of those changes, are an essential step for devising new adjunct therapies for existing AAPDs and for designing new drugs that increase therapeutic effects and reduce long-term abnormalities when administered to pediatric patients.

Longitudinal trends in the dispensing of psychotropic medications in Australia from 2009-2012: focus on children, adolescents and prescriber specialty

OBJECTIVE

Longitudinal trends in the dispensing of antidepressant, antipsychotic and ADHD medications from 2009-2012 were examined according to age and gender of patient and prescriber speciality. Of particular interest were changing trends in the prescription of psychotropic medications to children, adolescents and young adults.

METHOD

Dispensing data for government-subsidised antidepressant, antipsychotic and ADHD medications were obtained from the database maintained by the Department of Human Services. Results were expressed in terms of number of prescriptions dispensed.

RESULTS

Over the four- year study period, the dispensing of antidepressants, antipsychotics and ADHD medications showed overall increases of 16.1%, 22.7% and 26.1% respectively. The most rapid percentage increases in antidepressant and antipsychotic dispensing occurred in children aged 10-14 (35.5% and 49.1% respectively), while ADHD medication dispensing rose most rapidly in those aged 20-24 (70.9%). Dispensing to males was more common during childhood for all investigated classes while two-thirds of adult antidepressant prescribing was to female patients. The most commonly prescribed antidepressants varied by age and were as follows: fluoxetine (3-19 year olds), desvenlafaxine (20-24 years) and venlafaxine (>25 years). Risperidone was the most common antipsychotic dispensed to children under 15, quetiapine to adolescents and young adults (15-24 years), and olanzapine to adults. Methylphenidate was the most common ADHD medication in those aged under 25, and dexamphetamine the most common in adults. Most antidepressants and antipsychotics were prescribed by GPs (89.9% and 70.6% respectively), while the majority of ADHD medications were prescribed by paediatricians (59.1%).

CONCLUSIONS

Dispensing of psychotropic medications increased markedly from 2009 to 2012, with notable age-specific trends. General adherence to treatment guidelines is apparent, yet concerns exist regarding rapid increases in serotonin noradrenaline reuptake inhibitor (SNRI) antidepressant prescribing, the likely overmedication of persons with mild psychological distress, and the increasing use of powerful psychotropic medications in younger populations despite uncertain risk-benefit profiles.

Treating our youngest patients: psychotropic medications in early childhood

Over the past several decades there have been multiple studies indicating that infants, toddlers and preschoolers who develop emotional and behavioral problems may not simply outgrow their problems. Early intervention is ideal, and may help to maximize long-term functioning. When other interventions fail or do not fully address the symptoms, psychotropic medications can be very helpful, even in the preschool years. With limited scientific research in this population, the use of psychotropic medications in very young children can be challenging. The judicious use of these agents in this population will be discussed, including weighing the risks and benefits of prescribing to these most vulnerable patients.

Reducing substance use during adolescence: a translational framework for prevention

RATIONALE

Most substance use is initiated during adolescence when substantial development of relevant brain circuitry is still rapidly maturing. Developmental differences in reward processing, behavioral flexibility, and self-regulation lead to changes in resilience or vulnerability to drugs of abuse depending on exposure to risk factors. Intervention and prevention approaches to reducing addiction in teens may be able to capitalize on malleable brain systems in a predictable manner.

OBJECTIVE

This review will highlight what is known about how factors that increase vulnerability to addiction, including developmental stage, exposure to early life adversity (ranging from abuse, neglect, and bullying), drug exposure, and genetic predisposition, impact the development of relevant systems.

RESULTS AND CONCLUSIONS

Appropriate, early intervention may restore the normal course of an abnormal trajectory and reduce the likelihood of developing a substance use disorder (SUD) later in life. A considerable amount is known about the functional neuroanatomy and/or pharmacology of risky behaviors based on clinical and preclinical studies, but relatively little has been directly translated to reduce their impact on addiction in high-risk children or teenagers. An opportunity exists to effectively intervene before adolescence when substance use is likely to emerge.

A multicenter, randomized, controlled study of Training Executive, Attention, and Motor Skills (TEAMS) in Danish preschool children with attention-deficit/hyperactivity disorder: Rationale and description of the intervention and study protocol

Background:

Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent neurodevelopmental disorder that is often detected during the preschool years. Neuroimaging data indicate that children with ADHD have brains that are characterized by growth and functional anomalies. Data suggest that the diminution of ADHD symptoms is correlated with improved neural functioning and growth. On the basis of these findings, interventions that target neural growth, which indicates neural development, can possibly lead to a more enduring treatment for ADHD. Training Executive, Attention, and Motor Skills (TEAMS) is a non-pharmacological neurocognitive intervention program that targets preschool children with ADHD. The program is designed to stimulate neurocognitive growth through physical activity and play in combination with psychoeducation and guidance for the parents.

