Treatment-Resistant Depression in Adolescents: Clinical Features and Measurement of Treatment Resistance

Neuroticism and extraversion as predictors of first-lifetime onsets of depression, anxiety, and suicidality in high-risk adolescents

There is substantial evidence that personality traits, in particular neuroticism and extraversions predict depressive and anxiety episodes as well as suicidal ideation. However, little research has examined whether these traits predict the first onset of depressive and anxiety disorders and suicidal ideation. Moreover, the few studies to date have not adjusted for pre-existing subthreshold symptoms, assessed dimensionally. In this study, 144 adolescents were assessed at baseline, 9-, and 18-month follow-ups. Neuroticism and extraversion were assessed via self-report, and depressive and anxiety disorders and suicidal ideation were assessed with diagnostic interviews. Adjusting for age, sex, and baseline symptoms, logistic regression analyses showed that neuroticism predicted the first onset of depressive disorders. However, neither neuroticism nor extraversion predicted first onsets of anxiety disorders, extraversion did not predict depressive disorders, and neither trait predicted suicidal ideation onset or severity after adjusting for baseline symptoms. Neuroticism and extraversion may respectively predispose youth to depressive or anxiety disorders but not to suicidal ideation over and above pre-existing symptoms. Results have implications for the early identification of at-risk youth and prevention of depressive and anxiety disorders and suicidal ideation.

Efficacy and safety of low-frequency repetitive transcranial magnetic stimulation in adolescents with first-episode major depressive disorder: A randomized, double-blind, sham-controlled pilot trial

BACKGROUND

A few sham-controlled studies have examined the efficacy, safety, and tolerability of low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) in adolescents with first-episode major depressive disorder (FE-MDD).

METHODS

Forty adolescents (aged 13-17 years) with FE-MDD were randomly assigned to receive active rTMS (n = 20) or sham rTMS (n = 20) for 10 sessions over two weeks. The severity of baseline depressive symptoms and their improvement on the day immediately after the second, fourth, sixth, eighth, and tenth sessions were assessed with the 17-item Hamilton Depression Rating Scale (HAMD-17).

RESULTS

After completing 10 rTMS treatment sessions, there was no significant difference in antidepressant response (70.0 % vs. 60.0 %, p > 0.05) and antidepressant remission (55.0 % vs. 35.0 %, p > 0.05) between rTMS groups. The linear mixed model analysis did not show a significant group-by-time interaction (F = 1.26; p > 0.05) in the HAMD-17 scores. There was a significant time main effect on the speed of processing (F = 13.61; p < 0.05), but this did not differ significantly between groups (p > 0.05). There were no other main effects and group-by-time interactions in the other MATRICS Consensus Cognitive Battery domains (all p > 0.05). All adverse event categories, such as fatigue and headache, were similar in the two groups (all p > 0.05).

CONCLUSIONS

In this study that compared a combination of LF-rTMS + medication with sham + medication, LF-rTMS had higher response and remission rates than a sham procedure in adolescents with FE-MDD, but the change was not statistically significant. LF-rTMS is generally safe, with mild adverse effects and no negative impact on neurocognitive performance for adolescents with FE-MDD.

REGISTRATION NUMBER

ChiCTR2000037878.

A Multisite, 6-Month, Open-Label Study of Maintenance Transcranial Magnetic Stimulation for Adolescents with Treatment-Resistant Depression

Introduction: Transcranial magnetic stimulation (TMS) is a promising intervention for adolescents with treatment-resistant depression (TRD). However, the durability of TMS-related improvement in adolescents is unclear. This 6-month study followed adolescents with TRD who had responded to TMS and provided TMS retreatment for adolescents with a partial relapse. Methods: The study enrolled adolescents (12-21 years) with TRD who had at least a partial response to sham or active TMS in a randomized controlled trial. Partial response was defined as ≥25% reduction of Hamilton Depression Rating Scale-24 (HAMD24). Participants with a partial relapse (≥1 point increase in Clinical Global Impression-Severity) received retreatment with daily 10 Hz TMS sessions until depressive symptom severity returned to the baseline score or after 30 TMS treatments. Results: There were 84 eligible participants, 66 were enrolled, and 41 completed the 6-month study. Twenty-eight participants (42%) were retreated with TMS. TMS retreatment courses had a mean of 22 sessions. At the 6-month follow-up, the complete sample exhibited reduced depressive symptoms (mean HAMD24 of 5.24) compared with baseline at entry into follow-up (mean HAMD24 of 8.21). Baseline depressive symptom severity was positively correlated with the risk of partial relapse, while the number of previous TMS interventions showed no correlation with the risk of partial relapse. TMS was well tolerated. Conclusions: This is the largest, long-term follow-up study with TMS retreatment for adolescents with TRD. These findings demonstrate the feasibility and clinical effects of a TMS retreatment protocol for adolescents with TRD, following a standard course of acute TMS.

