Upregulated GABA Inhibitory Function in ADHD Children with Child Behavior Checklist-Dysregulation Profile: 123I-Iomazenil SPECT Study

The child behavior checklist-dysregulation profile (CBCL-DP) refers to a pattern of elevated scores on the attention problems, aggression, and anxiety/depression subscales of the child behavior checklist. The aim of the present study was to investigate the potential role of GABA inhibitory neurons in children with attention deficit/hyperactivity disorder (ADHD) and dysregulation assessed with a dimensional measure. Brain single photon emission computed tomography (SPECT) was performed in 35 children with ADHD using 123I-iomazenil, which binds with high affinity to benzodiazepine receptors. Iomazenil binding activities were assessed with respect to the presence or absence of a threshold CBCL-DP (a score ≥210 for the sum of the three subscales: Attention Problems, Aggression, and Anxiety/Depression). We then attempted to identify which CBCL-DP subscale explained the most variance with respect to SPECT data, using "age," "sex," and "history of maltreatment" as covariates. Significantly higher iomazenil binding activity was seen in the posterior cingulate cortex (PCC) of ADHD children with a significant CBCL-DP. The Anxiety/Depression subscale on the CBCL had significant effects on higher iomazenil binding activity in the left superior frontal, middle frontal, and temporal regions, as well as in the PCC. The present brain SPECT findings suggest that GABAergic inhibitory neurons may play an important role in the neurobiology of the CBCL-DP, in children with ADHD.

Antidepressant use and body mass index change in overweight adolescents: a historical cohort study

OBJECTIVE

Given the limited empirical data on antidepressant use and weight change in children, we performed a historical cohort study to assess change in age- and sex-standardized body mass index associated with antidepressant use among overweight adolescents diagnosed with a depressive disorder.

METHODS

We systematically reviewed electronic medical records from a tertiary academic medical center and identified adolescents (age 13-18 years) who were overweight (body mass index >85th percentile) and had a depression diagnosis. Patients were seen from January 1, 2000, through January 1, 2010. Age- and sex-standardized body mass index scores were calculated at initiation of antidepressant medication and at the end of treatment. Unmedicated patients had baseline and final age- and sex-standardized body mass index calculated using the first and last recorded measurements in the study period (maximum time between measures was 5 years).

RESULTS

In total, 435 patients (301 female) met our inclusion criteria; of these, 255 were prescribed an antidepressant (selective serotonin reuptake inhibitor, serotonin norepinephrine reuptake inhibitor, tricyclic antidepressant, or dopamine-norepinephrine reuptake inhibitor). Age- and sex-standardized body mass index significantly increased (F1,193=14.34; P<0.001) only for adolescents treated with selective serotonin reuptake inhibitors. For patients receiving other medications or no medication, age- and sex-standardized body mass index did not change significantly.

CONCLUSION

This study provides initial empiric evidence for a link between selective serotonin reuptake inhibitor use and weight gain in already overweight adolescents. Further study of antidepressant use and weight gain in other pediatric populations and in prospective studies is warranted.

Developmental aspects of cortical excitability and inhibition in depressed and healthy youth: an exploratory study

Objectives: The objective of this post-hoc exploratory analysis was to examine the relationship between age and measures of cortical excitability and inhibition.

Methods: Forty-six participants (24 with major depressive disorder and 22 healthy controls) completed MT, SICI, ICF, and CSP testing in a cross-sectional protocol. Of these 46 participants, 33 completed LICI testing. Multiple linear robust regression and Spearman partial correlation coefficient were used to examine the relationship between age and the TMS measures.

