Antidepressants and the adolescent brain

A Narrative Review of Depression and Suicide in Adolescent Females to Guide Assessment and Treatment Recommendations

STUDY OBJECTIVE

Suicide is a leading cause of death for adolescents. Medical professionals are increasingly being asked to screen for depressive symptoms and suicidal ideation with little training. The purpose of this paper is to review factors related to suicidal thoughts and actions, assessment of symptoms, and initial suggestions for treatment for medical providers.

METHODS

A literature review of risk and resilience factors, assessment measures, and treatment options for depression and suicidal ideation and behavior in adolescent females was conducted.

RESULTS

Given the higher risk of suicidal thoughts and depressive symptoms in adolescent females, accurate and thorough assessment of symptoms is recommended.

CONCLUSION

Medical providers should be aware of symptoms related to depression and suicidal ideation in order to provide more effective assessments. Recommendations for brief assessment measures that can be used in the clinic and possible first line treatments are provided.

Promising new pharmacological targets for depression: The search for efficacy

Pharmacological treatment of major depressive disorder (MDD) still relies on the use of serotonergic drugs, despite their limited efficacy. A few mechanistically new drugs have been developed in recent years, but many fail in clinical trials. Several hypotheses have been proposed to explain MDD pathophysiology, indicating that physiological processes such as neuroplasticity, circadian rhythms, and metabolism are potential targets. Here, we review the current state of pharmacological treatments for MDD, as well as the preclinical and clinical evidence for an antidepressant effect of molecules that target non-serotonergic systems. We offer some insights into the challenges facing the development of new antidepressant drugs, and the prospect of finding more effectiveness for each target discussed.

Risk of parental psychiatric disorders among adolescents with major depressive disorder according to response to antidepressant treatment: does the type of antidepressant matter?

BACKGROUND

The genetic load for major depressive disorder (MDD) may be higher in people who develop MDD earlier in life. This study aimed to investigate whether the parents of adolescents with MDD were more likely to have MDD, bipolar disorder (BD), schizophrenic disorder (SZ), alcohol use disorder, or substance use disorder than the parents of adolescents without MDD. We also examined whether the response to antidepressant treatment predicted the likelihood of parental psychiatric disorders.

METHODS

In all, 1,758 adolescents aged 12-19 years with antidepressant-resistant depression, 7,032 (1:4) age-/sex-matched adolescents with antidepressant-responsive depression and 7,032 (1:4) age-/sex-matched controls were included. Parental psychiatric disorders of individuals enrolled were assessed.

RESULTS

The parents of the adolescents with MDD were more likely to be diagnosed with MDD, BD, SZ, alcohol use disorder, or substance use disorder than the parents of the control group. The parents of adolescents who were antidepressant resistant and the mothers of adolescents who were either treatment resistant or treatment responsive were more likely to be diagnosed with a psychiatric disorder.

DISCUSSION

Our study demonstrated that parents of adolescents with MDD may be more likely to be diagnosed with MDD, BD, SZ, alcohol use disorder, or substance use disorder than parents of adolescents without MDD, suggesting the within-disorder transmission and cross-disorder transmission of these psychiatric disorders. Furthermore, the parent's sex and the response to antidepressant treatment may affect the within-disorder transmission of MDD.

Convergent molecular and structural neuroimaging signatures of first-episode depression

BACKGROUND

Convergent studies have demonstrated morphological abnormalities in various brain regions in depression patients. However, the molecular underpinnings of the structural impairments remain largely unknown, despite a pressing need for treatment targets and mechanisms. Here, we investigated the gray matter volume (GMV) alteration in patients with depression and its underlying molecular architecture.

METHODS

We recruited 195 first-episode, treatment-naïve depression patients and 78 gender-, age-, and education level-matched healthy controls (HCs) who underwent high-resolution T1-weighted magnetic resonance scans. Voxel-based morphometry (VBM) was adopted to calculate the GMV differences between two groups. Then we analyzed the spatial correlation between depression-induced alteration in GMV and density maps of 10 receptors/transporters deriving from prior molecular imaging in healthy people.

RESULTS

Compared to HCs, the depression group had significantly increased GMV in the left ventral portions of the ventral medial prefrontal cortex, parahippocampal gyrus, amygdala, the right superior parietal lobule and precuneus while decreased GMV in the bilateral hippocampus extending to the thalamus and cerebellum. The GMV alteration introduced by depression was spatially correlated with serotonin receptors (5-HT1a, 5-HT1b, and 5-HT2a), dopamine receptors (D1 and D2) and GABAergic receptor (GABAa) densities.

LIMITATIONS

The conclusions drawn in this study were obtained from a single dataset.

CONCLUSIONS

This study reveals abnormal GMV alteration and provides a series of neurotransmitters receptors possibly related to GMV alteration in depression, which facilitates an integrative understanding of the molecular mechanism underlying the structural abnormalities in depression and may provide clues to new treatment strategies.

Increased Readmission Rates in Younger Male Patients Due to Suicidal Risk in Newly Diagnosed Depressive Disorders After Initiation of Serotonin Reuptake Inhibitors

Background Depressive disorders have a prevalence of 322 million people worldwide and are a leading cause of morbidity. These disorders can affect individuals of all ages and can present over time. Due to the diversity in the presentation of depressive disorders, vigilance towards depressive disorders can lead to more timely and effective treatment. Serotonin Selective Reuptake Inhibitors (SSRIs) and Serotonin Norepinephrine Reuptake Inhibitors (SNRIs) are the first lines of treatment for these disorders. Moreover, the United States Food and Drug Administration (FDA) issued a black-box warning for several antidepressants, stating an increased risk of suicidality in individuals under 25 years old. However, the placement of this black-box warning has been controversial. In this study, the authors aim to investigate if there is a relationship between the use of SSRI or SNRI on patients with newly diagnosed depressive disorder and hospital readmission due to suicide-related events.  Methods For this retrospective cohort study, de-identified data were obtained from the HCA Healthcare database by searching for patients newly diagnosed with depressive disorders and started on SSRIs or SNRIs. Patient data were evaluated for readmissions due to suicide-related events within 90 days of discharge from the hospital and establishing their initial SSRI/SNRI prescription.  Results After data was obtained and evaluated via statistical analysis, the variables with statistical significance were: age (p-value = 0.0164) and sex (p-value = 0.0150). These two were significantly associated with the rate of readmission: younger and male patients had an increased risk of readmission due to suicide-related events within 90 days of discharge after starting SSRI, or SNRI, to treat depressive disorders. Conclusion These results support the importance of monitoring patients started on SSRI or SNRI, with particularly careful consideration in depressed young male patients.