Major challenges in youth psychopathology: treatment-resistant depression. A narrative review

Major depressive disorder (MDD) represents a major health issue in adolescents and young adults, leading to high levels of disability and profoundly impacting overall functioning. The clinical presentation of MDD in this vulnerable age group may slightly differ from what can be observed in adult populations, and psychopharmacological strategies do not always lead to optimal response. Resistance to antidepressant treatment has a prevalence estimated around 40% in youths suffering from MDD and is associated with higher comorbidity rates and suicidality. Several factors, encompassing biological, environmental, and clinical features, may contribute to the emergence of treatment-resistant depression (TRD) in adolescents and young adults. Furthermore, TRD may underpin the presence of an unrecognized bipolar diathesis, increasing the overall complexity of the clinical picture and posing major differential diagnosis challenges in the clinical practice. After summarizing current evidence on epidemiological and clinical correlates of TRD in adolescents and young adults, the present review also provides an overview of possible treatment strategies, including novel fast-acting antidepressants. Despite these pharmacological agents are promising in this population, their usage is expected to rely on risk-benefit ratio and to be considered in the context of integrated models of care.

Sex Differences in the Antidepressant and Neurocognitive Effects of Nonconvulsive Electrotherapy in Patients with Treatment-Refractory Depression

Objective

The objective of this study was to examine sex differences in the antidepressant and neurocognitive effects of adjunctive nonconvulsive electrotherapy (NET) in patients with treatment-refractory depression (TRD), which has not yet been thoroughly investigated.

Methods

The study enrolled 20 patients with TRD, comprising 11 males and 9 females, who underwent a series of 6 NET sessions. The 17-item Hamilton Depression Rating Scale (HAMD-17) was used to assess depressive symptoms, response, and remission at baseline and after the first, third, and sixth NET sessions. The Wisconsin Card Sorting Test (WCST) was used to assess neurocognitive function at baseline and after the sixth NET session.

Results

After completing 6 NET sessions, female patients experiencing TRD exhibited a higher inclination toward achieving an antidepressant response (77.8% vs. 45.5%, P  = .197) and antidepressant remission (22.2% vs. 0%, P  = .189) when compared to their male counterparts. No significant differences were observed in changes in the HAMD-17 and WCST subscale scores (all P > .05), including completing classification number, total error number, persistent error number, and random error number between males and females. Additionally, no significant correlations were observed between baseline WCST subscale scores and changes in HAMD-17 scores or endpoint scores, irrespective of sex (all P > .05).

Conclusion

These pilot findings suggest that female patients with TRD exhibited increased rates of achieving antidepressant response and remission after undergoing NET. However, further studies should be conducted to confirm these findings.

A retrospective examination of adjunctive L-methylfolate in children and adolescents with unipolar depression

BACKGROUND

Adjunctive l-methylfolate is commonly prescribed for children and adolescents with treatment-resistant mood disorders; however, the relationship between l-methylfolate augmentation across methylenetetrahydrofolate reductase (MTHFR) genotypes in youths with depressive symptoms is unclear.

METHODS

We retrospectively examined the electronic health records of patients (N = 412) with depressive symptoms associated with unipolar depressive disorders and their MTHFR C677T genotypes from 2013 to 2019. Patients were ≤18 years of age at the time of MTHFR pharmacogenetic testing. Treatment response was assessed with Clinical Global Impression-Improvement (CGI-I) score reported in the medical record.

RESULTS

Patients with an MTHFR C677T C/T or T/T genotype were more likely to be prescribed l-methylfolate when the clinician knew their MTHFR genotype (p < 0.0001, OR: 15.1, 95 % CI: [5.1, 44.2]), but not when the clinician did not know their genotype (p = 0.4, OR: 2.1, 95 % CI: [0.4, 11.4]). Change in baseline and endpoint CGI-I scores between patients with an MTHFR C677T variant who were prescribed and not prescribed l-methylfolate did not significantly differ (p = 0.39). Response rate was not associated with l-methylfolate prescription (p = 0.17) or l-methylfolate dose (p = 0.69).

LIMITATIONS

This was a retrospective study, which yielded a heterogeneous patient population and limited data availability (e.g., adherence). Patients are severely ill and may have a refractory illness that limits response to adjunctive l-methylfolate.

