Antidepressant exposure as a predictor of clinical outcomes in the Treatment of Resistant Depression in Adolescents (TORDIA) study

Machine Learning-Based Prediction of Escitalopram and Sertraline Side Effects With Pharmacokinetic Data in Children and Adolescents

Selective serotonin reuptake inhibitors (SSRI) are the first-line pharmacologic treatment for anxiety and depressive disorders in children and adolescents. Many patients experience side effects that are difficult to predict, are associated with significant morbidity, and can lead to treatment discontinuation. Variation in SSRI pharmacokinetics could explain differences in treatment outcomes, but this is often overlooked as a contributing factor to SSRI tolerability. This study evaluated data from 288 escitalopram-treated and 255 sertraline-treated patients ≤ 18 years old to develop machine learning models to predict side effects using electronic health record data and Bayesian estimated pharmacokinetic parameters. Trained on a combined cohort of escitalopram- and sertraline-treated patients, a penalized logistic regression model achieved an area under the receiver operating characteristic curve (AUROC) of 0.77 (95% confidence interval (CI): 0.66-0.88), with 0.69 sensitivity (95% CI: 0.54-0.86), and 0.82 specificity (95% CI: 0.72-0.87). Medication exposure, clearance, and time since the last dose increase were among the top features. Individual escitalopram and sertraline models yielded an AUROC of 0.73 (95% CI: 0.65-0.81) and 0.64 (95% CI: 0.55-0.73), respectively. Post hoc analysis showed sertraline-treated patients with activation side effects had slower clearance (P = 0.01), which attenuated after accounting for age (P = 0.055). These findings raise the possibility that a machine learning approach leveraging pharmacokinetic data can predict escitalopram- and sertraline-related side effects. Clinicians may consider differences in medication pharmacokinetics, especially during dose titration and as opposed to relying on dose, when managing side effects. With further validation, application of this model to predict side effects may enhance SSRI precision dosing strategies in youth.

Physiologically Based Pharmacokinetic Modeling to Unravel the Drug-gene Interactions of Venlafaxine: Based on Activity Score-dependent Metabolism by CYP2D6 and CYP2C19 Polymorphisms

BACKGROUND

Venlafaxine (VEN) is a commonly utilized medication for alleviating depression and anxiety disorders. The presence of genetic polymorphisms gives rise to considerable variations in plasma concentrations across different phenotypes. This divergence in phenotypic responses leads to notable differences in both the efficacy and tolerance of the drug.

PURPOSE

A physiologically based pharmacokinetic (PBPK) model for VEN and its metabolite O-desmethylvenlafaxine (ODV) to predict the impact of CYP2D6 and CYP2C19 gene polymorphisms on VEN pharmacokinetics (PK).

METHODS

The parent-metabolite PBPK models for VEN and ODV were developed using PK-Sim® and MoBi®. Leveraging prior research, derived and implemented CYP2D6 and CYP2C19 activity score (AS)-dependent metabolism to simulate exposure in the drug-gene interactions (DGIs) scenarios. The model's performance was evaluated by comparing predicted and observed values of plasma concentration-time (PCT) curves and PK parameters values.

RESULTS

In the base models, 91.1%, 94.8%, and 94.6% of the predicted plasma concentrations for VEN, ODV, and VEN + ODV, respectively, fell within a twofold error range of the corresponding observed concentrations. For DGI scenarios, these values were 81.4% and 85% for VEN and ODV, respectively. Comparing CYP2D6 AS = 2 (normal metabolizers, NM) populations to AS = 0 (poor metabolizers, PM), 0.25, 0.5, 0.75, 1.0 (intermediate metabolizers, IM), 1.25, 1.5 (NM), and 3.0 (ultrarapid metabolizers, UM) populations in CYP2C19 AS = 2.0 group, the predicted DGI AUC0-96 h ratios for VEN were 3.65, 3.09, 2.60, 2.18, 1.84, 1.56, 1.34, 0.61, and for ODV, they were 0.17, 0.35, 0.51, 0.64, 0.75, 0.83, 0.90, 1.11, and the results were similar in other CYP2C19 groups. It should be noted that PK differences in CYP2C19 phenotypes were not similar across different CYP2D6 groups.

CONCLUSIONS

In clinical practice, the impact of genotyping on the in vivo disposition process of VEN should be considered to ensure the safety and efficacy of treatment.

Venlafaxine's therapeutic reference range in the treatment of depression revised: a systematic review and meta-analysis

INTRODUCTION

The selective serotonin and norepinephrine reuptake inhibitor venlafaxine is among the most prescribed antidepressant drugs worldwide and, according to guidelines, its dose titration should be guided by drug-level monitoring of its active moiety (AM) which consists of venlafaxine (VEN) plus active metabolite O-desmethylvenlafaxine (ODV). This indication of therapeutic drug monitoring (TDM), however, assumes a clear concentration/effect relationship for a drug, which for VEN has not been systematically explored yet.

OBJECTIVES

We performed a systematic review and meta-analysis to investigate the relationship between blood levels, efficacy, and adverse reactions in order to suggest an optimal target concentration range for VEN oral formulations for the treatment of depression.

METHODS

Four databases (MEDLINE (PubMed), PsycINFO, Web of Science Core Collection, and Cochrane Library) were systematically searched in March 2022 for relevant articles according to a previously published protocol. Reviewers independently screened references and performed data extraction and critical appraisal.

RESULTS

High-quality randomized controlled trials investigating concentration/efficacy relationships and studies using a placebo lead-in phase were not found. Sixty-eight articles, consisting mostly of naturalistic TDM studies or small noncontrolled studies, met the eligibility criteria. Of them, five cohort studies reported a positive correlation between blood levels and antidepressant effects after VEN treatment. Our meta-analyses showed (i) higher AM and (ii) higher ODV concentrations in patients responding to VEN treatment when compared to non-responders (n = 360, k = 5). AM concentration-dependent occurrence of tremor was reported in one study. We found a linear relationship between daily dose and AM concentration within guideline recommended doses (75-225 mg/day). The population-based concentration ranges (25-75% interquartile) among 11 studies (n = 3200) using flexible dosing were (i) 225-450 ng/ml for the AM and (ii) 144-302 ng/ml for ODV. One PET study reported an occupancy of 80% serotonin transporters for ODV serum levels above 85 ng/ml. Based on our findings, we propose a therapeutic reference range for AM of 140-600 ng/ml.

CONCLUSION

VEN TDM within a range of 140 to 600 ng/ml (AM) will increase the probability of response in nonresponders. A titration within the proposed reference range is recommended in case of non-response at lower drug concentrations as a consequence of VEN's dual mechanism of action via combined serotonin and norepinephrine reuptake inhibition. Drug titration towards higher concentrations will, however, increase the risk for ADRs, in particular with supratherapeutic drug concentrations.

Escitalopram and Sertraline Population Pharmacokinetic Analysis in Pediatric Patients

BACKGROUND AND OBJECTIVE

Escitalopram and sertraline are commonly prescribed for anxiety and depressive disorders in children and adolescents. The pharmacokinetics (PK) of these medications have been evaluated in adults and demonstrate extensive variability, but studies in pediatric patients are limited. Therefore, we performed a population PK analysis for escitalopram and sertraline in children and adolescents to characterize the effects of demographic, clinical, and pharmacogenetic factors on drug exposure.

METHODS

A PK dataset was generated by extracting data from the electronic health record and opportunistic sampling of escitalopram- and sertraline-treated psychiatrically hospitalized pediatric patients aged 5-18 years. A population PK analysis of escitalopram and sertraline was performed using NONMEM. Concentration-time profiles were simulated using MwPharm++ to evaluate how covariates included in the final models influence medication exposure and compared to adult therapeutic reference ranges.