Efficacy and tolerability of antidepressant drugs in treatment of depression in children and adolescents: a network meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of antidepressants in treatment of depression disorder in children and adolescents by network meta-analysis.

METHODS

Databases of PubMed, Cochrane Library, EMBASE, Web of Science, PsycINFO, CBM, CNKI and Wanfang Data were searched for randomized controlled trials (RCT) related to antidepressants in treatment of children and adolescents with depression from inception to December 2021. Quality assessment and data extraction from the included RCTs were performed. Statistical analyses of efficacy and tolerability were conducted with Stata 15.1 software. Surface under the cumulative ranking (SUCAR) was used to rank the value of the antidepressants.

RESULTS

A total of 33 RCTs were included in 32 articles, involving 6949 patients. There are 13 antidepressants used in total, including amitriptyline, vilazodone, fluoxetine, selegiline, paroxetine, imipramine, desipramine, sertraline, nortriptyline, escitalopram, citalopram, venlafaxine and duloxetine. The results of network meta-analysis showed that the efficacy of duloxetine ( OR=1.95, 95% CI: 1.41-2.69), fluoxetine ( OR=1.73, 95% CI: 1.40-2.14), venlafaxine ( OR=1.37, 95% CI: 1.04-1.80) and escitalopram ( OR=1.48, 95% CI: 1.12-1.95) were significantly higher than that of placebos (all P<0.05); the probability cumulative ranks were duloxetine (87.0%), amitriptyline (83.3%), fluoxetine (79.0%), escitalopram (62.7%), etc. The results showed that the intolerability of patients receiving imipramine ( OR=0.15, 95% CI: 0.08-0.27), sertraline ( OR=0.33, 95% CI: 0.16-0.71), venlafaxine ( OR=0.35, 95% CI: 0.17-0.72), duloxetine ( OR=0.35, 95% CI: 0.17-0.73) and paroxetine ( OR=0.52, 95% CI: 0.30-0.88) were significantly higher than that of placebos (all P<0.05), and the probability cumulative ranks were imipramine (95.7%), sertraline (69.6%), venlafaxine (68.6%), duloxetine (68.2%), etc. Conclusion: Among 13 antidepressants, duloxetine, fluoxetine, escitalopram and venlafaxine are significantly better than placebo in terms of efficacy, but duloxetine and venlafaxine are less well tolerated.

The comparative effectiveness of antidepressants for youths with major depressive disorder: a nationwide population-based study in Taiwan

Background:

Guidelines recommend fluoxetine as a first-line medication for youths diagnosed with major depressive disorder (MDD). However, little is known about the long-term effectiveness of different antidepressants in juveniles in the real world. This study aimed to compare the effectiveness of antidepressants in youths with MDD.

Methods:

Youths (<20 years old) with a diagnosis of MDD who were new users of antidepressants were selected from a nationwide population-based cohort in Taiwan between 1997 and 2013. We divided a total of 16,981 users (39.9% male; mean age: 16.6 years) into 10 different antidepressant groups (fluoxetine, sertraline, paroxetine, venlafaxine, citalopram, escitalopram, bupropion, fluvoxamine, mirtazapine and moclobemide). Regarding treatment outcomes (hospitalisation and medication discontinuation), Cox proportional hazards regression models were applied to estimate the hazards of such outcomes.

Results:

Compared with the youths treated with fluoxetine, the bupropion-treated group demonstrated lower rates of hospitalisation and discontinuation. Mirtazapine-treated group demonstrated a higher hospitalisation risk mainly when administered for single depressive episodes. Furthermore, patients treated with sertraline and fluvoxamine had higher discontinuation rates. Among the younger teenage subgroups (< 16 years), significantly higher rates of discontinuation were observed in those treated with sertraline, escitalopram and fluvoxamine. Among the older teenage subgroups (⩾ 16 years), bupropion was superior to fluoxetine in preventing hospitalisation and discontinuation.

Conclusion:

We concluded that bupropion might surpass fluoxetine with regard to hospitalisation prevention and drug therapy maintenance among youths with MDD, while mirtazapine users demonstrated a higher hospitalisation risk. Our findings might serve as a reference for clinicians in future studies.

Preventive strategies for adolescent depression: What are we missing? A focus on biomarkers

Adolescent depression is an important global issue with several unmet needs that still must be addressed and, to date, there are only few effective preventive strategies to reduce the burden of this disorder worldwide. In this mini-review, the evidence and potential ways to improve an early detection will be discussed as well as prompt interventions by focusing on a better understanding of the risks underlying the developing of adolescent depression from both a sociodemographic and a biological perspective.

Long-term use of antidepressants, mood stabilizers, and antipsychotics in pediatric patients with a focus on appropriate deprescribing

It is estimated that 8% to 12% of youth are prescribed psychotropic medications. Those in foster care, juvenile justice systems, residential treatment facilities, and with developmental or intellectual disabilities are more likely to be prescribed high-risk regimens. The use of psychotropic medications in this age group is often off-label and can be associated with significant risk, warranting critical evaluation of their role. Landmark trials, pediatric-specific guidelines, and state-driven initiatives play critical roles in supporting evidence-based use of psychotropic medications in children. Overall, there is a lack of literature describing the long-term use of psychotropic medications in youth—particularly with regard to neurobiological, physical, and social changes that occur throughout development. Deprescribing is an important practice in child and adolescent psychiatry, given concerns for over-prescribing, inappropriate polytherapy, and the importance of reevaluating the role of psychotropic medications as children develop.