CONCLUSION

Clinicians prescribe l-methylfolate to children and adolescents with depressive symptoms associated with unipolar depressive disorders who have an MTHFR C677T variant, although augmentation may not be associated with treatment response, regardless of MTHFR genotype or dose.

Neurostructural Differences in Adolescents With Treatment-Resistant Depression and Treatment Effects of Transcranial Magnetic Stimulation

BACKGROUND

Despite its morbidity and mortality, the neurobiology of treatment-resistant depression (TRD) in adolescents and the impact of treatment on this neurobiology is poorly understood.

METHODS

Using automatic segmentation in FreeSurfer, we examined brain magnetic resonance imaging baseline volumetric differences among healthy adolescents (n = 30), adolescents with major depressive disorder (MDD) (n = 19), and adolescents with TRD (n = 34) based on objective antidepressant treatment rating criteria. A pooled subsample of adolescents with TRD were treated with 6 weeks of active (n = 18) or sham (n = 7) 10-Hz transcranial magnetic stimulation (TMS) applied to the left dorsolateral prefrontal cortex. Ten of the adolescents treated with active TMS were part of an open-label trial. The other adolescents treated with active (n = 8) or sham (n = 7) were participants from a randomized controlled trial.

RESULTS

Adolescents with TRD and adolescents with MDD had decreased total amygdala (TRD and MDD: -5%, P = .032) and caudal anterior cingulate cortex volumes (TRD: -3%, P = .030; MDD: -.03%, P = .041) compared with healthy adolescents. Six weeks of active TMS increased total amygdala volumes (+4%, P < .001) and the volume of the stimulated left dorsolateral prefrontal cortex (+.4%, P = .026) in adolescents with TRD.

CONCLUSIONS

Amygdala volumes were reduced in this sample of adolescents with MDD and TRD. TMS may normalize this volumetric finding, raising the possibility that TMS has neurostructural frontolimbic effects in adolescents with TRD. TMS also appears to have positive effects proximal to the site of stimulation.

Controversies In The Pharmacotherapy Of Adolescent Depression

BACKGROUND

Although fluoxetine and, in the USA, escitalopram are approved for depression in adolescence, substantial concern surrounds antidepressant use in youth. Major controversies regarding efficacy and safety (increased suicidality).

INTRODUCTION

The cathegory of depression is very broad and overinclusive, in terms of etiology, role of psychosocial adversities severity, episodicity, presentation, relationship with bipolarity. This heterogeneity, not fully controlled considered in Randomized Controlled Trials (RCTs), may account for the disappointing results on both efficacy and safety.

METHOD

Based on the available literature, we will address the following topics: a) controversies regarding the definition of depression as a unique homogeneous condition with a unique type of pharmacological treatment; b) controversies about the interpretation of data from Randomized Controlled Trials (RCTs) on the efficacy of pharmacological treatments in adolescent depression; c) the interpretation of data regarding the safety of antidepressant treatment in adolescent depression, particularly in terms of increased suicidal risk.

RESULTS

According to RCTs, antidepressants are minimally to moderately more effective than placebo, principally based on very high placebo responses, and only fluoxetine showed more evidence of efficacy. These differences in meta-analyses are sometimes statistically, but not clinically significant. Depression is a heterogeneous condition in terms of etiology, role of psychosocial adversities severity, episodicity, presentation, relationship with bipolarity. This heterogeneity may partly explain the low drug-placebo difference and the high placebo response (possibly related to a high level of natural recovery of the adolescent depression). In the National Institute of Mental Health (NIMH)-funded studies, including a lower number of study sites and more reliable enrollment procedures, lower placebo response rates and greater group differences between medication and placebo were found. Robust evidence supports an increased risk of emergent suicidality after starting antidepressants. A clear age effect on suicidal risk after antidepressants is supported by a comprehensive meta-analysis, showing that suicidal risk increased with decreasing age, being markedly greater in subjects aged between 18 and 25 years. However, the term suicidality is too broad, as it includes suicidal ideation, suicidal attempts, and completed suicide, with a hugely wide range of severity and pervasiveness. If emergent suicidality should be actively and carefully explored, empirical evidence, albeit weak, suggests that combined pharmacotherapy (antidepressant and/or lithium) associated with psychotherapy may be helpful in reducing pretreatment suicidal ideation and suicidal risk.