RESULTS

The final escitalopram cohort consisted of 315 samples from 288 patients, and the sertraline cohort consisted of 265 samples from 255 patients. A one-compartment model with a proportional residual error model best described the data for both medications. For escitalopram, CYP2C19 phenotype and concomitant CYP2C19 inhibitors affected apparent clearance (CL/F), and normalizing CL/F and apparent volume of distribution (V/F) to body surface area (BSA) improved estimations. The final escitalopram model estimated CL/F and V/F at 14.2 L/h/1.73 m2 and 428 L/1.73 m2, respectively. For sertraline, CYP2C19 phenotype and concomitant CYP2C19 inhibitors influenced CL/F, and empirical allometric scaling of patient body weight on CL/F and V/F was significant. The final sertraline model estimated CL/F and V/F at 124 L/h/70 kg and 4320 L/70 kg, respectively. Normalized trough concentrations (Ctrough) for CYP2C19 poor metabolizers taking escitalopram were 3.98-fold higher compared to normal metabolizers (151.1 ng/mL vs 38.0 ng/mL, p < 0.0001), and normalized Ctrough for CYP2C19 poor metabolizers taking sertraline were 3.23-fold higher compared to normal, rapid, and ultrarapid metabolizers combined (121.7 ng/mL vs 37.68 ng/mL, p < 0.0001). Escitalopram- and sertraline-treated poor metabolizers may benefit from a dose reduction of 50-75% and 25-50%, respectively, to normalize exposure to other phenotypes.

CONCLUSION

To our knowledge, this is the largest population PK analysis of escitalopram and sertraline in pediatric patients. Significant PK variability for both medications was observed and was largely explained by CYP2C19 phenotype. Slower CYP2C19 metabolizers taking escitalopram or sertraline may benefit from dose reductions given increased exposure.

Therapeutic Drug Monitoring in Children and Adolescents: Findings on Fluoxetine from the TDM-VIGIL Trial

Fluoxetine is the recommended first-line antidepressant in many therapeutic guidelines for children and adolescents. However, little is known about the relationships between drug dose and serum level as well as the therapeutic serum reference range in this age group. Within a large naturalistic observational prospective multicenter clinical trial ("TDM-VIGIL"), a transdiagnostic sample of children and adolescents (n = 138; mean age, 15; range, 7-18 years; 24.6% males) was treated with fluoxetine (10-40 mg/day). Analyses of both the last timepoint and all timepoints (n = 292 observations), utilizing (multiple) linear regressions, linear mixed-effect models, and cumulative link (mixed) models, were used to test the associations between dose, serum concentration, outcome, and potential predictors. The receiver operating curve and first to third interquartile methods, respectively, were used to examine concentration cutoff and reference values for responders. A strong positive relationship was found between dose and serum concentration of fluoxetine and its metabolite. Higher body weight was associated with lower serum concentrations, and female sex was associated with lower therapeutic response. The preliminary reference ranges for the active moiety (fluoxetine+norfluoxetine) were 208-328 ng/mL (transdiagnostically) and 201.5-306 ng/mL (depression). Most patients showed marked (45.6%) or minimal (43.5%) improvements and reported no adverse effects (64.9%). This study demonstrated a clear linear dose-serum level relationship for fluoxetine in youth, with the identified reference range being within that established for adults.

What Is the Added Benefit of Combining Cognitive Behavioral Therapy and Selective Serotonin Reuptake Inhibitors in Youth with Obsessive Compulsive Disorder? A Bayesian Hierarchical Modeling Meta-Analysis

Background: Treatment of obsessive-compulsive disorder (OCD) in children and adolescents frequently involves cognitive behavioral therapy (CBT), selective serotonin reuptake inhibitors (SSRIs), or their combination. However, how adding CBT to SSRIs affects the trajectory and magnitude of improvement has not been evaluated meta-analytically. Methods: We performed a meta-analysis using weekly data from prospective randomized parallel group trials of CBT and SSRIs in pediatric patients with OCD. Response was modeled for the change in the Child Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) using a Bayesian hierarchical model over 12 weeks. Results: Fourteen studies included pharmacotherapy arms, 4 studies included combined pharmacotherapy and psychotherapy, and 10 studies included a placebo or control arm. The studies included 1146 patients (mean age 12.7 ± 1.3 years, mean 42.1% female). In the logarithmic model of response, statistically significant differences in treatment effects for CBT+SSRI and SSRI monotherapy were observed compared with placebo (SSRI β = -3.59, credible interval [95% CrI]: -4.13 to -3.02, p < 0.001; SSRI+CBT β = -4.07, 95% CrI: -5.05 to -3.04, p < 0.001). Adding CBT to an SSRI produced numerically (but not statistically significantly) greater improvement over 12 weeks. Greater improvement was observed in studies with more boys (p < 0.001), younger patients (p < 0.001), and in studies with greater baseline symptom severity (p < 0.001). Conclusions: In children and adolescents with OCD, compared with placebo, both SSRIs and SSRI+CBT produced early and sustained improvement over 12 weeks, although the improvement was also related to sample characteristics. Longer term studies are needed to determine when the additive benefit of CBT emerges relative to SSRI monotherapy.

Treatment-resistant depression in children and adolescents

Major depressive disorder (MDD) in children and adolescents is a significant health problem, causing profound impairments in social, academic, and family functioning and substantial morbidity and mortality. Up to 15% of children and adolescents suffer from MDD, and a proportion, around 30 to 40% of them, failed to respond to initial selective serotonin reuptake inhibitor (SSRI) treatment. The only evidence-based recommendation is medication switching to another SSRI and augmentation with cognitive behavioral therapy. Newly developing treatment, including ketamine, transcranial magnetic stimulation, psychotherapy other than cognitive behavioral therapy, and combined pharmacotherapy with other interventions, requires further longitudinal controlled trials regarding efficacy and safety in this vulnerable population.

A National Retrospective Study of Antidepressants' Effects on Overdose and Self-Harm Among Adults Treated With Opioid Analgesics

OBJECTIVE

Because individuals with a history of depression who are receiving opioids are at higher risk for adverse events, the authors examined whether antidepressant treatment reduces risk for overdose and self-harm among individuals with a history of depression who receive opioids.

METHODS

Commercial insurance claims of individuals with a history of depression receiving opioids from 2007 to 2017 were used to quantify the association between antidepressant fills and adverse events among individuals after initiation of opioid treatment; the authors accounted for selection into treatment and used discrete-time, proportional hazards survival models.

RESULTS

Among 283,374 adults with a history of depression treatment, 8,203 experienced 47,486 adverse events from 2007 to 2017 in the 12 months after initiation of opioid treatment. Approximately half (N=144,052, 50.8%) filled an antidepressant prescription at least once in the 12 months after the opioid episode began. Individuals receiving antidepressants for at least 6 weeks had a reduced risk for any adverse event (adjusted odds ratio [AOR]=0.79, 95% confidence interval [CI]=0.65-0.97) as well as a reduced risk for opioid overdoses (AOR=0.78, 95% CI=0.64-0.96), overdoses from nonopioid controlled substances (AOR=0.76, 95% CI=0.62-0.94), overdoses from other substances (AOR=0.79, 95% CI=0.65-0.97), and other self-harm events (AOR=0.82, 95% CI=0.67-1.00).

CONCLUSIONS

Individuals with a history of depression who received opioid analgesics had a significantly lower risk for overdose and self-harm after they had been taking antidepressants for at least 6 weeks. Universal screening for mood disorders among individuals receiving opioids, and promptly providing evidence-based depression treatment when appropriate, may reduce adverse events.

Toward therapeutic drug monitoring of citalopram in depression? Insights from a systematic review

Background

Within the framework of individualized psychopharmacotherapy, therapeutic drug monitoring (TDM) has gained increasing relevance. In the absence of high-quality evidence, the TDM of citalopram (CIT) and the recommended therapeutic ranges of the plasma concentrations have been proposed by guidelines. However, the correlation between the plasma concentration of CIT and treatment outcomes has not been well established. Therefore, the aim of this systematic review was to evaluate the relationship between plasma CIT concentration and treatment outcomes in depression.

Research design and methods

PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Chinese databases (CNKI, Wanfang Data and Sinomed) were searched up to August 6, 2022. We included clinical studies evaluating the correlation between the plasma CIT concentration and treatment outcomes in patients with depression receiving CIT treatment. Outcomes measured included efficacy, safety, medication adherence, and cost-related outcomes. A narrative synthesis was performed to summarize findings from individual studies. This study was performed according to the Preferred Reporting Items for Systematic Reviews, Meta-Analysis (PRISMA) and the reporting guideline for Synthesis without meta-analysis (SWiM).