Impact of Inosine on Chronic Unpredictable Mild Stress-Induced Depressive and Anxiety-Like Behaviors With the Alteration of Gut Microbiota

Current antidepressants do not confer a clear advantage in children and adolescents with major depressive disorder (MDD). Accumulating evidence highlights the potential antidepressant-like effects of inosine on adult MDD, and gut microbiomes are significantly associated with MDD via the microbiota-gut-brain axis. However, few studies have investigated possible associations between inosine and gut microbiota in adolescents with MDD. The current study investigated the potential antidepressant effects of inosine in adolescent male C57BL/6 mice. After 4 weeks of chronic unpredictable mild stress (CUMS) stimulation, the mice were assessed by body weight, the sucrose preference test (SPT), open field test, and the elevated plus maze (EPM). The microbiota compositions of feces were determined by 16S rRNA gene sequencing. Inosine significantly improved CUMS-induced depressive and anxiety-like behaviors in adolescent mice including SPT and EPM results. Fecal microbial composition differed in the CON+saline, CUMS+saline, and CUMS+inosine groups, which were characterized by 126 discriminative amplicon sequence variants belonging to Bacteroidetes and Firmicute at the phylum level and Muribaculaceae and Lachnospiraceae at the family level. Muribaculaceae was positively associated with depressive and anxiety-like behaviors. KEGG functional analysis suggested that inosine might affect gut microbiota through carbohydrate metabolism and lipid metabolism pathways. The results of the study indicated that inosine improved depressive and anxiety-like behaviors in adolescent mice, in conjunction with the alteration of fecal microbial composition. Our findings may provide a novel perspective on the antidepressant effects of inosine in children and adolescents.

The Efficacy and Cognitive Effects of Acute Course Electroconvulsive Therapy Are Equal in Adolescents, Transitional Age Youth, and Young Adults

Objective: Electroconvulsive therapy (ECT) is the most effective acute treatment for depression, but its use in younger patients is rare and heavily regulated in many U.S. states. It is unclear whether age modifies treatment response or tolerability in adolescents, transitional age youth, and young adults. We examined the effects of ECT on depression and cognition in patients aged 16-30 years. Methods: A retrospective cohort study of patients aged 16-30 years receiving ECT between 2011 and 2020 who were evaluated with the Quick Inventory of Depressive Symptomatology (QIDS), the Behavior and Symptom Identification Scale-24 (BASIS-24), and the Montreal Cognitive Assessment (MoCA) at baseline and following treatment #10. Results: Among the 424 patients who met the inclusion criteria, ECT was associated with a decrease in depression symptoms (ΔQIDS -6.7; Kruskal-Wallis rank sum test; χ² = 293.37; df = 2; p < 0.0001) and improvement in overall self-reported mental health status (ΔBASIS-24 - 0.70; Kruskal-Wallis rank sum test; χ² = 258.5; df = 2; p < 0.0001) during the first 10 treatments, with a slight reduction in cognition as measured by the MoCA (ΔMoCA -1.1; Kruskal-Wallis rank sum test; χ² = 33.7; df = 1; p < 0.0001). Age was not a significant predictor of QIDS, BASIS-24, or MoCA changes. Conclusions: Among 424 patients aged 16-30 years receiving acute course ECT, age was not a significant predictor of improvement in depression, change in overall self-reported mental health status, or change in cognition. These results support the utility of ECT in the treatment of adolescents and young adults.

Impact of Antidepressant Prescriptions on Suicidal Behavior in Times of Severe Financial Strain

ABSTRACT

This descriptive study observes the relationship between antidepressant prescriptions and the suicide rate in Italy in the 2000s to the mid-2010s, which includes a period of severe economic crisis. The observation period was from 2000 to 2015. Suicide and unemployment rates disaggregated by age and sex were collected from the Italian Institute of Statistics. Statistical analyses were performed using correlations between suicide rates and the defined daily dose, with reference to selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), and other types of antidepressants. Fixed-effects panel regressions were also run. Increases in SSRIs prescriptions were associated with decreases in suicide rates among both men and women. However, when the analyses were adjusted for the rate of growth of the unemployment rate and for gross domestic product, the associations were weaker. The potential protective factor of SSRIs with respect to suicidal behavior may be reduced by severe recessions, especially when unemployment increases.

High-level psychotropic polypharmacy: a retrospective comparison of children in foster care to their peers on Medicaid

BACKGROUND

The use of antipsychotic medication and psychotropic polypharmacy has increased in the United States over the last two decades especially for children from low-income families and those in foster care. Although attention has been paid to providing greater insight, prescribing patterns remain concerning since there is a lack of evidence related to safety and efficacy. High-level psychotropic polypharmacy has not been described. We aim to compare the use of HLPP for children receiving Medicaid services and those in foster care and identify factors associated with the duration of use of high-level psychotropic polypharmacy. Additionally, we will examine the frequency of laboratory metabolic screening and emergency department, inpatient, and outpatient visits.

METHODS

A cross-sectional, secondary analysis of statewide data describes trends in high-level psychotropic polypharmacy from 2012 to 2017 and the prevalence and predictors of high-level psychotropic polypharmacy duration and resource use in 2017 for all children on Medicaid and those in foster care. High-level psychotropic polypharmacy included concurrent use, at least four classes of medications including an antipsychotic, and at least 30 days duration.

RESULTS

High-level psychotropic polypharmacy increased from 2012 to 2014 for both groups but stabilized in 2015-2016. Children in foster care showed a slight increase compared to their peers in 2017. There was no association between duration and demographic characteristics or foster care status. Diagnoses predicted duration. Neither group received metabolic monitoring at an acceptable rate.

CONCLUSIONS

Concerning patterns of high-level psychotropic polypharmacy and metabolic monitoring were identified. Cautious use of high-level psychotropic polypharmacy and greater oversight to ensure that these children are receiving comprehensive services like behavioral health, primary care, and primary prevention.

New generation antidepressants for depression in children and adolescents: a network meta-analysis

BACKGROUND

Major depressive disorders have a significant impact on children and adolescents, including on educational and vocational outcomes, interpersonal relationships, and physical and mental health and well-being. There is an association between major depressive disorder and suicidal ideation, suicide attempts, and suicide. Antidepressant medication is used in moderate to severe depression; there is now a range of newer generations of these medications.