Results: In the overall sample of 46 participants, age had a significant negative relationship with motor threshold (MT) in both the right (r_s = −0.49, adjusted p = 0.007; β = −0.08, adjusted p = 0.001) and left (r_s = −0.42, adjusted p = 0.029; β = −0.05, adjusted p = 0.004) hemispheres. This significant negative relationship of age with MT was also observed in the sample of depressed youth in both the right (r_s = −0.70, adjusted p = 0.002; β = −0.09, adjusted p = 0.001) and left (r_s = −0.54, adjusted p = 0.034; β = −0.05, adjusted p = 0.017) hemispheres, but not in healthy controls. In the sample of the 33 participants who completed LICI testing, age had a significant negative relationship with LICI (200 ms interval) in both the right (r_s = −0.48, adjusted p = 0.05; β = −0.24, adjusted p = 0.007) and left (r_s = −0.64, adjusted p = 0.002; β = −0.23, adjusted p = 0.001) hemispheres. This negative relationship between age and LICI (200 ms interval) was also observed in depressed youth in both the right (r_s = −0.76, adjusted p = 0.034; β = −0.35, adjusted p = 0.004) and left (r_s = −0.92, adjusted p = 0.002; β = −0.25, adjusted p = 0.001) hemispheres.

Conclusion: These findings suggest that younger children have higher MTs. This is more pronounced in depressed youth than healthy controls. LICI inhibition may also increase with age in youth.

An electronic health record driven algorithm to identify incident antidepressant medication users

OBJECTIVE

We validated an algorithm designed to identify new or prevalent users of antidepressant medications via population-based drug prescription records.

PATIENTS AND METHODS

We obtained population-based drug prescription records for the entire Olmsted County, Minnesota, population from 2011 to 2012 (N=149,629) using the existing electronic medical records linkage infrastructure of the Rochester Epidemiology Project (REP). We selected electronically a random sample of 200 new antidepressant users stratified by age and sex. The algorithm required the exclusion of antidepressant use in the 6 months preceding the date of the first qualifying antidepressant prescription (index date). Medical records were manually reviewed and adjudicated to calculate the positive predictive value (PPV). We also manually reviewed the records of a random sample of 200 antihistamine users who did not meet the case definition of new antidepressant user to estimate the negative predictive value (NPV).

RESULTS

161 of the 198 subjects electronically identified as new antidepressant users were confirmed by manual record review (PPV 81.3%). Restricting the definition of new users to subjects who were prescribed typical starting doses of each agent for treating major depression in non-geriatric adults resulted in an increase in the PPV (90.9%). Extending the time windows with no antidepressant use preceding the index date resulted in only modest increases in PPV. The manual abstraction of medical records of 200 antihistamine users yielded an NPV of 98.5%.

CONCLUSIONS

Our study confirms that REP prescription records can be used to identify prevalent and incident users of antidepressants in the Olmsted County, Minnesota, population.

Magnetic seizure therapy in an adolescent with refractory bipolar depression: a case report

Magnetic seizure therapy (MST) has shown efficacy in adult patients with treatment-resistant depression with limited impairment in memory. To date, the use of MST in adolescent depression has not been reported. Here we describe the first successful use of MST in the treatment of an adolescent patient with refractory bipolar depression. This patient received MST in an ongoing open-label study for treatment-resistant major depression. Treatments employed a twin-coil MST apparatus, with the center of each coil placed over the frontal cortex (ie, each coil centered over F3 and F4). MST was applied at 100 Hz and 100% machine output at progressively increasing train durations. Depressive symptoms were assessed using the 24-item Hamilton Depression Rating Scale and cognitive function was assessed with a comprehensive neuropsychological battery. This adolescent patient achieved full remission of clinical symptoms after an acute course of 18 MST treatments and had no apparent cognitive decline, other than some autobiographical memory impairment that may or may not be related to the MST treatment. This case report suggests that MST may be a safe and well tolerated intervention for adolescents with treatment-resistant bipolar depression. Pilot studies to further evaluate the effectiveness and safety of MST in adolescents warrant consideration.

Evidence for increased glutamatergic cortical facilitation in children and adolescents with major depressive disorder

CONTEXT

Converging lines of evidence implicate the glutamate and γ-aminobutyric acid neurotransmitter systems in the pathophysiology of major depressive disorder. Transcranial magnetic stimulation cortical excitability and inhibition paradigms have been used to assess cortical glutamatergic and γ-aminobutyric acid-mediated tone in adults with major depressive disorder, but not in children and adolescents.

OBJECTIVE

To compare measures of cortical excitability and inhibition with 4 different paradigms in a group of children and adolescents with major depressive disorder vs healthy controls.

