Special Populations: Treatment-Resistant Depression in Children and Adolescents

Interventional approaches to treatment resistant depression (DTR) in children and adolescents: A systematic review and meta-analysis

BACKGROUND

Major depressive disorder (MDD) is highly prevalent in youth. Conventional treatment paradigms primarily involve selective serotonin reuptake inhibitors (SSRIs) and psychotherapy, yet a significant proportion of this population exhibits treatment-resistant depression (TRD). In adults, interventional therapies like Electroconvulsive Therapy (ECT), repetitive Transcranial Magnetic Stimulation (rTMS), and ketamine have shown promise for TRD, but their comparative efficacy remains underexplored in Adolescent and pediatric population. This systematic review and meta-analysis aims to assess the relative effectiveness of ECT, rTMS, and ketamine in treating TRD among adolescents.

METHODS

Following PRISMA guidelines, we systematically searched databases for studies of ECT, rTMS, or ketamine for treatment-resistant depression in youth ages 10-24. Three reviewers independently screened for inclusion based on predefined criteria. Included observational and randomized controlled trials reported depression symptoms with measures like HDRS and MADRS in youth treated with ECT, rTMS, or ketamine. Two reviewers extracted data on interventions, patients, and depression symptom outcomes. Chance-adjusted inter-reviewer agreement was calculated. For meta-analysis, we pooled standardized mean differences (SMDs) in depression scores using random effects models and assessed heterogeneity with I2 statistics.

RESULTS

Meta-analysis of 10 observational studies examined SMD in depression scores for treatment resistant depression patients treated with ECT, ketamine, or rTMS. Patients treated with ECT had a significantly lower SMD of 1.99 (95 % CI 0.92-3.05, p < 0.001) compared to baseline. Patients treated with ketamine also had a significantly lower SMD of 1.58 (95 % CI 1.04-2.12, p < 0.001). Patients treated with rTMS had the lowest SMD of 2.79 (95 % CI 0.79-4.80, p = 0.006). There was no significant difference between the three groups overall (p > 0.05). Comparative analysis between ECT and ketamine found no significant difference in SMD (p = 0.387). Comparison of ECT versus rTMS found a significant difference in SMD favoring rTMS (p = 0.004). Comparison of ketamine versus rTMS suggested a potential difference in SMD favoring rTMS (p = 0.058). In summary, rTMS resulted in significantly larger reductions in depression scores than ECT, and potentially larger reductions than ketamine.

CONCLUSIONS

This meta-analysis illustrates the ability of rTMS, ECT, and ketamine to improve depression in youth. rTMS resulted in the largest improvements, highlighting its potential as a first-line treatment for pediatric treatment-resistant depression given its favorable side effect profile compared to ECT. Further research directly comparing these modalities is needed.

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.

Novel rapid treatment options for adolescent depression

There is an urgent need for novel fast-acting antidepressants for adolescent treatment-resistant depression and/or suicidal risk, since the selective serotonin reuptake inhibitors that are clinically approved for that age (i.e., fluoxetine or escitalopram) take weeks to work. In this context, one of the main research lines of our group is to characterize at the preclinical level novel approaches for rapid-acting antidepressants for adolescence. The present review summarizes the potential use in adolescence of non-pharmacological options, such as neuromodulators (electroconvulsive therapy and other innovative types of brain stimulation), as well as pharmacological options, including consciousness-altering drugs (mainly ketamine but also classical psychedelics) and cannabinoids (i.e., cannabidiol), with promising fast-acting responses. Following a brief analytical explanation of adolescent depression, we present a general introduction for each therapeutical approach together with the clinical evidence supporting its potential beneficial use in adolescence (mainly extrapolated from prior successful examples for adults), to then report recent and/or ongoing preclinical studies that will aid in improving the inclusion of these therapies in the clinic, by considering potential sex-, age-, and dose-related differences, and/or other factors that might affect efficacy or long-term safety. Finally, we conclude the review by providing future avenues to maximize treatment response, including the need for more clinical studies and the importance of designing and/or testing novel treatment options that are safe and fast-acting for adolescent depression.