OBJECTIVES

To investigate, via network meta-analysis (NMA), the comparative effectiveness and safety of different newer generation antidepressants in children and adolescents with a diagnosed major depressive disorder (MDD) in terms of depression, functioning, suicide-related outcomes and other adverse outcomes. The impact of age, treatment duration, baseline severity, and pharmaceutical industry funding was investigated on clinician-rated depression (CDRS-R) and suicide-related outcomes.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Specialised Register, the Cochrane Library (Central Register of Controlled Trials (CENTRAL) and Cochrane Database of Systematic Reviews (CDSR)), together with Ovid Embase, MEDLINE and PsycINFO till March 2020.

SELECTION CRITERIA

Randomised trials of six to 18 year olds of either sex and any ethnicity with clinically diagnosed major depressive disorder were included. Trials that compared the effectiveness of newer generation antidepressants with each other or with a placebo were included. Newer generation antidepressants included: selective serotonin reuptake inhibitors; selective norepinephrine reuptake inhibitors (SNRIs); norepinephrine reuptake inhibitors; norepinephrine dopamine reuptake inhibitors; norepinephrine dopamine disinhibitors (NDDIs); and tetracyclic antidepressants (TeCAs).

DATA COLLECTION AND ANALYSIS

Two reviewers independently screened titles/abstracts and full texts, extracted data, and assessed risk of bias. We analysed dichotomous data as Odds Ratios (ORs), and continuous data as Mean Difference (MD) for the following outcomes: depression symptom severity (clinician rated), response or remission of depression symptoms, depression symptom severity (self-rated), functioning, suicide related outcomes and overall adverse outcomes. Random-effects network meta-analyses were conducted in a frequentist framework using multivariate meta-analysis. Certainty of evidence was assessed using Confidence in Network Meta-analysis (CINeMA). We used "informative statements" to standardise the interpretation and description of the results.

MAIN RESULTS

Twenty-six studies were included. There were no data for the two primary outcomes (depressive disorder established via clinical diagnostic interview and suicide), therefore, the results comprise only secondary outcomes. Most antidepressants may be associated with a "small and unimportant" reduction in depression symptoms on the CDRS-R scale (range 17 to 113) compared with placebo (high certainty evidence: paroxetine: MD -1.43, 95% CI -3.90, 1.04; vilazodone: MD -0.84, 95% CI -3.03, 1.35; desvenlafaxine MD -0.07, 95% CI -3.51, 3.36; moderate certainty evidence: sertraline: MD -3.51, 95% CI -6.99, -0.04; fluoxetine: MD -2.84, 95% CI -4.12, -1.56; escitalopram: MD -2.62, 95% CI -5.29, 0.04; low certainty evidence: duloxetine: MD -2.70, 95% CI -5.03, -0.37; vortioxetine: MD 0.60, 95% CI -2.52, 3.72; very low certainty evidence for comparisons between other antidepressants and placebo). There were "small and unimportant" differences between most antidepressants in reduction of depression symptoms (high- or moderate-certainty evidence). Results were similar across other outcomes of benefit. In most studies risk of self-harm or suicide was an exclusion criterion for the study. Proportions of suicide-related outcomes were low for most included studies and 95% confidence intervals were wide for all comparisons. The evidence is very uncertain about the effects of mirtazapine (OR 0.50, 95% CI 0.03, 8.04), duloxetine (OR 1.15, 95% CI 0.72, 1.82), vilazodone (OR 1.01, 95% CI 0.68, 1.48), desvenlafaxine (OR 0.94, 95% CI 0.59, 1.52), citalopram (OR 1.72, 95% CI 0.76, 3.87) or vortioxetine (OR 1.58, 95% CI 0.29, 8.60) on suicide-related outcomes compared with placebo. There is low certainty evidence that escitalopram may "at least slightly" reduce odds of suicide-related outcomes compared with placebo (OR 0.89, 95% CI 0.43, 1.84). There is low certainty evidence that fluoxetine (OR 1.27, 95% CI 0.87, 1.86), paroxetine (OR 1.81, 95% CI 0.85, 3.86), sertraline (OR 3.03, 95% CI 0.60, 15.22), and venlafaxine (OR 13.84, 95% CI 1.79, 106.90) may "at least slightly" increase odds of suicide-related outcomes compared with placebo. There is moderate certainty evidence that venlafaxine probably results in an "at least slightly" increased odds of suicide-related outcomes compared with desvenlafaxine (OR 0.07, 95% CI 0.01, 0.56) and escitalopram (OR 0.06, 95% CI 0.01, 0.56). There was very low certainty evidence regarding other comparisons between antidepressants.

AUTHORS' CONCLUSIONS

Overall, methodological shortcomings of the randomised trials make it difficult to interpret the findings with regard to the efficacy and safety of newer antidepressant medications. Findings suggest that most newer antidepressants may reduce depression symptoms in a small and unimportant way compared with placebo. Furthermore, there are likely to be small and unimportant differences in the reduction of depression symptoms between the majority of antidepressants. However, our findings reflect the average effects of the antidepressants, and given depression is a heterogeneous condition, some individuals may experience a greater response. Guideline developers and others making recommendations might therefore consider whether a recommendation for the use of newer generation antidepressants is warranted for some individuals in some circumstances. Our findings suggest sertraline, escitalopram, duloxetine, as well as fluoxetine (which is currently the only treatment recommended for first-line prescribing) could be considered as a first option. Children and adolescents considered at risk of suicide were frequently excluded from trials, so that we cannot be confident about the effects of these medications for these individuals. If an antidepressant is being considered for an individual, this should be done in consultation with the child/adolescent and their family/caregivers and it remains critical to ensure close monitoring of treatment effects and suicide-related outcomes (combined suicidal ideation and suicide attempt) in those treated with newer generation antidepressants, given findings that some of these medications may be associated with greater odds of these events. Consideration of psychotherapy, particularly cognitive behavioural therapy, as per guideline recommendations, remains important.