DESIGN

Cross-sectional study examining medication-free children and adolescents (aged 9-17 years) with major depressive disorder compared with healthy controls. Cortical excitability was assessed with motor threshold and intracortical facilitation measures. Cortical inhibition was measured with cortical silent period and intracortical inhibition paradigms.

SETTING

University-based child and adolescent psychiatry clinic and neurostimulation laboratory.

PATIENTS

Twenty-four participants with major depressive disorder and 22 healthy controls matched for age and sex. Patients with major depressive disorder were medication naive and had moderate to severe symptoms based on an evaluation with a child and adolescent psychiatrist and scores on the Children's Depression Rating Scale-Revised.

MAIN OUTCOME MEASURES

Motor threshold, intracortical facilitation, cortical silent period, and intracortical inhibition.

RESULTS

Compared with healthy controls, depressed patients had significantly increased intracortical facilitation at interstimulus intervals of 10 and 15 milliseconds bilaterally. There were no significant group differences in cortical inhibition measures.

CONCLUSIONS

These findings suggest that major depressive disorder in children and adolescents is associated with increased intracortical facilitation and excessive glutamatergic activity.

Neurocognitive effects of repetitive transcranial magnetic stimulation in adolescents with major depressive disorder

OBJECTIVES

It is estimated that 30-40% of adolescents with major depressive disorder (MDD) do not receive full benefit from current antidepressant therapies. Repetitive transcranial magnetic stimulation (rTMS) is a novel therapy approved by the US Food and Drug Administration to treat adults with MDD. Research suggests rTMS is not associated with adverse neurocognitive effects in adult populations; however, there is no documentation of its neurocognitive effects in adolescents. This is a secondary post hoc analysis of neurocognitive outcome in adolescents who were treated with open-label rTMS in two separate studies.

METHODS

Eighteen patients (mean age, 16.2 ± 1.1 years; 11 females, 7 males) with MDD who failed to adequately respond to at least one antidepressant agent were enrolled in the study. Fourteen patients completed all 30 rTMS treatments (5 days/week, 120% of motor threshold, 10 Hz, 3,000 stimulations per session) applied to the left dorsolateral prefrontal cortex. Depression was rated using the Children's Depression Rating Scale-Revised. Neurocognitive evaluation was performed at baseline and after completion of 30 rTMS treatments with the Children's Auditory Verbal Learning Test (CAVLT) and Delis-Kaplan Executive Function System Trail Making Test.

RESULTS

Over the course of 30 rTMS treatments, adolescents showed a substantial decrease in depression severity. Commensurate with improvement in depressive symptoms was a statistically significant improvement in memory and delayed verbal recall. Other learning and memory indices and executive function remained intact. Neither participants nor their family members reported clinically meaningful changes in neurocognitive function.

CONCLUSION

These preliminary findings suggest rTMS does not adversely impact neurocognitive functioning in adolescents and may provide subtle enhancement of verbal memory as measured by the CAVLT. Further controlled investigations with larger sample sizes and rigorous trial designs are warranted to confirm and extend these findings.

Test-retest assessment of cortical activation induced by repetitive transcranial magnetic stimulation with brain atlas-guided optical topography

Repetitive transcranial magnetic stimulation (rTMS) is a technology that stimulates neurons with rapidly changing magnetic pulses with demonstrated therapeutic applications for various neuropsychiatric disorders. Functional near-infrared spectroscopy (fNIRS) is a suitable tool to assess rTMS-evoked brain responses without interference from the magnetic or electric fields generated by the TMS coil. We have previously reported a channel-wise study of combined rTMS/fNIRS on the motor and prefrontal cortices, showing a robust decrease of oxygenated hemoglobin concentration (Δ[HbO2]) at the sites of 1-Hz rTMS and the contralateral brain regions. However, the reliability of this putative clinical tool is unknown. In this study, we develop a rapid optical topography approach to spatially characterize the rTMS-evoked hemodynamic responses on a standard brain atlas. A hemispherical approximation of the brain is employed to convert the three-dimensional topography on the complex brain surface to a two-dimensional topography in the spherical coordinate system. The test-retest reliability of the combined rTMS/fNIRS is assessed using repeated measurements performed two to three days apart. The results demonstrate that the Δ[HbO2] amplitudes have moderate-to-high reliability at the group level; and the spatial patterns of the topographic images have high reproducibility in size and a moderate degree of overlap at the individual level.