Results

Eleven studies involving 538 patients were included in total. The reported outcomes were mainly efficacy (n = 11) and safety (n = 3); one study reported the duration of hospitalization, and no study reported medication adherence. Regarding the efficacy outcomes, three studies revealed the plasma CIT concentration-response relationship and proposed a lower limit of 50 or 53 ng/mL, whereas this was not found in the rest of the studies. Regarding adverse drug events (ADEs), one study reported more ADEs in the low-concentration group (<50 ng/mL vs. >50 ng/mL), which is not convincing from the perspective of pharmacokinetics/pharmacodynamics. Regarding the cost-related outcomes, only one study reported that the high CIT concentration group (≥50 ng/mL) contributed to shortening the hospitalization duration, but it did not provide detailed information, including direct medical expenses and multiple potential factors contributing to longer hospital stays.

Conclusions

A definite correlation between plasma concentration and clinical or cost-related outcomes of CIT cannot be drawn, whereas a tendency toward improved efficacy in patients with plasma concentration above 50 or 53 ng/mL was suggestive from limited evidence.

Pediatric Psychopharmacology for Depressive and Anxiety Disorders

Anxiety and depressive disorders are the most common psychiatric illnesses among children and adolescents. These disorders are associated with impairments in social, family, and educational functioning. This article summarizes the evidence base for psychopharmacologic interventions; the developmental pharmacology of selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs); and pharmacokinetic and pharmacodynamic differences between youths and adults that call for differences in dosage and affect response and tolerability. The authors also review the efficacy and tolerability of SSRIs and SNRIs in children and adolescents with depressive and anxiety disorder diagnoses, as well as data related to duration of therapy and SSRI/SNRI discontinuation in this population. Taken together, the current evidence suggests that SSRIs are the first-line psychopharmacologic intervention for youths with depressive and anxiety disorders, with SNRIs having a more limited role. These medications are safe and well tolerated, although emerging data and developmental pharmacologic concepts may help clinicians to choose from available SSRIs and to improve the efficacy and tolerability of these medications in children and adolescents.

[Therapeutic drug monitoring to optimize psychopharmacotherapy in children and adolescents - Update and guidelines for practice]

Therapeutic drug monitoring to optimize psychopharmacotherapy in children and adolescents - Update and guidelines for practice Abstract. Despite the improved evidence base, many uncertainties remain in child and adolescent psychiatric pharmacotherapy about the efficacy and tolerability of drugs, which are often prescribed off-label or in combination therapy in this age group. Because medium- to long-term use is unavoidable in many cases, clinicians should minimize adverse drug reactions as far as possible and tailor an effective dosage to the individual characteristics of the patient. Not only are children and adolescents particularly vulnerable to certain adverse drug effects, they are also exposed to iatrogenic risks from dosing or application errors, which can lead to under- or overdosing with correspondingly negative effects on the success of the therapy. In addition to determining a strict indication, it is therefore essential to establish precise dosage and systematic monitoring of the safety of the psychopharmacotherapy. This article introduces therapeutic drug monitoring as a useful clinical tool and describes how its correct application in practice can improve the efficacy as well as the safety and tolerability of psychotropic therapy in children and adolescents for the immediate benefit of patients. Keywords: Psychopharmacotherapy, adverse drug reactions, pharmacovigilance, therapeutic drug monitoring, quality assurance.

Selective Serotonin Reuptake Inhibitor Pharmacokinetics During Pregnancy: Clinical and Research Implications

Pregnancy and associated physiologic changes affect the pharmacokinetics of many medications, including selective serotonin reuptake inhibitors—the first-line pharmacologic interventions for depressive and anxiety disorders. During pregnancy, SSRIs exhibit extensive pharmacokinetic variability that may influence their tolerability and efficacy. Specifically, compared to non-pregnant women, the activity of cytochrome P450 (CYP) enzymes that metabolize SSRIs drastically changes (e.g., decreased CYP2C19 activity and increased CYP2D6 activity). This perspective examines the impact of pharmacokinetic genes—related to CYP activity on SSRI pharmacokinetics during pregnancy. Through a simulation-based approach, plasma concentrations for SSRIs metabolized primarily by CYP2C19 (e.g., escitalopram) and CYP2D6 (e.g., fluoxetine) are examined and the implications for dosing and future research are discussed.

Predictors, Moderators, and Mediators Associated With Treatment Outcome in Randomized Clinical Trials Among Adolescents With Depression: A Scoping Review

Importance

The application of precision medicine principles for the treatment of depressive disorders in adolescents requires an examination of the variables associated with depression outcomes in randomized clinical trials (RCTs).

Objective

To describe predictors, moderators, and mediators associated with outcomes in RCTs for the treatment of depressive disorders in adolescents.

Evidence Review

A scoping review of RCTs for the treatment of depression in adolescents was conducted. Databases searched included MEDLINE, Embase, APA PsycInfo, and CINAHL. Included publications tested predictors, moderators, and/or mediators associated with depression symptom outcomes (eg, symptom reduction, response, remission) in RCTs pertaining to the treatment of adolescents, ages 13 to 17 years. Predictors were defined as variables that were associated with depression outcomes, independent of treatment group. Moderators were defined as baseline variables that were associated with differential outcomes between treatment groups. Mediators were defined by a formal mediation analysis. In duplicate, variables were extracted and coded with respect to analysis type (univariable or multivariable), statistical significance, direction of effect size, reporting of a priori hypotheses, and adjustment for multiple comparisons. Aggregated results were summarized by variable domain and RCT sample.

Findings

Eighty-one articles reporting on variables associated with outcomes across 33 RCTs were identified, including studies of biological (10 RCTs), psychosocial (18 RCTs), and combined (4 RCTs) treatments as well as a service delivery model (1 RCT). Fifty-three variable domains were tested as baseline predictors of depression outcome, 41 as moderators, 19 as postbaseline predictors, and 5 as mediators. Variable domains that were reported as significant in at least 3 RCTs included age, sex/gender, baseline depression severity, early response to treatment, sleep changes, parent-child conflict, overall psychopathology, suicidal ideation, hopelessness, functional impairment, attendance at therapy sessions, and history of trauma. Two publications reported a priori hypotheses and adjustment for multiple comparisons, both finding that baseline depression severity and family conflict were associated with poorer outcomes.

Conclusions and Relevance

This review identified commonly researched variables requiring more scrutiny as well as underresearched variables to inform future study designs. Further efforts to discover predictors, moderators, and mediators associated with treatment response have great potential to optimize care for adolescents with depression.

Combining selective serotonin reuptake inhibitors and cognitive behavioral therapy in youth with depression and anxiety

BACKGROUND

Treatment studies of children and adolescents with internalizing disorders suggest that the combination of a selective serotonin reuptake inhibitor (SSRI) and cognitive behavioral therapy (CBT) consistently produces greater improvement than either treatment alone. We sought to determine how response to combined treatment varies across disorders (anxiety versus depression), and by specific patient characteristics.

METHODS

Three large National Institutes of Health-funded trials of children and adolescents with major depression (n = 2) and anxiety disorders (n = 1) were evaluated, each comparing CBT + SSRI to SSRI only, Bayesian Hierarchical Models (BHMs) were used, for endpoint response, time course of response and predictors of response in participants who received SSRI or SSRI+CBT.

RESULTS

SSRI+CBT significantly decreased symptoms by week 4 (p<0.001) across disorders. This improvement continued at week 8 and 12 (p<0.001); however, the additive benefit of CBT over SSRI monotherapy was not statistically significant until week 12 (p<0.001). The fastest response to SSRI+CBT was for patients who were younger, with milder baseline anxiety/depression symptoms and depressive disorders. The slowest response for SSRI+CBT was for boys, adolescents, minoritized children, those with severe symptoms and externalizing disorders.

LIMITATIONS

Limitations included inconsistent moderators, variation in the number of observations over time and a lack of genetic or pharmacokinetic variables related to SSRI exposure across studies.

CONCLUSIONS

The superiority of SSRI+CBT for youth with depression and anxiety is further supported. For purposes of rapid and greater relief, combination treatment is the superior approach across anxiety and depression and is robust to a range of participant characteristics. However, the added value of CBT (with an SSRI) occurs late in treatment. These findings represent a step towards understanding heterogeneity of treatment response and raise the possibility that interventions could be better tailored or adapted based on patient characteristics.