The stage-specifically accelerated brain aging in never-treated first-episode patients with depression

Depression associated with structural brain abnormalities is hypothesized to be related with accelerated brain aging. However, there is far from a unified conclusion because of clinical variations such as medication status, cumulative illness burden. To explore whether brain age is accelerated in never‐treated first‐episode patients with depression and its association with clinical characteristics, we constructed a prediction model where gray matter volumes measured by voxel‐based morphometry derived from T1‐weighted MRI scans were treated as features. The prediction model was first validated using healthy controls (HCs) in two Chinese Han datasets (Dataset 1, N = 130 for HCs and N = 195 for patients with depression; Dataset 2, N = 270 for HCs) separately or jointly, then the trained prediction model using HCs (N = 400) was applied to never‐treated first‐episode patients with depression (N = 195). The brain‐predicted age difference (brain‐PAD) scores defined as the difference between predicted brain age and chronological age, were calculated for all participants and compared between patients with age‐, gender‐, educational level‐matched HCs in Dataset 1. Overall, patients presented higher brain‐PAD scores suggesting patients with depression having an “older” brain than expected. More specially, this difference occurred at illness onset (illness duration <3 months) and following 2 years then disappeared as the illness further advanced (>2 years) in patients. This phenomenon was verified by another data‐driven method and significant correlation between brain‐PAD scores and illness duration in patients. Our results reveal that accelerated brain aging occurs at illness onset and suggest it is a stage‐dependent phenomenon in depression.

Fluoxetine-induced Systemic Hypertension in a 12-Year-Old Girl: A Case Report

ABSTRACT

Fluoxetine, a selective serotonin reuptake inhibitor, is an efficacious medication in social anxiety disorder with a generally well-tolerated adverse effect profile. However, infrequent side effects may occur during treatment. Here, we report a case of systemic hypertension in a 12-year-old female patient with social anxiety disorder receiving fluoxetine treatment. To the best of our knowledge, this is the first report of fluoxetine-induced systemic hypertension in children and adolescences.

Comparative efficacy and acceptability of antidepressants, psychotherapies, and their combination for acute treatment of children and adolescents with depressive disorder: a systematic review and network meta-analysis

BACKGROUND

Depressive disorders are common in children and adolescents. Antidepressants, psychotherapies, and their combination are often used in routine clinical practice; however, available evidence on the comparative efficacy and safety of these interventions is inconclusive. Therefore, we sought to compare and rank all available treatment interventions for the acute treatment of depressive disorders in children and adolescents.

METHODS

We did a systematic review and network meta-analysis. We searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, PsycINFO, ProQuest, CINAHL, LiLACS, international trial registries, and the websites of regulatory agencies for published and unpublished randomised controlled trials from database inception until Jan 1, 2019. We included placebo-controlled and head-to-head trials of 16 antidepressants, seven psychotherapies, and five combinations of antidepressant and psychotherapy that are used for the acute treatment of children and adolescents (≤18 years old and of both sexes) with depressive disorder diagnosed according to standard operationalised criteria. Trials recruiting participants with treatment-resistant depression, bipolar disorder, psychotic depression, treatment duration of less than 4 weeks, or an overall sample size of fewer than ten patients were excluded. We extracted data following a predefined hierarchy of outcome measures, and assessed risk of bias and certainty of evidence using validated methods. Primary outcomes were efficacy (change in depressive symptoms) and acceptability (treatment discontinuation due to any cause). We estimated summary standardised mean differences (SMDs) or odds ratios (ORs) with credible intervals (CrIs) using network meta-analysis with random effects. This study was registered with PROSPERO, number CRD42015020841.

FINDINGS

From 20 366 publications, we included 71 trials (9510 participants). Depressive disorders in most studies were moderate to severe. In terms of efficacy, fluoxetine plus cognitive behavioural therapy (CBT) was more effective than CBT alone (-0·78, 95% CrI -1·55 to -0·01) and psychodynamic therapy (-1·14, -2·20 to -0·08), but not more effective than fluoxetine alone (-0·22, -0·86 to 0·42). No pharmacotherapy alone was more effective than psychotherapy alone. Only fluoxetine plus CBT and fluoxetine were significantly more effective than pill placebo or psychological controls (SMDs ranged from -1·73 to -0·51); and only interpersonal therapy was more effective than all psychological controls (-1·37 to -0·66). Nortriptyline (SMDs ranged from 1·04 to 2·22) and waiting list (SMDs ranged from 0·67 to 2·08) were less effective than most active interventions. In terms of acceptability, nefazodone and fluoxetine were associated with fewer dropouts than sertraline, imipramine, and desipramine (ORs ranged from 0·17 to 0·50); imipramine was associated with more dropouts than pill placebo, desvenlafaxine, fluoxetine plus CBT, and vilazodone (2·51 to 5·06). Most of the results were rated as "low" to "very low" in terms of confidence of evidence according to Confidence In Network Meta-Analysis.

INTERPRETATION

Despite the scarcity of high-quality evidence, fluoxetine (alone or in combination with CBT) seems to be the best choice for the acute treatment of moderate-to-severe depressive disorder in children and adolescents. However, the effects of these interventions might vary between individuals, so patients, carers, and clinicians should carefully balance the risk-benefit profile of efficacy, acceptability, and suicide risk of all active interventions in young patients with depression on a case-by-case basis.

FUNDING

National Key Research and Development Program of China.

Causes of drug discontinuation in patients with major depressive disorder in China

BACKGROUND

This research was designed to investigate patient-reported and doctor-reported reasons for the discontinuation of pharmacological treatment in Chinese patients with major depressive disorder (MDD), which was part of the National Survey on Symptomatology of Depression (NSSD) from 2014 to 2015.

METHODS

This cross-sectional study included 649 patients who had discontinued antidepressant medications and 711 patients who had remained on them, selected from a group of 3516 candidates who have had at least one depressive episode. Differences in the two groups' sociodemographic factors, clinical characteristics, medication use, and self-reported reasons for drug discontinuation were compared via Student's t-test or chi-square test. Logistic regression analysis was then used to determine the association of all non-subjective dichotomous and ordinal categorical variables, including the additional 63 items of our physician-evaluated symptomatic assessment, with drug compliance.