Psychiatric pharmacogenomics in pediatric psychopharmacology

This article provides an overview of where psychiatric pharmacogenomic testing stands as an emerging clinical tool in modern psychotropic prescribing practice, specifically in the pediatric population. This practical discussion is organized around the state of psychiatric pharmacogenomics research when choosing psychopharmacologic interventions in the most commonly encountered mental illnesses in youth. As with the rest of the topics on psychopharmacology for children and adolescents in this publication, a clinical vignette is presented, this one highlighting a clinical case of a 16 year old genotyped during hospitalization for recalcitrant depression.

Increased cortical excitability with prefrontal high-frequency repetitive transcranial magnetic stimulation in adolescents with treatment-resistant major depressive disorder

OBJECTIVE

To examine changes in motor cortical excitability in adolescent subjects receiving 30 sessions of high-frequency prefrontal repetitive transcranial magnetic stimulation (rTMS).

METHODS

Eight adolescents with treatment-resistant major depressive disorder (MDD) enrolled in an open augmentation trial of 10 Hz rTMS. Resting motor thresholds were obtained by the visualization of movement method with a maximum likelihood threshold hunting computer algorithm at baseline and after every five sessions of rTMS. Motor threshold was recorded as the percentage of total machine output at each measurement.

RESULTS

Motor threshold data from baseline, weeks 2, 4, and 5 were included in a mixed model repeated measure analysis to examine a change in least square mean effect over time. The omnibus effect did not reach statistical significance (F=1.25, p=0.32). However, multiple comparisons from the overall model demonstrated a decrease in the least square mean motor threshold. The mean contrast from baseline to week 5 approached significance (p=0.07). Moreover, a post-hoc analysis with a Wilcoxon signed ranks test demonstrated a significant decrease at week 5 (p=0.03).

CONCLUSIONS

This suggests that high-frequency rTMS may increase cortical excitability in adolescents with treatment-resistant MDD.

Applications of transcranial magnetic stimulation (TMS) in child and adolescent psychiatry

Transcranial magnetic stimulation (TMS) is emerging as a new treatment and neurophysiological research tool for psychiatric disorders. Recent publications suggest that this modality will also serve as a treatment and research tool in child and adolescent psychiatry. Current reports on therapeutic trials of repetitive transcranial magnetic stimulation (rTMS) in adolescents have primarily focused on depression. However, other pilot work involves the treatment of attention-deficit/hyperactivity disorder (ADHD), autism and schizophrenia. Neurophysiological studies typically utilize single and paired-pulse TMS paradigms which index cortical excitability and inhibition. Initial studies have focused on ADHD, autism, and depression. General knowledge regarding TMS among child and adolescent psychiatrists is lacking. The aim of this review is to provide an overview of TMS in the context of child and adolescent psychiatry, discuss recent therapeutic and neurophysiological studies, and examine relevant ethical considerations.

Adjunctive use of repetitive transcranial magnetic stimulation in depressed adolescents: a prospective, open pilot study

OBJECTIVE

Depression is often a serious and debilitating illness in adolescents. Unfortunately, a significant number of adolescents do not respond to antidepressant medications or psychotherapy. Repetitive transcranial magnetic stimulation (rTMS) is a novel treatment intervention shown to benefit depression in adults. This study considered rTMS as an adjunctive treatment in adolescents with major depressive disorder.

METHOD

This prospective, open, multicenter trial of active adjunctive rTMS was conducted with 8 adolescents with DSM-IV-TR major depressive disorder (MDD) that had not responded sufficiently to 2 adequate antidepressant medication trials. All subjects were maintained on a stable dose of a selective serotonin reuptake inhibitor during the trial. Thirty daily rTMS treatments were given 5 days per week over 6 to 8 weeks. rTMS was applied to the left dorsolateral prefrontal cortex (120% of motor threshold; 10 Hz; 4-second trains; 26-second intertrain interval; 75 trains) for a total of 3,000 stimulations per treatment session.