Population:

Children between the ages of three and six years from Region Zealand in Denmark who have been diagnosed with ADHD are offered participation in the trial. According to a calculation of the strength needed to result in a statistically significant outcome, the estimated group size should be, at minimum, 87 children. On the basis of Region Zealand’s visitation history records, the cohort is expected to include approximately 100 to 120 children.

Method:

The intervention groups participate in eight weekly group sessions that consist of separate parent and children’s groups. The control groups receive the standard treatment program as outlined by the clinical guidelines of Region Zealand. The ADHD Rating Scale-IV and the Danish version of the Strengths and Difficulties Questionnaire are used to assess ADHD symptom severity before and after the intervention and to monitor the duration of the outcome. A comparative analysis of data from the intervention and control groups will illustrate the study’s results.

Study aim:

This is a multicenter, randomized, controlled, single-blind, parallel-group study with the primary aims of testing the TEAMS concept and investigating whether the intervention significantly lowers ADHD symptoms and increases the functionality level after the intervention as compared with the control group. A secondary aim is to monitor the duration and endurance of the outcome for six months after the intervention. This study is currently in progress. Full results and conclusions will be reported after the study’s completion in 2015.

Chronic fluoxetine treatment changes S100B expression during postnatal rat brain development

BACKGROUND

Fluoxetine, a selective serotonin reuptake inhibitor, is approved for treatment of childhood depression. In rats, fluoxetine influences neuronal development, but it is unclear whether it also influences glia development. S100B is a glia-derived calcium-binding protein, which may influence the development of serotonergic fibers and, vice versa, serotonin may influence the expression of S100B.

OBJECTIVES

The purpose of this study was to investigate whether fluoxetine treatment influences the expression of S100B during postnatal development, and whether potential changes are regionally dependent upon the time frame of drug administration.

METHODS

S100B gene expression and S100B protein expression in three different brain regions (frontal cortex, hippocampus, and striatum) were studied by real-time polymerase chain reaction (PCR) and immunohistochemistry, respectively. First, a short-term effect, 24 hours after a 14 day fluoxetine treatment (5 mg/kg/bw s.c.) of rats either from postnatal day (PD) 1 to 15, 21 to 35, or 50 to 64, was investigated. Then, the same treatment was used to analyze S100B gene and protein levels at PD 90 (long-term effect).

RESULTS

At PD 90, a significant increase of gene and protein expression was observed in all regions if rats were treated during PDs 21-35, whereas treatment during other periods had no long-term effects. A short-term effect 24 hours after fluoxetine treatment was found for almost all development stages and regions, demonstrated by a significant increase of S100B.

CONCLUSIONS

These results support recent research indicating a highly drug-sensitive period (i.e., periadolescence) of rat brain development. Therefore, further clinical studies should be performed to clarify whether such a sensitive period also exists in children.

Olanzapine treatment of adolescent rats alters adult reward behaviour and nucleus accumbens function

Antipsychotic drugs are increasingly used in children and adolescents to treat a variety of psychiatric disorders. However, little is known about the long-term effects of early life antipsychotic drug (APD) treatment. Most APDs are potent antagonists or partial agonists of dopamine (DA) D₂ receptors; atypical APDs also have multiple serotonergic activities. DA and serotonin regulate many neurodevelopmental processes. Thus, early life APD treatment can, potentially, perturb these processes, causing long-term behavioural and neurobiological sequelae. We treated adolescent, male rats with olanzapine (Ola) on post-natal days 28-49, under dosing conditions that approximate those employed therapeutically in humans. As adults, they exhibited enhanced conditioned place preference for amphetamine, as compared to vehicle-treated rats. In the nucleus accumbens core, DA D₁ receptor binding was reduced, D₂ binding was increased and DA release evoked by electrical stimulation of the ventral tegmental area was reduced. Thus, adolescent Ola treatment enduringly alters a key behavioural response to rewarding stimuli and modifies DAergic neurotransmission in the nucleus accumbens. The persistence of these changes suggests that even limited periods of early life Ola treatment may induce enduring changes in other reward-related behaviours and in behavioural and neurobiological responses to therapeutic and illicit psychotropic drugs. These results underscore the importance of improved understanding of the enduring sequelae of paediatric APD treatment as a basis for weighing the benefits and risks of adolescent APD therapy, especially prophylactic treatment in high-risk, asymptomatic patients.