RESULTS

Compared to the spontaneous drug discontinuation (SDD) group, the drug adherence (DA) group had significantly lower rates of the following: family history of mental disease (9.0% vs 13.6%), highest level of education achieved being post-graduate or above (1.6% vs 4.7%), smoking (5.8% vs 9.7%), and other health problems (33.9% vs 42.4%) (p's < 0.05). On the other hand, first-episode depression (48.5% vs 21.9%) and taking of mood stabilizer(s) (8.3% vs 5.6%) were higher in the former group than in the latter (p's < 0.05). Logistic Regression Analysis showed that five symptoms, such as depressed mood, were correlated positively with SDD, while another six symptoms, such as psychomotor retardation, were correlated negatively with it. The receiver operating characteristic (ROC) curve of this model yielded an area under the curve (AUC) of 0.701 (95% CI, 0.673-0.729). Notably, there were three main reasons given by patients in the DA group as to why they discontinued their medication(s): (1) concern about long-term side effects (36.1%), (2) no perceived need for taking said medication(s) long-term (34.2%), and (3) believing oneself to have been cured completely (30.0%).

CONCLUSIONS

The aforementioned factors may affect patient compliance and elicit maladaptive thinking even from patients with good educational backgrounds, increasing the risk of drug discontinuation. Compliance of pharmacological treatment might be improved by increasing clarification and elucidation of different symptom clusters to the patient and combating the main reasons for drug discontinuation.

Evidence available for patient-identified priorities in depression research: results of 11 rapid responses

OBJECTIVES

Patient priority setting projects (PPSPs) can reduce research agenda bias. A key element of PPSPs is a review of available literature to determine if the proposed research priorities have been addressed, identify research gaps, recognise opportunities for knowledge translation (KT) and avoid duplication of research efforts. We conducted rapid responses for 11 patient-identified priorities in depression to provide a map of the existing evidence.

DESIGN

Eleven rapid responses.

DATA SOURCES

Single electronic database (PubMed).

ELIGIBILITY CRITERIA

Each rapid response had unique eligibility criteria. For study designs, we used a stepwise inclusion process that started with systematic reviews (SRs) if available, then randomised controlled trials and observational studies as necessary.

RESULTS

For all but one of the rapid responses we identified existing SRs (median 7 SRs per rapid response, range 0-179). There were questions where extensive evidence exists (ie, hundreds of primary studies), yet uncertainties remain. For example, there is evidence supporting the effectiveness of many non-pharmacological interventions (including psychological interventions and exercise) to reduce depressive symptoms. However, targeted research is needed that addresses comparative effectiveness of promising interventions, specific populations of interest (eg, children, minority groups) and adverse effects.

CONCLUSIONS

We identified an extensive body of evidence addressing patient priorities in depression and mapped the results and limitations of existing evidence, areas of uncertainty and general directions for future research. This work can serve as a solid foundation to guide future research in depression and KT activities. Integrated knowledge syntheses bring value to the PPSP process; however, the role of knowledge synthesis in PPSPs and methodological approaches are not well defined at present.

Chronic fluoxetine treatment of juvenile zebrafish (Danio rerio) does not elicit changes in basal cortisol levels and anxiety-like behavior in adulthood

Exposure to selective serotonin reuptake inhibitors (SSRIs) during development may elicit long-term neuroadaptive changes that could alter the basal regulation of stress-associated physiological and behavioral processes later in life. Currently, the effects of juvenile fluoxetine exposure in rodent models appear to be dependent on the developmental window targeted as well as the duration of drug exposure. The zebrafish (Danio rerio) model is rapidly becoming a useful tool in pharmacological research and can be used to help elucidate some of the long-term effects of fluoxetine exposure prior to sexual maturation on neuroendocrine and behavioral stress markers. In the current study, juvenile zebrafish were chronically exposed to fluoxetine hydrochloride (0 or 100 μg/L) for 14 days (31–44 days post-fertilization (dpf)), then were left untreated until young adulthood. Starting at 90 dpf, basal neuroendocrine stress and behavioral responses of zebrafish were assessed. Cortisol was extracted from the young adult zebrafish body (trunk) and quantified via enzyme-linked immunosorbent assay (ELISA). Anxiety-like behaviors were assessed in response to introduction to the novel tank test. It was expected that juvenile exposure to fluoxetine would (1) reduce basal cortisol levels and (2) elicit anxiolytic effects in the novel tank test in adulthood. However, fluoxetine exposure during the juvenile period was not associated with alterations in basal levels of cortisol nor were there any significant changes in anxiety-like behavior in the young adult zebrafish. Thus, in zebrafish, it does not appear that SSRI exposure during the juvenile period has a long-term adverse or maladaptive impact on the basal expression of cortisol and anxiety-like behavior in adulthood. Further studies are needed to determine if SSRI exposure during this developmental window influences neuroendocrine and behavioral responses to acute stress.

Challenges in the diagnosis and treatment of pediatric obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) affects 1%-3% of children worldwide and has a profound impact on quality of life for patients and families. Although our understanding of the underlying etiology remains limited, data from neuroimaging and genetic studies as well as the efficacy of serotonergic medications suggest the disorder is associated with the fundamental alterations in the function of cortico-striato-thalamocortical circuits. Significant delays to diagnosis are common, ultimately leading to more severe functional impairment with long-term developmental consequences. The clinical assessment requires a detailed history of specific OCD symptoms as well as psychiatric and medical comorbidities. Standardized assessment tools may aid in evaluating and tracking symptom severity and both individual and family functioning. In the majority of children, an interdisciplinary approach that combines cognitive behavioral therapy with a serotonin reuptake inhibitor leads to meaningful symptom improvement, although some patients experience a chronic, episodic course. There are limited data to guide the management of treatment-refractory illness in children, although atypical antipsychotics and glutamate-modulating agents may be used cautiously as augmenting agents. This review outlines a clinical approach to the diagnosis and management of OCD, highlighting associated challenges, and limitations to our current knowledge.

Meaning and medication: a thematic analysis of depressed adolescents' views and experiences of SSRI antidepressants alongside psychological therapies

BACKGROUND

Adolescence is a key period of risk for the emergence of Major Depressive Disorder (MDD). The prescription of selective serotonin re-uptake inhibitors (SSRIs) for the treatment of depression in adolescents is an issue of worldwide controversy, and evidence regarding their safety and efficacy is inconclusive. In the UK, NICE guidelines have recently recommended offering SSRIs to adolescents alongside psychological therapy or on their own if therapy is refused. Thus, SSRIs are increasingly becoming a major component of treatment for adolescents. This study qualitatively explored adolescents' views and experiences of SSRIs within their accounts of engaging in a psychological therapy for depression, particularly focusing on meanings they attached to medication-use.