Pharmacogenetically Guided Escitalopram Treatment for Pediatric Anxiety Disorders: Protocol for a Double-Blind Randomized Trial

Current pharmacologic treatments for pediatric anxiety disorders (e.g., selective serotonin reuptake inhibitors (SSRIs)) frequently use "one size fits all" dosing strategies based on average responses in clinical trials. However, for some SSRIs, including escitalopram, variation in CYP2C19 activity produces substantial variation in medication exposure (i.e., blood medication concentrations). This raises an important question: would refining current SSRI dosing strategies based on CYP2C19 phenotypes increase response and reduce side effect burden? To answer this question, we designed a randomized, double-blind trial of adolescents 12-17 years of age with generalized, separation, and/or social anxiety disorders (N = 132). Patients are randomized (1:1) to standard escitalopram dosing or dosing based on validated CYP2C19 phenotypes for escitalopram metabolism. Using this approach, we will determine whether pharmacogenetically-guided treatment-compared to standard dosing-produces faster and greater reduction in anxiety symptoms (i.e., response) and improves tolerability (e.g., decreased risk of treatment-related activation and weight gain). Secondarily, we will examine pharmacodynamic variants associated with treatment outcomes, thus enhancing clinicians' ability to predict response and tolerability. Ultimately, developing a strategy to optimize dosing for individual patients could accelerate response while decreasing side effects-an immediate benefit to patients and their families. ClinicalTrials.gov Identifier: NCT04623099.

Pediatric Therapeutic Drug Monitoring for Selective Serotonin Reuptake Inhibitors

Therapeutic drug monitoring (TDM) is uncommon in child and adolescent psychiatry, particularly for selective serotonin reuptake inhibitors (SSRIs)—the first-line pharmacologic treatments for depressive and anxiety disorders. However, TDM in children and adolescents offers the opportunity to leverage individual variability of antidepressant pharmacokinetics to shed light on non-response and partial response, understand drug-drug interactions, evaluate adherence, and characterize the impact of genetic and developmental variation in pharmacokinetic genes. This perspective aims to educate clinicians about TDM principles and examines evolving uses of TDM in SSRI-treated youths and their early applications in clinical practice, as well as barriers to TDM in pediatric patients. First, the impact of pharmacokinetic genes on SSRI pharmacokinetics in youths could be used to predict tolerability and response for some SSRIs (e.g., escitalopram). Second, plasma concentrations are significantly influenced by adherence, which may relate to decreased efficacy. Third, pharmacometric analyses reveal interactions with proton pump inhibitors, oral contraceptives, cannabinoids, and SSRIs in youths. Rapid developments in TDM and associated modeling have enhanced the understanding of variation in SSRI pharmacokinetics, although the treatment of anxiety and depressive disorders with SSRIs in youths often remains a trial-and-error process.

The Impact of Marijuana on Antidepressant Treatment in Adolescents: Clinical and Pharmacologic Considerations

The neuropharmacology of marijuana, including its effects on selective serotonin reuptake inhibitor (SSRI)/antidepressant metabolism and the subsequent response and tolerability in youth, has received limited attention. We sought to (1) review clinically relevant pharmacokinetic (PK) and pharmacodynamic (PD) interactions between cannabinoids and selected SSRIs, (2) use PK models to examine the impact of cannabinoids on SSRI exposure (area under curve (AUC)) and maximum concentration (C_MAX) in adolescents, and (3) examine the frequency of adverse events reported when SSRIs and cannabinoids are used concomitantly. Cannabinoid metabolism, interactions with SSRIs, impact on relevant PK/PD pathways and known drug–drug interactions were reviewed. Then, the impact of tetrahydrocannabinol (THC) and cannabidiol (CBD) on exposure (AUC₂₄) and C_MAX for escitalopram and sertraline was modeled using pediatric PK data. Using data from the Food and Drug Administration Adverse Events Reporting System (FAERS), the relationship between CBD and CYP2C19-metabolized SSRIs and side effects was examined. Cannabis and CBD inhibit cytochrome activity, alter serotonergic transmission, and modulate SSRI response. In PK models, CBD and/or THC increases sertraline and es/citalopram concentrations in adolescents, and coadministration of CBD and CYP2C19-metabolized SSRIs increases the risk of cough, diarrhea, dizziness, and fatigue. Given the significant SSRI–cannabinoid interactions, clinicians should discuss THC and CBD use in youth prescribed SSRIs and be aware of the impact of initiating, stopping, or decreasing cannabinoid use as this may significantly affect es/citalopram and sertraline exposure.

Thoughtful Clinical Use of Pharmacogenetics in Child and Adolescent Psychopharmacology

AACAP's recent policy statement on Clinical Use of Pharmacogenetic Tests in Prescribing Psychotropic Medications for Children and Adolescents¹ recommends that "clinicians avoid using pharmacogenetic testing to select psychotropic medications in children and adolescents." We agree that there are limitations to the nascent evidence base for using pharmacogenetics, especially in combinatorial form (eg, test results that bin medications based on multiple genes). However, all-or-nothing recommendations fail to recognize the nuance and context of this testing and contrast with the AACAP Facts for Families on pharmacogenetic testing. Moreover, pharmacogenetic testing may inform dosing for antidepressants that are commonly used in child and adolescent psychiatry (eg, sertraline, escitalopram, citalopram, fluvoxamine) as well as the tolerability of some psychotropic medications. With this in mind, we wish to remind the AACAP community of the accumulating evidence and to highlight important principles of pharmacogenetic testing in youths. Specifically: 1) pharmacogenetic testing is not always performed by commercial companies and is not always combinatorial; 2) dosing recommendations or assessment of risk for severe hypersensitivity reactions are based on pharmacogenetics in the Food and Drug Administration (FDA)-approved product inserts for several medications commonly prescribed to children (eg, citalopram, aripiprazole, atomoxetine, carbamazepine, oxcarbazepine at www.fda.gov/drugs/science-and-research-drugs/table-pharmacogenomic-biomarkers-drug-labeling); 3) expert consensus guidelines for dosing or identifying hypersensitivity risk for these drugs are available from the National Institutes of Health (NIH)-supported Clinical Pharmacogenetics Implementation Consortium (CPIC, www.cpicpgx.org/), which provides transparent, regularly updated, and evidence-based evaluations of pharmacogenetic data;² and 4) randomized trials are not required for clinical dose adjustments; for example, dose adjustments because of decreased hepatic function or concomitant interacting medications are based on pharmacokinetic data, similar to many pharmacokinetic gene-based recommendations from CPIC.

In Reply

Thank you for the opportunity to respond to the letter, "Thoughtful Clinical Use of Pharmacogenetics in Child and Adolescent Psychopharmacology." We appreciate the thoughtful consideration by Ramsey et al.¹ of the American Academy of Child and Adolescent Psychiatry (AACAP) policy statement on the Clinical Use of Pharmacogenetic Tests in Prescribing Psychotropic Medications for Children and Adolescents.² In this reply, we will highlight many of the important points that the authors have included and will also express our concerns regarding some of the authors' conclusions in light of the current level of evidence.

Higher venlafaxine serum concentrations necessary for clinical improvement? Time to re-evaluate the therapeutic reference range of venlafaxine

BACKGROUND

The therapeutic reference range for venlafaxine in antidepressant treatment has been defined as 100 to 400 ng/mL. However, in an everyday setting active moiety concentrations above the therapeutic reference range were often reported.

AIM

The aim of this study was to re-evaluate the therapeutic reference range of venlafaxine.

METHODS

In-patients (⩽60 years) with major depressive episodes receiving antidepressant monotherapy with venlafaxine during routine clinical treatment were included in this observational study. Depressive symptom severity was evaluated on a weekly basis using the Hamilton Depression Rating Scale (HAMD-21), and therapeutic drug monitoring analyses were performed. Resting electrocardiograms were analyzed in week 3, week 5 and week 7 of study participation.

RESULTS

Clinical improvement from baseline to week 4 was significantly associated with increasing serum concentrations of the active moiety of venlafaxine (N = 23, Pearson correlation, p = 0.009), but not with the dose of venlafaxine. Patients achieving remission showed significantly higher serum concentrations than patients achieving response/non-response (Kruskal-Wallis test, p = 0.019). Moreover, in patients with serum concentrations above 400 ng/mL time to remission and time to response was significantly shorter than in patients with concentrations below 400 ng/mL (Mantel-COX test, p = 0.001; p = 0.010). QTc time was below the upper limit of a normal QTc time (450 ms) for all patients.