Updates on treatment of attention-deficit/hyperactivity disorder: facts, comments, and ethical considerations

OPINION STATEMENT

Within the last 2 years the bulk of information on evidence based treatments in ADHD was reviewed quite intensively and new empirical studies could be added. This update reports comprehensively about actual and essential facts in the field related to brain development and sensitive periods, predictors of treatment, safety of medication, value of naturalistic studies, new drugs and complementary medicine, behavioral interventions including neurofeedback and psychosocial treatment, treatment of comorbidity, and ethical considerations including preventive aspects. The updated combination of well selected evidence based treatments (ie, pharma plus non-pharma) seems to be clinically and ethically recommended as also suggested by the European and American guidelines on ADHD.

Experience and the developing prefrontal cortex

The prefrontal cortex (PFC) receives input from all other cortical regions and functions to plan and direct motor, cognitive, affective, and social behavior across time. It has a prolonged development, which allows the acquisition of complex cognitive abilities through experience but makes it susceptible to factors that can lead to abnormal functioning, which is often manifested in neuropsychiatric disorders. When the PFC is exposed to different environmental events during development, such as sensory stimuli, stress, drugs, hormones, and social experiences (including both parental and peer interactions), the developing PFC may develop in different ways. The goal of the current review is to illustrate how the circuitry of the developing PFC can be sculpted by a wide range of pre- and postnatal factors. We begin with an overview of prefrontal functioning and development, and we conclude with a consideration of how early experiences influence prefrontal development and behavior.

Preventive interventions for ADHD: a neurodevelopmental perspective

It is proposed that the time is ripe for the development of secondary preventive interventions for attention-deficit/hyperactivity disorder (ADHD). By targeting preschool children, a developmental stage during which ADHD symptoms first become evident in most children with the disorder, many of the adverse long-term consequences that typify the trajectory of ADHD may be avoided. A dynamic/interactive model of the biological and environmental factors that contribute to the emergence and persistence of ADHD throughout the lifespan is proposed. Based on this model, it is argued that environmental influences and physical exercise can be used to enhance neural growth and development, which in turn should have an enduring and long-term impact on the trajectory of ADHD. Central to this notion are 2 hypotheses: 1) environmental influences can facilitate structural and functional brain development, and 2) changes in brain structure and function are directly related to ADHD severity over the course of development and the degree to which the disorder persists or remits with time. We present experimental and correlational data supporting the first hypothesis and longitudinal data in individuals with ADHD supporting the second. The case is made for initiating such an intervention during the preschool years, when the brain is likely to be more "plastic" and perhaps susceptible to lasting modifications, and before complicating factors, such as comorbid psychiatric disorders, academic failure, and poor social and family relationships emerge, making successful treatment more difficult. Finally, we review recent studies in young children with ADHD that might fall under the umbrella of secondary prevention.

Antidepressants and adolescent brain development

Despite being a first-line treatment for adolescent depression and anxiety, antidepressant drugs appear to have questionable efficacy and carry an increased risk of adverse effects in this population. The neural mechanisms underlying this phenomenon are currently unknown. Recent research into the neural effects of alcohol and recreational drugs suggests that the developmental trajectory of the adolescent brain may be particularly vulnerable to pharmacological disturbance. It is therefore important to consider whether prescription psychotropic drugs may have analogous effects. This article reviews the contribution of recent preclinical, clinical and pharmacogenetic literature to current knowledge on the short-term and enduring neural effects of antidepressants on the adolescent brain, with a particular focus on the major neurotransmitter systems and neuroplasticity.

The science of brain and biological development: implications for mental health research, practice and policy

OBJECTIVE

This article provides a summary of the complex interaction between genetics and experience which shapes the development of neurobiological systems, particularly in the prenatal/early childhood and adolescent periods.

METHOD

Key factors that influence brain structure and function, and mechanisms through which experience impacts risk for mental health disorders presented in this Special Issue are linked with suggestions for future directions in child and youth mental health research, policy and practice.

RESULTS

SUGGESTED AREAS TO APPLY EVIDENCE PRESENTED IN THIS SPECIAL ISSUE INCLUDE: enhancing research in the differential impact of psychoactive drugs on the developing brain; introducing content on brain and biological development to professional development and post-secondary curriculum; increased involvement of the family in recognition, prevention and treatment of mental health disorders; and, creation of evidenced-informed child and youth mental health policies.

CONCLUSIONS

As more evidence accumulates on how early experience impacts the structure and function of the developing brain, these findings should be applied to how mental illness may be better prevented, recognized and treated in child and adolescent populations.