RESULTS

Seven of 8 adolescents completed all 30 treatments. rTMS was well tolerated, and no significant safety issues were identified. Suicidal ideation was present at baseline in 3 of the adolescents, and it improved during treatment. The primary outcome measure was the Children's Depression Rating Scale-Revised (CDRS-R); results improved significantly from baseline (mean [SD]) (65.9 [6.6]) to treatment 10 (50.9 [12]), P < .02. The CDRS-R scores continued to improve through the rTMS treatment series at treatment 20 (40.1 [14]), P < .01; treatment 30 (32.6 [7.3]), P < .0001; and at 6-month follow-up (32.7 [3.8]), P < .0001.

CONCLUSIONS

This prospective open trial suggests that rTMS is a safe, feasible, and potentially effective adjunctive therapy for treatment-resistant MDD in adolescents.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00587639.

Psychomotor retardation in depression: biological underpinnings, measurement, and treatment

Psychomotor retardation is a long established component of depression that can have significant clinical and therapeutic implications for treatment. Due to its negative impact on overall function in depressed patients, we review its biological correlates, optimal methods of measurement, and relevance in the context of therapeutic interventions. The aim of the paper is to provide a synthesis of the literature on psychomotor retardation in depression with the goal of enhanced awareness for clinicians and researchers. Increased knowledge and understanding of psychomotor retardation in major depressive disorder may lead to further research and better informed diagnosis in regards to psychomotor retardation. Manifestations of psychomotor retardation include slowed speech, decreased movement, and impaired cognitive function. It is common in patients with melancholic depression and those with psychotic features. Biological correlates may include abnormalities in the basal ganglia and dopaminergic pathways. Neurophysiologic tools such as neuroimaging and transcranial magnetic stimulation may play a role in the study of this symptom in the future. At present, there are three objective scales to evaluate psychomotor retardation severity. Studies examining the impact of psychomotor retardation on clinical outcome have found differential results. However, available evidence suggests that depressed patients with psychomotor retardation may respond well to electroconvulsive therapy (ECT). Current literature regarding antidepressants is inconclusive, though tricyclic antidepressants may be considered for treatment of patients with psychomotor retardation. Future work examining this objective aspect of major depressive disorder (MDD) is essential. This could further elucidate the biological underpinnings of depression and optimize its treatment.

Functional connectivity of brain structures correlates with treatment outcome in major depressive disorder

Identifying biosignatures to assess the probability of response to an antidepressant for patients with major depressive disorder (MDD) is critically needed. Functional connectivity MRI (fcMRI) offers the promise to provide such a measure. Previous work with fcMRI demonstrated that the correlation in signal from one region to another is a measure of functional connectivity. In this pilot work, a baseline non-task fcMRI was acquired in 14 adults with MDD who were free of all medications. Participants were then treated for 8 weeks with an antidepressant and then clinically re-evaluated. Probabilistic anatomic regions of interest (ROI) were defined for 16 brain regions (eight for each hemisphere) previously identified as being important in mood disorders. These ROIs were used to determine mean time courses for each individual's baseline non-task fcMRI. The correlations in time courses between 16 brain regions were calculated. These calculated correlations were considered to signify measures of functional connectivity. The degree of connectivity for each participant was correlated with treatment outcome. Among 13 participants with 8 weeks follow-up data, connectivity measures in several regions, especially the subcallosal cortex, were highly correlated with treatment outcome. These connectivity measures could provide a means to evaluate how likely a patient is to respond to an antidepressant treatment. Further work using larger samples is required to confirm these findings and to assess if measures of functional connectivity can be used to predict differential outcomes between antidepressant treatments.