CONCLUSION

The serum concentration of the active moiety and not the dose determined the effect of venlafaxine. Shorter remission times without ECG alterations in patients with serum concentrations above the therapeutic reference range suggest a re-evaluation of the therapeutic reference range for venlafaxine in larger studies.

What next? A Bayesian hierarchical modeling re-examination of treatments for adolescents with selective serotonin reuptake inhibitor-resistant depression

BACKGROUND

Psychiatrists frequently struggle with how to sequence treatment for depressed adolescents who do not respond to an adequate trial of a selective serotonin reuptake inhibitor (SSRI). This study leveraged recent statistical and computational advances to create Bayesian hierarchal models (BHMs) of response in the treatment of SSRI-resistant depression in adolescents study to inform treatment planning.

METHODS

BHMs of individual treatment trajectories were developed and estimated using Hamiltonian Monte Carlo no u-turn sampling. From the Monte Carlo pseudorandom sample, 95% credible intervals, means, posterior tail probabilities, and so forth, were determined. Then, for the random effects model, posterior tail probabilities were used to create Bayesian two-tailed p values to evaluate the null hypotheses: no difference in efficacy between SSRIs and venlafaxine. The robustness of the results was examined using the fixed effects model of treatment comparisons.

RESULTS

In patients not receiving cognitive behavioral therapy (CBT; n = 168), SSRIs produced greater and faster improvement in depressive symptoms compared to venlafaxine (p = .015). No differences in response or trajectory of response for symptoms of anxiety were detected between SSRIs and venlafaxine (p = .168). For patients receiving CBT (n = 162), SSRIs and venlafaxine produced similar improvements in symptoms of anxiety and depression.

CONCLUSIONS

Findings from this novel computational approach suggest that a second trial of an SSRI is warranted for depressed adolescents who fail to respond to initial SSRI treatment.

Psychotropic drug concentrations and clinical outcomes in children and adolescents: a systematic review

INTRODUCTION

The use of psychotropic drugs in children and adolescents is widespread but associated with suboptimal treatment effects. Therapeutic drug monitoring (TDM) can improve safety of psychotropic drugs in children and adolescents but is not routinely performed. A major reason is that the relationship between drug concentrations and effects is not well known.

AREAS COVERED

This systematic review evaluated studies assessing the relationship between psychotropic drug concentrations and clinical outcomes in children and adolescents, including antipsychotics, psychostimulants, alpha-agonists, antidepressants, and mood-stabilizers. PRISMA guidelines were used and a quality assessment of the retrieved studies was performed. Sixty-seven eligible studies involving 24 psychotropic drugs were identified from 9,298 records. The findings were generally heterogeneous and the majority of all retrieved studies were not of sufficient quality. For 11 psychotropic drugs, a relationship between drug concentrations and side-effects and/or effectiveness was evidenced in reasonably reported and executed studies, but these findings were barely replicated.

EXPERT OPINION

In order to better support routine TDM in child- and adolescent psychiatry, future work must improve in aspects of study design, execution and reporting to demonstrate drug concentration-effect relationships. The quality criteria proposed in this work can guide future TDM research. Systematic review protocol and registration PROSPERO CRD42018084159.

A systematic review of interventions for treatment resistant major depressive disorder in adolescents

To update a comparative effectiveness review (1980-2011) of treatments for adolescents whose depressive episode or disorder (MDE/MDD) did not respond to one or more trials of SSRI antidepressants. MEDLINE, Cochrane Central, PsychINFO, Cochrane Database of Systematic Reviews, EMBASE, CINAHL, and AMED were searched in addition to the grey literature. We spanned May 2011 to September 1, 2017 and included only articles in English. 11 new studies were reviewed based on the criteria of having tested a comparative treatment in adolescents with MDD or MDE who were confirmed to have failed one or more SSRI trials. Data were extracted using standardized forms and a reference guide in DistillerSR; a second reviewer verified the accuracy of the data fields and discrepancies were resolved by consensus. One trial (N = 29) found a small benefit of escalating doses of fluoxetine and the treatment of adolescent depression study (TORDIA, N = 334) found significant benefits of combined SSRI or venlafaxine treatment with CBT for most outcomes. No new studies were identified since the previous review (2012). One trial is currently registered that will be a cross over trial of rTMS; other registered trials are open label. Multiple secondary data analyses of TORDIA have identified important predictors of treatment response and relapse. No new comparative studies were identified since the original review. Trials are desperately needed to identify new treatments for youth with SSRI resistant MDD. These youth should not be deemed as treatment resistant until completing one or two failed trials of SSRI combined with evidence-based psychotherapy.

Effects of the Proton Pump Inhibitors Omeprazole and Pantoprazole on the Cytochrome P450-Mediated Metabolism of Venlafaxine

BACKGROUND AND OBJECTIVE: An increasing trend in prescribing proton pump inhibitors (PPIs) inevitably increases the risk of unwanted drug-drug interactions (DDIs). The aim of this study was to uncover pharmacokinetic interactions between two PPIs-omeprazole and pantoprazole-and venlafaxine.

METHODS

A therapeutic drug monitoring database contained plasma concentrations of venlafaxine and its active metabolite O-desmethylvenlafaxine. We considered three groups: a group of patients who received venlafaxine without confounding medications (non-PPI group, n = 906); a group of patients who were comedicated with omeprazole (n = 40); and a group of patients comedicated with pantoprazole (n = 40). Plasma concentrations of venlafaxine, O-desmethylvenlafaxine and active moiety (venlafaxine + O-desmethylvenlafaxine), as well as dose-adjusted plasma concentrations, were compared using non-parametrical tests.

RESULTS

Daily doses of venlafaxine did not differ between groups (p = 0.949). The Mann-Whitney U test showed significantly higher plasma concentrations of active moiety, as well as venlafaxine and O-desmethylvenlafaxine, in both PPI groups [p = 0.023, p = 0.011, p = 0.026, +29% active moiety, +27% venlafaxine, +36% O-desmethylvenlafaxine (pantoprazole); p = 0.003, p = 0.039 and p < 0.001, +36% active moiety, +27% venlafaxine, +55% O-desmethylvenlafaxine (omeprazole)]. Significantly higher concentration-by-dose (C/D) values for venlafaxine and active moiety were detected in the pantoprazole group (p = 0.013, p = 0.006, respectively), while in the omeprazole group, C/D ratios for all three parameters-venlafaxine, O-desmethylvenlafaxine and active moiety-were significantly higher (p = 0.021, p < 0.001 and p < 0.001, respectively).

CONCLUSIONS

Significantly higher plasma concentrations for all parameters (venlafaxine, O-desmethylvenlafaxine, active moiety) suggest clinically relevant inhibitory effects of both PPIs, most likely on the cytochrome P450 (CYP) 2C19-mediated metabolism of venlafaxine. The findings might be the result of different degrees of CYP2C19 involvement, therefore the inhibition of CYP2C19 by both PPIs may lead to an increased metabolism via CYP2D6 to O-desmethylvenlafaxine.

CYP2C19-Guided Escitalopram and Sertraline Dosing in Pediatric Patients: A Pharmacokinetic Modeling Study

Objective: Cytochrome P4502C19 (CYP2C19) is a highly polymorphic gene that encodes an enzyme that metabolizes escitalopram and sertraline, two selective serotonin reuptake inhibitors (SSRIs) that are FDA approved for pediatric use and commonly used to treat anxiety and depressive disorders in youth. Using pharmacokinetic (PK) models in adolescents, we sought to (1) model SSRI dosing across CYP2C19 phenotypes to compare SSRI exposure (area under curve, AUC) and maximum concentration (Cmax), (2) evaluate the impact of b.i.d. dosing (in rapid metabolizers [RM] and ultrarapid metabolizers [UM]) on SSRI exposure and Cmax, and (3) determine pharmacogenomically-informed dosing strategies to provide similar exposure across CYP2C19 phenotypes in adolescents. Methods: Using PK parameters in CYP2C19 phenotype groups and previously reported pediatric PK data for escitalopram and sertraline, we modeled exposure (AUC0-24) and Cmax and determined CYP2C19-guided dosing strategies. Results: Compared with normal CYP2C19 metabolizers treated with either escitalopram or sertraline, Cmax and AUC0-24 were higher in slower metabolizers and lower in patients with increased CYP2C19 activity, although the magnitude of these differences was more pronounced for escitalopram than for sertraline. For escitalopram, poor metabolizers (PMs) require 10 mg/day and UMs require 30 mg/day to achieve an exposure that is equivalent to 20 mg/day in a normal metabolizer (NM). For sertraline, to achieve AUC0-24 and Cmax similar to NMs receiving 150 mg/day, PMs require 100 mg/day, whereas a dose of 200 mg/day was required in rapid and UMs. For UMs, b.i.d. escitalopram dosing was necessary to achieve comparable trough levels and exposure to NMs. Conclusions: This simulation study raises the possibility that achieving similar escitalopram and sertraline plasma concentrations could require dose adjustments in CYP2C19 poor metabolizers and UMs, although the magnitude of these differences were more pronounced for escitalopram than for sertraline. However, prospective trials of pharmacogenomically guided dosing in the pediatric population are needed to extend the findings of these modeling studies.