DISCUSSION

Moderate to severe depression should be treated with psychotherapy and/or fluoxetine, the best-supported medication, and treatment-resistant adolescents should always receive combined treatment with psychotherapy. Suicidal ideation, particularly with a plan, should be actively explored before starting an antidepressant, as a reason for the closest monitoring. Emergent suicidality after starting antidepressants, as well as antidepressant-related activation, should also be closely monitored and may lead to antidepressant discontinuation. Although no response to pharmacotherapy and psychotherapy may occur in up to 40% of depressed adolescents, possible predictors or mediators of poorer response in adolescents are uncertain, and only a few studies support possible treatment strategies. Finally, studies exploring the efficacy of antidepressants in specific depression subtypes, i.e., based on prevalent psychopathological dimensions (apathy, withdrawal, impulsivity), are warranted.

Therapeutic applications of transcutaneous auricular vagus nerve stimulation with potential for application in neurodevelopmental or other pediatric disorders

Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) as a newly developed technique involves stimulating the cutaneous receptive field formed by the auricular branch of the vagus nerve in the outer ear, with resulting activation of vagal connections to central and peripheral nervous systems. Increasing evidence indicates that maladaptive neural plasticity may underlie the pathology of several pediatric neurodevelopmental and psychiatric disorders, such as autism spectrum disorder, attention deficit hyperactivity disorder, disruptive behavioral disorder and stress-related disorder. Vagal stimulation may therefore provide a useful intervention for treating maladaptive neural plasticity. In the current review we summarize the current literature primarily on therapeutic use in adults and discuss the prospects of applying taVNS as a therapeutic intervention in specific pediatric neurodevelopmental and other psychiatric disorders. Furthermore, we also briefly discuss factors that would help optimize taVNS protocols in future clinical applications. We conclude from these initial findings that taVNS may be a promising alternative treatment for pediatric disorders which do not respond to other interventions.

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.

Parental Attitudes Toward Use of Ketamine in Adolescent Mood Disorders and Suicidality

Objectives: Investigation into parental decision-making processes involving ketamine is of high priority, given the necessary role of parents in consenting to treatment. In this study, we examined parental attitudes toward the emerging use of ketamine in adolescent mood disorders and suicidality. Methods: Two hundred eighty-three English-speaking parents completed an online survey using Amazon Mechanical Turk on psychiatric use of ketamine, acceptability of treatment, and their perceptions of ketamine treatment. Data quality control measures were used to mitigate invalid reporting. Results: Parents reported high acceptability toward use of ketamine for suicidality, major depressive disorder, and bipolar disorder in adolescents. Primary concerns around ketamine involved its potential side effects and lack of United States Food and Drug Administration (FDA) approval. Responses indicated a preference for short-term applications and less invasive routes of administration for ketamine. Parent history of mental illness, familiarity with psychological treatments, and comfort using other mental health interventions in their children predicted greater acceptability of ketamine. Conclusion: Although ketamine is not currently approved by the FDA for psychiatric use in children nor recommended outside of research protocols, these findings suggest that parents have interest in the application of ketamine as a treatment for pediatric mood disorders and point to future directions for research and clinical orientation.

Left prefrontal transcranial magnetic stimulation for treatment-resistant depression in adolescents: a double-blind, randomized, sham-controlled trial

Treatment-resistant depression (TRD) is prevalent and associated with a substantial psychosocial burden and mortality. There are few prior studies of interventions for TRD in adolescents. This was the largest study to date examining the feasibility, safety, and efficacy of 10-Hz transcranial magnetic stimulation (TMS) for adolescents with TRD. Adolescents with TRD (aged 12-21 years) were enrolled in a randomized, sham-controlled trial of TMS across 13 sites. Treatment resistance was defined as an antidepressant treatment record level of 1 to 4 in a current episode of depression. Intention-to-treat patients (n = 103) included those randomly assigned to active NeuroStar TMS monotherapy (n = 48) or sham TMS (n = 55) for 30 daily treatments over 6 weeks. The primary outcome measure was change in the Hamilton Depression Rating Scale (HAM-D-24) score. After 6 weeks of blinded treatment, improvement in the least-squares mean (SE) HAM-D-24 scores were similar between the active (-11.1 [2.03]) and sham groups (-10.6 [2.00]; P = 0.8; difference [95% CI], - 0.5 [-4.2 to 3.3]). Response rates were 41.7% in the active group and 36.4% in the sham group (P = 0.6). Remission rates were 29.2% in the active group and 29.0% in the sham group (P = 0.95). There were no new tolerability or safety signals in adolescents. Although TMS treatment produced a clinically meaningful change in depressive symptom severity, this did not differ from sham treatment. Future studies should focus on strategies to reduce the placebo response and examine the optimal dosing of TMS for adolescents with TRD.

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.