METHODS

The qualitative study reports data from semi-structured interviews conducted 12-months post-treatment with 12 adolescents who were clinically referred and treated for depression as part of the IMPACT trial. The interviews were analysed using Thematic Analysis.

RESULTS

Four themes were identified: 'a perceived threat to autonomy', 'a sign of severity', 'a support, not a solution', and 'an ongoing process of trial and error'.

CONCLUSIONS

This study highlights the value of bringing adolescents' voices into the broader debate on the use of antidepressants in their age group and in the development of future guidelines. Future implications for research and clinical practice are discussed.

A pilot study of GABAB correlates with resting-state functional connectivity in five depressed female adolescents

Connectivity features based on resting-state (RS) functional magnetic resonance imaging (fMRI) demonstrate great promise as biomarkers to guide diagnosis and treatment in major depressive disorder (MDD). However, there is a pressing need for valid, reliable biomarkers closer to the bedside for clinical research and practice. This study directly compared RS-fMRI connectivity features with transcranial magnetic stimulation (TMS) neurophysiological measures, long interval cortical inhibition (LICI) and cortical silent period (CSP), in female adolescents with MDD. LICI-200 showed the most significant associations with RS functional connectivity features, demonstrating its potential to evaluate the neurochemical underpinnings of network features in MDD.

Editorial Perspective: Antidepressants and the depressed adolescent

A paper considering the role of antidepressants for adults with major depression was recently published in the Lancet, a world leading medical journal (Cipriani et al. 2018). The review was the largest ever on this topic based on 28,552 citations including 522 trials comprising 116,477 participants. The authors note that, in adults with major depression, all antidepressants were more efficacious than placebo. In head-to-head studies, the authors also note that agomelatine, amitriptyline, escitalopram, mirtazapine, paroxetine, venlafaxine, and vortioxetine were more effective than other antidepressants whereas fluoxetine, fluvoxamine, reboxetine, and trazodone were the least efficacious. The authors report that the standardised mean difference was 0.3 a moderate effect size for any antidepressant over placebo, this is confirmatory of past reviews noting rather similar magnitudes of effect. In clinical terms the results suggest a choice for practitioners in regard to their individual patients. For many adult depressed patients however, there is also the implication that antidepressants may not work. The old adage 'what works for whom' remains unanswered. What does seem reasonable to conclude is that we have learnt that these medications are clinically effective and the questions for research now must be who is likely to benefit and who is not, how do these medicines work, and what is the best long-term management of responders as the majority of studies have focused on acute response only.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Targeting opioid receptor signaling in depression: do we need selective κ opioid receptor antagonists?

The opioid receptors are a family of G-protein coupled receptors (GPCRs) with close structural homology. The opioid receptors are activated by a variety of endogenous opioid neuropeptides, principally β-endorphin, dynorphins, leu- and met-enkephalins. The clinical potential of targeting opioid receptors has largely focused on the development of analgesics. However, more recent attention has turned to the role of central opioid receptors in the regulation of stress responses, anhedonia and mood. Activation of the κ opioid receptor (KOP) subtype has been shown in both human and rodent studies to produce dysphoric and pro-depressive like effects. This has led to the idea that selective KOP antagonists might have therapeutic potential as antidepressants. Here we review data showing that mixed μ opioid (MOP) and KOP antagonists have antidepressant-like effects in rodent behavioural paradigms and highlight comparable studies in treatment-resistant depressed patients. We propose that developing multifunctional ligands which target multiple opioid receptors open up the potential for fine-tuning hedonic responses mediated by opioids. This alternative approach towards targeting multiple opioid receptors may lead to more effective treatments for depression.

National time trend changes in psychotropic medication of child and adolescent psychiatric inpatients across Finland

BACKGROUND

There have been no comprehensive studies on trends in psychotropic medication use in child and adolescent inpatient settings. The aim of this nationwide study was to report changes in the psychotropic medication given to child and adolescent psychiatric inpatients across Finland and the factors associated with those changes.

METHODS

We asked the psychiatrist responsible for each inpatient to complete a questionnaire that included questions about the pharmacological treatment and background information. The data were collected on all inpatients on one selected study day in 2000 and 2011. Changes in the use of regular psychotropic medication were studied by comparing the data on 504 patients in 2000 and 412 patients in 2011.

RESULTS

The study showed that there had been a significant increase in the use of psychotropic medication from 2000 to 2011. According to the multivariate analysis, the increase in psychotropic medication was associated with the study year (in 2000 39%, in 2011 58%), but could not be explained by changes in diagnostic profiles, age distribution, suicidality, violence or the Children's Global Assessment Scale scores. The use of combined psychotropic medication increased from 9% in 2000 to 25% in 2011. The increase in the use of antipsychotics among child inpatients was particularly noteworthy, with an increase from 10% to 32%.

CONCLUSIONS

There is a need for evidence-based studies to clarify recommendations for indications and treatment practices when using psychotropic medication in children and adolescents. Cross-cultural studies of the use of psychotropic medication are warranted.

Efavirenz is related to neuropsychiatric symptoms among adults, but not among adolescents living with human immunodeficiency virus in Kilimanjaro, Tanzania

OBJECTIVES

To explore the relationship between Efavirenz (EFV) and neuropsychiatric symptoms among adults and adolescents living with human immunodeficiency virus (HIV) in Kilimanjaro, Tanzania.

METHODS

Cross-sectional study among HIV-infected adults (age 18-65) and adolescents (age 12-17) on antiretroviral treatment attending Kilimanjaro Christian Medical Centre, Moshi, Tanzania. Neuropsychiatric symptoms were measured using the Hospital Anxiety and Depression Scale (HADS), the Symptom Checklist 90 (SCL-90) and the Mini-International Neuropsychiatric Interview (MINI). manova and chi-squared tests were used to test differences between EFV and non-EFV-treated participants.