Influence of CYP2C19 Metabolizer Status on Escitalopram/Citalopram Tolerability and Response in Youth With Anxiety and Depressive Disorders

In pediatric patients, the selective serotonin reuptake inhibitors (SSRIs) escitalopram and citalopram (es/citalopram) are commonly prescribed for anxiety and depressive disorders. However, pharmacogenetic studies examining CYP2C19 metabolizer status and es/citalopram treatment outcomes have largely focused on adults. We report a retrospective study of electronic medical record data from 263 youth < 19 years of age with anxiety and/or depressive disorders prescribed escitalopram or citalopram who underwent routine clinical CYP2C19 genotyping. Slower CYP2C19 metabolizers experienced more untoward effects than faster metabolizers (p = 0.015), including activation symptoms (p = 0.029) and had more rapid weight gain (p = 0.018). A larger proportion of slower metabolizers discontinued treatment with es/citalopram than normal metabolizers (p = 0.007). Meanwhile, faster metabolizers responded more quickly to es/citalopram (p = 0.005) and trended toward less time spent in subsequent hospitalizations (p = 0.06). These results highlight a disparity in treatment outcomes with es/citalopram treatment in youth with anxiety and/or depressive disorders when standardized dosing strategies were used without consideration of CYP2C19 metabolizer status. Larger, prospective trials are warranted to assess whether tailored dosing of es/citalopram based on CYP2C19 metabolizer status improves treatment outcomes in this patient population.

The Impact of Antidepressant Dose and Class on Treatment Response in Pediatric Anxiety Disorders: A Meta-Analysis

OBJECTIVE

To determine the trajectory and magnitude of antidepressant response as well as the effect of antidepressant class and dose on symptomatic improvement in pediatric anxiety disorders.

METHOD

Weekly symptom severity data were extracted from randomized, parallel group, placebo-controlled trials of selective serotonin reuptake inhibitors (SSRIs) and selective serotonin-norepinephrine reuptake inhibitors (SNRIs) in pediatric anxiety disorders. Treatment response was modeled for the standardized change in continuous measures of anxiety using Bayesian updating. Posterior distributions for each study served as informative conjugate prior to distributions update subsequent study posteriors. Change in symptom severity was evaluated as a function of time, class and, for SSRIs, standardized dose.

RESULTS

Data from 9 trials (SSRIs: n = 5; SNRIs, n = 4) evaluating 7 medications in 1,673 youth were included. In the logarithmic model of treatment response, statistically, but not clinically, significant treatment effects emerged within 2 weeks of beginning treatment (standardized medication-placebo difference = -0.054, credible interval [CI] = -0.076 to -0.032, p = .005, approximate Cohen's d ≤ 0.2) and by week 6, clinically significant differences emerged (standardized medication-placebo difference = -0.120, CI = -0.142 to -0.097, p = .001, approximate Cohen's d = 0.44). Compared to SNRIs, SSRIs resulted in significantly greater improvement by the second week of treatment (p = .0268), and this advantage remained statistically significant through week 12 (all p values <.03). Improvement occurred earlier with high-dose SSRI treatment (week 2, p = .002) compared to low-dose treatment (week 10, p = .025), but SSRI dose did not have an impact on overall response trajectory (p > .18 for weeks 1-12).

CONCLUSIONS

In pediatric patients with generalized, separation, and/or social anxiety disorders, antidepressant-related improvement occurred early in the course of treatment, and SSRIs were associated with more rapid and greater improvement compared to SNRIs.

Primary Pediatric Care Psychopharmacology: Focus on Medications for ADHD, Depression, and Anxiety

The evidence base for psychopharmacologic interventions in youth with depressive and anxiety disorders as well as attention/deficit hyperactivity disorder (ADHD) has dramatically increased over the past two decades. Psychopharmacologic interventions commonly utilized in the pediatric primary care setting-selective serotonin (norepinephrine) reuptake inhibitors (SSRIs/SSNRIs), stimulants and α2 agonists-are reviewed. General pharmacologic principles are summarized along with class-related side effects and tolerability concerns (e.g., suicidality and activation in antidepressant-treated youth as well as insomnia, irritability, anorexia in stimulant-treated pediatric patients). Selected landmark trials of antidepressant medications in youth with depressive disorders [Treatment of Adolescent Depression Study (TADS) and the Treatment of SSRI-Resistant Depression Study (TADS)] and anxiety disorders [Child/Adolescent Anxiety Multimodal Study (CAMS) and Child/Adolescent Anxiety Multimodal Extended Long-term Study (CAMELS)] are described in addition to the Multimodal Treatment of ADHD Study. Finally, available data are presented that are related to prediction of treatment outcomes in youth with depressive disorders, anxiety disorders, and ADHD.

Antidepressants and Suicidality

We review the evidence that antidepressants either increase or decrease the risk for suicidal ideation and behavior in adolescents. Meta-analyses of randomized clinical trials (RCTs) indicate a small increased risk for suicidal events in adolescents and young adults, but a protective effect in older adults. In contrast, pharmacoepidemiologic studies show a protective effect across the life span. Explanations for occurrence of suicidal events in younger patients and for the apparent contradiction between RCT and pharmacoepidemiologic studies are offered. Guidance for clinicians is provided on explaining the risk-benefit ratio of antidepressants and how to monitor and attenuate for suicidal risk.

Increased Serum Levels of Oxytocin in 'Treatment Resistant Depression in Adolescents (TRDIA)' Group

Objective

‘Treatment-resistant depression’ is depression that does not respond to an adequate regimen of evidence-based treatment. Treatment-resistant depression frequently becomes chronic. Children with treatment-resistant depression might also develop bipolar disorder (BD). The objective of this study was to determine whether serum levels of oxytocin (OXT) in treatment-resistant depression in adolescents (TRDIA) differ from non-treatment-resistant depression in adolescents (non-TRDIA) or controls. We also investigated the relationships between serum OXT levels and the clinical symptoms, severity, and familial histories of adolescent depressive patients.

Methods

We measured serum OXT levels: TRDIA (n = 10), non-TRDIA (n = 27), and age- and sex- matched, neurotypical controls (n = 25). Patients were evaluated using the Children’s Depression Rating Scale-Revised (CDRS-R) and the Depression Self-Rating Scale for Children-Japanese Version (DSRS-C-J). The patients were also assessed retrospectively using the following variables: familial history of major depressive disorder and BD (1st degree or 2nd degree), history of disruptive mood dysregulation disorder, recurrent depressive disorder (RDD), history of antidepressant activation.

Results

Serum levels of OXT among the TRDIA and non-TRDIA patients and controls differed significantly. Interestingly, the rates of a family history of BD (1st or 2nd degree), RDD and a history of antidepressant activation in our TRDIA group were significantly higher than those of the non-TRDIA group.

Conclusions

Serum levels of OXT may play a role in the pathophysiology of TRDIA.

Exposure-outcome analysis in depressed patients treated with paroxetine using population pharmacokinetics

Purpose

This study investigated population pharmacokinetics of paroxetine, and then performed an integrated analysis of exposure and clinical outcome using population pharmacokinetic parameter estimates in depressed patients treated with paroxetine.

Patients and methods

A total of 271 therapeutic drug monitoring (TDM) data were retrospectively collected from 127 psychiatric outpatients. A population nonlinear mixed-effects modeling approach was used to describe serum concentrations of paroxetine. For 83 patients with major depressive disorder, the treatment response rate and the incidence of adverse drug reaction (ADR) were characterized by logistic regression using daily dose or area under the concentration–time curve (AUC) estimated from the final model as a potential exposure predictor.