Emerging treatment options in bipolar disorderin adolescents: focus on ziprasidone

Bipolar disorder is a debilitating, and chronic condition in adolescents. The rate of diagnosis and treatment is increasing in adolescents despite considerable controversy regarding criteria for diagnosis. Atypical antipsychotics have been studied extensively for adult and adolescent bipolar disorder. Ziprasidone is an atypical neuroleptic with novel receptor-binding activity and a favorable side effect profile. It has been marketed in the US since 2000, and now has several indications approved by the US Food and Drug Administration. Emerging case reports, open-label studies, and randomized controlled trials suggest that it may have a role in the management of adolescent bipolar disorder. Somnolence, akathisia, tachycardia, and prolonged corrected QT intervals are major safety concerns. There are no definitive guidelines for dosing ziprasidone in adolescents based on current literature. However, optimal treatment may involve dosages near the adult range. Given minimal data and understanding of its effects on cardiac conduction, it might be prudent to obtain electrocardiograms prior to initiation and during treatment. While not a first-line medication choice for adolescents struggling with bipolar disorder, it may be considered in certain situations in which metabolic side effects and weight gain are of concern.

Using simultaneous repetitive Transcranial Magnetic Stimulation/functional Near Infrared Spectroscopy (rTMS/fNIRS) to measure brain activation and connectivity

INTRODUCTION

Simultaneously acquiring functional Near Infrared Spectroscopy (fNIRS) during Transcranial Magnetic Stimulation (rTMS) offers the possibility of directly investigating superficial cortical brain activation and connectivity. In addition, the effects of rTMS in distinct brain regions without quantifiable behavioral changes can be objectively measured.

METHODS

Healthy, nonmedicated participants age 18-50 years were recruited from the local community. After written informed consent was obtained, the participants were screened to ensure that they met inclusion criteria. They underwent two visits of simultaneous rTMS/fNIRS separated by 2 to 3 days. In each visit, the motor cortex and subsequently the prefrontal cortex (5 cm anterior to the motor cortex) were stimulated (1 Hz, max 120% MT, 10 s on with 80 s off, for 15 trains) while simultaneous fNIRS data were acquired from the ipsilateral and contralateral brain regions.

RESULTS

Twelve healthy volunteers were enrolled with one excluded prior to stimulation. The 11 participants studied (9 male) had a mean age of 31.8 (s.d. 10.2, range 20-49) years. There was no significant difference in fNIRS between Visit 1 and Visit 2. Stimulation of both the motor and prefrontal cortices resulted in a significant decrease in oxygenated hemoglobin (HbO(2)) concentration in both the ipsilateral and contralateral cortices. The ipsilateral and contralateral changes showed high temporal consistency.

DISCUSSION

Simultaneous rTMS/fNIRS provides a reliable measure of regional cortical brain activation and connectivity that could be very useful in studying brain disorders as well as cortical changes induced by rTMS.

Neuroleptic malignant syndrome associated with atypical antipsychotics in pediatric patients: a review of published cases

OBJECTIVE

To retrospectively examine published cases of neuroleptic malignant syndrome (NMS) in patients aged 18 and below who had been treated with atypical antipsychotics (clozapine, risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole).

DATA SOURCES

Information was collected via MEDLINE searches in February 2006 and May 2007. The term neuroleptic malignant syndrome was used and cross-referenced with individual atypical antipsychotics. The authors also contacted (by telephone and in writing) pharmaceutical companies that produce and market atypical antipsychotics for any data on NMS.

STUDY SELECTION

Twenty case reports (written in English only and published from 1991-2007) were identified and reviewed. These publications all described symptoms of NMS in patients aged 18 or younger who had been treated with atypical antipsychotics.

DATA EXTRACTION

Data were reviewed and compared with 3 diagnostic criteria (DSM-IV-TR, Levenson's, and Caroff and Mann's) for NMS. Interventions and outcomes were also reviewed.

DATA SYNTHESIS

Twenty case reports were identified and presented with a descriptive approach. Sixteen cases met criteria for NMS, with at least 1 of the diagnostic sets utilized. The majority of cases involved male subjects. All patients recovered.

CONCLUSIONS

Young patients can develop NMS during treatment with atypical antipsychotics. Symptoms of this disorder are consistent with those described in adults. Although NMS is rare in this population, clinicians should maintain a high index of suspicion. Appropriate caution in treating children and adolescents with any antipsychotic is warranted.