RESULTS

A total of 215 adults and 150 adolescents participated. About 52% of adults and 37% of adolescents used EFV. Among adults, depression scores were higher for those on EFV (HADS (Cohen's D: 0.38; P = 0.02) and SCL-90 (Cohen's D: 0.24; P = 0.03). Among adolescents, those on EFV had lower scores on depression (HADS (Cohen's D: 0.3; P = 0.02) and SCL-90 (Cohen's D: 0.1; P = 0.02). About 10% of adults reported suicidal thoughts, but there was no difference between those on EFV and those without. Lastly, adults on EFV reported higher levels of problematic alcohol use (P = 0.003).

CONCLUSIONS

In line with the previous studies, EFV is associated with depressive symptoms and problematic alcohol use among HIV-infected adults in Tanzania. In contrast, EFV was associated with lower levels of depressive symptoms in adolescents in Tanzania. Particularly among adults, close monitoring of depressive symptoms and alcohol use is indicated.

Transcranial Direct Current Stimulation: Considerations for Research in Adolescent Depression

Adolescent depression is a prevalent disorder with substantial morbidity and mortality. Current treatment interventions do not target relevant pathophysiology and are frequently ineffective, thereby leading to a substantial burden for individuals, families, and society. During adolescence, the prefrontal cortex undergoes extensive structural and functional changes. Recent work suggests that frontolimbic development in depressed adolescents is delayed or aberrant. The judicious application of non-invasive brain stimulation techniques to the prefrontal cortex may present a promising opportunity for durable interventions in adolescent depression. Transcranial direct current stimulation (tDCS) applies a low-intensity, continuous current that alters cortical excitability. While this modality does not elicit action potentials, it is thought to manipulate neuronal activity and neuroplasticity. Specifically, tDCS may modulate N-methyl-d-aspartate receptors and L-type voltage-gated calcium channels and effect changes through long-term potentiation or long-term depression-like mechanisms. This mini-review considers the neurobiological rationale for developing tDCS protocols in adolescent depression, reviews existing work in adult mood disorders, surveys the existing tDCS literature in adolescent populations, reviews safety studies, and discusses distinct ethical considerations in work with adolescents.

How do antidepressants influence the BOLD signal in the developing brain?

Depression is a highly prevalent life-threatening disorder, with its first onset commonly occurring during adolescence. Adolescent depression is increasingly being treated with antidepressants, such as fluoxetine. The use of medication during this sensitive period of physiological and cognitive brain development produces neurobiological changes, some of which may outlast the course of treatment. In this review, we look at how antidepressant treatment in adolescence is likely to alter neurovascular coupling and brain energy use and how these changes, in turn, affect our ability to identify neuronal activity changes between participant groups. BOLD (blood oxygen level dependent) fMRI (functional magnetic resonance imaging), the method most commonly used to record brain activity in humans, is an indirect measure of neuronal activity. This means that between-group comparisons – adolescent versus adult, depressed versus healthy, medicated versus non-medicated – rely upon a stable relationship existing between neuronal activity and the BOLD response across these groups. We use data from animal studies to detail the ways in which fluoxetine may alter this relationship, and explore how these alterations may influence the interpretation of BOLD signal differences between groups that have been treated with fluoxetine and those that have not.

Early Antipsychotic Treatment in Juvenile Rats Elicits Long-Term Alterations to the Dopamine Neurotransmitter System

Prescription of antipsychotic drugs (APDs) to children has substantially increased in recent years. Whilst current investigations into potential long-term effects have uncovered some alterations to adult behaviours, further investigations into potential changes to neurotransmitter systems are required. The current study investigated potential long-term changes to the adult dopamine (DA) system following aripiprazole, olanzapine and risperidone treatment in female and male juvenile rats. Levels of tyrosine hydroxylase (TH), phosphorylated-TH (p-TH), dopamine active transporter (DAT), and D₁ and D₂ receptors were measured via Western blot and/or receptor autoradiography. Aripiprazole decreased TH and D₁ receptor levels in the ventral tegmental area (VTA) and p-TH levels in the prefrontal cortex (PFC) of females, whilst TH levels decreased in the PFC of males. Olanzapine decreased PFC p-TH levels and increased D₂ receptor expression in the PFC and nucleus accumbens (NAc) in females only. Additionally, risperidone treatment increased D₁ receptor levels in the hippocampus of females, whilst, in males, p-TH levels increased in the PFC and hippocampus, D₁ receptor expression decreased in the NAc, and DAT levels decreased in the caudate putamen (CPu), and elevated in the VTA. These results suggest that early treatment with various APDs can cause different long-term alterations in the adult brain, across both treatment groups and genders.

The neuroscience and context of adolescent depression

Adolescent depression is a growing public health concern with an increased risk of negative health outcomes, including suicide. The use of antidepressants and psychotherapy has not halted its increasing prevalence, and there is a critical need for effective prevention and treatment. We reviewed the neuroscience of adolescent depression, with a focus on the neurocircuitry of sustained threat and summarised contextual factors that have an impact on brain development and the pathophysiology of depression. We also reviewed novel treatment models.

CONCLUSION

Attention to the relevant neurocircuitry and contextual factors implicated in adolescent depression is necessary to advance prevention and treatment development.

The Involvement of Genes in Adolescent Depression: A Systematic Review

Numerous studies have reported on the roles of genetic factors in the development of depression in adolescents and young adults. However, there are few systematic reviews that update our understanding of adolescent depression with the biological findings identifying the roles of gene expression and/or polymorphism(s). This review systematically summarized the findings that clearly identified the contribution of a gene to the risk of depression in adolescents between the ages of 10 and 19 years old and young adults between the ages of 20 and 25 years old. Data were obtained through searching PubMed, Embase, and Web of Science. A total of 47 studies on early adolescence and three studies on young adults were included in the current review. Most articles studied genes in the serotonergic system (n = 26), dopaminergic system (n = 3), and the Brain-derived neurotropic factor (BDNF) gene (n = 12). 92.3% of studies (24/26) identified positive associations of 5-HTTLPR polymorphism with depressive illness or depressive symptoms. 83.3% of studies (10/12) found positive association between BDNF Val66Met genotype and adolescent depressive symptoms. More studies should be conducted on the 18 genes reported in a few studies to clarify their roles in the risk for adolescent depression.