Results

One compartment model was developed. The apparent clearance of paroxetine was affected by age as well as daily dose administered at steady-state. Overall treatment response rate was 72%, and the incidence of ADR was 30%. The logistic regression showed that exposure predictors were not associated with treatment response or ADR in the range of dose commonly used in routine practice. However, the incidence of ADR increased with the increase of daily dose or AUC for the patients with multiple concentrations.

Conclusion

In depressed patients treated with paroxetine, TDM may be of limited value for individualization of treatment.

Systematic Review and Meta-Analysis: Early Treatment Responses of Selective Serotonin Reuptake Inhibitors in Pediatric Major Depressive Disorder

OBJECTIVE

Selective serotonin reuptake inhibitors (SSRIs) are the first-line pharmacological treatment for pediatric major depressive disorder (MDD). We conducted a meta-analysis to examine the following: the time-course of response to SSRIs in pediatric depression; whether higher doses of SSRIs are associated with an improved response in pediatric depression; differences in efficacy between SSRI agents; and whether the time-course and magnitude of response to SSRIs is different in pediatric and adult patients with MDD.

METHOD

We searched PubMed and CENTRAL for randomized controlled trials comparing SSRIs to placebo for the treatment of pediatric MDD. We extracted weekly symptom data from trials to characterize the trajectory of pharmacological response to SSRIs. Pooled estimates of treatment effect were calculated based on standardized mean differences between treatment and placebo groups.

RESULTS

The meta-analysis included 13 pediatric MDD trials with a total of 3,004 patients. A logarithmic model indicating that the greatest benefits of SSRIs occurred early in treatment best fit the longitudinal data (log[week] = 0.10, 95% CI = 0.06-0.15, p < .0001). There were no significant differences based on maximum SSRI dose or between particular SSRI agents. SSRIs were demonstrated to have a smaller benefit in pediatric compared to adult MDD.

CONCLUSION

Treatment gains in pediatric MDD are greatest early in treatment and are, on average, minimal after 4 weeks of SSRI pharmacotherapy in pediatric MDD. Further research is needed using individual patient data to examine the power of early SSRI response (e.g., 2-4 weeks) to predict outcomes in short-term pharmacological trials.

The influences of CYP2D6 genotypes and drug interactions on the pharmacokinetics of venlafaxine: exploring predictive biomarkers for treatment outcomes

RATIONALE

Two biomarkers: concentration ratio of O-desmethylvenlafaxine/venlafaxine and concentration sum of venlafaxine + O-desmethylvenlafaxine were adopted to indicate venlafaxine responses, but neither is validated.

OBJECTIVES

To evaluate the ability of two biomarkers in reflecting venlafaxine pharmacokinetic variations, and to further examine their relationship with venlafaxine treatment outcomes.

METHODS

Two well-defined influencing factors: CYP2D6 genotypes and drug interactions were enriched into a three-period crossover study to produce venlafaxine pharmacokinetic variations: In each period, healthy CYP2D6 extensive metabolizers (EM group; n = 12) and CYP2D6*10/*10 intermediate metabolizers (IM group; n = 12) were pretreated with clarithromycin (CYP3A4 inhibitor), or nothing (control), or clarithromycin + paroxetine (CYP3A4 + CYP2D6 inhibitors), before administration of a single-dose of 75 mg venlafaxine. Both biomarkers were evaluated (1) for their relationship with the influencing factors in healthy volunteers and (2) for their relationships with the venlafaxine responses/adverse events reported in two patient studies.

RESULTS

Significant venlafaxine pharmacokinetic variations were observed between the EM and IM groups (geometric mean ratio [95 % CI] of area under the curve, 3.0 [1.8-5.1] in the control period), and between the control and clarithromycin + paroxetine periods (4.1 [3.5-4.7] and 2.0 [1.7-2.4] in the EM and IM group, respectively). O-Desmethylvenlafaxine/venlafaxine was superior to venlafaxine + O-desmethylvenlafaxine to reflect the influencing factors. In the patient studies, O-desmethylvenlafaxine/venlafaxine > 4 showed high precision in predicting venlafaxine responders/partial-responders (92 %) and patients without venlafaxine-related adverse events (88 %); the O-desmethylvenlafaxine/venlafaxine < 4 and venlafaxine + O-desmethylvenlafaxine > 400 ng/ml combination showed higher precision (100 %) than O-desmethylvenlafaxine/venlafaxine < 4 alone (65 %) in predicting venlafaxine non-responders.

CONCLUSION

We propose using O-desmethylvenlafaxine/venlafaxine for CYP2D6 phenotyping, and O-desmethylvenlafaxine/venlafaxine with venlafaxine + O-desmethylvenlafaxine for predicting venlafaxine treatment outcomes in future prospective studies.

Plasma fluoxetine concentrations and clinical improvement in an adolescent sample diagnosed with major depressive disorder, obsessive-compulsive disorder, or generalized anxiety disorder

Fluoxetine (FLX) has been one of the most widely studied selective serotonin reuptake inhibitors in adolescents. Despite its efficacy, however, 30% to 40% of patients do not respond to treatment.

AIMS

The aim of this study was to evaluate whether clinical improvement or adverse events are related to the corrected dose of FLX at 8 and 12 weeks after starting treatment in a sample of adolescents diagnosed with major depressive disorder, obsessive-compulsive disorder, or generalized anxiety disorder.

METHODS

Seventy-four subjects aged between 10 and 17 years participated in the study. Clinical improvement was measured with the Clinical Global Impression-Improvement Scale, whereas the UKU (Udvalg for Klinske Undersogelser) scale was administered to assess adverse effects of treatment.

RESULTS

Fluoxetine per kilograms of body weight was related to serum concentration of FLX, NORFLX (norfluoxetine), FLX + NORFLX, and FLX/NORFLX. No relationship was found between dose-corrected FLX levels and therapeutic or adverse effects. No differences in serum concentrations were found between responders and nonresponders to treatment. Sex differences were observed in relation to dose and FLX serum concentration. The analysis by diagnosis revealed differences in FLX dose between obsessive-compulsive disorder patients and both generalized anxiety disorder and major depressive disorder patients.

CONCLUSIONS

Fluoxetine response seems to be influenced by factors such as sex, diagnosis, or certain genes that might be involved in the drug's pharmacokinetics and pharmacodynamics. Clinical and pharmacogenetic studies are needed to elucidate further the differences between treatment responders and nonresponders.

Evidence for the management of adolescent depression

Adolescent depression is a prevalent and disabling condition resulting in emotional suffering and social and educational dysfunction. Care for adolescent depression is suboptimal and could be improved through the development and use of quality indicators (QIs). This article reports on the development of a care pathway and QIs for the primary and specialty care management of adolescent depression from case identification through symptom remission. It presents evidence from a review of adolescent clinical practice guidelines and research literature to support QIs at critical nodes in the pathway, and describes implications for practice based on existing evidence. Barriers to measure development are identified, including gaps in empirical evidence, and a research agenda is suggested.

The bidirectional relationship between body mass index and treatment outcome in adolescents with treatment-resistant depression

OBJECTIVE

Depression and obesity are associated, but the impact of obesity on depression treatment outcome, or, conversely, the impact of treatment on body mass index (BMI) in depressed adolescents has not been reported. In this article, we examine the bidirectional relationships between BMI and treatment response in adolescents with treatment-resistant depression.

METHOD

Participants in the Treatment of Selective Serotonin Reuptake Inhibitor (SSRI) Resistant Depression in Adolescents (TORDIA) study had height and weight assessed at baseline, weekly for the first 6 weeks, biweekly for the next 6 weeks, and monthly from weeks 12 through 24. The impact of baseline BMI as a predictor and moderator of treatment response was assessed. In addition, participants' changes in BMI were assessed as a function of specific treatment assignment and treatment response.

RESULTS

Participants assigned to SSRIs had a greater increase in BMI-for-age-sex z-score and weight than did those assigned to venlafaxine. Post-hoc, those treated with paroxetine or citalopram had the biggest increases in BMI, relative to fluoxetine or venlafaxine. Overweight or obesity was neither a predictor nor a moderator of treatment outcome, nor of subsequent BMI change.

CONCLUSIONS

Overweight status does not appear to affect treatment response in adolescents with resistant depression. The successful treatment of depression does not appear to favorably affect weight or BMI. Fluoxetine and venlafaxine are less likely to cause an increase in BMI than paroxetine or citalopram.

Impact of treatments for depression on comorbid anxiety, attentional, and behavioral symptoms in adolescents with selective serotonin reuptake inhibitor-resistant depression

OBJECTIVE

To assess the relative efficacy of antidepressant medication, alone and in combination with cognitive behavioral therapy (CBT), on comorbid symptoms of anxiety, attention, and disruptive behavior disorders in participants in the Treatment of Resistant Depression in Adolescents (TORDIA) trial.

METHOD

Adolescents with selective serotonin reuptake inhibitor (SSRI)-resistant depression (N = 334) were randomly assigned to a medication switch alone (to another SSRI or to venlafaxine) or to a medication switch plus CBT. Anxiety, attention-deficit/hyperactivity disorder (ADHD), and disruptive behavior disorder (DBD) symptoms were assessed by psychiatric interview and self-report at regular intervals between baseline and 24 weeks. The differential effects of medication and of CBT, and the impact of remission on the course of comorbid symptoms and diagnoses, were assessed using generalized linear mixed models.

RESULTS

Remission was associated with a greater reduction in scalar measures of anxiety, ADHD, and DBDs, and a greater decrease in the rate of diagnosed anxiety disorders. The correlations between the changes in symptoms of depression on the CDRS-R and anxiety, ADHD, and oppositional symptoms were modest, ranging from r = 0.12 to r = 0.28. There were no significant differential treatment effects on diagnoses, or corresponding symptoms.

CONCLUSION

The achievement of remission had a beneficial effect on anxiety, ADHD, and DBD symptoms, regardless of the type of treatment received. There were no differential effects of medication or CBT on outcome, except for a nonsignificant trend that those adolescents treated with SSRIs showed a greater decrease in rates of comorbid DBDs relative to those treated with venlafaxine. Clinical trial registration information-Treatment of SSRI-Resistant Depression In Adolescents (TORDIA); http://clinicaltrials.gov/; NCT00018902.

Child and adolescent depression intervention overview: what works, for whom and how well?

The authors review the currently available evidence-based treatments of child and adolescent major depressive disorder. Medication monotherapy, namely with selective serotonin reuptake inhibitors, is supported by large clinical trials in adolescents. For mild to moderate depression, cognitive behavior therapy (CBT) and interpersonal therapy are reasonable options as monotherapies. There is also evidence that the combination of medication and CBT is superior to medication alone for accelerating the pace of treatment response and remission, despite some negative studies. Response, remission, and recurrence rates after acute treatment and during long-term follow-ups are also presented and discussed.

Developmentally informed pharmacotherapy for child and adolescent depressive disorders

This article reviews evidence-based pharmacotherapy for children and adolescents with depression. Several randomized controlled trials (RCTs) support the use of fluoxetine for the treatment of childhood and adolescent depression as well as escitalopram in the treatment of adolescent depression. To date, one RCT has demonstrated the effectiveness of sertraline or citalopram for the treatment of major depressive disorder in youth. Only a small number of RCTs for depression have included children, and none of these trials were adequately powered to detect differences in the efficacy of medication between children and adolescents.

Out of the black box: treatment of resistant depression in adolescents and the antidepressant controversy

OBJECTIVE

The purpose of this article is to describe the effects of the pediatric antidepressant controversy on the Treatment of Serotonin-Selective Reuptake Inhibitor (SSRI) Resistant Depression in Adolescents (TORDIA) trial.

METHOD

Adolescents, ages 12-18 years, with SSRI resistant depression were randomized to one of four treatments for a 12 week trial: Switch to different SSRI, switch to an alternate antidepressant (venlafaxine), switch to an alternate SSRI plus cognitive behavior therapy (CBT), or switch to venlafaxine plus CBT.

RESULTS

The health advisories and "black box" warnings regarding suicidality and antidepressants in adolescents occurred during the course of the TORDIA trial. Revisions to the protocol, multiple-consent form changes, and re-consenting of patients were necessary. Recruitment of participants was adversely affected.

CONCLUSION

Despite a cascade of unforeseen events that delayed the completion of the study, the TORDIA trial resulted in clinically important information about treatment-resistant depression in adolescents.

Treatment-resistant depression: therapeutic trends, challenges, and future directions

BACKGROUND

Patients with major depression respond to antidepressant treatment, but 10%-30% of them do not improve or show a partial response coupled with functional impairment, poor quality of life, suicide ideation and attempts, self-injurious behavior, and a high relapse rate. The aim of this paper is to review the therapeutic options for treating resistant major depressive disorder, as well as evaluating further therapeutic options.

METHODS

In addition to Google Scholar and Quertle searches, a PubMed search using key words was conducted, and relevant articles published in English peer-reviewed journals (1990-2011) were retrieved. Only those papers that directly addressed treatment options for treatment-resistant depression were retained for extensive review.

RESULTS

Treatment-resistant depression, a complex clinical problem caused by multiple risk factors, is targeted by integrated therapeutic strategies, which include optimization of medications, a combination of antidepressants, switching of antidepressants, and augmentation with non-antidepressants, psychosocial and cultural therapies, and somatic therapies including electroconvulsive therapy, repetitive transcranial magnetic stimulation, magnetic seizure therapy, deep brain stimulation, transcranial direct current stimulation, and vagus nerve stimulation. As a corollary, more than a third of patients with treatment-resistant depression tend to achieve remission and the rest continue to suffer from residual symptoms. The latter group of patients needs further study to identify the most effective therapeutic modalities. Newer biomarker-based antidepressants and other drugs, together with non-drug strategies, are on the horizon to address further the multiple complex issues of treatment-resistant depression.

CONCLUSION

Treatment-resistant depression continues to challenge mental health care providers, and further relevant research involving newer drugs is warranted to improve the quality of life of patients with the disorder.

Treatment-resistant depression in adolescents: review and updates on clinical management

Treatment-resistant depression (TRD) in adolescents is prevalent and impairing. We here review the definition, prevalence, clinical significance, risk factors, and management of TRD in adolescents. Risk factors associated with TRD include characteristics of depression (severity, level of hopelessness, and suicidal ideation), psychiatric and medical comorbidities, environmental factors (family conflict, maternal depression, and history of abuse), and pharmacokinetics and other biomarkers. Management options include review of the adequacy of the initial treatment, re-assessment for the above-noted factors that might predispose to treatment resistance, switching antidepressants, and augmentation with medication or psychotherapy. Other modalities, such as electroconvulsive therapy, vagal nerve stimulation, and repetitive transcranial magnetic stimulation, are also reviewed.

Pharmacokinetically and clinician-determined adherence to an antidepressant regimen and clinical outcome in the TORDIA trial

OBJECTIVE

Nonadherence to antidepressant treatment may contribute to poor outcome and to suicidal adverse events in adolescent depression. We examine the relationship between adherence and both clinical response and suicidal events in participants in the Treatment of Resistant Depression in Adolescents (TORDIA) study.

METHOD

The relationship between adherence to medication and clinical outcome was assessed in 190 treatment-resistant depressed adolescents who were randomized to one of four cells: switch to another selective serotonin reuptake inhibitor (SSRI), switch to venlafaxine, or either of these two medication switches plus cognitive behavioral therapy. Plasma levels of antidepressant drug and metabolites were determined after 6 and 12 weeks of treatment. A twofold or greater variation in the dose-adjusted concentration of drug plus metabolites (level/dose ratio [LDR]) was defined as nonadherence. Nonadherence was also determined by clinician pill counts (CPC) of the proportion of prescribed pills that were unused and was defined as having greater than 30% of the prescribed pills remaining.

RESULTS

LDR and CPC showed low concordance. LDR was unrelated to clinical response. CPC adherence was related to a higher response rate overall (adherent, 63.0% versus nonadherent, 47.2%, p = .03). Approximately half (50.8%) of the sample surveyed showed evidence of nonadherence by CPC. Neither measure of adherence was related to the occurrence of suicidal events or to the pace of decline in suicidal ideation.

CONCLUSIONS

Clinician pill counts may be a relevant measure of adherence that is related to outcome under formal clinical trial conditions in depressed adolescents. Nonadherence appears to be a common and significant source of treatment nonresponse. Clinical Trial Registration Information-Treatment of SSRI-Resistant Depression in Adolescents (TORDIA); http://www.clinicaltrials.gov; NCT00018902.